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 A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>