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 September 20, 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 September 20, 2014).

Share This



More Plants & Animals News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
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:
from the past week

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