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Aug
20

Data Reporting: Treatment of Outliers

Excerpted from the Southeastern Regional Implementation Manual (SERIM)

 7.4 Data Reporting and Statistics for Bioassay and Bioaccumulation Testing

 7.4.1 Definition and Treatment of Outliers

In most biological testing, some data points will be either much smaller or much larger then would be reasonably expected. Intuitively, outliers can be thought of as individual observations that are "far away" from the rest of the data. Outliers can be the result of faulty data, erroneous procedures, or invalid assumptions regarding the underlying distribution of all the data points that could potentially be sampled. In practice, a small number of outliers can be expected from a large number of samples including those that follow a normal distribution. Several techniques are available for outlier detection. Tests that involve hypothesis testing on data assumed to be normally distributed include Grubb's test, Rosner's test, and Dixon's test. The main advantage of using one of these formal statistical procedures is the ability to limit the risk of falsely flagging a valid data point as an "outlier".

When suspecting that a data point might be an outlier during the statistical analysis of bioassay and bioaccumulation data, the analysis should be performed twice, once with the suspected outlier and again without it. Both results should be reported and an explanation of why the outlier is believed to deserve exclusion or inclusion with the analysis should be presented. Such an explanation should not rely solely on the fact that some statistical test detected the outlier. In general, the more environmentally conservative approach should be utilized.

Citation: USEPA/USACE. 2008. Southeast Regional Implementation Manual (SERIM) for Requirements and Procedures for Evaluation of the Ocean Disposal of Dredged Material in South­eastern U.S. Atlantic and Gulf Coast Waters. EPA 904-B-08-001. U.S. Environmental Protection Agency Region 4 and U.S. Army Corps of Engineers, South Atlantic Division, Atlanta, GA. http://www.epa.gov/region4/water/oceans/documents/SERIM_Final_August 2008.pdf

 

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Aug
08

SERIM: Water Quality Criteria

 

Water Quality Criteria

Excerpted from the Southeastern Regional Implementation Manual (SERIM)

3.2.1.1 Screen to Determine WQC Compliance

 

A screening method utilizing sediment chemistry can be used to determine compliance. The screen assumes that all of the contaminants in the dredged material are released into the water column during the disposal operation (see Section 10.1.1 of the 1991 Green Book). If the numerical model predicts that the concentration of all COCs released into the water column are less than the applicable WQC, the marine WQC LPC is satisfied.

The model needs to be run only for the COC that requires the greatest dilution. If the contaminant requiring the greatest dilution is shown to meet the LPC, all of the other contaminants that require less dilution will also meet the LPC. The contaminant that would require the greatest dilution is determined by calculating the dilution that would be required to meet the applicable marine WQC. To determine the required dilution (Dr), the following equation is solved for each COC:

Dr = (Cs-Cwq) / (Cwq - Cds)                                 [Eq. 3-1]

where

Cs =    concentration of the contaminant in the dredged material elutriate, expressed as micrograms per liter (μg/L) as determined by either equation 3-1 below or by elutriate chemical analytical results discussed in Section 3.2.1.2.

Cwq =  applicable marine WQC (EPA WQC or state WQS), in (μg/L)

Cds =   background concentration of the constituent at the disposal site water column, in μg/L

NOTE:Dilution is defined as the volume of ambient water in the sample divided by the volume of elutriate water in the sample.

Note that most contaminant results are reported in micrograms per kilogram (μg/kg) dry weight. To convert the contaminant concentration reported on a dry-weight basis to the contaminant concentration in the dredged material, the dry-weight concentration must be multiplied by the mass of dredged-material solids per liter of dredged material:

                                  [Eq. 3-2]

where 

Cdw =  contaminant concentration in dredged material, reported on a dry-weight basis (μg/kg)

ns =    percent solids as a decimal

G =    specific gravity of the solids. Use 2.65 if site-specific data are not available.

A table showing each contaminant and the dilution required to meet the WQC should be provided with the analysis. Alternatively, a module in the STFATE model can be used. The module requires the solids concentration (g/L), which is the term in brackets in Equation 3-2 above multiplied by 1000.

The concentration of the contaminant that would require the greatest dilution is then modeled using a numerical mixing model. Model input parameters are specific to each proposed dredging project and each ocean disposal site. Standard STFATE input parameters for each disposal site are being developed with each ODMDS-specific SMMP. They are included in Appendix G along with additional guidance on model usage. The key parameters derived from the dispersion model are the maximum concentration of the contaminant in the water column outside the boundary of the disposal site during the 4-hour initial-mixing period or anywhere in the marine environment after the 4-hour initial-mixing period. If both of these concentrations are below the applicable marine WQC, the WQC LPC is met and no additional testing is required to determine compliance with the WQC. If either of these concentrations exceeds the WQC, additional testing is necessary to determine compliance with the WQC, as described in the next section.

 

 

Citation: USEPA/USACE. 2008. Southeast Regional Implementation Manual (SERIM) for Requirements and Procedures for Evaluation of the Ocean Disposal of Dredged Material in South­eastern U.S. Atlantic and Gulf Coast Waters. EPA 904-B-08-001. U.S. Environmental Protection Agency Region 4 and U.S. Army Corps of Engineers, South Atlantic Division, Atlanta, GA. http://www.epa.gov/region4/water/oceans/documents/SERIM_Final_August 2008.pdf

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Jul
31

A Brief History of the Gulf Sturgeon

A Brief History of the Gulf Sturgeon

 

sturgeon 1The Gulf Sturgeon (Acipenser oxyrinchus desotoi) are modern descendants of a group of ancient freshwater fish called Chondrostei which, along with alligators and crocodiles, were able to survive the mass extinction of the Mesozoic Era. Gulf Sturgeon have been known to swim into both fresh and saltwater to feed and uniquely possess a protruding suction mouth that makes it easy to obtain food from riverbeds, lakebeds, and the bottom of the Gulf of Mexico. Gulf Sturgeon have an average lifespan of 20 to 25 years and grow to a maximum length of 7½ feet, with an average body weight of 150 to 200 lbs., but have been known to reach weights of up to 300 lbs. Gulf Surgeon males become sexually mature at about age 8 and spawn every year after that, while the females become sexually mature at age 12 and spawn only three to four times during their lifespan. Females require 3 years to develop each batch of 200,000 to 500,000 eggs, of which only few will actually survive. Disease, water quality, predators, and a number of other factors claim 99.999% of eggs, hatchlings, and juveniles. USGS calculates that females need to successfully produce only two offspring to maintain a stable population.

In 1991 the federal government granted protection to the Gulf Sturgeon under the Endangered Species Act after a massive population decline occurred due in part to over fishing, damming of rivers, and pollution. Thanks to the many agencies, organizations, and private citizens that have continued to work together to help maintain accurate scientific research and field data, this species that links back 200 million years can still be found among today’s aquatic fauna.

 

A word from the field from ANAMAR’s Christine Smith:sturgeon 2

“Here are some photos from today’s USGS sturgeon-tagging effort.  We caught about 15 fish on the Suwannee near Manatee Springs.  Normally they catch more, but the DO [dissolved oxygen] was pretty low in the area.  We scanned for previous tags, weighed, measured fork and total length, tagged, and took blood samples.  Prior to fishing we ran a few sidescan transects to try to identify individual sturgeon as well as habitat.”

–Christine Smith on July 30, 2013

 

(Photos courtesy of Christine Smith)

 

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Jul
26

Word From the Field: San Francisco DODS Survey

ANAMAR’s biologist Jason Seitz recently assisted EPA and USACE in a benthic survey of the San Francisco Deep Ocean Disposal Site (SF-DODS) aboard the R/V Point Sur 50 miles off the coast of San Francisco. During the survey, Jason and other crew spotted many of nature’s majestic creatures. In the following paragraph Jason lists some of the species observed during the survey.

“We encountered several species of marine mammals during the SF-DODS survey, including humpback whales, northern right whale dolphins, Pacific white-sided dolphins, Rizzo’s dolphins, sea otters, seals, and sea lions.  We also encountered pelagic birds such as black-footed albatross, storm petrels, shearwaters, murres, murrelets, and tufted puffins.”

