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Apr
08

The Covid-19 Conundrum: How to Stay Fit, Active and Motivated During a Time of Social Distancing

“There are a lot of things we can’t control during this crisis, so we need to focus on what we can control.”

-Arnold Schwarzenegger

The Covid-19 pandemic has turned the lives of the majority of us upside-down recently.  In order to reduce the spread of the contagion, most of the world is practicing social distancing.  Here in the U.S., many states and local governments are administering ‘shelter in place’ procedures.  In Florida, most if not all the gyms and fitness studios are closed as of this writing in an attempt to curb the spread of the virus.  Mercifully, outdoor activities are still allowed in many areas of the U.S. and elsewhere as long as the activity is conducted while adhering to social-distancing guidelines such as to stay 6 feet away from others and avoid assembling in groups.  Outdoor activities that are allowed can include walking, hiking, running, and biking.  This blog will show some ideas of how one can stay active and fit in this difficult time. 

social distancing2

Do you enjoy running?  Here are some interesting ideas:

Maybe a virtual 5k, 10k, or half marathon strikes your fancy?  There’s a fun virtual Top Run Challenge, themed after the ‘80s movie Top Gun, complete with a great medal, here: https://www.virtualpaceseries.com/?gclid=CjwKCAjw95D0BRBFEiwAcO1KDDa_vXZ99_FcWw0AVIMV-PqAlXhioR8YDSzKbmDWe0WOHilA4OL3aBoCDCwQAvD_BwE

Have you thought of trying to Run Every Single Street in your city or town?  Rickey Gates has.  Here’s his fun and thought-provoking video on his quest to run every single street in Los Angeles:

https://www.youtube.com/watch?v=jy_W5qsjB5U

More of a trail runner?  Try applying the same idea to Run Every Single Trail in your area.  This is the sort of project that can keep you engaged for weeks or even months, depending on the miles of trails available to you and the amount of time you have available.

Bummed that your ultramarathon was canceled due to the virus?  How about this virtual Yeti Ultra 24-hour Challenge in April?  Run 5 miles every 4 hours over a 24-hour period.  That’s 30 miles total.  You can run the miles any way that’s available to you—such as on a treadmill, on road, or on trail,  It can be done on any day in April and you get a cool shirt that supports a print shop in Alabama (and you will also have bragging rights).  Sign up at https://ultrasignup.com/register.aspx?did=76840&fbclid=IwAR01ZWo8um02TtsH_veywpzNHCaNEipj2M9HilGB56-VGdBtzIvftaBMVsWk

Are you interested in unusual formats for running goals?  How about this Quarantine Backyard Ultra?  This interesting virtual event can fit any goal as it challenges one to complete as many laps as possible:

https://personalpeak.ca/quarantinebackyard/register/

Miss the gym and don’t have a lot of barbells or dumbells laying around the house?  Arnold Schwartzenegger has some great ideas for home workouts using mostly one’s own bodyweight:

https://www.menshealth.com/fitness/a31818878/arnold-schwarzenegger-home-workout-plan/

Do you enjoy obstacle course racing (OCR) events commonly called mud runs?  Here are some ideas:

Sam Abbitt of the Savage Race OCR series has some challenges that can be done from home:

https://savagerace.com/savage-anywhere/

Are you a cyclist?  There is a good selection of virtual challenges online for cyclists.  Here’s some links for more information:

The Great Cycle Challenge, https://greatcyclechallenge.com/Pages/how-it-works/virtual-challenges

Race Your Pace Bike Challenges, https://www.raceatyourpace.com/bike/

If yoga is what you’re into, there are many online classes to choose from.  Here are a few:

The non-profit Yoga4Change has a series of yoga videos available: https://www.youtube.com/channel/UCZpwrT1k2hEuHwZwqmh7t2g

Glo offers unlimited yoga, pilates, and meditation classes from 5 to 90 minutes long, https://www.glo.com/

Yoga Download offers beginner-level yoga, https://www.yogadownload.com/

Yoga International offers advanced-level yoga, https://yogainternational.com/start/30days?irclickid=SU-02gykDxyOWFH0MdV3iVCmUki0OuQmPwBWxw0&utm_source=impact&utm_medium=affiliate&utm_campaign=SPP-2104074-Dotdash&irgwc=1

YogiApproved offers yoga on a budget, https://www.yogiapproved.com/classes/

Want to do other types of workouts from home or in the park? Grokker has cardio, dance, and weight training: https://grokker.com/individuals

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Mar
25

What in the world is a compound modifier?

When two words act as one to modify a noun, they become a compound modifier.  For example: 

The deep-draft vessel went aground in the harbor.

As used here, neither deep nor draft could stand alone to describe vessel, so the term is hyphenated to indicate that they used as a single unit, or a compound modifier.

Sometimes, however, a compound modifier should not be hyphenated.  When the modifying term contains an adverb ending in “ly,” there is no need to add a hyphen because the “ly” lets the reader know that it is part of a word pair modifying a noun. 

See the explanation from section 7.86 of The Chicago Manual of Style:

Compounds formed by an adverb ending in -ly plus an adjective or participle (such as largely irrelevant or smartly dressed) are not hyphenated either before or after a noun, since ambiguity is virtually impossible.  (The -ly ending with adverbs signals to the reader that the next word will be another modifier, not a noun.)

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Jul
10

Log In vs. Login

This term is always a problem and it seems that most people want to use “login” exclusively. 

As a verb (shows action), use two words:  log in

As a noun or an adjective, use one word:  login

Source:  https://writingexplained.org/log-in-or-login-difference

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Mar
07

Bird vs. Reflective Window Tint: A Two-Year Experiment Exploring Methods to Break the Cycle of Bird Collisions with Reflective Windows

Introduction:

(Written in October of 2017)

Bird v. Reflective Window

It was a regular morning, just like every other morning in the office, until THUD--a bird flew into my office window.  Disoriented, the bird flapped its wings trying to get a grasp on what had just happened, only to find itself unable to orient.  Exhausted and stunned, the bird gave up and lay on its side under the nearest shrub.  I could see that its pulse was rapid, so I knew it was still alive.  Knowing there wasn’t much I could do, I decided to just keep my eye on it from a distance.  Within minutes, I began to hear the call of another bird.  Sure enough, two young birds swooped in to check on the disoriented bird.  After about 15 minutes, I went back outside to check on the bird and noticed that it’s breathing appeared to have significantly slowed and I began to wonder if it was still alive. I decided to investigate within a little closer proximity. 

This is when I became aware of the critical situation happening with birds and my office windows.  Upon approaching the shrubbery beneath the office windows, I noticed other bird carcasses in different stages of decomposition, all appeared to have died intact and in close proximity to the office’s reflective windows.  At this moment, all of the mysterious window thuds I had heard throughout the years began to make sense.  I thought to myself, there is a problem here, something is attracting these birds.

bird 1

bird 2

I decided to do some research as to why birds fly into windows.  I wanted to do something to prevent more bird injuries.  It didn’t take much research to learn that reflective glass confuses birds by showing them a reflection of the landscape, thus fooling them into thinking they are flying into a natural setting rather than into a piece of mirrored glass.  This made perfect sense to me, so now I needed to find a way to interfere with the reflections so birds would be less likely to fall victim to this deception.  I found information on reflective prey-bird decals and other methods claiming to be the solution to the ‘bird flying into the window’ phenomenon, but for a more immediate fix, I decided to tape a sheet of white copy paper to each of the office windows where the bird carcasses were found.

bird 4

I decided to keep checking the shrubs for more carcasses, but remained hopeful that this method would help eliminate the bird fatalities by breaking up the reflective illusion in the glass. 

Updates:

(Later that day)

The bird that hit the window managed to fly away.

(One week later)

I ordered hawk decals from a company called Window Alert and positioned the decals on either side of the white copy paper I displayed the previous week.  

bird 5

Conclusion:

I am pleased to report that it has now been two years since the reflective prey-bird decals and white copy paper were hung in the windows and I haven’t observed one bird/window collision or noticed any bird carcasses in the shrubs.  I think it would be fair to conclude that either the white paper or the reflective prey-bird decals or a combination of both have served as a reliable way to help deter birds from flying into our reflective windows.

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Dec
13

Is “Data” a Singular or a Plural Noun?

In modern writing and speech (e.g., newspapers, magazines), the word data is often used with a singular verb.  However, datum is the singular form of this noun and needs a singular verb (e.g., is, was) and data is the plural form, which requires a plural verb (e.g., are, were).  Although this topic has been debated at length, the scientific community tends to prefer the stricter interpretation that data is always to be treated as a plural noun.

Data = Plural

Datum = Singular

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Nov
02

What Is the Difference Between an Acronym and an Initialism?

An acronym is a word derived from the first letter (or first few letters) of several other words.  A prime example is SCUBA (self-contained underwater breathing apparatus).  Other examples are NATO (North Atlantic Treaty Organization) and NOLA (New Orleans, LA).

An initialism is an abbreviation that uses the first letter of each major word in a phrase but does not form a new word.  Rather, the actual letters are pronounced.  A couple of examples are EPA for Environmental Protection Agency and FBI for Federal Bureau of Investigation.

Click here for Merriam-Webster’s take on these terms.

http://www.merriam-webster.com/words-at-play/whats-an-acronym?utm_campaign=newsletter&utm_medium=email&utm_source=wotd&utm_content=promo

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Sep
18

How the Lionfish Is Becoming King of the Gulf and What We Can Do About It

You’ve likely heard about the introduction and expansion within the western North Atlantic of the invasive lionfish.  You’ve read the headlines about this venomous predator from the Indo-Pacific region that’s well established along the southeastern United States, Bermuda, Bahamas, and the Caribbean, and now in the Gulf of Mexico (since at least 2010).  Lionfish have been reported along the eastern U.S. since the early 1980s, but the first verified report wasn’t until 1992, off North Carolina.  You’ve read about its propensity to cause trouble for the native reef ecosystems where it now resides.  The detrimental effects of the (likely intentional) introduction of the red lionfish (Pterois volitans), and possibly also the devil firefish (P. miles), include direct predation on native fishes, crabs, and shrimps and competition with native reef species for limited resources.  Lionfish are likely direct competitors of such species as black sea bass and certain snappers and, as a result, populations of these native predators are expected to decrease. 

Since first recorded in the Gulf of Mexico in 2010, lionfish populations have grown exponentially, covering most, if not all, suitable hardbottom and reef habitats along the West Florida Shelf.  In addition to direct consumption of native reef species by the lionfish, potential indirect effects caused by this introduced invasive predator include:

  • The declines of reef carnivores and reef omnivores as a result of lionfish predation is predicted to lead to increased populations of their benthic invertebrate prey (excluding shrimp).
    • This is a form of what’s called ‘trophic cascade’ effect.
  • Modest increases in populations of gray triggerfish, Vermilion snapper, and possibly tilefishes due to release from competition with other native reef carnivores.
    • This is a form of what’s called ‘competitive release’ effect.

It is currently unclear if lionfish populations in the Gulf of Mexico have reached carrying capacity (the maximum number of lionfish that the Gulf can support).  In 2013, Dauphin Island Sea Lab reported densities of lionfish on artificial reefs at 14.7 lionfish/100 m2, which was among the highest densities recorded in the western Atlantic at that time (O’Connor 2016).

What can be done to mitigate the effects of lionfish dubbing themselves King of the Gulf?  Recent research by University of Florida researchers suggests some possible ways of helping our native fishes.  Although lionfish are clearly here to stay, their numbers can be reduced somewhat through exploitation such as overfishing.  Given sufficient fishing pressure, local impacts may be partially mitigated, allowing native reef species a bit of relief, assuming the fishing pressure is kept up over time.  Here’s how you can do your part in controlling lionfish in U.S. waters:

  • Support the development of lionfish fisheries through the purchase of lionfish products at your local fish market or favorite seafood restaurant
  • Directly control introduced lionfish by spearing or capturing them within the Gulf of Mexico or western Atlantic
  • Consider contributing to a non-profit organization involved in lionfish control and research, such as Reef Environmental Education Foundation (REEF) (www.reef.org)

The following photos of prepared lionfish dishes are meant to inspire the consumption of these beautiful, yet oh-so-invasive fish and encourage the development of a market for this species in Florida and elsewhere!

lionfish 1 FILEminimizer

lionfish 2 FILEminimizer

lionfish 3 FILEminimizer

Sources

Chagaris, D., S. Binion, A. Bogdanoff, K. Dahl, J. Granneman, H. Harris, J. Mohan, M.B. Rudd, M.K. Swenarton, R. Ahrens, M. Allen, J.A. Morris, and W.F. Patterson III.  2015.  Modeling lionfish management strategies on the West Florida Shelf: Workshop Summary and Results.  University of Florida, Gainesville, FL.

Chagaris, D., S. Binion-Rock, A. Bogdanoff, K. Dahl, J. Granneman, H. Harris, J. Mohan, M.B. Rudd, M.K. Swenarton, R. Ahrens, W.F. Patterson III, J.A. Morris Jr., and M. Allen.  2017.  An ecosystem-based approach to evaluating impacts and management of invasive lionfish. Fisheries 42:421–431.

O’Connor, R.  2016.  NISAW 2016 – An Update on the Lionfish Situation in the Panhandle.  UF Institute of Food and Agricultural Services Extension, Gainesville, FL.  Accessed online 07/24/18 at http://nwdistrict.ifas.ufl.edu/nat/2016/02/21/nisaw-2016-an-update-on-the-lionfish-situation-in-the-panhandle/

A special thank you to Momoyaki sushi restaurant in Gainesville, Florida, for being one of the few restaurants in the area to feature lionfish.  http://momoyaki.com/contact/

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Aug
22

Exciting New Research on the Largetooth Sawfish Reveals the True Range of this Enigmatic Species in the United States

Well ahead of International Sawfish Day (October 17) is this concise paper that Jason, and his colleague John Waters, recently published in Gulf and Caribbean Research on the largetooth sawfish (Pristis pristis).  Sawfishes have been in the scientific spotlight for several years now, as populations in many areas are reduced and in need of conservation and research.  Jason and his coauthor attempt to clarify and correct some of the misleading information about the U.S. range of this enigmatic saw-snouted shark-like beasty.  Hopefully, this species will be found to still occur in Texas waters, such as by environmental DNA survey techniques.  If and when this occurs, critical habitat can be designated following implementing regulations 50 CFR § 424.12, provision 5(f). Click here for the PDF: Ppristis-range-in-the-U.S-Seitz-and-Waters-2018 

Seitz, J.C. and J.D. Waters.  2018.  Clarifying the range of the endangered largetooth sawfish in the United States.  Gulf and Caribbean Research 29:15–22.

 

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Jul
26

In Search of Absolute Sharkness During Shark Week: Swimming with Whale Sharks

Every year, from May through September, whale sharks congregate in a small area off the Yucatan Peninsula of Mexico where the Mexican Caribbean meets the Gulf of Mexico.  They are attracted to this area due to upwelling of cool, nutrient-rich water (the Yucatan Current) that encourages relatively high densities of zooplankton near the surface.  These largest of all living fishes are planktivores.  They use both ram-feeding and vacuum-feeding strategies to capture tiny organisms (about 2 mm and up [Anonymous 2010]) and small schooling fishes.  The upwelling of the Yucatan Current off the peninsula is productive enough that whale sharks, locally known as tiburones ballena, (Rhincodon typus in scientific lingo) are thought to travel from all corners of the Gulf of Mexico and the Caribbean during summer to this tiny feeding ground to feast on the abundant food there. 

For those of us interested in the hydrographics behind the upwelling, this paragraph is for us!  The Yucatan Current north of Cape Catoche, Holbox Island, experiences bottom friction at depths of 220 to 250 meters along the Yucatan Shelf, probably due to the underwater presence of one or more seamounts.  The current glances of the seamounts and then rises at a rate of 2 to 10 meters per second towards the surface.  In the summer months, the upwelling creates a two-layered water column, with the upwelled water moving westward across the shelf and creating a cyclonic gyre north of Cape Catoche (Merino 1997).  This process is strongest during summer, resulting in the upwelled water occasionally breaking the surface and providing nutrients for plankton to thrive.

This year, ANAMAR senior biologist Jason Seitz traveled to the Yucatan to experience for himself these beautiful and harmless sharks.  He and his wife, Jenny, arrived by ferry in Holbox Island in Quintana Roo in July and took three excursions out to the whale shark feeding ground north of Cape Catoche to swim with the gentle giants.  As luck would have it, they were not only able to swim with several large whale sharks, but also were fortunate enough to swim with another amazing beast—the giant manta! 

See the photographs above of the whale shark and manta (Mobula cf. birostris) encounter that Jason and Jenny experienced off Holbox Island and view the video below.  Enjoy!

All the photographs and the video are by the author, Jason Seitz.

Sources

Merino, M.  1997. Upwelling on the Yucatan Shelf: hydrographic evidence.  Journal of Marine Systems 13:101–121.

Anonymous.  2010.  Whale Shark, Rhincodon typus, Mexico.  Deep Motion, Redwood City, CA.

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Jul
12

GRAMMAR: Me, Myself, and I

Good grammar is important in business dealings, whether spoken or written.  Here are a couple of guidelines to help you communicate effectively.

Reflexive Pronouns:  Me, Myself, and I

When you’re unsure of whether to use me or I in a sentence that includes you and at least one other person, just think of how you would use it if you were talking about only yourself. 

          Incorrect:      Will you please make hotel reservations for John and I?

          Correct:         Will you please make hotel reservations for [John and] me?

          Correct:         John and I need you to make hotel reservations for us.

Myself is correct only when you are the subject and the object of the sentence and you are emphasizing the action.  The sentence below is correct, but would be fine without myself.

Correct:         I made the reservations myself.

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Jun
01

IDIQ Explained

Indefinite Delivery, Indefinite Quantity contract vehicles, better known by the acronym IDIQ, are a mainstay in the contracting world.  ANAMAR Environmental Consulting, like many other government contracting firms, identifies, competes for, and wins IDIQ contracts on a regular basis.  Understanding IDIQs, in both form and function, is critical to understanding our business model and how we provide high-quality environmental services to our government clients year in and year out.

What is an IDIQ?

IDIQs possess all the critical elements that define a contract (mutual assent, valid offer and acceptance, consideration, etc. – read more here).  But unlike a contract that exists to deliver a single, defined instance of a product or service, an IDIQ exists to serve as a ‘vehicle’ through which multiple future contracts (referred to as task orders for services or delivery orders for products) are awarded to a contract holder.  The key element that defines an IDIQ and differentiates it from a definitive contract is the indeterminate number and value (within prescribed limits) of future task or delivery orders at the time of contract inception (see FAR 16.504).  In other words, when the government awards an IDIQ to one or more bidders, it does not know how much of a specific product or service it will need over a defined period of time.  The IDIQ contract vehicle affords the government flexibility to order as much (or as little, above a specified minimum) of that particular product or service as it needs over the life of the contract, as long as it does not exceed pre-negotiated limits.

Types of IDIQs

IDIQs are also referred as ‘task order contracts,’ a term that is rolled in to another acronym often encountered when firms and contracting personnel discuss IDIQs: the MATOC.  A MATOC, or multiple award task order contract, is simply an IDIQ with multiple awardees.  Task or delivery orders under a MATOC are effectively competed twice: first, when the MATOC is competed and bidders are selected, and second when each task or delivery order is competed among the contract awardees.  By contrast, single award task order contracts (sometimes referred to as SATOCs), are awarded to only a single bidder, with all of the task or delivery orders for that contract being automatically awarded to the winning firm.  The Federal Acquisition Regulations (FARs) express an explicit preference for MATOCs over SATOCs (see FAR 16.504(c)) due to the additional competition for the ultimate award of task or delivery orders afforded by MATOCs.  Despite this multiple award preference, SATOCs are commonplace across government contracting, accounting for approximately 60 percent of dollars obligated governmentwide.  A 2017 Government Accountability Office report found that the primary reason for this prevalence of SATOCs across the government was the necessity for a single responsible contractor to handle multiple integrally related task orders.  In the world of small business contracting, firms like ANAMAR often find that government agencies must weigh the potential savings offered by competing task orders under MATOCs with the additional administrative burden imposed by managing that same competition.

Conclusion

IDIQs are popular across the government, come in many forms, and serve many purposes.  More importantly, IDIQs continue to evolve as government and industry find new ways to deliver efficient and cost-effective products and services to the agencies that serve the American people.  The staff at ANAMAR Environmental Consulting seek to remain well-informed on the evolution of IDIQs in contracting, and are poised to compete for and win these contract vehicles to continue to provide the same high-quality service we have delivered to the Government for the past 18 years.

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Apr
24

ANAMAR Senior Biologist Teams with Other Fish Experts in Producing the First Estimates of Age and Growth in Wild Southern Stingrays (Hypanus americanus)

stingray w caption FILEminimizer

A 2018 study published in the peer-reviewed journal Gulf and Caribbean Research represents a collaborative effort between ANAMAR biologist Jason Seitz and colleagues at the University of New England and the Florida Fish and Wildlife Research Institute.  Southern stingrays (Hypanus americanus, previously Dasyatis americana) were sampled and measured at fishing tournaments from 2004 and 2012 in Charlotte Harbor, Florida.  Vertebral centra obtained from the stingrays were sectioned and mounted on slides, and their growth bands were counted by two independent readers.  A total of 18 female southern stingrays, measuring from 412 to 1127 mm disc width (DW) were aged.  Ages ranged from 0 to 17 years.  The results suggest that southern stingrays obtain relatively old ages (17 years) and large sizes (to at least 1127 mm DW).  The results are comparable to other large stingray species such as the brown stingray (Bathytoshia lata; to at least 24 years and 1790 mm DW) and the common stingray (Dasyatis pastinaca; to at least 16 years and 1140 mm DW).  The results are also comparable to size-at-width data from a captive population of southern stingrays (13 years for a 1000-mm DW captive female, compared to an estimated 12 years for a 1005-mm DW wild female in this study).  The age-at-width estimates given in the 2018 study provide a preliminary foundation for future studies on age and growth of southern stingrays for the generation of mortality rates, production rates, and growth models, such as a Von Bertalanffy growth function or a Gompertz function, once ages of each life stage are obtained.  This study is the first investigation of the age-at-widths of wild southern stingrays. 

Here is a link to the open-access paper: Southern-stingray-age-and-growth-FINAL-2018

Source

Hayne, A.H.P., G.R. Poulakis, J.C. Seitz, and J.A. Sulikowski.  2018.  Preliminary age estimates for female Southern Stingrays (Hypanus americanus) from southwestern Florida, USA.  Gulf and Caribbean Research 29:SC1–4.  DOI:10.18785/gcr.2901.03  

 

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Feb
28

Probably More Than You Wanted to Know about Rattlesnake Venom: Purpose, Chemical Composition and Effects on the Body

An anonymous letter to The Pennsylvania Journal in December 1775 describes how the writer observed an image of a rattlesnake depicted on a drum belonging to a Marine with the words ‘Don’t Tread on Me’ spelled underneath the snake’s image.  The writer went on to theorize as to why this symbol was chosen by the Marine and its intended meaning.  The writer began by outlining the characteristics that distinguish rattlesnakes from other animals and supposed why these same properties may be appropriately used to symbolize the United States of America:

“I recollected that her eye excelled in brightness, that of any other animal, and that she has no eye-lids.  She may therefore be esteemed an emblem of vigilance.  She never begins an attack, nor, when once engaged, ever surrenders: she is therefore an emblem of magnanimity and true courage.  As if anxious to prevent all pretensions of quarreling with her, the weapons with which nature has burnished her, she conceals, in the roof of her mouth, so that, to those who are unacquainted with her, she appears to be a most defenseless animal; and even when those weapons are shown and extended for her defense, they appear weak and contemptible; but their wounds however small, are decisive and fatal.  Conscious of this, she never wounds ‘till she has generously given notice, even to her enemy, and cautioned him against the danger of treading on her.

       -An American Guesser”

Although the above paragraph was written anonymously, history scholars believe the writer to have been Benjamin Franklin.  The entire letter can be viewed at http://greatseal.com/symbols/rattlesnake.html.

This short blog will consider the venom attributes of rattlesnakes.

What is the Purpose of Rattlesnake Venom?

There are two main categories of venoms: those that are intended to subdue prey and those that are intended to dissuade predators.  Rattlesnakes evolved their venom to subdue prey and to begin the process of digestion.  Figure 1 shows a timber rattlesnake (Crotalus horridus) in the act of consuming an eastern gray squirrel (Sciurus carolinensis) after subduing it with venom.  They have a special suite of proteins and enzymes to help accomplish this task.  Unfortunately, although rattlesnakes evolved their venom for use in obtaining food rather than as a defensive measure, a defensive bite nonetheless has the effect of these digestive compounds tearing through bodily tissues and causing pain, swelling, and necrosis. 

Rattlesnake blog pic1 FILEminimizer

Figure 1This timber rattlesnake (Crotalus horridus) was photographed by the author while it consumed an eastern gray squirrel (Sciurus carolinensis) in Alachua County, Florida, after subduing it with venom.  This snake is among the population thought to have a higher concentration of neurotoxic venom than populations north of Interstate 10.

Photographed and copyrighted by the author, Jason Seitz

What Is Rattlesnake Venom Composed of?

The venom of rattlesnakes is a mixture of hemotoxins and neurotoxins, but are mostly hemotoxins.  Hemotoxins target tissues and blood, causing hemorrhaging and necrosis.  Their venom is really a cocktail of chemical elements.  Neurotoxins target the nervous system, some of which can cause paralysis.  While each species of venomous snake has its own particular cocktail of proteins and enzymes compared to other species, there is some evidence to suggest that the relative concentration of neurotoxins to hemotoxins may vary regionally even within a given species of snake.  For instance, a significant percentage of the timber rattlesnakes south of Interstate 10 (I-10) in Florida are believed by some researchers to have a higher concentration of neurotoxic venom than do timber rattlers north of this corridor.  The various proteins and enzymes in rattlesnake venom have a synergistic effect that has evolved to trigger total cardiovascular collapse of the snake’s intended prey.  When a rattler bites in defense, the effects are watered down due to the large size of a person compared to their prey (typically a rodent).

Some recent works by scientists have found that some forms of hemotoxic venoms are not immunogenic, meaning that they do not trigger an immune response by the victim.  They slip by the immune system of the envenomated animal so no antibodies are produced to fight the toxins.  This is troubling since antivenoms are produced by injecting venom into a large animal, typically a horse, and later harvesting the antibodies created by the horse that can be later used to treat bite victims. 

Hemotoxin venoms such as those of rattlesnakes begin to disassemble the structural components of blood vessels and tissues as soon as they are injected.  This is done by metalloproteases, which are proteases enzymes that use a metal as a catalyst in the hydrolysis of peptide bonds.  Because these enzymes break down even the proteins responsible for keeping the cell walls of blood vessels intact, localized hemorrhaging results, sending blood into surrounding tissues.  The same metalloproteases also act to break down skeletal muscles.  Another component of rattler toxin, phospholipases cause the death of muscle tissue by attacking their cellular membranes.  Some of these phospholipases have enzymes that create holes in the muscle cell walls by breaking apart the phospholipids that hold the membranes together.  Other phospholipases use as‑yet‑unidentified means of destroying muscle cells. 

There are still other enzymes contained within rattler venom that cause destruction.  These include hyaluronidases and serine proteases, each having its own type of destructive mechanism.  Some chemical compounds from the venom travel far from the site of the bite and wreak havoc on blood vessels and skeletal muscles elsewhere in the body. 

In addition to the destructive actions of the venom components themselves, some proteins trick our own immune system to fight against our own cells.  Specifically, the actions of metalloproteases and phospholipases trigger an immune response at the site of the wound.  Immune cells such as leukocytes signal an increased immune response by releasing messengers such as interleukin-6.  Since the venom components are not a cohesive force, and with no bacteria to attack, the immune system instead launches an attack that adds to the destruction of our own tissues.  The damage done by our own immune system is doubly troubling considering that antivenom does not help to mitigate its effects.  Studies have found that, when the immune system is shut down, necrotic effects of snake venom are greatly reduced.  The use of Benadryl, for instance, can lessen the swelling and edema associated with envenomation.

A Note on Conservation

Although snakes are often feared and persecuted throughout much of their ranges in the United States and elsewhere, they nonetheless occupy a valuable place in the ecology of many ecosystems.  There are hundreds of species of snakes in the U.S., but only a small portion of them are venomous.  For example, in Florida there are 50 species of snakes but only 6 (12%) of those species are venomous.  Venomous snakes can be safely and effectively avoided by using common sense.  If a snake is thought to be venomous, or if it is not known whether it is venomous, the safe thing to do is to leave it alone.  Remember that most bite victims are bitten because they are attempting to handle or kill the snake. 

Snakes perform valuable services such as controlling rodents and other pests.  A recent study has shown that timber rattlesnakes may reduce the incidence of Lyme disease in the northeastern U.S. by preying on the host (rodents) that carries the tick that spreads the disease.  An estimated 2,500 to 4,500 ticks were removed from the northeastern U.S. study areas each year by timber rattlesnakes consuming their mammal hosts.  

Recent research suggests that rattlesnakes may help disperse the seeds of grasses and other plants.  Rodents eat grass seeds and those of other plants, but the seeds do not normally survive through the digestive process of rodents.  However, rodents often carry the seeds in their cheek pouches, and if the rodent is then killed and eaten by a rattlesnake, these seeds are capable of passing through the snake’s digestive tract and remaining viable.  Three species of desert-dwelling rattlesnakes were found to have consumed rodents with seeds in their cheek pouches and that the seeds are capable of germinating in the snake’s colon and may be passed with the snake’s feces, allowing dispersal of the plant propagules.

Rattlesnakes and many other species of snakes are experiencing declines in populations in the United States due to loss of habitat, continued persecution, and emerging diseases such as the snake fungus Ophidiomyces ophiodiicola.  The eastern diamondback rattlesnake (Crotalus adamanteus) (Figure 2) has declined to the point where the species has been petitioned for protection as a threatened species under the Endangered Species Act.

Rattlesnake blog pic2 FILEminimizer

Figure 2The eastern diamondback rattlesnake (Crotalus adamanteus) is one of the more well-known (and often persecuted) rattlesnake species.
Photographed and copyrighted by the author, Jason Seitz

A Fun Way to Report your Amphibian and Reptile Sightings Using Citizen Science

Use the HerpMapper mobile phone app to record and submit your amphibian and reptile sightings!  It’s fun, simple, and easy to do.  See the website https://www.herpmapper.org/ for more information and to download the app.

Sources

Adkins, C.L., D.N. Greenwald, D.B. Means, B. Matturro, and J. Ries.  2011.  Petition to List the Eastern Diamondback Rattlesnake (Crotalus adamanteus) as Threatened under the Endangered Species Act. Petition submitted 08/11/11 to U.S. Fish and Wildlife Service (USFWS), Washington, D.C., and USFWS Region 4, Atlanta, GA.

Brown, W.S.  1993.  Biology, Status, and Management of the Timber Rattlesnake (Crotalus horridus): A guide for Conservation.  Society for the Study of Amphibians and Reptiles, Herpetological Circular No. 22, The University of Kansas, Lawrence, KS.

Kabay, E., N.M. Caruso, and K.R. Lips.  2013.  Timber Rattlesnakes May Reduce Incidence of Lyme Disease in the Northeastern United States.  98th Annual Meeting of the Ecological Society of America, 08/06/13, Minneapolis, MN.  Accessed online 02/05/18 at https://eco.confex.com/eco/2013/webprogram/Paper44305.html.

Lorch, J.M, S. Knowles, J.S. Lankton, K. Michell, J.L. Edwards, J.M. Kapfer, R.A. Staffen, E.R. Wild, K.Z. Schmidt, A.E. Ballmann, D. Blodgett, T.M. Farrel, B.M. Glorioso, L.A. Last, S.J. Price, K.L. Schuler, C.E. Smith, J.F.X. Wellehan, Jr., and D.S. Blehert.  2016.  Snake fungal disease: an emerging threat to wild snakes.  Philosophical Transactions of the Royal Society B 371: 20150457.  Accessed online 02/13/18 at http://rstb.royalsocietypublishing.org/content/royptb/371/1709/20150457.full.pdf.

Reiserer, R.S., G.W. Schuett, and H.W. Greene.  2018.  Seed ingestion and germination in rattlesnakes: overlooked agents of rescue and secondary dispersal.  Proceedings of the Royal Society B: 285: 20172755. http://dx.doi.org/10.1098/rspb.2017.2755.

Robertson, M.  2017.  pers. comm. regarding regional differences in neurotoxins in the timber rattlesnake.

Wilcox, C.  2016.  Venomous, How Earth’s Deadliest Creatures Mastered Biochemistry.  Scientific American / Farrar, Straus, and Giroux, New York, NY.

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Jan
30

Military Ocean Terminal Sunny Point: Army's Primary East Coast Deepwater Port

Many of us probably don’t think about the importance of dredging in relation to national security and maintaining access to our military bases and terminals.  Maintaining access to navigation basins, access channels, and berthing areas is a critical component in our nation’s ability to accomplish its military and national security mission.  When these waterways and berthing areas become shoaled, the immediate capacity of a facility or base to transport materials and personnel is reduced or delays are incurred until full project capabilities are restored through dredging. 

ANAMAR recently sampled and tested dredge material at the Military Ocean Terminal Sunny Point (MOTSU), which is one of the largest military terminals in the world.  It is a high-security facility that is constantly patrolled by boats with armed soldiers.  And for good reason—MOTSU is the key ammunition shipping point on the Atlantic coast for the Department of Defense and is the Army's primary east coast deepwater port.  As the world's largest military terminal, Sunny Point ships more explosive cargo and equipment to the nation's armed forces and allies than any other facility.  The mission of the facility is to be prepared to quickly and effectively support the U.S. military and allies through the shipment of munitions, ordnance, or other military materials in response to any global situation or military requirement.  The maintenance of navigation depth at MOTSU is a prerequisite to maintaining a high state of operational preparedness at the facility.

Built in 1951, the terminal serves as a transfer point between rail cars, trucks, and ships during the import or export of weapons, ammunition, explosives, tanks, and military equipment for the U.S. Army.  MOTSU sprawls across 8,600 acres on the west side of the Cape Fear River, near the towns of Boiling Spring Lakes and Southport.  A vast majority of MOTSU’s real estate is longleaf and loblolly pine forest, which provides a barrier between shipping operations and the general public.  To prevent harm to the surrounding community, there is a 2,100-acre buffer zone on Pleasure Island (Carolina, Kure, Wilmington, and Fort Fisher beaches) and a 4,300-acre buffer in Brunswick County.  Despite its isolation, Sunny Point is an impressive facility.  Its three huge docks can handle several ships simultaneously.  Large cranes and 62 miles of tracks within the terminal move military supplies and explosive cargo.  The two most controversial cargoes shipped through the terminal were World War II nerve gas in 1970 and European spent nuclear fuel rods in 1994.

Sources:

Mims, Bryan.  2015.  Secrets of Sunny Point.  Our State Magazine.  May 26, 2015.  https://www.ourstate.com/military-ocean-terminal-sunny-point/.  Accessed 01/02/18.

Wikipedia.  https://en.wikipedia.org/wiki/Military_Ocean_Terminal_Sunny_Point  Accessed 01/29/18.

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May
19

Word of the Day: Throes

Ok, so it’s not a very common word, but don’t confuse “throes” (which means to be in severe pain or in the midst of an agonizing struggle) with “throws” (which means to toss or propel something through the air).

EXAMPLES:

I won’t be able to meet you for lunch because we are in the throes of a large proposal.

In baseball, a pitcher throws balls to the catcher (and hopes the batter doesn’t hit it first).

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Nov
10

Dispelling Myths about the Coyote in Florida, Or, Probably More Than You Wanted to Know about the Coyote in Florida

If you live in Florida you’ve probably heard people talk about coyotes (Canis latrans) in Florida.  Below are facts gleaned from the literature regarding this interesting mammal.

How Did the Coyote Get Its Name?

The accepted common name ‘coyote’ comes from the Aztec term for the species, Coyotl.  Other names used for this species in North America include coyóte (Mexican), brush-wolf, prairie-wolf, American jackal, and little wolf (Beebe 1964).

Why Did Coyotes Expand Their Range into the Eastern United States and Florida?

Most of us know that coyotes are not native to the eastern U.S., including Florida.  Their range has historically been limited to the western U.S. (Layne 1997).  Humans eliminated gray wolves and red wolves from the eastern U.S. in the early- to mid-1900s, with the red wolf being last recorded in Florida at that time (Beebe 1964).  Wolves were apparently a major constraint on the range of the coyote, so their recent absence from parts of the U.S. allowed for the natural expansion of the coyote’s range.  Thus, the expansion of the coyote into Florida and elsewhere in the eastern U.S. is most likely due to humans extirpating the wolves in this area.  Humans may have helped the coyote become established in Florida through accidental release or escape and (or) intentional release (Layne 1997), such as for hunting. 

Here’s a timeline of the presence of the coyote in Florida:

  • Pre-historic: Coyote fossils found in Florida geology dating to the Pleistocene (2.6 million to 11,700 years ago) (Webb 1974)
  • European colonization: No evidence of the species in Florida (Layne 1997)
  • 1970s: Coyotes were already well established in northern Florida (Layne 1997)
  • Early 1980s: The species was distributed through the middle of the Florida peninsula, from Hamilton County to Polk County (Brady and Campell 1983)
  • 1982: First sighting in Highlands County in southern Florida (Layne 1997)
  • 1988: The coyote’s range extended south to Broward and Collier counties (Wooding and Hardisky 1990)
  • 1995: A survey of coyote tracks by R. McBride found they were widely distributed in Highlands and Polk counties (Layne 1997)
  • 1991: Coyotes killed or trapped in Charlotte and Desoto counties (Layne 1997)
  • 2007: Coyotes documented in every county in Florida, and populations in Florida continue to increase (McCown and Scheick 2007)

What Habitats Do Coyotes Use Most Often?

In Florida, coyotes frequent improved pastures, native prairies, and citrus groves according to a survey by R. McBride cited in Layne (1997).  Den sites are located along brushy slopes, areas of thick undergrowth of vegetation, inside hollow logs, within rocky ledges, and burrows made either by adult coyotes or by other mammals.  Tunnels leading to the den may be 5 to 25 feet long (1.5 to 7.5 meters).  The den chamber itself measures about 1 foot (0.3 meters) in width and is commonly located 3.3 feet (1 meter) below-ground.  Coyotes may undertake seasonal migrations between habitats in some areas of North America (Novak 1999).

What Is the Average Size of the Coyote’s Home Range?

A coyote can cover a distance of about 2.5 miles (4 km) in a night while searching for a meal.  They traveled an average distance of 19.3 miles (31 km) from the point of capture in a tagging study in Iowa, but one individual covered a whopping 200 miles (323 km) during that study (Novak 1999).  A coyote tagged in south-central Canada traveled a record distance of 338 miles (544 km) from the point of capture (Carbyn and Paquet 1986).  Home range sizes vary greatly, from 3 to 31 square miles (8 to 80 km2).  Males have larger home ranges than do females, and male ranges overlap one another considerably.  Females ranges are smaller and do not overlap with those of other females (Novak 1999).

What’s the Average Population Density for Coyotes?

Population densities are generally between 0.1 and 0.2 coyotes per square mile (0.2 to 0.4 individuals/km2), but can be as high as 1.2 individuals per square mile (2.0/km2) in areas having extremely favorable conditions (Knowlton 1972, Bekoff 1977).  A study of coywolves (hybrid of coyote x eastern gray wolf [Canis lupus lycaon]) living north of Boston, Massachusetts, found a very high population density in fall and winter, at 1.1 to 1.3 individuals per square mile (2.9 to 3.4 individuals/km2) and 0.8 individuals per square mile (2.0 individuals/km2), respectively (Way 2011).

When Are Coyotes Most Active?

Coyotes can be active at any time of day or night, but they are mainly nocturnal and crepuscular (Novak 1999) (crepuscular means active around dawn and dusk [insect-eating bats are another example of crepuscular mammals]).

Does a Coyote Sighting Mean They Are More Common in the Area Than in Other Areas?

Coyotes are found in every Florida county.  Their level of abundance cannot be measured merely by anecdotal sightings since coyotes try to blend in with their surroundings and not be seen.  Sightings of coyotes do not necessarily mean that they are more abundant where sighted.  Coyotes are wherever there is suitable habitat, regardless of whether or not they are seen.  A sighting only confirms that coyotes are present.

What Do Coyotes Eat?

Coyotes mainly eat small mammals.  Rabbits and rodents make up the bulk (90%) of their diet in most areas.  Larger animals such as deer are also commonly eaten, but mostly as scavenged carcasses, although sometimes after a chase in which several coyotes worked together to take down the animal.  Other food items include fishes (which they are capable of snatching from streams!), lizards, snakes, birds such as turkeys, insects, grasses, fruits (including watermelon, persimmon, and various wild berries), and seeds (Novak 1999, Coates et al. 2002).  A tracking study conducted in Tucson, Arizona, found that over a 33-day period during November 2005 through February 2006, a group of eight coyotes killed 19 domestic cats (Harris Environmental Group 2015).  This interesting study further strengthens the idea that domestic cats are much better off if kept entirely indoors.  The coyote is also capable of preying on small domestic dogs (McCown and Scheick 2007).  Livestock are occasionally taken but the impact on livestock numbers is minimal (Novak 1999).  In the western U.S., where coyotes share their range with American badgers, the two species have been documented to form hunting partnerships whereby the coyote uses its excellent sense of smell to locate burrowing rodents, and the badger uses its powerful legs and claws to dig out the prey, which they then share (Novak 1999).

How Often Do Coyotes Prey on Domestic Livestock Like Cattle?

It is true that coyotes can kill and consume livestock including calves, poultry, pigs, and goats (Coates et al. 2002).  However, coyotes are not a serious problem to livestock (with the possible exception of sheep [Coates et al. 2002]) in most parts of their range, and reports of livestock damage from this species appear to be driven by popular perception and emotional reactions.  In the words of the past Chief Game Biologist for Mississippi, H.E. Alexander, “Reports of livestock damage from these animals seems to be more dependent on popular attitudes and emotional reactions to conspicuous evidence of depredations at some time and place than on actual fluctuations [of coyote populations]” (Beebe 1964).  Coyotes are not a major concern to livestock producers in Florida according to McCown and Scheick (2007).

What’s the Average Size and Weight of an Adult Coyote?

Adult male coyotes weigh 18 to 44 pounds (8 to 20 kg).  Adult females weigh 15 to 40 pounds (7 to 18 kg).  Coyotes living in northern regions weigh more, on average, than do those living in southern regions of North America (Nowak 1999).  The average weight of a coyote in Alaska is 40 pounds (18 kg), contrasting with the average weight of 25 pounds (11.5 kg) for coyotes living in the deserts of Mexico according to Gier (1975).  An unusually heavy coyote from Canada that weighed 46 pounds (21 kg) was noted by Beebe (1964).  The largest coyotes are those living in the northeastern United States, owing to enhanced nutrition there and (or) hybridization with the gray wolf (Nowak 1999).  In general, coyotes are larger than foxes but smaller than wolves (Coates et al. 2002).

How Fast Can Coyotes Run?

Coyotes are very speedy runners!  Picture this: a coyote racing in the World Championships in Athletics against legendary world record-holder Usain Bolt.  Usain runs a breathtakingly fast time of 9.58 seconds for the 100‑meter sprint.  That’s 23.4 miles per hour (mph) (37.7 km/hour)!  Now, let’s focus on the coyote.  The coyote explodes out of the starting line at a staggering pace, crossing the finish line in about half the time (4.47 seconds) it took Usain to cover the same distance!  That’s right, coyotes are fast and capable of running at speeds of up to 50 mph (80.5 km/hour) (Sooter 1943, Fisher 1975).  Although Novak (1999) gives a top speed of 64 mph (103 km/hour), this is higher than what is stated by most other sources.  Coyotes are clearly one of the fastest terrestrial mammals in North America.

Coyote Reproduction 101

Litter size averages about 6 pups but ranges from 2 to 12 pups.  Large numbers of pups have been found in a single den but were probably the result of litters from more than one female.  Females produce only one litter annually (Novak 1999).  Mating occurs during January through March, and gestation takes about 2 months (Coates et al. 2002).  Parturition (birthing) takes place in spring.  The pups weigh only about 8.8 ounces (250 grams) at birth.  Their eyes don’t open until day 14.  Young emerge from the den within about 3 weeks of birth and are fully weaned at about 9 months, at about which time they approach the weight and size of adult coyotes.  The average life span is less than 6 years, with the most significant mortality being within the first year of life (Coates et al. 2002).  The maximum longevity was recorded at 14.5 years in the wild, but most wild coyotes do not survive this long.  One long-lived captive coyote lived 21 years and 10 months (Jones 1982).

Do Coyotes Sometimes Hybridize with Other Canids?

Coyotes are well known to interbreed with domestic dogs (producing what are called ‘coydogs’).  Coyotes also interbreed with eastern gray wolves (Way 2011) as well as with red wolves (Canis lupus rufus), producing ‘coywolves’.  The offspring produced are fertile. 

What Are the Regulations on Hunting Coyotes in Florida?

The hunting and trapping of coyotes is allowed year-round throughout Florida (http://myfwc.com/‌hunting/season-dates).  However, a permit from the Florida Fish and Wildlife Conservation Commission (FWC) is needed for using steel traps, such as leg-hold traps.  More information on how to apply for a steel trap permit is found at http://myfwc.com/license/wildlife/nuisance-wildlife/steel-traps/.  FWC keeps a list of nuisance-wildlife trappers at https://public.myfwc.com/HGM/NWT/NWTSearch.aspx?.

Sources

Beebe, B.F.  1964.  American Wolves, Coyotes, and Foxes.  David McKay Co., Inc., New York, NY.

Bekoff, M.  1977.  Social behavior and ecology of the African Canidae: A review.  Pp. 120–142.  In: M.W. Fox (ed.)  The Wild Canids: Their Systematics, Behavioral Ecology and Evolution.  R.E. Krieger Publishing Co., Inc., Malabar, FL.

Brady, J.R. and H.W. Campell.  1983.  Distribution of coyotes in Florida.  Florida Field Naturalist 11:40–41.

Carbyn, L.N. and P.C. Paquet.  1986.  Long distance movement of a coyote from Riding Mountain National Park.  Journal of Wildlife Management 50:89.

Coates, S.F., M.B. Main, J.J. Mullahey, J.M. Schaefer, G.W. Tanner, M.E. Sunquist, and M.D. Fanning.  2002.  The Coyote (Canis latrans): Florida’s Newest Predator [online resource].  Wildlife Ecology and Conservation Dept. document WEC124, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, UF, Gainesville, FL.  Accessed 04/22/15 at http://edis.ifas.ufl.edu/pdffiles/UW/UW12700.pdf.

Fisher, J.  1975.  The plains dog moves east.  National Wildlife 13(2):1417.

Gier, H.T.  1975.  Ecology and behavior of the coyote (Canis latrans).  Pp. 247–262.  In: M.W. Fox (ed.) The Wild Canids: Their Systematics, Behavioral Ecology, and Evolution.  Van Nostrand Reinhold, New York, NY.

Harris Environmental Group, Inc.  2015.  Coyote’s Eat Cats! [online resource].  Accessed 04/22/15 at http://www.heg-inc.com/2009/08/coyotes-eat-cats/.

Jones, M.L.  1982.  Longevity of captive mammals.  Der Zoologische Garten 52:113–128.

Knowlton, F.F.  1972.  Preliminary interpretations of coyote population mechanics with some management implications.  Journal of Wildlife Management 36:369–382.

Layne, J.  1997.  Nonindigenous mammals. Pp 157–186.  In: D. Simberloff, D.C. Schmitz, and T.C. Brown (eds.), Strangers in Paradise, Impact and Management of Nonindigenous Species in Florida.  Island Press, Washington, D.C.

MacCown, W. and B. Scheick.  2007.  The Coyote in Florida [online resource].  Florida Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Tallahassee, FL.  Accessed 04/22/15 at http://myfwc.com/media/1228800/CoyoteWhitePaperFinal.pdf.

Nowak, R.M.  1999.  Walker’s Mammals of the World, Sixth Edition, Volume I.  The Johns Hopkins University Press, Baltimore, MD.

Sooter, C.A.  1943.  Speed of a predator and prey.  Journal of Mammalogy 24:102–103.

Way, J.G.  2011.  Record pack-density of eastern coyotes/coywolves (Canis latrans x lycaon).  The American Midland Naturalist 165(1):201–203.

Webb, S.D.  1974.  Chronology of Florida Pleistocene mammals.  In: S.D. Webb (ed.), Pleistocene Mammals of Florida.  University Press of Florida, Gainesville, FL.

Wilson, L.D. and L. Porras.  1983.  The Ecological Impact of Man on the South Florida Herpetofauna.  The University of Kansas Museum of Natural History Special Publication No. 9, University of Kansas, Lawrence, KS.

Wooding, J.B. and T.S. Hardisky.  1990.  Coyote distribution in Florida.  Florida Field Naturalist 18:12–14.

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May
21

Florida’s Introduced Nonindigenous and Invasive Mollusks (Clams and Snails): Final Installment of Our 3-part Series on Biological Invasions in Florida

This article discusses the species of introduced mollusks (bivalves and gastropods, better known as clams and snails) of Florida’s terrestrial and aquatic habitats along with a general discussion of the possible effects of biological invasions on native wildlife and habitats.  The first part of this three-part series was on introduced fishes in the state, and the second was on introduced amphibians and reptiles.  This discussion on introduced mollusks of Florida will wrap up our series!

As of this writing, at least 31 species of nonindigenous mollusks representing 17 families have been introduced to Florida (Exhibit 3).  Of these, about 68% have established breeding populations in one or more counties.  There are at least 5 species of introduced clams and 26 species of introduced snails, including terrestrial, freshwater, and marine species.  Of these mollusks, about 68% have established breeding populations in one or more counties.  Examples of established invasive species include the Asian green mussel (Perna viridis) (Exhibit 1) and the giant East African snail (Achatina fulica) (Exhibit 2).  

Jason Mullusks exhibit 1

Exhibit 1.  Asian Green Mussels (Perna viridis) Coat the Lower Surface of a Buoy in Tampa Bay, Florida.  The Species Is Introduced and Invasive throughout Florida’s Coastline.  The Barnacles in the Photo Are Most Likely Striped Barnacles (Balanus amphitrite)—Another Invasive Species in Florida.  Source: UF Fisheries & Aquatic Sciences (http://sfrc.ufl.edu/greenmussel/).

Some well-known negative effects of introduced snails are large-scale consumption and decimation of native vegetation and out-competing native species through direct competition for limited resources and through predation on their eggs and young. 

The giant East African snail (Achatina fulica) is a member of a family that contains the largest land snails in the world (Abbott 1989).  The species was first introduced to Florida in 1966 when a young boy brought three live snails from Hawaii (where it is also introduced) to Miami as pets.  Upon discovery of the smuggled snails, the boy’s grandmother released the snails into her garden.  Over the next several years the snails multiplied and spread to neighboring lands.  Florida state agricultural authorities were eventually alerted to the establishment of this destructive species and the species was eradicated by 1972 to the tune of $300,000 (Abbott 1989) to more than $1 million (FDACS 2011).  Between 1966 and 1972, the three specimens brought to Florida by the boy had multiplied to over 18,000 snails.  One specimen of the Miami colony reportedly measured a whopping seven inches in shell length (Abbott 1989)! 

In September 2011, the giant East African snail was found to have been reestablished in Miami after the Florida Department of Agriculture and Consumer Services responded to a call from a Miami homeowner.  Within 6 months, over 40,000 snails were collected in Miami by state and federal authorities (USDA 2012).  Although authorities are working hard to remove all the individuals of this species from Florida, the eradication will prove very difficult and the likelihood of complete eradication currently appears low.

The giant East African snail is introduced and invasive in several other parts of the world, including Hawaii and other islands in the Pacific, the Philippines, Madagascar, and parts of Asia.  The species is known to consume some 500 species of plants in both agricultural and natural areas.  Because the snail requires large amounts of calcium to grow and strengthen its great shell, the species causes damage to plaster and stucco while consuming these products for their calcium content.  It is a known carrier of a parasitic nematode that is capable of spreading meningitis in humans (FDACS 2011). 

The parasitic nematode known as rat lungworm (Angiostrongylus cantonensis) is carried by the giant East African snail and has an interesting life cycle.  The larvae are ingested by the snail (the intermediate host of the worm) when feeding on rat feces (don’t ask).  The larvae grow and approach maturity inside the snail.  It takes the consumption of an infected snail by a rat (the definitive host) for the parasitic nematode to complete its life cycle by reaching maturity and producing eggs inside the rat.  The mature nematode eggs hatch into larvae while still within the rat and are expelled with the rat’s feces.  People can become infected by eating undercooked or raw (who eats raw snails?) infected snails.  People may also become infected by eating raw produce such as lettuce that contains a small snail or slug.  An infected person cannot transmit the disease to other people.  Infection of rat lungworm in humans is rare in the continental United States, but at least one case was recorded in 1993 in New Orleans where a boy ingested a raw snail (apparently on a dare) and became infected with rat lungworm.  The parasitic nematode is host-specific and humans are not its intended host, so the parasite typically dies inside an infected person, even without treatment.  However, the symptoms range from headache, muscle aches, stiff neck, skin irritation, fever, nausea, and vomiting until the parasite dies (CDC 2010). 

In 2012, a captive orangutan (Pongo sp.) housed in Miami was found to have been infected with the rat lungworm.  The animal had a history of eating snails.  Researchers from the University of Florida collected snails and rat feces from around the area where the orangutan was housed and examined the samples for evidence of the parasitic nematode.  Several of the snails and all of the rat feces tested positive for rat lungworm (UF 2015).  The species of snails found to have been infected included the introduced species Asian trampsnail (Bradybaena similaris), garden zachrysia (Zachrysia provisoria), and the striate drop (Alcadia striata) (J. Slapcinsky, Florida Museum of Natural History, Gainesville, FL, pers. comm. 03/03/015).

Although reducing the effects of invasive nonindigenous species (such as those listed in Exhibit 2) is an important part of restoration and management efforts in natural areas of Florida and elsewhere, introduced mollusks are typically a lower priority than other organisms, such as invasive plants or fishes, except when they are known carriers of disease or damage agricultural crops or other property.  Nonetheless, invasive organisms of all kinds can cause significant stress to native ecosystems and biological invasion is widely viewed as a major cause of the reduction in native plant and animal diversity (Elton 1958, Wilcove et al. 1998).  Invasive species are known to affect most natural areas of the United States (Villazon 2009) and worldwide (Sala et al. 2000).

It should go without saying that the intentional introduction of any nonindigenous species, whether it be a plant or animal and regardless of size or assumed innocuousness, should never be attempted.  The reasons are many and the costs can be severe in terms of biological effects, human health, and economic impacts.  Nonindigenous species introduced to new areas have the capacity to explode in numbers and outcompete native species for limited resources such as food, water, and shelter.  Native species are at a competitive disadvantage because they have not had time to evolve defense mechanisms that would otherwise allow them to successfully compete against the introduced species.  The introduced species can have a competitive edge where it is introduced outside its native range partly because these species lack the predators they would have in their native range.  This idea was coined fairly recently by scientists with the term ‘predator release’.  The competition between native and nonindigenous species can result in the extinction of native species, spread of diseases and parasites, and displacement of whole communities, and may even cause physical changes to the environment. 

Exhibit 2.  Nonindigenous Mollusks Recorded in Florida

Scientific Name

Common Name

Locality Records

Current Status

BIVALVES

CLAMS

   

CORBICULIDAE

BASKET CLAMS

   

Corbicula fluminea

Asian Clam

Throughout inland waterways of FL

Established (throughout inland waterways of FL)

DREISSENIDAE

     

Dreissena polymorpha

Zebra Mussel

Hillsborough Co. (1969)

Collected

MYCETOPODIDAE

(a family of freshwater pearly mussels)

   

Anodontites trapesialis

(a freshwater mussel)

Palm Beach Co. (1980)

Failed

MYTILIDAE

(a family of marine mussels)

   

Perna viridis

Asian Green Mussel

Throughout the Atlantic and Gulf coasts of FL

Established (throughout FL coastline)

SPHAERIIDAE

PEA CLAMS

   

Pisidium punctiferum

Striate Peaclam

Not specified

Established (throughout inland waterways of FL)

GASTROPODS

SLUGS & SNAILS

   

ACHATINIDAE

GIANT AFRICAN SNAILS

   

Achatina fulica

Giant East African Snail

Broward & Miami-Dade Co.

Eradicated by 1972 (Miami-Dade Co.)

Re-established by 2011 (Miami-Dade Co.)

Recently Established by 2014 (Broward Co.)

Archachatina marginata

Banana Rasp Snail, Giant West African Snail

Hillsborough Co.

Collected (1992)

AMPULLARIIDAE

APPLE SNAILS

   

Marisa cornuarietis

Giant Ramshorn Snail (marketed in the aquarium trade as ‘Columbian Ramshorn’)

Throughout inland waterways of FL

Established (throughout inland waterways of FL)

Pomacea canaliculata

Channeled Apple Snail

Collier, Duval, Hillsborough, Indian River, Leon, Palm Beach, Pasco, & Seminole Co.

Established (much of FL)

Pomacea diffusa

Spike-Topped Apple Snail

Alachua, Broward, Collier, Hillsborough, Miami-Dade, Monroe, & Palm-Beach Co.

Established (Broward, Monroe, & Palm-Beach Co.)

Unknown (Miami-Dade Co.)

Collected (Alachua, Collier, & Hillsborough Co.)

Pomacea haustrum

Titan Apple Snail

Miami-Dade & Palm Beach Co.

Collected (Miami-Dade & Palm Beach Co.)

Pomacea maculata

Giant Apple Snail

Alachua, Collier, Hernando, Hillsborough, Indian River, Lake, Leon, Manatee, Miami-Dade, Orange, Pasco, & Polk Co.

Established (throughout)

BRADYBAENIDAE

(a family of terrestrial pulmonate snails)

   

Bradybaena similaris

Asian Trampsnail

Throughout most of FL

Established (throughout)

BULIMULIDAE

(a family of terrestrial pulmonate snails)

   

Bulimulus guadalupensis

West Indian Bulimulus

Broward, Duval, Lake, Manatee, Miami-Dade, & Palm Beach Co.

Established (Duval & Miami-Dade Co.)

Unknown (Broward, Lake, Manatee, & Palm Beach Co.)

CAMAENIDAE

(a family of terrestrial pulmonate snails)

   

Caracolus marginella

Banded Caracol

Miami-Dade Co.

Unknown

Zachrysia provisoria

Garden Zachrysia, Cuban Land Snail

Broward, Collier, Hillsborough, Miami-Dade, Monroe, Palm Beach, Pinellas, & Sarasota Co.

Established (most of the eight counties)

HELICINIDAE

(a family of tropical terrestrial operculate snails)

   

Alcadia striata

Striate Drop

Broward, Manatee, & Miami-Dade Co.

Established (Miami-Dade Co.)

Unknown (Broward & Manatee Co.)

Helix aspersa

Brown Garden Snail

Broward, Hillsborough, Jefferson, Miami-Dade, & Orange Co.

Unknown

MURICIDAE

MUREX SNAILS

   

Rapana venosa

Veined Rapa Whelk

Monroe Co.

Failed

PLANORBIDAE

RAMSHORN SNAILS

   

Biomphalaria glabrata

Bloodfluke Planorb

Lee Co. at Sanibel Island & an unspecified location

Unknown (Sanibel Island)

Collected (unspecified location)

STREPTAXIDAE

(a family of carnivorous pulmonate snails)

   

Huttonella bicolor

Two-tone Gulella

Alachua Co.

Established

SUBULINIDAE

(a family of small terrestrial pulmonate snails)

   

Allopeas gracile

Graceful Awlsnail

Alachua, Marion, & Volusia Co.

Established (Alachua Co.)

Unknown (elsewhere)

Lamellaxis micra

Tiny Awlsnail

Throughout most of Florida

Established (throughout)

Opeas pumilum (O. hannense ?)

Dwarf Awlsnail

Alachua, Collier, Duval, Jefferson, Hillsborough, Levy, Miami-Dade, Orange, Putnam, & St. Johns  Co.

Established (throughout)

Opeas Pyrgula

Sharp Awlsnail

Alachua, Broward, Hillsborough, Orange, Palm Beach, Volusia, & Wakulla Co.

Unknown but likely established (Alachua, Broward, Hillsborough, Orange, Palm Beach, Volusia, & Wakulla Co.)

THIARIDAE

THIARID SNAILS

   

Melanoides tuberculatus

Red-Rim Melania (marketed in the aquarium trade as ‘Malaysian Trumpet Snail’)

Alachua, Brevard, Broward, Citrus, Collier, Hendry, Hillsborough, Lake, Marion, Martin, Miami-Dade, Okeechobee, Orange, Palm Beach, St. Johns, & Volusia Co.

Established (throughout)

Melanoides turriculus

Fawn Melania

Alachua, Hillsborough, Lake, Marion, Orange, & Volusia Co.

Established (throughout)

Tarebia granifera

Quilted Melania

Alachua, Citrus, Columbia, Hillsborough, Lake, Levy, Marion, & Pasco Co.

Established (throughout)

Thiara scabra

Pagoda Tiara

Martin & Palm Beach Co.

Unknown (Martin & Palm Beach Co.)

VIVIPARIDAE

MYSTERY SNAILS

   

Cipangopaludina chinensis malleata

Chinese Mysterysnail

Lee, Pinellas, & Polk Co.

Collected (Pinellas & Polk Co.)

Established (Lee Co.)

Cipangopaludina japonica

Japanese Mysterysnail

Kissimmee Co.

Collected

Sources: Florida Museum of Natural History (http://www.flmnh.ufl.edu/scripts/dbs/malacol_pub.asp), USGS Nonindigenous Aquatic Species online database (http://nas.er.usgs.gov/queries/SpeciesList.aspx?Group=Mollusks&Sortby=1&state=FL), Seitz (2014), J.C.Seitz unpublished data.

Sources:

Abbott, R.T.  1989. Compendium of Landsnails.  A Color Guide to More than 2,000 of the World’s Terrestrial Shells.  American Malacologists, Inc., Melbourne, FL.

Centers for Disease Control (CDC).  2010.  Parasites – Angiostrongyliasis (Also Known as Angiostrongylus Infection) [online resource].  Accessed 03/24/15 at http://www.cdc.gov/parasites/angiostrongylus/‌gen_info/faqs.html#whatangiostrongylus#whatangiostrongylus.

Elton, C.S.  1958.  The Ecology of Invasions by Animals and Plants. Methuen and Co., Ltd., Strand, London.

Florida Department of Agriculture and Consumer Services (FDACS).  2011.  Florida Department of Agriculture and Consumer Services Identified Giant African Land Snails in Miami-Dade County [online resource].  Accessed 03/24/15 at http://www.freshfromflorida.com/News-Events/Press-Releases/2011-Press-Releases/Florida-Department-of-Agriculture-and-Consumer-Services-Identifies-Giant-African-Land-Snails-in-Miami-Dade-County.

Florida Museum of Natural History (FLMNH).  2015.  Invertebrate Zoology Master Database [online resource].  Accessed 03/23/15 at http://www.flmnh.ufl.edu/scripts/dbs/malacol_pub.asp.

Sala, O.E. F.S. Chapin, J.J. Armesto, E. Berlow, J. Bloomfield, R. Dirzo, E. Huber-Sanwald, L.F. Huenneke, R.B. Jackson, A. Kinzig, R. Leemans, D.M. Lodge, H.A. Mooney, M. Oesterheld, N.L. Poff, M.T. Sykes, B.H. Walker, M. Walker, and D.H. Wall.  2000.  Global biodiversity scenarios for the year 2100. Science 287:1770–1774.

Seitz, J.C.  2014.  Assessing Stream-mediated Seed and Shoot Dispersal of Invasive Plants in an Urban Riparian Wetland [thesis].  University of Florida, Gainesville, FL.

University of Florida (UF).  2015.  UF Researchers: Rare Parasite Colonizing Snails in South Florida [online resource].  Accessed 03/24/15 at http://news.ufl.edu/archive/2015/02/uf-researchers-rare-parasite-colonizing-snails-in-south-florida.html#prettyPhoto.

U.S. Department of Agriculture (USDA).  2012.  Escargot? More like Escar-No! [online resource].  Accessed 03/24/15 at http://blogs.usda.gov/2012/04/19/escargot-more-like-escar-no/.

U.S. Geological Survey (USGS).  2015.  NAS – Nonindigenous Aquatic Species [online resource].  Accessed 03/23/15 at http://nas.er.usgs.gov/queries/SpeciesList.aspx?Group=Mollusks&Sortby=1&state=FL.

Villazon, K.A.  2009.  Methods to Restore Native Plant Communities after Invasive Species Removal: Marl Prairie Ponds and an Abandoned Phosphate Mine in Florida.  MS thesis, University of Florida, Gainesville, FL.

Wilcove, D.S., D. Rothstein, J. Dubow, A. Phillips, and E. Losos.  1998.  Quantifying threats to imperiled species in the United States. Bioscience 48:607–615.

Wilson, L.D. and L. Porras.  1983.  The Ecological Impact of Man on the South Florida Herpetofauna.  The University of Kansas Museum of Natural History Special Publication No. 9, University of Kansas, Lawrence, KS.

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Sep
01

What can fossils tell us about the rock surrounding them? Fossil scallops in the Coquille River as a case study

During a benthic survey off the Coquille River, Oregon, in September 2013, ANAMAR was collecting samples of epifauna using a 12-foot otter trawl when suddenly the gear encountered unidentified rock.  The trawl net snagged and the cable instantly snapped, losing the gear on the seafloor in about 45 feet of water.  Although many attempts were made to recover the trawl using a grapple hook off the deck of the survey vessel (R/V Pacific Storm), the gear was too entangled on the seafloor to be brought up with that method.  Directly following completion of the benthic survey, an ANAMAR subcontractor returned to the site and recovered the trawl gear using SCUBA divers.  The trawl was still in good shape and the remaining trawl tows were completed for the survey.  In addition to finding the trawl gear, the divers also observed several fossil scallop shells embedded in the rock on the seafloor.  The fossil scallops were in excellent condition (see images below).  The divers were able to pry a few of the fossil shells loose for closer inspection and photography.

Fossil Scallops Coquille Pic1

Because the area where the survey took place is an ocean dredged material disposal site (ODMDS), information on the naturally occurring rocks found there is of interest to agencies tasked with managing the site (U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency).  For this reason, and also out of personal interest, I began collaborating with paleontologists to determine the identity of the fossil scallops in the hopes of learning more about the rock they were found in.  I soon found my answer after contacting specialists at the Burke Museum of Natural History in Seattle, Washington.  Dr. Elizabeth Nesbitt, Curator of Paleontology, graciously identified the fossil scallops as either Patinopecten coosensis or P. oregonensis based on photos I sent her.  The flared portions of the shell adjacent to the hinge (called auricles) serve as key characteristics differentiating these two species.  These fossils lacked auricles so they could not be identified beyond these two species.  However, based on the fossils and the associated matrix, Dr. Nesbitt was able to identify the rock formation the fossils were found in!

The rocks and fossils are part of the Empire Formation which is better known from exposures about 20 miles south of the Coquille River, at Cape Blanco, Oregon.  The Empire Formation, composed mostly of sandstone, along with the fossils it contains, are as old as 12 million years (Miocene) but it is theorized to be closer to 8 to 5 million years (Miocene-Pliocene epoch boundary).  Since we know the identity of the rock as being part of the Empire Formation, we therefore know something about its composition.  In this case, the rocks that snagged the trawl gear must have been composed of sandstone and some siltstone.  This formation represents sands deposited in what was then a small marine basin, which now is only represented by Coos Bay.  It is probable that other rocks within the ODMDS are also fossiliferous sandstone/siltstone from the Empire Formation.

The above is an example of how fossils can help us infer the identity of the surrounding substrate.  In this case, the identity of the fossil scallops, along with the matrix attached to the fossils, were used to pinpoint the exact formation they represent.  Knowing the formation, we then were able to learn more about the composition and approximate geological age of surrounding rocks that represent the same formation.  All this information came from observing and collecting a handful of fossils incidental to recovering of some equipment from the seafloor!

Interestingly, the French word for scallop is Coquille.  Thus, the Coquille River, where the fossils were collected, was actually named after a scallop!

Sources:

Ehlen, J.  1967.  Geology of state parks near Cape Arago, Coos County, Oregon.  The Ore Bin 29(4):61–82. 

Nesbitt, E.  Department of Paleontology, Burke Museum of Natural History, University of Washington, Seattle, WA.  Pers. comm. 12/06/13.

Portell, R.W.  Department of Invertebrate Paleontology, Florida Museum of Natural History, University of Florida, Gainesville, FL.  Pers. comm. 11/18/13.

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Aug
21

Why do sturgeon jump?

The jumping of Gulf sturgeon (Acipenser oxyrinchus desotoi) on the Suwannee River is well publicized and is widely known among Floridians.  Some jumping sturgeon have even caused injuries to unfortunate boaters who get in the way of these armored aerial acrobats.  Sturgeon jump most often in the early morning, and each fish averages one jump per day.  Jumping is not confined to large individuals either, as fish as small as one foot long will jump.  Most jumping activity occurs from June to early July, when some reaches of the river can experience as many as 6 to 10 jumps per minute!  The most intense jumping occurs when the water level is low, before the summer convective storm season sets in.  Yes, the fact that these massive timeless fish jump is not the question here.  They jump.  We know.  What’s not well publicized is why exactly these sturgeon feel the need to jump in the first place. 

Gulf sturgeon are not trying to shed ectoparasites as many believe, nor are they trying to capture prey.  The jumping is also unrelated to spawning.  They are not reacting to the presence of boats.

They loiter in the deep dark pools of the Suwannee River and other Gulf Slope rivers from April through September and slowly digest the 20 percent of body fat they put on during the previous 6 months of easy living and easy feeding in the Gulf of Mexico.  When in the Suwannee, they seldom feed, so put that fishing pole away.

Resting in the sluggish deep recesses of the Suwannee, Gulf sturgeon are conserving energy.  But just hovering above the river bottom requires neutral buoyancy.  Similar to how a SCUBA diver adjusts his BC, these fish must add air to the swim bladder.  Air slowly leaks out of the swim bladder and is absorbed in the surrounding tissues.  To keep from scraping along the bottom and to swim more efficiently in the sluggish current, the swim bladder must be refilled an average of once daily.  Since the swim bladder in Gulf sturgeon is connected to the digestive tract by a duct, the bladder can be recharged by gulping air.  But how does a fish, being totally aquatic as they are, find any atmospheric air to gulp?  Well we have nearly reached our answer to why they jump. 

Any SCUBA diver knows that you can’t descend easily through the water column with a BC full of air, even with dive weights.  By the same principle, a sturgeon can’t just rise gently to the surface, take a big gulp of air, and glide back down into the depths.  Did I mention that while sturgeon are lollygagging in the river, they are also chatting up a storm?  Call them gabby or chatty, Gulf sturgeon really know how to bend an ear (or otolith, in this case).  These fish communicate with one another via a series of snapping sounds.  Jumping high up into the air and then falling powerfully back into the water, with a loud report, and swimming directly to the bottom serves two purposes.  The main purpose is to allow the fish to gulp air and yet have enough momentum to reach the river bottom immediately afterward (despite the increased buoyancy from the added air).  The secondary purpose may be to communicate.  Immediately prior to jumping, these fish emit a series of snapping sounds, and following the belly-flop-style smack when entering the water, the sturgeon emit more snapping sounds.  The role jumping plays in sturgeon communication, if any, is far from clear, and would be very difficult to prove scientifically.  However, it seems probable that these fish are communicating with one another using not just snapping sounds (which have been recorded by U.S. Geological Survey scientists and heard by SCUBA divers), but perhaps also by the splash following a jump.  So next time you encounter a jumping sturgeon while enjoying a lazy day on the Suwannee, ask it why it jumps.  Listen carefully to its answer and don’t be surprised if its response sounds something like “snap, snap-snap, snaaap, snaaap, snap”.

Source and Suggested Reading:

Sulak, K.  2013.  Catching air – those magnificent jumping Suwannee sturgeons.  American Currents 38(2):23–25. 

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Mar
06

What fossil animal remains are in the sediment at Charleston Harbor and what can they tell us about the age of the sediment?

charlestonphoto1

Harbor sediment is often subjected to physical, chemical, toxicological, and bioaccumulation analyses as part of dredging projects that keep our harbors navigable; however, the fossils in the sediment often go unnoticed and unappreciated during such testing.  What can the fossil remains—the critters that once inhabited the area—tell us about the age and history of the sediment?  An ANAMAR biologist set out to learn just that, by sieving about 5 gallons of extra material from a recent sediment sampling event at Charleston Harbor, South Carolina.

The sample was collected with a vibracore sampler at the area of Mount Pleasant Range and Benice Reach.  The matrix was a mixture of shells, sand, silt, and clay.  The particles smaller than the 2-mm mesh size screen were washed away during the sieving process.  The remaining shells and other hard objects were left to dry over a few week’s time.  The remains were then identified and photographed. 

So what was found?

The sample contained:

  • Crustacean remains
    • Crab and shrimp claws
    • Barnacle shells
  • Echinoid (sea urchin) spines
  • Mollusk shells
    • Ark shells of the order Arcoida
    • Limpets of the genus Diodora sp.
    • Many other gastropod and bivalve shells
  • Shark teeth
    • Hemipristis serra (extinct snaggletooth shark)
    • Physogaleus (Galeocerdo) contortus (extinct tiger shark)
    • Galeocerdo cuvier (modern [extant] tiger shark)
    • Hundreds of small teeth from other carcharhinids (requiem sharks)
  • Shark vertebrae
  • Ray teeth
    • Dasyatis sp. or Himantura sp. (stingrays)
    • Rhinopteridae and/or Myliobatidae (cownose rays, eagle rays)
    • cf. Paramobula fragilis and cf. Plinthicus stenodon (extinct devil rays)
  • Bony fish remains:
    • Otoliths (ear bones)
    • Teeth from Sphyraena sp. (barracuda)
  • Undetermined bone fragments
  • Apatite (a phosphate-containing mineral)

charlestonphoto3

 

Estimating the age of the sediment based on fossil remains

The snaggletooth shark Hemipristis serra occurred during the Pleistocene (12,000 to 2.6 million years ago) to the Eocene (34 million to 56 million years ago) and its fossil remains indicate warm, well-oxygenated marine conditions back then (Cappetta 1987).  The extinct tiger shark Physogaleus (Galeocerdo) contortus occurred during the Miocene (5 million to 23 million years ago) (possibly also during the Eocene) and is a characteristic fossil of the Southeastern Coastal Plain (Cappetta 1987).  The devil ray teeth were damaged but appeared to resemble the extinct species Paramobula fragilis of the Oligocene epoch (23 to 34 million years ago) and Plinthicus stenodon of the Miocene (Cappetta 1987, www.elasmo.com).

Charleston2

The tiger shark Galeocerdo cuvier and many other requiem shark species are still around today.  The stingray genera Dasyatis and Himantura, the eagle rays, and the cownose rays are also still around today, although the stingray genus Himantura is now absent from the western North Atlantic.  Similarly, the barracuda genus Sphyraena is still around today including four modern species inhabiting the western North Atlantic (Robins and Ray 1986).

charlestonphoto5

Identification of the invertebrate remains was not yet attempted to the lowest practical taxonomic level, but they appeared to range in age from the Holocene (recent) to the Pleistocene (12,000 to 2.6 million years ago) based on initial observations. 

Based on the shark and ray fauna represented by fossils, the sediment taken from Charleston Harbor probably dates back to the Miocene.  Given that some fish and invertebrate remains may be modern, the sediment probably also includes relatively recently deposited material.  The fact that multiple geological epochs appear to be represented in the sediment is typical for fluvial (riverine) deposits such as in Charleston Harbor.  In addition to the fossil remains, the mineral apatite, containing phosphate, was found as smooth spherical black stones.  Mineral identification was made by W.G. Harris (pers. comm.).

 charlestonphoto6

Sources Cited:

Cappetta, H.  1987.  Handbook of Paleoichthyology, Chondricththyes II. Mesozoic and Cenozoic Elasmobranchii.  Gustav Fischer Verlag, Stuttgart, Germany.

Harris, W.G.  2013.  Professor of Soil Mineralogy, Soil and Water Science Department, University of Florida, Gainesville, FL. Pers. Comm.

Robins, C.R. and G.C. Ray.  1986.  A Field Guide to Atlantic Coast Fishes. North America.  Houghton Mifflin Co., New York, NY.

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