Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Blue marlin in gulf have high mercury levels

13.09.2004


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."

Keith Randall | EurekAlert!
Further information:
http://www.tamu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Collapse of the European ice sheet caused chaos

27.06.2017 | Earth Sciences

NASA sees quick development of Hurricane Dora

27.06.2017 | Earth Sciences

New method to rapidly map the 'social networks' of proteins

27.06.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>