-Jason Seitz


    b2ap3_thumbnail_Black-footed-albatross.JPG           

SF-DODS, an ocean disposal site for dredged materials, is regulated under the Marine Protection, Research, and Sanctuaries Act of 1972 (MPRSA) and co-managed by USACE San Francisco District and EPA Region 9. SF-DODS is also the nation’s deepest disposal site. It is located along the continental slope in water depths of about 3000 meters and is just outside the Gulf of the Farallones National Marine Sanctuary.

 

b2ap3_thumbnail_ODMS-Sampling-aboard-the-Point-Sur.JPG

 

Photo's courtesy of Jason Seitz

 

 

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Jun
19

Significant Figures, Decimal Places, and Rounding Part II

Part II Rounding Rules

When the data collected have more sig figs than needed, the results should be rounded. Rounding removes superfluous digits from a number and can make it easier to use in subsequent calculations and evaluations.

First, determine how many digits or decimal places the final result should be reported to, then find the next digit to the right. If its value is 0, 1, 2, 3, or 4, drop that digit and all subsequent digits. If the value is 6, 7, 8, or 9, increase the preceding digit (the last one that will be reported) by 1, and then drop all subsequent digits and decimal places from the number. If the last digit or decimal place to be reported is a 9, it will increase to a 0 and the next digit or decimal place to the left will be increased by 1. Follow the same rule for any additional 9s.

If the value is 5, then there are two possible rules to follow. Under standard rounding rules, the preceding digit or decimal place should be increased by one, with the same rules applying as if it were greater than 5. This is called the round-up rule. The alternate rule is that if the value is a 5, the last digit or decimal place to be reported should be left as-is if it is an even number and increased by 1 if it is an odd number. This is called the round-to-even rule.

Examples:

1.34 rounded to one decimal place would round to 1.3.

1.995 rounded to two decimal places would round to 2.00.

134 rounded to the 10’s place would round to 130.

1523 rounded to the 100’s place would round to 1500.

A note about spreadsheets: Spreadsheet programs (e.g., Excel) allow for the easy presentation and numerical evaluation of large quantities of data, which makes them very useful in a wide range of applications, including report preparation. If using Excel to perform rounding functions, there are two limitations the user should be aware of. First, Excel always rounds up and does not have a simple built-in round-to-even function. Second, Excel does not have a rounding function for integers (i.e., numbers cannot be rounded to the nearest 10s or 100s place) and puts trailing 0s in place of sig figs.

Examples:

1.25 in Excel will round to 1.3, as opposed to 1.2 by using the round-to-even rule.

1392 cannot be rounded any further in Excel, whereas it can be presented as 1390 by rounding to the nearest 10s place and as 1400 by rounding to the nearest 100s place.

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Jun
19

Potentially Polluted Shipwrecks Along U.S. Shores Undergo Remediation

Potentially Polluted Shipwrecks Along U.S. Shores Undergo Remediation

NOAA’s Findings on Potentially Polluting Shipwrecks Found in U.S. Waters

In 2010 Congress appropriated $1 million in funds toward identifying the most significant polluted shipwrecks along U.S. waters. With the help of the Remediation of Underwater Legacy Environmental Threats (RULET), U.S. Coast Guard, Regional Response Teams (RRTs) and NOAA, a complete investigation was conducted listing 20,000 vessels wrecked in U.S. waters. Of the 20,000 wrecked vessels, the RULET database narrowed down 573 wrecks within the U.S. Exclusive Economic Zone (U.S. EEZ) that could pose a substantial oil pollution threat. Another investigation was launched and of the 573 potential threats, 107 were found to be capable of causing substantial pollution. Eliminations were calculated due to the violent nature of the shipwrecks, structural reductions and demolitions already conducted due to navigational hazards, etc. Further investigations were conducted based on vessel contents, condition, environmental sensitivity, and other factors. NOAA then used a series of vessel-related risk factors based on current knowledge and best professional judgment to assess physical integrity and pollution potential as well as other factors that may impact potential removal operations if such operations were undertaken. Vessels that scored low were screened out and 87 remained on the priority list. Fifty-three of the 87 remaining ships were sunk in an act of war, 10 in a collision, 5 in a fire, 4 in a grounding, 10 in a storm, and 5 were sunk in an unknown or other cause. During recovery activities, a number of historical and cultural concerns with the wartime wrecks also surfaced, as some are gravesites and most contain ammunitions and other hazardous cargos.

