Featured Research

from universities, journals, and other organizations

Blue Marlin In Gulf Have High Mercury Levels, Study Shows

Date:
September 14, 2004
Source:
Texas A&M University
Summary:
As sport fishes go, the blue marlin is a king of sorts – highly prized for its beautiful shape and its ferocious fighting ability when hooked. That's the good news. The bad news is that many blue marlin caught in the Gulf of Mexico contain 20 to 30 times the acceptable levels of mercury.

GALVESTON, Sept. 10, 2004 – As sport fishes go, the blue marlin is a king of sorts – highly prized for its beautiful shape and its ferocious fighting ability when hooked.

That's the good news. The bad news is that many blue marlin caught in the Gulf of Mexico contain 20 to 30 times the acceptable levels of mercury.

Texas A&M University at Galveston researchers Jay Rooker and Gary Gill are trying to learn why the mercury levels are so high in blue marlin compared to similar fishes and why so many of them are potentially toxic timebombs.

Funded by the McDaniel Charitable Foundation of Santa Fe, Texas, the project aims to find answers to several key questions related to mercury accumulation in the flesh of pelagic fishes (those such as marlin, sharks, cobia, amberjacks and others). Rooker and graduate student Yan Cai sampled pelagic fishes in the Upper Gulf Coast region, from Port Aransas to Venice, La.

"We are attempting to get a good coverage area in the northwestern Gulf of marlin and other species in our survey of fish tissue mercury," Rooker says from his Galveston office.

Mercury is a highly toxic substance that is easily absorbed into tissues of aquatic creatures, especially fish. Human consumption of fish that contain mercury can pose severe health problems.

The harmful effects of mercury on living organisms range from kidney damage to reproductive failure and birth defects. The issue of elevated mercury content in seafood has received a great deal of public awareness in Gulf Coast states in recent years and several articles have focused on the possibility that oil and gas platforms in the Gulf of Mexico are the major source of the mercury problem in the Gulf.

To investigate the source question, Rooker, Gil and Cai are examining mercury in pelagic fishes from areas with high concentration of petrochemical industries or production platforms and comparing these with other regions.

Also, the team is using unique natural biomarkers (stable isotopes and fatty acids) to determine the feeding history of these fishes, and will use this information to see if feeding patterns influence the level of mercury found in the tissue of top-level predators.

Rooker says one reason marlin may have higher mercury levels deals with the fish's size and feeding patterns. Although most blue marlin caught in the Gulf are approximately 200 to 400 pounds, some can weigh more than 1,000 pounds and can live up to 20 years, and because they are so large, they tend to eat larger than average fish, ones that likely contain higher levels of mercury. Over time, the amount of fish they consume is considerable, meaning mercury levels in each blue marlin will continue at a sustained rate over a period of years.

"In simple terms, marlin may have more mercury because they eat larger prey and live longer than other fishes," Rooker explains.

"Still, the story appears to be more complex and we are in the process of examining other large pelagic fishes, and comparing our results to blue marlin."

Rooker says that preliminary data show fish with levels appear to have similar feeding histories. In addition, the team has found several species captured in Texas waters have higher mercury levels than those closer to Louisiana.

"This appears to be a source issue," Rooker believes. "But this is something we need to examine more closely."

He says sport fishermen who have caught marlin should not be overly alarmed, but should be informed of what they've hooked. "I would recommend that they be aware of the problem, and they may want to limit their consumption of sport fishes caught," he adds.

"We've just scratched the surface on this problem," he believes.

"The mercury levels we discovered surprised us and were much higher than we had anticipated. What we need to look at now are the diet patterns of these fishes and the exact locations they've been found. Is there an undeniable link to petrochemicals that is causing these higher mercury levels? We need to find the mechanism that is triggering all of this."

###

For more information on his study, see the Pelagic Fisheries Conservation Program Web site at http://www.tamug.edu/pelagic.


Story Source:

The above story is based on materials provided by Texas A&M University. Note: Materials may be edited for content and length.


Cite This Page:

Texas A&M University. "Blue Marlin In Gulf Have High Mercury Levels, Study Shows." ScienceDaily. ScienceDaily, 14 September 2004. <www.sciencedaily.com/releases/2004/09/040913084953.htm>.
Texas A&M University. (2004, September 14). Blue Marlin In Gulf Have High Mercury Levels, Study Shows. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2004/09/040913084953.htm
Texas A&M University. "Blue Marlin In Gulf Have High Mercury Levels, Study Shows." ScienceDaily. www.sciencedaily.com/releases/2004/09/040913084953.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins