Featured Research

from universities, journals, and other organizations

New Satellite Tags Track Movements Of Atlantic Bluefin Tuna

Date:
August 14, 1998
Source:
Stanford University
Summary:
A new satellite tagging technology has proven that it can help resolve the mysteries of tuna migration at a time when management strategies for these remarkable and commercially valuable fish are in dispute and their breeding population is in sharp decline.

A new satellite tagging technology has proven that it can help resolve the mysteries of tuna migration at a time when management strategies for these remarkable and commercially valuable fish are in dispute and their breeding population is in sharp decline.

The microprocessor tags, deployed in 1996 and 1997 by scientists from Stanford University, the Monterey Bay Aquarium and the National Marine Fisheries Service, revealed that tunas tagged off Cape Hatteras, N.C., were able to move as far as 1,670 nautical miles in 90 days -- and that some fish crossed the line separating eastern and western management zones for the bluefin fishery.

"The results of our work indicate that pop up technology works, and that survivorship is high. The fact that the bluefin spread out in 90 days across the western Atlantic and into the western margins of the eastern Atlantic management zone indicates these fish are on the move," said Dr. Barbara Block of the Tuna Research and Conservation Center (TRCC), a collaborative effort between Stanford University and the Monterey Bay Aquarium.

The findings appear in the Aug. 4 issue of the Proceedings of the National Academy of Sciences.

The new tags, called satellite pop-up tags, pop free of the fish at a preprogrammed time, float to the surface and beam their accumulated data via satellite to scientists in the lab, revealing where the fish moved and what ocean temperatures they favored.

Giant bluefin tuna, which can fetch as much as $80,000 apiece in the Tokyo seafood market, currently are managed as two separate Atlantic stocks with limited mixing between the western and eastern Atlantic. Using this management strategy, breeding stocks in the western Atlantic have declined by more than 80 percent over the past 22 years, and eastern Atlantic bluefin of similar ages have fallen by 50 percent during the same period. Western Atlantic tuna are managed under a strict annual quota; eastern Atlantic bluefin have been managed under catch quotas only since 1995, with a 25 percent reduction to be fully implemented this year.

"It's now possible -- and imperative -- to make use of satellite tag technology to determine the extent of transatlantic migrations," Block says. "In that way, management strategies can reflect fish behavior in the real world. With this technology it will be possible to manage giant bluefin tuna so mature breeding stocks could recover in our lifetime."

A 1994 report by the National Research Council recommended that fisheries scientists test the stock structure theories to confirm whether bluefin tuna are one or two stocks in the Atlantic Ocean.

"We believe that the advanced tagging technologies currently being applied to Atlantic bluefin tuna could provide essential information for resolving questions about the existence of one or two management units," added Eric Prince, chief of the migratory fishery biology division of the National Marine Fisheries Service in Miami, Florida.

According to Block, the satellite tags can be used to provide similar information about other pelagic fish species whose lives are equally mysterious. To date, she and her colleagues have put the tags on bluefin and yellowfin tuna, blue and striped marlins and salmon sharks.

What sets the satellite tags apart from other fish-tagging methods is the fact that scientists can recover the data without relying on tagged fish being caught and the tags voluntarily turned in to their labs by fishermen.

Historically, about 13 percent of conventional bluefin tags ;have been recovered. In the 1996 and 1997 experiments, data were recovered from 35 of 37 satellite tags. Importantly, this indicates high survivorship of the tag-and-release fish.

The tags were developed in collaboration with Paul Howey of Telemetry 2000, Inc. Tagging took place in a collaboration among the TRCC, the National Marine Fisheries Service and the recreational fishing community off Cape Hatteras. The research was financed by the National Marine Fisheries Service, the Packard Foundation, the MacArthur Foundation, and the National Science Foundation. Wild fish up to 234 kg were tagged at Cape Hatteras with techniques developed using captive yellowfin tuna at the TRCC. Extensive work with captive tunas demonstrated that the tags can be attached without harm to the fish, either in the lab or in the field.

Data from the 1997 study found that two out of the 37 bluefin tuna crossed between management zones and four additional bluefin were within 5 degrees longitude of the stock boundary meridian.

Researchers with the TRCC and NMFS plan to tag between 600 and 1,000 giant Atlantic bluefin tuna by the year 2000. This will enable them to rigorously test the stock structure hypothesis.

For copies of the paper, please contact the Office of News and Public Information at the Proceedings of the National Academy of Sciences, 202-334-2138, pnasnews@nas.edu.


Story Source:

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


Cite This Page:

Stanford University. "New Satellite Tags Track Movements Of Atlantic Bluefin Tuna." ScienceDaily. ScienceDaily, 14 August 1998. <www.sciencedaily.com/releases/1998/08/980814065659.htm>.
Stanford University. (1998, August 14). New Satellite Tags Track Movements Of Atlantic Bluefin Tuna. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/1998/08/980814065659.htm
Stanford University. "New Satellite Tags Track Movements Of Atlantic Bluefin Tuna." ScienceDaily. www.sciencedaily.com/releases/1998/08/980814065659.htm (accessed July 28, 2014).

Share This




More Plants & Animals News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) 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