University of Miami Saves Research Fish from Hurricane Irma

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In preparation for Hurricane Irma, the team at the University of Miami Experimental Fish Hatchery successfully transported valuable research fish into the world’s largest hurricane simulator – SUSTAIN (SUrge-STructure-Atmosphere INteraction Facility) – at the University of Miami Rosenstiel School of Marine and Atmospheric Science.

SUSTAIN’s tank can house nearly 40,000 gallons of water and generate the force of an intense Category 5 hurricane. Researchers use it to study wind, wave, and storm surge of tropical cyclones to understand what happens during landfall and how to better prepare for them.

Dr. Dan Benetti, Director of Aquaculture at the University of Miami and co-PI on RECOVER, explains the importance of saving particular fish from the outdoor hatchery facility.

“Some of our broodstock, or breeding adult fish, are irreplaceable because it may take years and more than one generation to develop a genetically based selective breeding program. Hence, we have to consider the cost and effort that it has taken to have developed a certain group of breeders and also the years ahead, as there are research grants and projects and contracts depending and relying on the offspring of those breeders.”

Thanks to the team’s quick thinking they were able to save many valuable fish including cobia, hogfish, and endangered Nassau grouper.

Unlike the cobia broodstock that were transported, broodstock mahi-mahi like those used for RECOVER research, had to be left at the hatchery facility. Our team’s success with capturing wild fish off Miami as well as their extraordinarily fast growth rates mean they repopulate quickly if necessary. Surprisingly, however, many of these mahi-mahi survived the ordeal and the team is working hard to repair damages and get production back on schedule.

Ironically, the safest place for many of these important fish during a hurricane was in a machine that creates hurricanes.

 


2017 Mahi-mahi Tagging Expedition

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Ten miles off the coast of Miami, a 96-foot research vessel drifts along the deep-blue waters of the Gulf Stream. A fishing rod bends dramatically followed immediately by the scream of drag. Martin Grosell tightens his grip and holds on.

“He’s a big one!” he exclaims, as a 30lb bull mahi-mahi erupts from the water in a flash of gold and green. The rest of the crew readily looking on from their assigned posts. One is standing on the bottom of a narrow set of dive-stairs at the ships stern, holding an outstretched sling like a catcher waiting for a pitch. Another, scribbles down the fish’s activity level as “excellent” on her clipboard.

The large fish is gently guided into the awaiting sling along the water’s surface after a lengthy battle.

“Get the tail up! Get the tail up!” someone yells. As the fish tussles and desperately tries to escape.

With the quick a tug of a rope the sling closes just in time.

Dr. Grosell and the others are part of a group of scientists from the RECOVER consortium at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science investigating the impacts of oil spills on mahi-mahi.

Mahi-mahi are a popular commercial and sportfish throughout the world – often targeted by recreational fishermen for their strength and acrobatics on the line. After the Deepwater Horizon disaster in 2010, scientists were concerned how mahi-mahi and other economically important fish – like tuna – would respond to the oil.

“Our previous studies have shown oil exposure negatively impacts these fish in a variety of ways from heart function to vision to swim performance,” says PhD student Lela Schlenker, the experiment’s lead scientist. “Those tests have all been done in a lab setting. What we’re trying to do here is see how oil impacts their survival out in the wild, but first we need to better understand how they behave in the wild under control conditions.”

To answer these questions Lela and the RECOVER team are off the coast of Miami outfitting wild mahi-mahi with pop-up satellite archival tags or PSATs.

“These tags will collect important temperature, depth, and migration data over 96 days,” she says.

Additionally, the PSATs will collect acceleration information which is going to tell her whether these fish are spawning. Lela and the team will remain at sea for the next three days aboard the University of Miami’s research ship the R/V Walton Smith conducting the largest mahi-mahi tagging experiment to date.

In the past, mahi-mahi have been tagged with some success, but most tags have not stayed attached for longer than 10 days. The team hopes to increase the tag retention and survivability of these fish by trying something new – holding them for 24 hours in 1,320-gallon recovery tanks aboard the ship to recover from angling and handling stress before they are released.

A task easier said than done.

Accompanying the Walton Smith on this expedition is an experienced local fishing charter out of Miami – the Miss Britt. The Miss Britt is acting as the research teams eyes and ears while at sea; using their extensive fishing knowledge and speed to track down schools of mahi-mahi and then radio a rendezvous location to the Walton Smith.

By the time Walton Smith arrives, the crew of this Miss Britt is already hooked up on a few mahi-mahi. The two crews work together using the appropriately named “tennis ball method” to transfer lines – and fish – between vessels.

A tennis ball whizzes by overhead (an unusual sight ten miles out at sea) from the stern of the Walton Smith and lands into the outstretched hands of the Miss Britt’s deckhand.

A perfect cast.

The deckhand unclips the ball and attaches the line to their leader with the hooked-up mahi-mahi. The fish – now on the Walton Smith’s line – is reeled in, but not without a fight. Once close enough, the fish is gently guided into the awaiting sling.

Here the clock starts and time is of the essence.

The mahi-mahi is quickly carried up the stairs in the sling and lowered into a bin of oxygenated water. This is to keep the fish as healthy as possible throughout the procedure. The entire team works in unison to quickly de-hook, measure, tag, sample, and record. The fish is then immediately placed in one of the onboard recovery tanks. The whole process is very fast – from sling to tank in about 1:40 seconds – and is reminiscent of a NASCAR pit crew.

Over the next 24 hours, the fish are closely monitored, ensuring the water chemistry and temperature are at the ideal levels to help the fish recover from the stressful catch and tagging procedure. When time is up, the mahi-mahi is corralled into the sling one more time and gently lowered down into the sea.

“This is the first time an experiment like this has been done, and it’s incredible to see this fish swim off healthy at the end of it,” says Schlenker. “They have a ton of spirt and they’re usually very happy get away from us, which is a good thing.”

At the end of the three-day cruise, nine fish were successfully tagged and released.

The next step for Lela and the RECOVER team is to patiently wait until the tags detach from the fish, float to the surface, and send the data back to the lab.

“This’ll be exciting to see where these fish go, how they travel, and what sort of environments they’re in. This is really important information for managing mahi-mahi and learning more about their ecology”.

 

Watch the trailer for an upcoming documentary about the experiment here:

 

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This research was made possible by a grant from the Gulf of Mexico Research Initiative (GoMRI) to the RECOVER Consortium.

The Gulf of Mexico Research Initiative (GoMRI) is a 10-year independent research program established to study the effect, and the potential associated impact, of hydrocarbon releases on the environment and public health, as well as to develop improved spill mitigation, oil detection, characterization and remediation technologies. An independent and academic 20-member Research Board makes the funding and research direction decisions to ensure the intellectual quality, effectiveness and academic independence of the GoMRI research. All research data, findings and publications will be made publicly available. The program was established through a $500 million financial commitment from BP. For more information, visit http://gulfresearchinitiative.org/.

Special thanks to our supporters at:

Saltwater Brewery

TH2O

Costa

Miss Britt Sportfishing

 


Congratulations Dr. Graciel Diamante!

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We are extremely proud to introduce Dr. Graciel Diamante. It has been an honor working with her on RECOVER and we wish her the very best in her new endeavors. Below, please find a word from Dr. Schlenk.

“Graciel defended her dissertation on August 10 and is now a recipient of a PhD from the Environmental Toxicology Graduate Program at UCR.  She has been an extraordinary student during her time here at UCR.  As a former participant in the Research in Science and Engineering (RISE) program at her undergraduate institution, she became  very active in student mentorship through the RISE program at UCR and has supervised at least 3 female undergraduate students (one of which was also a RISE student).  It has been very exciting to see her perpetuate the mentorship she received to other under-represented female students.

Her project initially evaluated the role of estrogen signaling as a target for developmental toxicity in zebrafish.  She  began assessing linkages between membrane bound g-protein coupled estrogen receptors (GPERs) and cardiac development of zebrafish. Her objective was to evaluate receptor activation, Calcium signaling and cardiac development in fish embryos by hydroxylated PAHs observed in the Gulf of Mexico.  She published two first-author papers in Aquatic Toxicology, and has a third about to be submitted on microRNA evaluations of oil in Mahi. In addition, her Introduction is currently in revision as a book chapter in an upcoming book from Dr. Warren Burggren. She has been a co-author on at least 5 other publications in ES&T, ES&T letters, and PLOSone (Most related to RECOVER)  As you can clearly see, Graciel has been tremendously productive during her tenure here.

She was a GoMRI scholar last year. She has also attended and made multiple presentations at several Society of Environmental Toxicology and Chemistry (SETAC) meetings at the regional and National levels and was recently selected for an oral presentation at the International Symposium of Pollutant Responses in Marine Organisms in Japan.

From a personal perspective, she is probably one of the hardest workers I’ve ever had in my laboratory.  During her initial studies with zebrafish, we had a pathogenic infestation causing her to repeat essentially a year’s worth of work. She never complained the entire time. So, what she has been able to accomplish over the past 4 years is truly amazing.  

It is her desire to remain in Southern California and pursue either a postdoctoral position or teaching position at the community college level.  We sincerely wish her the best, and will definitely miss her.”


Study Finds UV Exposure Late in Mahi-Mahi Embryo Development Enhances Oil Toxicity

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Story by Maggie Dannreuther

Researchers conducted laboratory experiments on mahi-mahi embryos to determine the effects of ultraviolet radiation (UV) and oil co-exposure during different times in their development. The team observed that UV affected the success of mahi-mahi hatch in all exposure scenarios compared to controls but was highest (a 1.6- to 6-fold increase) when co-exposure occurred late in embryonic development. Co-exposure with weathered surface oil reduced heart rate in hatched larvae. The results suggest that the developmental window when co-exposure occurs may affect the degree of oil toxicity and exacerbate cardiac effects in developing fish. The researchers published their findings in Environmental Toxicology and ChemistryExposure to ultraviolet radiation late in development increases the toxicity of oil to mahi-mahi (Coryphaena hippurus) embryos.

The Deepwater Horizon oil spill overlapped with the spawning of many pelagic Gulf of Mexico fish species including mahi-mahi, an ecologically and economically important sport fish. “Oil on its own is toxic to fish,” explained study authors Aaron Roberts and Lauren Sweet. “However, other stressors found in the fish’s environment such as ultraviolet radiation can enhance the toxicity of oil several fold. Because these embryos are found in surface waters, it’s likely that they were exposed to both UV and PAHs [polycyclic aromatic hydrocarbons] during the spill. If we do not account for the effects of these secondary stressors, we may underestimate the effects that oil has on aquatic ecosystems.”

Previous research done under the Natural Resource Damage Assessment demonstrated that PAH compounds negatively affected cardiac function and morphological development in mahi-mahi embryos and reduced swim velocity in juveniles. The studies also suggested that natural UV light increases PAH toxicity to mahi-mahi embryos 5-fold during the first 48 hours of development. “UV light damages aquatic organisms in much the same way that people get sunburns,” explained Roberts and Sweet. “While we wear sunscreen to prevent getting a sunburn, oil acts as an ‘anti-sunscreen’ and causes more damage.”

Exposure trials used varying concentrations of high-energy water accommodated fractions (HEWAFs) for Macondo source oil and weathered oil from skimming operations. Roberts explained that the dose concentrations of naturally weathered surface oil (10μg/L) was within the range of concentrations reported during the spill (0 – 84μg/L; Diercks et al., 2010) and similar to previous NRDA-sponsored work (Alloy et al., 20162017). Dose concentrations for source oil were higher, because oil had not undergone weathering, and ranged from 4.5-29ug/L. Following UV and oil exposure, the researchers documented the number of alive and dead embryos and larvae to quantify hatching success and filmed embryos exposed to surface oil to quantify heart rate.

“Interestingly, this period of sensitivity late in development coincides with dramatic changes in their physiology that may contribute to this sensitivity, such as changes in buoyancy, metabolic rate, and yolk sac depletion,” explained Roberts. “Taken together, these data suggest that pelagic fish embryos are more sensitive to oil just prior to hatch.” The researchers note that future work is necessary to better understand the extent of late-development UV exposure cardiac dysfunction and cardiac-independent deformities.

Data are publicly available through the Gulf of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at doi:10.7266/N7JH3J60.

The study’s authors are Lauren E. SweetJason Magnuson, T. Ross Garner, Matthew M. Alloy, John D. StieglitzDaniel BenettiMartin Grosell, and Aaron P. Roberts.

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This research was made possible in part by a grant from the Gulf of Mexico Research Initiative (GoMRI) to the Relationship of Effects of Cardiac Outcomes in Fish for Validation of Ecological Risk (RECOVER)consortium.

The Gulf of Mexico Research Initiative (GoMRI) is a 10-year independent research program established to study the effect, and the potential associated impact, of hydrocarbon releases on the environment and public health, as well as to develop improved spill mitigation, oil detection, characterization and remediation technologies. An independent and academic 20-member Research Board makes the funding and research direction decisions to ensure the intellectual quality, effectiveness and academic independence of the GoMRI research. All research data, findings and publications will be made publicly available. The program was established through a $500 million financial commitment from BP. For more information, visit http://gulfresearchinitiative.org/.

© Copyright 2010- 2017 Gulf of Mexico Research Initiative (GoMRI) – All Rights Reserved. Redistribution is encouraged with acknowledgement to the Gulf of Mexico Research Initiative (GoMRI). Please credit images and/or videos as done in each article. Questions? Contact web-content editor Nilde “Maggie” Dannreuther, Northern Gulf Institute, Mississippi State University (maggied@ngi.msstate.edu).


Virtual Lab Creates More “Wow” Moments in Science Discovery

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Story by Maggie Dannreuther

A child’s face lit up with wonder as she peered into a microscope for the first time and discovered a new world. Researchers at the Miami-based RECOVER consortium want experiences like this to happen more often for more students, so they designed and developed the RECOVER Virtual Lab. Now, scientists can engage students ages 8 and older anywhere anytime with an innovative lab experience that is accessible online and soon through the Apple App Store.

Ph.D. student Christina Pasparakis at Ocean Kids in Miami, FL

Ph.D. student Christina Pasparakis at Ocean Kids in Miami, FL

RECOVER Outreach lead Daniel DiNicola explained how the virtual lab came about, “In the consortium’s beginning, Martin Grosell [RECOVER Director] and I wanted to increase the public’s awareness and use of RECOVER’s visually-engaging experiments. We wanted something interactive that schools or public venues like museums could use.” The virtual lab is a consortium legacy product that will teach oil spill science for years to come and increases their classroom reach around the world.

The lab’s development began in earnest using the same team that built the RECOVER website. “We liked that they already understood the research and that they work close by at the University of Miami’s main campus,” explained DiNicola. Development took about eight months and included storyboarding, wire framing, script development, filming, post production, data visualization, app design, and coding.

 

Internal beta testing for the virtual lab gave the RECOVER team feedback that improved science accuracy. “It was extremely beneficial to work alongside the scientists whose work is featured in the app,” said DiNicola. “The scientists offered insight and guidance that helped us refine the product and identify bugs.”

The pilot lesson, Fish Treadmills, is geared toward middle school, high school, and college students. Future lessons will include an experiment on visual acuity, fish embryonic and larval development, and social interactions. “All our lessons will feature one RECOVER graduate student acting as the virtual lab partner and explaining their research,” explained DiNicola. “We believe this is a great way for our students to practice valuable science communication skills as well as show their enthusiasm for their work.”

An evaluation component is built into the app to help determine and quantify the virtual lab’s success. Grade-specific quizzes available after every lesson will give the RECOVER team valuable insights into the lesson’s effectiveness. The demographic and location data collected by the quizzes will help identify use and participation trends. The RECOVER team hopes to publish their findings on the tool’s effectiveness using the evaluation data.

Grade-specific workbooks and transcripts for educators and student The Gs are available for download. Future plans for the virtual lab include more lessons for younger elementary students. For more information, visit the RECOVER website.

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This research was made possible in part by a grant from the Gulf of Mexico Research Initiative (GoMRI) to the Relationship of Effects of Cardiac Outcomes in Fish for Validation of Ecological Risk (RECOVER) consortium.

ulf of Mexico Research Initiative (GoMRI) is a 10-year independent research program established to study the effect, and the potential associated impact, of hydrocarbon releases on the environment and public health, as well as to develop improved spill mitigation, oil detection, characterization and remediation technologies. An independent and academic 20-member Research Board makes the funding and research direction decisions to ensure the intellectual quality, effectiveness and academic independence of the GoMRI research. All research data, findings and publications will be made publicly available. The program was established through a $500 million financial commitment from BP. For more information, visit http://gulfresearchinitiative.org/.

© Copyright 2010- 2017 Gulf of Mexico Research Initiative (GoMRI) – All Rights Reserved. Redistribution is encouraged with acknowledgement to the Gulf of Mexico Research Initiative (GoMRI). Please credit images and/or videos as done in each article. Questions? Contact web-content editor Nilde “Maggie” Dannreuther, Northern Gulf Institute, Mississippi State University (maggied@ngi.msstate.edu).


Derek Nelson Wins UNT 2016 Graduate Student Innovator Award

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Measuring environmental impact

Previous research revealed that exposure to crude oil caused some fish to swim slower.

Working with faculty mentor Dane Crossley, professor of biology, Nelson and other researchers are trying to learn why.

Nelson implants sensors on the fishes’ hearts to monitor cardiac functions such as heart rate, stroke volume and contractility and other aspects of the heart.

His mahi-mahi study was published in Aquatic Toxicology in November and he has presented some of his findings thus far at conferences for the Gulf of Mexico Research Institute, the Society of Environmental Toxicology and Chemistry, and the Society of Integrative and Comparative Biology.

Article courtesy of the University of North Texas. To see the complete list of award winners please click here.


Study Examines Gulf Killifish Rapid Adaptive Resistance to Contaminants

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Story courtesy of the Gulf of Mexico Research Initiative

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Scientists conducted exposure experiments on Gulf killifish populations with known adaptions to common environmental contaminates to determine how rapid adaptation affects future fish health. The researchers found that larvae from killifish that adapted to dioxin-like compounds exhibited higher resistance to oxidative stress and carbamates than did killifish larvae from areas with little-to-no known toxicant exposure. These findings suggest that adaptive toxicant resistance may involve multiple mechanistic pathways.  The team published their findings in Aquatic Toxicology: Cross-resistance in Gulf Killifish (Fundulus grandis) populations resistant to dioxin-like compounds.

Previous research identified that killifish populations in the Houston Ship Channel, which has a long history of industrial pollution, rapidly adapted to resist developmental cardiac deformities caused by a complex mixture of toxicants. The expectation was that the toxin-resistant adaptation passed on to the next generation but came with physiological trade-offs such as increased sensitivity to other environmental stressors, such as hypoxia. However, no such tradeoff could be established.

dubansky_killifishtrapshoustonchanel

Contaminated site along the Houston Ship Channel where elevated levels of toxicants are coincident with resistant populations of Gulf killifish. Here, traps are set in a small tidal cut amid trash and debris to collect resistant fish for study. Photo by Benjamin Dubansky.

Author Benjamin Dubansky noted the significance of the study’s findings, “It is astounding to see not only a fish population that appears to be unbothered by PAHs [polycyclic aromatic hydrocarbons] and other contaminants that would otherwise be lethal, but also that this trait is transmitted from one generation to the next.” He continued, “However, we did observe some interesting differences between populations, which are now driving the research in new directions to help better understand the long-term effects of toxicant exposure on fish populations.”

Author Warren Burggren emphasized the study’s contributions to understanding oil spill impacts and recovery, “In a research area where there are such frequent findings of long-term environmental disruption and damage, it’s encouraging to see that some key organisms can develop resistance to human-induced environmental degradation. This encourages us to think that some effects can be mitigated relatively quickly through the natural characteristics of the organisms.”

The study’s authors are Elias M. Oziolor, Benjamin Dubansky, Warren W. Burggren, and Cole W. Matson.

Data are publicly available through the Gulf of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at doi: 10.7266/N7513W6W; doi: 10.7266/N78S4MWF.

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This research was made possible in part by a grant from the Gulf of Mexico Research Initiative (GoMRI) to the Relationship of Effects of Cardiac Outcomes in Fish for Validation of Ecological Risk (RECOVER)consortium. Other funding sources included the Baylor University’s C. Gus Glasscock, Jr. Endowed Fund for Excellence in Environmental Sciences and the Office of the Vice Provost for Research.

The Gulf of Mexico Research Initiative (GoMRI) is a 10-year independent research program established to study the effect, and the potential associated impact, of hydrocarbon releases on the environment and public health, as well as to develop improved spill mitigation, oil detection, characterization and remediation technologies. An independent and academic 20-member Research Board makes the funding and research direction decisions to ensure the intellectual quality, effectiveness and academic independence of the GoMRI research. All research data, findings and publications will be made publicly available. The program was established through a $500 million financial commitment from BP. For more information, visit http://gulfresearchinitiative.org/.


Good Eats and Good Times at the Coconut Grove Seafood Festival

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On Sunday October 16th, Christina Pasparakis, Rachael Heuer, Yadong Wang, Dan DiNicola, and Emma Esch from the RECOVER team participated at the 2016 Coconut Grove Seafood Festival Ecodiscovery Zone presented by Celebration of the Seas Foundation.

“The Coconut Grove Seafood Festival is all about celebrating seafood, waterfront living and giving people their fill of the freshest, tastiest delicacies of the sea. Bushels of shrimp, oysters, crawfish, lobster, clams and fresh fish will soon overflow in Miami, just in time for the opening of stone crab season in October.” The festival also offers live music and local artist exhibitions to draw in the Miami masses.

The event also presented an Ecodiscovery Zone in the center of the festival for visitors to learn about marine and environmental issues pressing to the local communities. Joining RECOVER in this area, was fellow GoMRI consortium CARTHE, along with the University of Miami Shark Tagging and Rescue a Reef programs.

Early morning thunderstorms parted once the gates opened and hundreds of hungry guests came piling in the festival grounds. At the Ecodiscovery Zone, the groups were able to share their research and knowledge with attendees including displaying live samples of mahi embryos and corals and decorating their own drift plates to track ocean currents. For RECOVER, it was a unique opportunity to educate people about a species of fish that was readily available to eat at many of the vendor tents. Visitors at these kinds of outreach activities are always fascinated to learn how fast mahi grow, and as a result, how it contributes to a sustainable fish population.

View some of our photos below!

 


Study Suggests Wider Range of Mahi-Mahi’s Genetic Responses to Oil Exposure

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Story courtesy of the Gulf of Mexico Research Initiative

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Scientists used novel bioinformatics to investigate molecular-level changes over time and toxicity pathways in mahi-mahi embryos and larvae exposed to Deepwater Horizon oil. They observed that weathered oil (collected from slick skimming operations) induced more pronounced gene expression changes than a non-weathered source oil (collected from the subsea containment system directly over the wellhead). The tools predicted impairment of heart rates and increased pericardial edema which the researchers observed in the fish. The method also predicted disturbances in eye and nervous system development. These results suggest new genetic and developmental toxicity pathways targets associated with Deepwater Horizon oil. They published their findings in Environmental Science and Technology: Time- and oil-dependent transcriptomic and physiological responses to Deepwater Horizon oil in mahi-mahi (Coryphaena hippurus) embryos and larvae.

The timing and location of the oil spill coincided with the spawning window for many economically and ecologically important Gulf of Mexico fish species. Natural weathering processes can significantly alter the composition and structure of individual polyaromatic hydrocarbons in the water column possibly increasing oil toxicity. This study builds on recent research about early life stage fish heart health and oil exposure. Researchers conducted exposure experiments with mahi-mahi embryos and water-accommodated fractions of weathered and non-weathered oil at 24, 48, and 96 hours post-fertilization. Using high throughput RNA sequencing and gene signature identification software (On-RAMP; Ingenuity Pathway Analysis), the team analyzed the regulatory directions of gene expression, making it possible to predict additional biochemical, cellular, and tissue pathways targets for the oil.

The researchers observed that both oils induced similar molecular responses at 24 hours, but there were more prominent changes in gene expression in weathered oiled treatments at 48 and 96 hours. The number of genes that were differentially expressed increased from 196 (48 hours) to 1,469 (96 hours) in weathered-oil treatments compared to increases of 128 to 297, respectively, in non-weathered oil treatments. The study provides more detailed genomic responses which indicate affecting specific molecular functions may be altered.

“By understanding how fossil fuels cause toxicity, we can have a better understanding of the risks associated with these contaminants and determine regulatory or management strategies that reduce risks,” commented study co-author Daniel Schlenk. “This experiment was the first to demonstrate that weathered oil more significantly altered gene expression than unweathered oil and suggests that there are multiple targets of oil toxicity to this species at this life stage, including the heart, eye, and neurological systems.”

The researchers noted that their use of rapid genomics annotation analyses coupled with advanced informatics tools may be useful elsewhere to identify species specific molecular and physiological responses to environmental contamination.

Data are publicly available through the Gulf of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.org (doi:10.7266/N7BG2M0J).

The study’s authors are Elvis Genbo Xu, Edward M. Mager, Martin Grosell, Christina Pasparakis, Lela S. Schlenker, John D. Stieglitz, Daniel Benetti, E. Starr Hazard, Sean M. Courtney, Graciel Diamante, Juliane Freitas, Gary Hardiman, and Daniel Schlenk.

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This research was made possible in part by a grant from the Gulf of Mexico Research Initiative (GoMRI) to theRelationship of Effects of Cardiac Outcomes in Fish for Validation of Ecological Risk (RECOVER)consortium. Other funding sources included the Medical University of South Carolina College of Medicine and the Genomics Shared Resource, Hollings Cancer Center.

The Gulf of Mexico Research Initiative (GoMRI) is a 10-year independent research program established to study the effect, and the potential associated impact, of hydrocarbon releases on the environment and public health, as well as to develop improved spill mitigation, oil detection, characterization and remediation technologies. An independent and academic 20-member Research Board makes the funding and research direction decisions to ensure the intellectual quality, effectiveness and academic independence of the GoMRI research. All research data, findings and publications will be made publicly available. The program was established through a $500 million financial commitment from BP. For more information, visithttp://gulfresearchinitiative.org/.


Weathered Oil in Gulf of Mexico May Threaten Development of Fish Embryos and Larvae

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UC Riverside-led study, focusing on Mahi embryos and larvae, shows this toxic oil affects developing heart, eye and neurological function

Story courtesy of , UC Riverside – July 11, 2016

RIVERSIDE, Calif. – The Deepwater Horizon (DWH) oil spill, in which nearly three million barrels of crude oil got released in 2010 into the northern Gulf of Mexico, is the worst oil disaster in US history, contaminating the spawning habitats for many fishes. A research team led by an environmental scientist at the University of California, Riverside has now found that ultraviolet light is changing the structure of the DWH oil components into something more toxic, further threatening numerous commercially and ecologically important fishes.

“Ours is the first experiment evaluating the effects of DWH oil on the genetic responses of Mahi embryos and larvae,” said Daniel Schlenk, a professor of aquatic ecotoxicology, who led the study published in Environmental Science and Technology.  “It is also the first experiment of this nature on a lifestage and species that was likely exposed to the oil.  We found that the weathering of oil had more significant changes in gene expression related to critical functions in the embryos and larvae than the un-weathered oil. Our results predict that there are multiple targets of oil for toxicity to this species at the embryonic life stage.”

First, the researchers exposed the fish embryos to the oils at three different time points: 24 hour post fertilization, 48 hour post fertilization, and 96 hour post fertilization. (Hatching to larvae in Mahi occurs at 48 hour post fertilization; the researchers bracketed this time point at 24 hour post fertilization and 96 hour post fertilization.) Then, the researchers collected transcripts of all the genetic information at each time point and evaluated these transcripts using novel bioinformatic methods. Finally, they evaluated the toxicity and heart functions in animals using the embryos’ gene expression to predict biochemical, cellular, and tissue targets where the oil was causing an effect.

For their experiments, Schlenk and his team from the University of Miami collected Mahi off the coast of Miami, Fla., and exposed embryos to two types of oil: one set of embryos was exposed to slick oil (weathered) from the spill while another set was exposed to oil that came from the source of the spill. The researchers carried out the experiment this way because fish in the northern Gulf of Mexico had been exposed during the spill to both types of oil. Their study attempted to understand which of the two oils – slick oil or source oil – is worse for the fish and how oil affects development.

“We found that the heart, eye and neurological function were affected,” Schlenk said. “In collaboration with other consortia members from the Universities of Miami, Texas, and North Texas, we are now following up with these results.  Previous studies have shown that the heart is the primary target for oil. Our study shows that in addition to heart function, risk and recovery should also examine eye and neuronal function.”

Schlenk believes that it is imperative for environmental scientists to understand how contaminants cause toxicity so that uncertainties in risk assessments can be diminished.

“By understanding how fossil fuels cause toxicity we can have a better understanding of the risks associated with these contaminants and determine regulatory or management strategies that reduce risks of these substances,” he said. “To this day, we remain uncertain of the magnitude of the DWH oil spill effects, particularly in sensitive life stages of fish. We are also uncertain of whether biota exposed to the oil can recover, or have recovered, from this event. And we are still uncertain about how compounds present in oil or any other combustion byproduct or fossil fuel cause toxicity.”

The approximately four-month study was expedited by a unique software, On-RAMP, that the researchers used to identify the gene signatures from the fish.

“Normally, it can take months to annotate the genes and identify the regulatory directions of expression,” Schlenk explained. “But by using On-RAMP, we could identify the genomic responses in a matter of weeks, allowing pathway analyses with sophisticated software normally only used for human/mice responses.”

The research was funded by the Gulf of Mexico Research Initiative, Grant No: SA-1520, as well as the Relationship of Effects of Cardiac Outcomes in fish for Validation of Ecological Risk (RECOVER) consortium.

Schlenk was joined in the research by Elvis Genbo Xu, Graciel Diamante and Juliane Freitas at UC Riverside; Edward M. Mager, Martin Grosell, Christina Pasparakis, Lela S. Schlenker, John D. Stieglitz, and Daniel Benetti at the University of Miami, Fla.; and E. Starr Hazard, Sean M. Courtney and Gary Hardiman at the Medical University of South Carolina. Xu is a postdoctoral researcher in Schlenk’s lab. Diamante is a Ph.D. graduate student in environmental toxicology.  Freitas, a visiting student from Brazil, helped with some of the analyses.

Next, the research team will follow up with whole animal physiological and behavioral effects to see if the newly identified molecular responses can be linked to function.