Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Winter Flounder On The Fast Track To Recovery

17.04.2007
UNH Researchers Find Fishery Shows Promise For Stock Enhancement

Winter flounder – sold in markets as flounder or lemon sole – in the Gulf of Maine went into serious decline in the 1980s, taking with it a major commercial and recreational fishery. Despite stringent fishing regulations, it’s estimated that it could take more than a decade for winter flounder to regain its once-robust place in New England coastal waters.

Now, researchers at the University of New Hampshire are setting the winter flounder (Pseudopleuronectes americanus) fishery on the fast track to recovery. New research indicates that winter flounder is a good candidate for stock enhancement, in which juvenile fish hatched from wild brood stock are raised in captivity and released into the wild.

“We’re studying winter flounder because we think they are an excellent local candidate for stock enhancement,” says Elizabeth Fairchild, a post-doctoral researcher in zoology at the University of New Hampshire who has worked with professor of zoology W. Huntting Howell on winter flounder stock enhancement for a decade. “We know how to raise them, and we’ve learned how to release them in a way that maximizes their survival.”

Raising the juvenile flounder is, in many ways, the easy part. The process begins in what Fairchild calls the “honeymoon tank” in UNH’s Coastal Marine Laboratory in New Castle. Commercial fishermen provide the wild brood stock; Fairchild and colleagues expertly gauge their readiness for releasing sperm and eggs then give the males and females their privacy: “We let the fish spawn on their own,” she says, noting that stock enhancement is most effective when the raised fish are as similar as possible to the wild fish they’ll ultimately breed with.

The work gets tricky – and makes for fascinating research -- when the juveniles reach the size of a potato chip and are ready to join their wild brethren in the shallow coastal waters where winter flounder naturally spawn. “Hatchery-bred fish are different than wild fish,” says Fairchild. They haven’t been exposed to predators, for instance; nor have they had to forage for food. “For stock enhancement to work, the raised fish must be as fit as the wild fish.” Much of her research turns on the challenge of making the cultured fish more wild.

In a study published in the “Journal of Fish Biology,” Fairchild examined several factors that she hypothesized made hatchery flounder more vulnerable to predators: the amount of time it took them to conceal themselves by changing skin color and pattern and burying themselves in sediment, the rate at which gulls preyed on white versus dark-colored flounder on sediment, and the fish’s behavioral reactions to predators. Her findings led her to test the effectiveness of acclimatization cages, marine halfway houses that give hatchery-raised fish a protected introduction to the wild blue sea.

Fairchild’s current studies build on explorations of optimal release strategies. Earlier this month, she released 1,000 one-year-old juveniles in the Hampton-Seabrook Estuary several months ahead of their usual summertime launch; she’s hoping that earlier release will mitigate the juvenile flounders’ vulnerability to green crabs, which are less prevalent in the spring than the summertime. Unlike in previous releases, when divers submerged crab-proof acclimatization cages of flounder into 20 feet of water prior to release, Fairchild and a team of researchers released the flounder directly into the Hampton River. “The cages were like snack cages for the green crabs,” says Fairchild, noting that the predators clustered around the cages hungrily awaiting the juveniles’ release. “It was like ringing the dinner bell.”

Fairchild tags the juveniles so she can track their survival over time. She’s also starting to explore pre-release conditioning for hatchery-raised fish, to see if they can be “trained” to have the same reactions to predators and predation as the wild flounder. And she’s starting to explore the hatchery-raised flounders’ impact on the wild population. “We want to be sure we’re not displacing or otherwise harming the wild fish,” she says.

“Targeted at the restoration of commercial and recreational fish and shellfish, enhancement is becoming a very important tool in NOAA’s fishery management tool box,” says Michael Rubino, aquaculture program manager for the National Oceanographic and Atmospheric Administration (NOAA).

Fairchild’s work is part of SCORE, the Science Consortium for Ocean Replenishment, which is a national research group dedicated to developing scientifically-based marine stock enhancement technology. SCORE is funded through NOAA and is part of UNH’s Atlantic Marine Aquaculture Center, a center for aquaculture research and technology development. For more information, go to www.amac.unh.edu/stock_enhancement/stock_about.html or http://zoology.unh.edu/faculty/howell/grad/efairchild/fairchild.html.

Beth Potier | EurekAlert!
Further information:
http://www.unh.edu

More articles from Ecology, The Environment and Conservation:

nachricht Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University

nachricht Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München

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: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>