All 87 vessels received a proper companion screening report, each of which contained an overall score and preliminary vessel-specific recommendations for further action, ranging from awareness within the local response community, to monitoring, to further assessment and planning for underwater remediation. More details are contained in NOAA’s published March 2013 online report.

 
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May
30

Sediment Testing Interference Series – Part IV

Specific Types of Interferences and Solutions (continued from Part III)

Toxicological Interferences

Whereas chemical testing is used to determine the concentration of target contaminants in a sediment sample, toxicological testing is used to determine the effects of the sediment on the survival and development of multiple representative species. Since the organisms will be affected by the sediment as a whole, and since the material is typically a mixture of sand, silt, and clay with numerous chemical contaminants present, it may be difficult or impossible to determine the exact cause of high mortality or abnormal development. Several interferences, or confounding factors, have been identified, however, and are described below.

Ammonia

Above certain levels, ammonia is highly toxic to most marine organisms. It is also a non-persistent toxicant in the environment, and procedures have been developed to help reduce ammonia to more tolerable levels for the test organisms. These procedures were initially developed for the more sensitive benthic species, but, with EPA approval, can also be applied to other organisms under certain circumstances.

Total Organic Carbon (TOC) Availability and Quality

Changes in the nature of TOC in the dredge material may pose limitations to test organism survival. Organic compounds can change over time, particularly with changes in temperature, moisture content, and oxygen availability. If the quality of TOC degrades over time, it can affect the survival of certain species, e.g., for Leptocheirus plumulosus due to poor quality food in the sediment. Though the sediment may have low toxicity, survival can be substantially reduced. Providing a small amount of food for the organisms during analysis alleviates the problem and allows for a more accurate determination of toxicity.

Salinity

Marine organisms are sensitive to the salinity of the test sediment. Sediment collected from far upstream or from terrestrial locations will often have much lower saline levels than sediment from offshore locations and could cause stress to the test organisms and increase mortality. An acclimatization period for the sediment, typically lasting a few days to 3 weeks, will gradually expose the sediment to saline. Once the acclimatization is completed, the test organisms can be added and testing can commence.

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May
28

Sediment Testing Interference Series – Part III

Specific Types of Interferences and Solutions (continued from Part II)

Organic Interferences

Organic compounds (PAHs, pesticides, PCBs) are typically measured by either mass spectroscopy or retention time. Because of a preliminary extraction procedure, salt does not interfere in the analysis of organic compounds, but sediment can still be affected by matrix interferences in a number of ways.

  • Complex organic molecules can bind together or degrade over time and form non-target compounds.
  • New contaminants that have the same characteristic mass or retention time as the target analyte can be introduced into the environment (from leaking vessels or industrial runoff, for example).
  • Sediment will likely settle into separate layers, leading to different chemical and physical characteristics in each layer. The sediment will require thorough homogenization prior to analysis to ensure that it is representative of the site.

There are a variety of solutions to eliminate or minimize potential interferences during preparation and analysis.

  • Commercially available cartridges are used to remove or “clean up” interfering (non-target) compounds for most organic analytical groups, such as PAHs, pesticides, and PCBs.
  • Using more-sensitive equipment can help distinguish target compounds from interfering compounds. High resolution mass spectroscopy (HRMS) is often used for testing parameters such as dioxins and PCBs to narrowly target specific compounds. Results from these procedures will often be much more sensitive than when ordinary mass spectrometer tests are applied, but these procedures are also considerably more costly. As one example, the cost for analyzing PCBs by gas chromatography is around $200 per sample, but for HRMS it is around $800 per sample.
  • Different types of detectors are available for different analyses. For example, an electron capture detector is useful for pesticide and PCB analysis.
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May
22

Sediment Testing Interference Series – Part II

Specific Types of Interferences and Solutions

 

Metals Interferences

Most metals analyses are performed by spectroscopy, generally by inductively coupled plasma (ICP) with or without a mass spectrometer attached. A small volume of prepared sample will be introduced into the instrument and energized using an argon plasma. The resulting plume will emit light at specific wavelengths in proportion to the concentration of contaminants present in the sample and is read using a detector measuring across a narrow band pass. For example, copper will emit light at a wavelength of 324.7 nm. When dealing with high-saline samples, various cations (including sodium, calcium, and magnesium) will be present. Calcium is a potential interfering element because it emits at a wavelength peak of 316.9 nm and with a band pass that overlaps that of copper.

Several options exist for dealing with these interferences:

  • Extract the metals into an organic reagent, such as methyl isobutyl ketone, effectively removing the salt interferences.
  • Change instrumentation. For example, use a borohydride generator for selenium analysis.
  • Prepare instrument standards in the same matrix as the project samples. This procedure will work if the interfering metals or compounds are of moderate concentrations.

A 2010 project audited by ANAMAR provides a good example that saline interferences can produce false positive readings. Based upon historical results, background levels for copper are typically around 1 µg/L. The results found for this project were in the range of 150 to 170 µg/L, and further evaluation by the ADDAMS model was indicated since the sample levels were above the federal water quality criteria. A review by the contractor and the analytical laboratory indicated that all batch QC was within limits, and the data appeared to have been analyzed and reported correctly. After some investigation, it was found that the contractor for this project did not include any procedures to reduce the saline interferences before analysis.

After discussion among the contractor, USACE, and EPA, it was determined that the copper analysis would be re-done using a saline-reduction procedure. Due to holding times and an insufficient volume of sample collected on the first sampling event, the contractor had to return to the project site to collect additional sediment and site water. Upon analysis of the elutriate using the saline-reduced sample, copper levels fell in line with historical levels, and further evaluation of the elutriate by the ADDAMS model was no longer necessary.

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Apr
18

Sediment Testing Interference Series – Introduction - Part I

During the course of an environmental dredging project, samples will be collected and sent to one or more laboratories for analysis. For most dredging projects, the samples collected will be of a complex nature and will often contain various types of interferences that must be addressed during analysis to ensure that the most accurate results are reported to the client and to the regulatory agency reviewing the results for final sediment disposal options.

Interferences may be found in any type of analytical testing. For dredging projects, such as those falling under MPRSA Section 103 protocols, testing will be required for physical, chemical, and toxicological parameters. This four-part blog will describe the most typical and lesser-known types of interferences.

Chemical Interferences during Chemical Analysis

Chemical matrix interferences are encountered when the project sample contains a constituent that either produces a signal indistinguishable from a target analyte or attenuates the target signal. Elutriate samples for ocean dredging projects have many common types of matrix interferences (e.g., saline) for trace metals analysis. In addition, the chemical composition of the project samples may have interfering compounds specific to the sampling location.

The most common interference found when analyzing dredge material is saline interference with the analysis of metals. Other analyses prone to matrix interferences include pesticides, PCBs, and PAHs. Laboratory methodology has been developed to address the most common interferences, either through laboratory sample preparation or by adjusting instrument settings for specific sample matrices. If such procedures cannot completely eliminate an interference, the data will be qualified or the method detection limit will be elevated, and an explanation for the interference will be provided by the laboratory.

 

Author: Paul Berman, B.S - QA Officer/Staff Scientist

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Apr
11

Center for Integrated Modeling and Analysis of Gulf Ecosystems

       b2ap3_thumbnail_C-image.JPG

 

The College of Marine Science at the University of South Florida has been on the scene of the Deepwater Horizon Blowout since April of 2010, and many faculty members continue to participate in the ongoing research. The Gulf of Mexico Research Initiative awarded funding for eight research consortia to study the impacts of the oil in the Gulf of Mexico ecosystem and the College is proud to host one of these centers. The Center for the Integrated Modeling and Analysis of the Gulf Ecosystem (C-IMAGE) is an international group of distinguished scientists interested in the integrated study of the fate, transport, and effects of oil and dispersants as they interact with the Gulf of Mexico marine environment.

Our study begins at the well head where hot high pressure petroleum fluids exit into a cold seawater environment. The thermodynamics of the oil/gas/seawater system deep on the seafloor determine the initial phase composition, bubble/droplet size and density. Moving forward in space and time, the petroleum compounds and aggregations are advected by the ocean circulation. Chemical and biological processes of dispersion, dissolution and degradation then provide the trophic level connections which determine the spatial interactions with biota and ultimately the potential for the oil/gas/dispersant mixture to affect populations, communities, and the overall ecosystem.

To date, C-IMAGE scientists have spent more than 80 days onboard research vessels in the Gulf of Mexico collecting water, sediment, and biological samples. Some samples have been sent to our partners in Hamburg for high pressure biodegradation experiments, some to Calgary to see how the oil partitions as it ages and weathers and many of them are being analyzed here at USF looking at oil concentrations in sediments, PAH concentrations in fish tissue, phytoplankton impacts, and toxicity impacts. Laboratory experiments are underway in the Netherlands at Wageningen University to determine the toxicity of oil with and without dispersants. Sediments are being analyzed to determine the impact of oil on microbial assemblages and to find signs of recovery. These studies are closely integrated, results from one feeding into parameterizations for another. By looking at the Gulf of Mexico holistically, we can better understand the impact of not only this oil spill, but future breaches.

C-IMAGE’s Education and Outreach team through USF’s College of Marine Science is working with elementary, middle and high schools through hosting a Teacher at Sea program where teachers can instruct their classrooms remotely from research vessels while engaging students in the process of conducting ocean research. Getting the message out about our research is important; we produced two podcasts with Mind Open Media that are publicly distributed and have more coming as our research progresses. We are also partnering up with the Pier Aquarium to produce an oil spill module for the “Secrets of the Sea” exhibit while participating in the St. Pete Science Festival.

Some of our College’s faculty members are also active in another GoMRI funded consortium, Deep-C , hosted by Florida State University.

Some C-IMAGE attributed publications:

Surface evolution of the Deepwater Horizon oil spill patch: Combined effects of circulation and wind-induced drift

Matthieu Le Hénaff, Vassiliki H. Kourafalou, Claire B. Paris, Judith Helgers, Zachary M. Aman, Patrick J. Hogan, and Ashwanth Srinivasan Environmental Science & Technology 2012 46 (13), 7267-7273

Detection of anomalous particles from the Deepwater Horizon oil spill using the SIPPER3 underwater imaging platform

Sergiy Fefilatyev,Kurt Kramer,Lawrence O. Hall,Dmitry B. Goldgof, Rangachar Kasturi,Andrew Remsen,Kendra Daly In proceedings of 2011 IEEE 11th International Conference on Data Mining Workshops (ICDMW), Vancouver, BC, Canada, December 11, 2011.

Label-noise reduction with support vector machines

Sergiy Fefilatyev, Matthew Shreve, Kurt Kramer, Lawrence Hall, Dimitry Goldgof, Rangachar Kasturi, Kendra Daly, Andrew Remsen, Horst Bunk International Conference on Pattern Recognition (ICPR), 2012 21st, pp.3504-3508, 11-15 November 2012.

Evolution of the Macondo well blowout: Simulating the effects of the circulation and synthetic dispersants on the subsea oil transport

Claire B.Paris, Matthieu Le Henaff, Zachary M. Aman, Ajit Subramaniam, Judith Helgers, Dong-Ping Wang, Vassiliki H. Kourafalou, and Ashwanth Srinivasan Environmental Science and Technology 201246(24), 13293-13302.

Sand bottom microalgal production and benthic nutrient fluxes on the northeastern Gulf of Mexico nearshore shelf

J. G. Allison, M. E. Wagner, M. McAllister, A. K. J. Ren, R. A. Snyder Gulf and Caribbean Research 201325.

Enhancing the ocean observing system to meet restoration challenges in the Gulf of Mexico

S. A. Murawski, W.T. Hogarth Oceanography 2013 26(1),10–16.

As C-IMAGE turns the corner on 2013, our researchers have been pushing the science forward, making great strides in answering some of the very important questions about the oil spill budget and impacts of the oil and the dispersant. Here are some important milesontes:

  1. In a modeling study led by Dr. Claire Paris of the University of Miami, researchers found that the amount oil reaching the sea surface may have been the same independent of dispersant application. Based on fundamental oil droplet size models, the authors estimate that the turbulent discharge of oil resulted in naturally small droplets contributing to the observed deep intrusion.
  2. The instrumentation to study biodegradation of oil and oil/dispersant mixtures at high pressures is up and running at the Technical University of Hamburg. Microbial samples with oil from the Gulf of Mexico are brought to high pressures in closed chambers and oxygen consumption is measured as a proxy for microbial activity. Initial results indicate high pressure increases biodegradation rates slightly. More experiments are ongoing.
  3. In an attempt to close the oil budget from the blowout, the latest estimates are that about 20% of the oil is unaccounted for. Researchers in C-IMAGE and other GoMRI funded consortia are working together to investigate the mechanisms that contribute to this 20% making its way to the seafloor, becoming part of the Gulf’s sedimentary record. The processes of the oil and dispersant interacting with particles in the water column and the mechanisms transporting this material to the seafloor require the marriage of lab and field work conducted at USF and many of our partner sites.
  4. The short and long term impacts of the oil on many fish species in the Gulf is being tackled at USF with assistance from Mote Marine Laboratory and the University of South Alabama. Hundreds of liver, blood, bile, and muscle samples from fish are analyzed for PAH exposure and stable isotope analysis and otoliths for age and growth studies. There are elevated polycyclic aromatic hydrocarbon (PAH) concentrations in fish liver samples collected to the south and east of the DWH spill and to the north and east on the west Florida shelf. PAHs are the most toxic and potentially carcinogenic substances in cruise oil. These PAH levels are above the baseline for this region. Liver PAH composition of red snapper is likely picking up the chemical signature of the oil out of the Macondo Well. Impacts on important economic species such as red snapper and tilefish are being assessed.

 

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Apr
09

Scientists Venture to the Southern Ocean (Antarctic) to Study the Effects of Ocean Acidification…

antarctic ocean

http://www.ocean-news.com/news-archives/ocean-energy/2573-ocean-acidification-in-the-southern-ocean

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Mar
22

Springs Celebration/Chili Cookoff

ginniesprings

The 6th annual Springs Celebration and Chili Cookoff will be held Saturday, 3/23 at O'Leno State Park.  A canned food donation gets you in the gate.  Music, dance troupes, exhibits, springs awareness, and chili!

http://www.alachuacounty.us/Depts/EPD/WaterResources/GroundwaterAndSprings/Pages/Santa-Fe-River-Springs-Basin-Working-Group.aspx

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Mar
12

Public Meeting - RESTORE Act (Deepwater Horizon)

DEP and FWC will co-host a meeting Wednesday, March 13, 2013 to gather public input for project ideas leveraging the funds from the RESTORE Act.  The RESTORE Act, which was passed by Congress on June 29, 2012 and signed into law on July 6, 2012 by the President, provides a vehicle for Clean Water Act civil and administrative penalties from the Deepwater Horizon oil spill.  Meeting details below..

Wednesday, March 13, 2013
Florida Fish and Wildlife Conservation Commission’s Research Institute
100 Eighth Ave. SE
St. Petersburg, FL 33701
6:00 p.m. EST Open House / Registration
6:30 – 9:00 p.m. EST Meeting & Public Comment

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Dec
07

It’s time for Sediment Testing Q & A!

Q: The physical results for sediment I’m evaluating for offshore disposal show that the material is over 90% sand. Do I need to perform chemical and bioassay analysis on this material?

A*: Tier I evaluations begin with a comparison of existing physical information on the proposed dredged material with the three exclusion criteria of 40 CFR Section 227.13(b). If the dredged material meets at least one of these criteria, additional testing is not required. The three exclusion criteria are indicated below:

(1) The dredged material is composed predominately of sand, gravel, rock, or any other naturally occurring bottom material with particle sizes larger than silt, and the material is found in areas of high current or wave energy such as streams with large bed loads or coastal areas with shifting bars and channels; or
(2) The dredged material is for beach nourishment or restoration and is composed predominately of sand, gravel, or shell with particle sizes compatible with material on the receiving beach; or
(3) When: a. The material proposed for disposal is substantially the same as the substrate at the proposed dump site; and b. The site from which the material proposed for disposal is to be taken is far removed from known sources of pollution so as to provide a reasonable assurance that such material has not been contaminated by such pollution.

*Information was obtained from The Southeast Regional Implementation Manual (SERIM) for Requirements and Procedures for Evaluation of the Ocean Disposal of Dredged Material in Southeastern U.S. Atlantic and Gulf Coast Waters The SERIM was prepared by the US EPA Region 4 and the US Army Corps of Engineers – South Atlantic Division, with assistance from ANAMAR in accordance with federal authorities.

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