Deep-C Scientists Capture First Greenland Shark in the Gulf of Mexico
12-foot shark an unexpected find near the site of the Deepwater Horizon oil spill
ST. TERESA, FL (August 15, 2013) - A research team led by scientists from the Florida State University Coastal & Marine Laboratory (FSUCML) returned on August 5, 2013 from a marine expedition with a fish story worth telling... and documenting. During a seven-day research cruise aboard the RV Apalachee, the team caught a 12-foot Greenland shark (Somniosus microcephalus), also known as the gurry shark or grey shark, the first of its kind to be captured in the Gulf of Mexico.
The Greenland shark is one of the largest of all predatory sharks and generally considered a polar species. Notably, the water temperature where the Gulf of Mexico specimen was captured was 4.12°C, comparable to temperatures where these sharks more commonly reside… in the shallow waters near Canada or off the coasts of Greenland and Iceland. The shark was captured at a depth of 1,749 meters (nearly 6,000 feet) only 25 km (~15 miles) from the site of the Deepwater Horizon blowout (the Macondo well head).
Prior video evidence suggested the presence of these creatures in the region. In 2001, a remotely operated vehicle (ROV) inspecting oil and gas prospecting structures recorded a large sleeper shark believed to be a Greenland shark at a depth of 2,657 meters in Alaminos Canyon off the Texas coast.
“But this is the first documented capture in the Gulf,” said Dr. Dean Grubbs, Chief Scientist and Marine Biologist at the Coastal and Marine Laboratory. “It’s exciting to see and a noteworthy addition to the more than 100 species of fishes we’ve collected on regularly scheduled cruises in this area.”
The purpose of these marine expeditions (this was the sixth Dr. Grubbs has led to sample stations near the site of the 2010 Deepwater Horizon oil spill) is to study deep sea fish communities of the northern Gulf of Mexico and examine these organisms for exposure to and metabolism of toxins that may be related to the oil blowout. During the voyage that resulted in this extraordinary catch, the R/V Apalachee logged more than 2,800 KM (~1,750 miles) and researchers sampled fishes captured in traps and on hooks set at depths ranging from 70 to 1,749 meters deep. A multitude of samples were collected from the more than 450 fishes that were caught. These samples are used in a variety of studies of taxonomic relationships, reproductive systems, life history patterns, food webs and diets, mercury accumulation and toxicology. The researchers captured 31 species of bony fishes ranging in size from 10 cm snailfish to giant snake eels >200 cm in length, 13 species of sharks ranging from small 25 cm catsharks to tiger sharks nearly 400 cm long. The team even caught two species of slimy hagfishes.
While still onboard the RV Apalachee, FSU researchers conducted detailed analysis of the shark’s form to aid in developing mophological keys to separate the three global species of giant sleeper sharks. In addition, they have provided genetics samples to colleagues at the University of Windsor in Canada, who are studying global population structure of Greenland sharks, for genetic verification. The researchers collected samples of bile from the gall bladder, liver and blood for toxicological analyses to be conducted at the University of North Florida to examine potential exposure to and metabolism of toxins associated with the oil spill. Muscle samples will be used to place the specimen in a food web model using stable isotopes and also to examine mercury concentrations in the tissues.
This work by marine biologists, biogeochemists and other ocean science specialists is being conducted as part of the FSU-led Deep-C Consortium (deep-c.org) which is funded by the Gulf of Mexico Research Initiative (GoMRI). The scientific crew included FSU Research Professors Dr. Dean Grubbs and Dr. Chip Cotton, FSU graduate student Johanna Imhoff, University of North Florida graduate students Arianne Leary and Amanda Brown, and volunteer Allison Ferreira. The R/V Apalachee was piloted by Captain Rosanne Weglinski and Assistant Captain Hugh Williams.
Note: The overarching goal of this research is to provide the scientific information necessary to facilitate responsible management and conservation of populations of fishes, especially sharks and their relatives. Some who read the information regarding the first capture of a Greenland shark in the Gulf of Mexico as part of the Deep-C Consortium’s research may question the necessity for lethally sampling this shark. Click here to read more...
The Deep-C (Deep Sea to Coast Connectivity in the Eastern Gulf of Mexico) Consortium is a long-term, interdisciplinary study of deep sea to coast connectivity in the northeastern Gulf of Mexico. The study is investigating the environmental consequences of petroleum hydrocarbon release in the deep Gulf on living marine resources and ecosystem health. Deep-C research is made possible by a grant from BP/The Gulf of Mexico Research Initiative.
Dr. Dean Grubbs is Associate Research Faculty at Florida State University and the Associate Director of Research at FSU Coastal & Marine Laboratory in St. Teresa, FL. Dr. Grubbs is studying the fishes from the continental shelf to the deep sea to determine how they were affected by the Deepwater Horizon oil spill. As part of a research effort led by the Florida State University -- the Deep-C Consortium -- he is concentrating on defining the predator-prey interactions of the fishes found in benthic communities throughout the Panhandle Bight and northern part of the West Florida Shelf.
A long-term, interdisciplinary study of deep sea to coast connectivity in the northeastern Gulf of Mexico.