Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Crustacean brawls caught on camera

12.02.2002


Underwater video reveals lobsters behaving badly.


Going to pot: scientists are re-assessing their lobster traps
© Winsor H. Watson, III


Kitchen confidential: surveillance cameras crack down on lobster trap layabouts



A lobster-pot is more like a Wild West saloon than a cunningly laid snare. Lobsters show up for food and a fight, and only the unlucky few get reeled in, underwater video footage is revealing.

Camera recordings show that lobster traps catch a mere 6% of the animals that enter them. The result suggests that lobsters’ rowdy behaviour could be confusing attempts to count and size them, and so to manage the fishery1.


"Predicting the future of the population is difficult," says Stanley Cobb, who studies lobsters at the University of Rhode Island in Kingston. "Traps may not be sampling all parts of the population." Egg-bearing females, for example, seem to avoid them, says Cobb.

Lobster numbers are usually estimated from the catches of experimental traps. To gauge


The traps soon attracted a crowd of brawling crustaceans. "They hate each other," says Watson. "They compete outside the trap for the next opportunity to enter, and occupants fight off those trying to come in."

Traps have a ’kitchen’ where bait is kept. This leads to two ’parlours’ where lobsters are supposedly held. They also have emergency exits to let undersized animals out.

Lobsters, however, don’t play fair: "75% of them went right back out the entrance," says Watson. The few that were caught tended to be larger specimens that could fight off intruders, and were interrupted mid-meal. "We call it the restaurant hypothesis," Watson says.

What’s the catch?

"A lot of lobstermen feel that traps are really feeding stations," says Cobb. New England’s lobster fishery is in good health - perhaps, says Cobb, because of all the bait that fishermen put out. Lobster catches worth about $200 million are landed each year in Maine alone.

But researchers are not sure how long the good times can go on. "We catch about 90% of lobsters bigger than the legal size limit. I’m concerned we’re fishing too heavily," says Watson. Catches are beginning to decline in the southern area of the fishery, and there are signs that disease is damaging the crustaceans.

Researchers would like to be able to read any warning signs, so that they can move to avert possible crashes, rather than have to repair a shattered fishery. To do this, they may need new ways of counting lobsters - one possibility Watson suggests is a trap that can catch multiple lobsters by moving them away from the entrance, "like a maze".


References

  1. Jury, S. H., Howell, H., O’Gradt, D. F. & Watson, W. H. III Lobster trap video: in situ surveillance of the behaviour of Homarus americanus in and around traps. Marine and Freshwater Research, 52, 1125 - 1132 , (2001).

    JOHN WHITFIELD | © Nature News Service

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>