RINNASHARK SEA ANGLING CLUB WATERFORD
* IF You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!If you have any problems with the registration process or your account login, please contact rinnasharksac@gmail.com
* BORN TO FISH

Latest topics
» Master Angler 2017 information
Thu 12 Oct - 10:55 by barry

» passage sat 11-2pm
Mon 2 Oct - 21:57 by barry

» 2017 MARTIN HALLEY MEMORIAL OPEN COMPETITION
Mon 2 Oct - 11:06 by barry

» Fishing Cod Baits
Mon 11 Sep - 9:40 by Admin

» 2017 Master Angler
Fri 25 Aug - 8:47 by Sharky

» !!!!CHANGE OF DATE!!!!
Wed 19 Jul - 10:34 by barry

» Shock Waves Tope
Mon 17 Jul - 10:06 by Admin

» Fish and Film
Sat 24 Jun - 17:55 by Admin

» Dunmore East Small Boats Festival 2017
Mon 29 May - 23:28 by Sharky

» Juvenile Fixtures and Results 2017
Tue 16 May - 15:29 by Sharky

» 2017 Juvenile Fixture
Mon 24 Apr - 21:17 by Admin

» Ian Tyldesley 3 hrs · Hayle, United Kingdom · Great day out with Sam Narbett on Bluefin Charters made Amazing by hooking up with this monster Porbeagle Shark . Took nearly 1 hour 30 mins to get along side
Sun 9 Apr - 16:07 by Admin

» Boat fishing for juvenile s
Tue 4 Apr - 15:14 by barry

» Munster juvenile 2017
Thu 30 Mar - 8:54 by barry

» Salt rod holdall for sale.
Wed 29 Mar - 21:00 by AC

» 2017 Juvenile Fixture
Sun 5 Mar - 9:45 by Admin

» 2017 Fixtures Snr and Juv + Boats Competition Results
Mon 27 Feb - 22:25 by barry

» small boats
Mon 27 Feb - 22:05 by barry

» RINNASHARK SAC Today's Compettion has been moved to CHEEKPOINT @ 3pm
Sun 26 Feb - 10:11 by Admin

» Irish Specimen Fish Report 2016
Thu 26 Jan - 9:18 by Admin

» Major Boat Competitions 2017
Tue 3 Jan - 22:27 by barry

» Boat Master angler 2016
Tue 3 Jan - 22:15 by barry

» Rinnashark Juvenile Fixtures & Results 2016
Mon 12 Dec - 18:21 by Sharky

» Well done Alan Mulcahy
Mon 5 Dec - 18:21 by Admin

» 2017 TIDES Waterford
Sat 26 Nov - 11:32 by Admin

» Juvenile Master Angler 2016
Tue 22 Nov - 21:11 by Sharky

» Tramore Bay Trawlers/Fishing Boats
Sun 20 Nov - 8:57 by Admin

» 2016 Fixtures & Results
Thu 13 Oct - 21:23 by Sharky

» 2016 Master Angler
Thu 13 Oct - 21:16 by Sharky

» Mackerel in Youghal
Thu 4 Aug - 9:29 by Admin

TEAM IRELAND U16/U21
Philip Griffen
Doing it all wrong Dad
Alan & Jamie
SHARK
HOME NATIONS CUP U16
BARRY
GERRY
RAY WITH HOME NATIONS CUP
NICE TOPE
Tramore Bass NO2
Ladies

Scientists are starting a novel project to investigate whether overfishing alters fish behaviour

View previous topic View next topic Go down

Scientists are starting a novel project to investigate whether overfishing alters fish behaviour

Post by Admin on Mon 19 Sep - 9:53

Scientists are starting a novel project to investigate whether overfishing alters fish behaviour and changes their pattern of development.

Over exploitation of stocks has already been shown to select for smaller fish.

A team reporting at the meeting of the European Society for Evolutionary Biology in Germany will deliberately remove the largest individuals from populations of lab-bred guppies.

The experiment is designed to uncover what is happening in our oceans.

"There are clear indications that almost all... commercial fish are shrinking," said marine biologist Carl Lundin, who directs the International Union for the Conservation of Nature's Global Marine and Polar Program.

For mass spawning fish such as cod, there is a great advantage to maintaining older, larger females because they are very efficient at restocking the population.

And if industrial fishing selectively removes the largest individuals, explained Dr Lundin, the industry suffers as populations are reduced to the smallest fish.

However, smaller seafood is unlikely to be the only consequence of industrial fishing; research has also shown that fish in the oceans are reproducing earlier.
Experimental evolution

Now evolutionary biologist Beatriz Diaz Pauli and her colleagues from the University of Norway have begun an experiment that they hope will help uncover what other changes we can expect to see in the oceans' fishes.

The team established nine populations of guppies, each comprising 500 to 900 individuals. Over the next few years, Ms Diaz plans to remove all the fish that measure over 16mm from three of her tanks.

In the remaining tanks, Ms Diaz will purge fish under 16mm, or take fish independent of their size - regimens that will act as a control for the effects of changing the density of fish in the tanks.
Fish tanks (Credit: B.Diaz/U of Bergen) The researchers will run experiments to establish the mating habits of the fish

The team will then painstakingly record the changes that they see in the fish's growth rate, age and size of maturation, reproductive effort, and mating and feeding behaviours.

The team hopes to unpick whether the shifts they see are a result of fish moulding themselves to a new environment - a so-called plastic response - or are a consequence of genetic changes.

Plastic responses are not inherited. For example, an organism might reach a smaller body size if it gets little food as a juvenile, but its young would not inherit this propensity to be small.

Genetic responses, by contrast, are inherited, and even if a future generation is returned to an environment where food is plentiful, it would remain small.

Determining the nature of the changes in the fish will help scientists understand how stocks might recover if over exploitation stopped or breeding grounds were protected.

"If we set aside 20-30% of the habitat where reproduction... of key commercial fish stocks [occurs], we are much more likely to avoid these types of problems," said Dr Lundin.

He added that carrying out experiments of this type allows researchers to control other factors that could affect the fishes' survival and concentrate on just the consequences of overexploitation.
avatar
Admin
Admin
Admin

Male
Number of posts : 1114
Age : 69
Location : WATERFORD
Reputation : 6
Registration date : 2008-03-12

View user profile http://www.rinnasharksac.net

Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum