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


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.

2016 University of Miami Sports Hall of Fame Celebrity Fishing Tournament


Story courtesy of Judy Layne 

MIAMI, June 28, 2016 – The Habitat for Humanity of the Upper Keys / University of Miami Sports Hall of Fame (UMSHoF) Celebrity Fishing Tournament Presented by Yamaha and Caribee Boat Sales has wrapped its 6th annual tournament. It was held June 24-25 at Founders Park at Mile Marker 87 on the Overseas Highway in Islamorada, Fla. This unique event gives anglers the opportunity to fish alongside some of their favorite Canes All-Stars and mingle with dozens of celebrity participants. The tournament has continued to be a huge success with over 500 participants, making it one of the largest tournaments in the Florida Keys.

This year’s tournament was co-hosted by University of Miami Hall of Famers and football greats, Alonzo Highsmith and Melvin Bratton. The tournament weekend began Friday evening with a kick-off party, final boat registration, silent auction and captains’ meeting followed on Saturday by a full day of fishing. On Saturday afternoon, while the Offshore Boats weighed their fish and the Inshore Boats turned in their score cards, Centennial Bank provided a BBQ for the participants and spectators.

Dr. Georgina Cox and Lela Schlenker from the RECOVER team were on site at the weigh-in festivities to share their research with anglers and attendees. It was a great opportunity for our scientists to interact with a knowledgeable and passionate audience that care about the long-term sustainability of the species we study.

After all the fish were weighed and the inshore score cards tallied the results were the following:


1st Place – Tracy Kerdyk on See Shores with a 35.5 lb. Dolphin – Winning $3,000

2nd Place – Luke Waddell on Stage Two with a 29.1 lb Dolphin – Winning $2,000

3rd Place – Chris Martinez on Monster Catch with a 26.9 lb. Dolphin – Winning $1,000

4th Place – Tanya Toro on Halftime with a 25.2 lb Dolphin

5th Place – Chris Martinez on Monster Catch with a 24 lb. Dolphin

Top Lady Anger – Tracy Kerdyk on See Shores with a 35.5 lb. Dolphin

Top Junior – Luke Waddell on Stage Two with a 29.1 lb Dolphin

King of Fish – Jim Marco on Priority with a 19.7 lb. Wahoo – Winning $500


Master of the Ocean – Contagious with 108.1 points – Winning $5,865.00

1st Place Bucket of Bucks – Monster Catch with 68.8 points – Winning $1,615.00

2nd Place Bucket of Bucks – Contagious with 60.6 points – Winning $969.00

3rd Place Bucket of Bucks – Tiki with 48.8 points – Winning $646.00


Grand Slam Winner – Luca Musico on Line Management with 70.5 overall points

Longest Sea Trout – Kathy Gillen on Dave Denkert – 23” Sea Trout

Longest Snook – Luca Musico on Line Management – 30.5” Snook

Longest Redfish – Kathy Gillen on Dave Denkert – 20” Redfish

The Weigh-in was followed by the Grady White Boats Awards Dinner catered by Mangrove Mike’s Café. There were auctions, music, games and more. A portion of the tournament proceeds will go to Habitat for Humanity of the Upper Keys, The Buoniconti Fund to Cure Paralysis, Coastal Conservation Association and the UMSHoF.

“We are pleased to have Yamaha Motors and Caribee Boats as presenting sponsors for our 6th Annual University of Miami Sports Hall of Fame Celebrity Fishing Tournament,” said Gerard Loisel, President of the UMSHoF. “It is thanks to the commitment of these, and all of our great sponsors, donors and participants that our tournament continues to grow each year.”

Jack Niedbalski from Habitat for Humanity of the Upper Keys added; “Not only are we fortunate, but also proud to be a benefactor of this great summer classic charity tournament. From the entire Habitat for Humanity-Upper Keys Board of Directors we thank all our friends from the U of M Sports Hall of Fame Fishing Tournament for allowing us to be a part of the “U”.”

Tournament Information

The 6th Annual Habitat for Humanity of the Upper Keys/UMSHoF Celebrity Dolphin Fishing Tournament is presented by Yamaha and Caribee Boat Sales and brought to participants by the Monroe County Tourist Development Council. For more information visit, call (305) 667-0399 or contact the Tournament Director, Judy Layne at Follow the tournament on Facebook at and Instagram at .

About the University of Miami Sports Hall of Fame (UMSHoF)

Nestled on the Coral Gables campus of the University of Miami, the UMSHoF is a 501(c)(3) corporation whose main purpose is to recognize those student athletes, coaches and administrators who have brought acclaim to the university through their accomplishments and championships. The showcase for the UMSHoF and the repository of the great sports traditions of the University of Miami is the Tom Kearns Sports Hall of Fame Building, located next door to the Hecht Athletic Center on San Amaro Drive. On display are photos and memorabilia representing the 300 inductees, National Championship Trophies, and artifacts that span the 90 year athletic history of the university. The UMSHoF displays include memorabilia from all of the university sports programs. For information about planning a visit, participating in one of the annual fundraising event or contributing to the UMSHoF, visit, send an email to or contact Executive Director John Routh directly at (305) 284-2775.

Photos courtesy of Endless Imagery