Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Track Atlantic bluefin tuna to learn migration, habitat secrets

New fish-tagging studies of young bluefin tuna in Atlantic waters off New England by researchers at the University of Massachusetts Amherst are offering the first fishery-independent, year-round data on dispersal patterns and habitat use for the popular game fish. The availability of miniaturized pop-up satellite tags suitable for smaller (two- to five-year-old) fish helped make the research possible.

Fisheries oceanographer Molly Lutcavage and lead author Benjamin Galuardi say the work shows that scientists now have tools to directly observe bluefin tuna annual migration patterns and vertical habitat use (depth) in the Atlantic and Mediterranean oceans in detail not possible in earlier studies. This new information should lead to better understanding of bluefin tuna ecology, catch patterns and management of wild stocks that provide a multi-million dollar sport fishery from Maine to North Carolina.

Lutcavage, director of UMass Amherst's Marine Research Station and the Large Pelagics Research Center (LPRC) in Gloucester, says, "Our tagging data are important because for the first time we've got direct measurements of bluefin tuna movements and habitat associations. In other words, their travel routes, depth and temperature patterns, and where they intersect with recreational fisheries."

Galuardi, an LPRC scientist and doctoral candidate in the Graduate School of Marine Science at UMass Dartmouth, led the analysis of data returned from pop-up satellite tags used in this study, as well as oceanographic conditions across bluefin migration paths. Details are reported in today's issue of the Public Library of Science One (PLoS) journal.

"Knowing the dispersal patterns of these young fish after they leave their nursery grounds and learning their year-round habitat needs are important goals for the commercial fishery of adult bluefin tuna, as well," she adds. For example, these tunas' winter and spring movements and behavior of juveniles have largely been unknown until now.

For this study, Lutcavage, Galuardi and fishermen partners deployed 58 miniature pop-up satellite archival tags (PSAT) and 132 implanted archival tags on juvenile Atlantic bluefin tuna between 2005 and 2009. Because only one archival tag was retrieved, data reported are mainly from 26 PSATs.

To deploy the PSATs, fish were caught by hook and line and brought aboard the boat to attach a miniaturized PSAT to the fish's fin by a tether and dart anchored at the base of the fin. These were programmed to record external temperature, depth and daily position based on light sensor readings every 15 minutes and to release after 12 months. Later models also recorded light level. Once at the surface, the PSAT tags transmitted the collected data to receivers on earth-orbiting satellites. The data were then transmitted to the researchers, allowing scientists to trace the fish's journeys and habitat over the previous year.

The authors report that all tagged bluefin tuna remained in the northwest Atlantic for the duration observed, and, in summer months they stayed in coastal waters from Maryland to Cape Cod out to the continental shelf. In the winter, they wandered more widely, exiting the Gulf of Maine and ranging south to the South Atlantic Bight (North Carolina to Florida), the northern Bahamas and the Gulf Stream edge.

Lutcavage and Galuardi found that vertical habitat patterns showed juvenile bluefin primarily occupied shallow depths, averaging about 16 to 40 feet (5 to 12 meters) and relatively warm water, averaging 64 to 70 degrees F (about 18 to 21 degrees C). In winter, they frequented deeper water and showed more variable depth patterns.

"These findings are the first long-term view into a year in the life of a juvenile bluefin tuna in the western Atlantic," Lutcavage notes. "The geographic and vertical concentration of summer habitat had been suspected due to patterns in the recreational fishery, but was not confirmed until this study. In addition, little information existed on what these fish did in winter months when the fishery does not operate. This information provides a window into what areas and conditions are important for growth and survival of juvenile bluefin tuna."

The authors add, "Our tagging results reveal annual dispersal patterns, behavior and oceanographic associations of juvenile Atlantic bluefin tuna that were only surmised in earlier studies. Fishery independent profiling from electronic tagging also provides spatially and temporally explicit information for evaluating dispersal rates, population structure and fisheries catch patterns and supports development of direct assessments."

Janet Lathrop | EurekAlert!
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>