Navigation Links
New tracking tags are providing fish-eye views of ways to manage depressed fisheries
Date:3/13/2009

New tracking and observing technologies are giving marine conservationists a fish-eye view of conditions, from overfishing to climate change, that are contributing to declining fish populations, according to a new study.

Until recently, scientists provided fishery managers only such limited data as stock counts and catch estimates, said Charles Greene, Cornell professor of ocean sciences and lead author of the study published in the March issue (Vol. 22, No. 1) of the journal Oceanography.

But new advances in miniature sensors and fish-tracking tags, ocean observing systems and computer models are providing much more insight into environmental changes and how fish are responding behaviorally and biologically to such changes, thereby enabling better modeling to predict fish populations. As a result, researchers are making more informed recommendations for strategies to address falling fish populations.

Obtaining real-world data is essential, stressed Greene. "Many of the commercial fish populations in the world are pretty highly depressed. It's a bleak picture in terms of the status of many wild marine fish populations."

For example, the Atlantic bluefin tuna fishery, which can garner more than $15,000 per fish, is managed as two separate stocks, one in the Eastern Atlantic basin, with a breeding ground in the Mediterranean, and another in the western basin, with a breeding ground in the Gulf of Mexico. Both stocks are not sustainably harvested, and the western population has declined by roughly 90 percent over the last 25 years, despite strict quotas.

A project known as Tag A Giant (TAG) uses an implanted tag in the tuna to record external pressure, internal and external temperature and ambient light, though the tuna must be recaptured to recover these data. TAG also uses a pop-up tag that is attached to the tuna but self releases, floats to the surface and transmits data on each tuna's external conditions via satellite. The tags help researchers estimate geo-locations and track each fish's daily movements.

According to the study, new TAG data have revealed that as tuna grow, they swim all over the Atlantic, and that the fish from the two stocks commingle. Past failure to account for this mixing of the two stocks has led to unsustainable management practices, especially for tuna originating in the Gulf of Mexico, Greene said. New strategies must account for mixing stocks, since fishing in the eastern basin has undermined the quotas and recovery plans for the western basin stock.

With regard to Pacific salmon, fishery managers have assumed that juveniles traveling from spawning grounds to the ocean face great mortality along heavily dammed rivers, like the Snake-Columbia river system, than in undammed rivers. Thus, they collected juveniles and transported them past the Snake-Columbia river system's eight dams before releasing them downstream. However, adult salmon numbers returning from the ocean did not increase.

The Pacific Ocean Shelf Tracking project, which tagged juvenile fish, showed that the smaller, less developed fish were dying in high numbers in the lower river and coastal ocean. This kind of knowledge will help managers test and adapt their strategies in wild-fish systems, which historically have been hard to monitor.


'/>"/>

Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University
Source:Eurekalert

Related biology news :

1. Tracking feline memories on the move
2. Louisiana Tech researchers investigate tracking, sensors to assist Air Force
3. NIH recognizes Clemson nanotechnology for molecule tracking
4. GestureTek/Imagination Launch AirPoint, Worlds First Hand-Tracking Unit, for Shell Group.
5. Tracking stroke
6. Tracking influenzas every movement
7. Tracking prions
8. Paleozoic sediment curve provides new tool for tracking sea-floor sediment movements
9. Tracking down the cause of mad cow disease
10. Scientists achieve first tracking of salmon from headwaters in Rockies through Pacific to Alaska
11. Oral rinses used for tracking HPV-positive head and neck cancers holds promise for cancer screening
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/1/2016)... , February 1, 2016 ... advancements to drive global touchfree intuitive gesture control market ... --> Rising sales of consumer electronics coupled with ... control market size through 2020 ... electronics coupled with new technological advancements to drive global ...
(Date:1/25/2016)... , Jan. 25, 2016   Unisys Corporation (NYSE: ... at John F. Kennedy (JFK) International Airport, New York ... (CBP) identify imposters attempting to enter the United ... belong to them. pilot testing of the system ... at three terminals at JFK during January 2016. --> ...
(Date:1/20/2016)... LONDON , Jan. 20, 2016 A ... positioned to directly benefit from the explosion in genomics ... from Howe Sound Research. A range of dynamic trends ... ...... - personalized medicine - pharmacogenomics - pathogen ... economies with large markets - greater understanding of the ...
Breaking Biology News(10 mins):
(Date:2/11/2016)... ATLANTA , Feb. 11, 2016  Wellcentive ... a Portland, Oregon -based community ... to provide population health analytics, quality reporting and ... help FamilyCare strengthen its team of quality managers, ... reporting to the provider groups serving FamilyCare members. ...
(Date:2/11/2016)... ... February 11, 2016 , ... ... 150 years, continues today to pursue the highest level of accuracy and quality ... the AR9 Refractometer and the AR5 Refractometer. Accurate, reliable and tough enough ...
(Date:2/10/2016)... 10, 2016  The Maryland House of Delegates and ... that University of Maryland School of Medicine Dean ... of Maryland Medical System President and CEO Robert ... the highest honor given to the public by the ... Dean Reece and Mr. Chrencik for their contributions ...
(Date:2/10/2016)... , Feb. 10, 2016  Allergan plc (NYSE: ... announced that Brent Saunders , Allergan,s CEO and ... a fireside chat session at the RBC Capital Markets ... p.m. ET at The New York Palace Hotel in ... will be webcast live and can be accessed on ...
Breaking Biology Technology: