Catch 'em if you can

Fish are starting to wise up to anglers' tricks

ANGLING folklore that claims fish learn how to avoid capture seems to be true. A study of trout fishing published last week in New Zealand demonstrates for the first time that fish constantly exposed to anglers become "streetwise", staying out of sight and avoiding the bait. Likewise, fish caught once remember to avoid falling for the same ruse again for at least a month.

John Hayes and Roger Young of the Cawthron Institute in Nelson investigated the phenomenon after veteran anglers complained that fish were becoming harder to catch. "They said the fish were getting a bit too smart," says Hayes.

The researchers set out to catch brown trout that were old hands in the heavily fished Owen River near Murchison and naive trout in a remote river of the Kahurangi National Park, which is usually inaccessible to anglers. They asked two experienced anglers to visit each river on four fishing trips over a single season. On each three-day trip, observers recorded the number of fish caught and marked them with a coloured tag to identify them the next time.

Despite the fished stretches of the two rivers having the same density of trout, the savvy fish from the Owen were far trickier to land. Only 58 were caught in the Owen, compared with 157 in the remote river.

Trout in the remote region, which had never encountered anglers before, showed a distinct pattern of learning. They went to ground after being caught, failing to appear again until subsequent trips. On the first day in the remote site, each angler would typically catch 10 fish. But the haul vanished almost to nothing on the third day.

"Fish in the remote river were very sensitive to anglers," says Hayes. "They would hide and would not come back. And once fish had been caught, they were more difficult to catch next time." The pattern was mixed on the Owen, depending less on the anglers and more on higher water temperatures, which

Contact: Claire Bowles
New Scientist

Page: 1 2

Related biology news :

1. Catching evolutions henchmen in the act
2. A global warming Catch-22?

Post Your Comments:

(Date:5/16/2017)... TEANECK, N.J. , May 16, 2017  Veratad ... leading provider of online age and identity verification solutions, ... the K(NO)W Identity Conference 2017, May 15 thru May ... Ronald Regan Building and International Trade Center. ... across the globe and in today,s quickly evolving digital ...
(Date:4/24/2017)... -- Janice Kephart , former 9/11 Commission ... LLP (IdSP) , today issues the following statement: ... 6, 2017 Executive Order: Protecting the Nation ... instilled with greater confidence, enabling the reactivation of ... are suspended by until at least July 2017). ...
(Date:4/17/2017)... 2017 NXT-ID, Inc. (NASDAQ: NXTD ) ... of its 2016 Annual Report on Form 10-K on Thursday April ... ... in the Investor Relations section of the Company,s website at ... at http://www.sec.gov . 2016 Year Highlights: ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... ... analysis platform specifically designed for life science researchers to analyze and interpret ... Rosalind Franklin, who made a major contribution to the discovery of the ...
(Date:10/11/2017)... ... October 11, 2017 , ... ComplianceOnline’s Medical Device Summit is back ... 8th June 2018 in San Francisco, CA. The Summit brings together current and former ... CEOs, board directors and government officials from around the world to address key issues ...
(Date:10/11/2017)... , ... October 11, 2017 , ... Disappearing forests and ... lives of over 5.5 million people each year. Especially those living in larger cities ... Treepex - based in one of the most pollution-affected countries globally - decided to ...
(Date:10/10/2017)... (PRWEB) , ... October 10, ... ... development-stage cancer-focused pharmaceutical company advancing targeted antibody-drug conjugate (ADC) therapeutics, today confirmed ... targeted HPLN (Hybrid Polymerized Liposomal Nanoparticle), a technology developed in collaboration with ...
Breaking Biology Technology:
Cached News: