Navigation Links
Study of bigeye tuna in Northwest Atlantic uses new tracking methods
Date:7/31/2014

AMHERST, Mass. A first-of-its-kind study of bigeye tuna movements in the northwestern Atlantic Ocean led by Molly Lutcavage, director of the Large Pelagics Research Center at the University of Massachusetts Amherst, found among other things that these fish cover a wide geographical range with pronounced north-south movements from Georges Bank to the Brazilian shelf, and they favor a high-use area off Cape Hatteras southwest of Bermuda for foraging.

This NOAA-funded research, which used a new approach to study one of the most important commercial tuna species in the Atlantic, provides the longest available fishery-independent record of bigeye tuna movements to date. Data should help researchers to further characterize habitat use and assess the need for more monitoring in high-catch areas.

Results appear this week in an early online edition of the Canadian Journal of Fisheries and Aquatic Science.

Fisheries oceanographer Lutcavage says, "Although Atlantic bigeye tuna are delivering high prices to the U.S. commercial fleet and are highly sought by recreational fishermen and fishing tournaments, there's been a surprising lack of scientific research on this species. And in contrast to the Pacific, where tuna fisheries programs have deployed over 400,000 tags over 25 years, the Atlantic lacks the fisheries infrastructure that would increase the odds of recovering tags. We have to rely on popup satellite tags that are fishery independent to make sure we get information back from the tuna."

Two earlier electronic tagging studies by others yielded relatively short tracking data, 113 days or fewer, and did not allow for seasonal analysis of movement or exploration of an alternate stock composition hypotheses, Lutcavage and colleagues note. Bigeye are currently managed as a single Atlantic stock, she explains, and the greater resolution of habitat use and migratory behavior revealed in this study are important first steps towards determining whether or not a more complex management approach may be warranted.

Working with pelagic longline vessel captains Scott Drabinowicz and John Caldwell of the FV Eagle Eye II out of Fairhaven, Mass., Lutcavage, with LPRC colleagues Tim Lam and doctoral candidate Ben Galuardi, deployed 21 pop-up satellite archival tags (PSAT) on adult bigeye tuna between 2008 and 2010 in the northwest Atlantic. The sea captains fit tags on fish in good condition and return them to the sea. The PSATs were programmed to record relative light level, temperature and pressure (depth) every two minutes for eight or 12 months.

Lutcavage, Lam and Galuardi were able to collect full-resolution time series data from a total of nine tags, providing data ranging from one to 292 days. The team also downloaded remote sensing and climatological information from the NOAA to characterize possible associations between bigeye tuna movement and behavior and environmental factors.

Among variables they analyzed were the bigeyes' use of the deep scattering layer for foraging. That is an ocean layer of marine life that rises and falls in relation to diurnal vertical migration. The researchers also looked at lunar influences on swimming depth, horizontal movements, plus vertical activity and factors influencing it such as temperature.

Lam explains, "Bigeye tuna dive deeply, like clockwork, at dusk and dawn, making it hard to use light-based geolocation methods to estimate their daily locations. Here, we showcase a new positioning technique to get around the problem of low light levels at depth by using temperature and the bigeyes' spatial ecology and movements in the western Atlantic. But there's much more to learn."

The authors hope their results will inform the International Commission for the Conservation of Atlantic Tuna's upcoming tagging effort and assist ICCAT scientists as they plan new research to better understand the population.

Alain Fonteneau, an emeritus scientist at France's Institut de Recherches pour le Dveloppement and a recognized expert member of scientific panels that manage regional tuna fisheries worldwide, called this work "fantastic." He says, "Although we don't see major unexpected surprises in these results, as we often see with Atlantic bluefin tuna results, this paper is the first one in the scientific literature to provide very new and very interesting results on bigeye vertical and geographical movements in the western Atlantic," he points out.

Fonteneau adds, "Although these real observations are based on a small number of PSAT tags, they are much more comprehensive than the traditional catch-and-effort fishery data, at one time the only type available to ICCAT tuna scientists. It would clearly be of major scientific interest to develop this type of work at the scale of the entire Atlantic Ocean."


'/>"/>

Contact: Janet Lathrop
jlathrop@admin.umass.edu
413-545-0444
University of Massachusetts at Amherst
Source:Eurekalert  

Related biology news :

1. UF study advances DNA revolution, tells butterflies evolutionary history
2. Study of twins discovers gene mutation linked to short sleep duration
3. Study finds benefits to burning Flint Hills prairie in fall and winter
4. UT Dallas study reveals effect of loud noises on brain
5. New international tree nut council study looks at nuts, diabetes and metabolic syndrome
6. Study: Marine pest provides advances in maritime anti-fouling and biomedicine
7. Healthy lifestyle may buffer against stress-related cell aging, study says
8. Study suggests disruptive effects of anesthesia on brain cell connections are temporary
9. Study finds Europes habitat and wildlife is vulnerable to climate change
10. Dinosaurs fell victim to perfect storm of events, study shows
11. Study: Climate change and air pollution will combine to curb food supplies
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Study of bigeye tuna in Northwest Atlantic uses new tracking methods
(Date:11/17/2016)... , Nov. 17, 2016  AIC announces that it has just released a ... organizations that require high-performance scale-out plus high speed data transfer storage solutions. ... ... ... Setting up a high performance ...
(Date:11/14/2016)... 14, 2016  Based on its recent ... & Sullivan recognizes FST Biometrics with the ... Visionary Innovation Leadership. FST Biometrics emerged as ... market by pioneering In Motion Identification (IMID) ... seamless, and non-invasive verification. This patented solution ...
(Date:6/21/2016)... VANCOUVER, British Columbia , June 21, 2016 ... been appointed to the new role of principal ... has been named the director of customer development. ... , NuData,s chief technical officer. The moves reflect ... development teams in response to high customer demand ...
Breaking Biology News(10 mins):
(Date:12/8/2016)... ... December 08, 2016 , ... Lajollacooks4u, San Diego’s premier team building ... team building events, new program offerings and company expansion. , This is ... to include groups of over 30 people. Ever since, Lajollacooks4u has seen significant demand ...
(Date:12/8/2016)... 8, 2016  Renova™ Therapeutics, a biotechnology company ... and type 2 diabetes, announced that it has ... virus (AAV) vector developed in the laboratory of ... Stanford University. The company plans to use this ... product pipeline. "Early research has ...
(Date:12/8/2016)... -- Oxford Gene Technology (OGT), The ... range with the launch of the SureSeq myPanel™ NGS Custom ... in familial hypercholesterolemia (FH). The panel delivers single nucleotide variation ... small panel and allows customisation by ,mix and match, of ... LDLR , P C SK9 , ...
(Date:12/8/2016)... ... ... This CAST literature review and report looks at problems caused by the ... effects in countries that are major global commodity exporters and importers, which show that ... low level presence (LLP) puts large volumes of trade worth billions of dollars at ...
Breaking Biology Technology: