Tuesday, 15 January 2013

Potential harvest of most fish stocks largely unrelated to abundance

Fisheries managers should sharpen their ability to spot environmental conditions that hamper or help fish stocks, rather than assuming that having a certain abundance of fish assures how much can be sustainably harvested.

Wednesday, 9 January 2013

The Giant Squid videoed

Click for larger image
Architeuthis: read more at Encyclopedia of Life
(Newser)– Discovery is about to release the Kraken: Until now, the giant squid had never been caught on video in its natural habitat. But Japan's National Science Museum has managed to capture the footage. Discovery Channel will air the footage in the special “Monster Squid: The Giant Is Real,” on Sunday, Jan. 27 at 10PM EST as the season finale of the Curiosity series.

Wednesday, 2 January 2013

Managing invasive alien fish, Cedarberg

Invasion of the Rondegat River in the Cedarberg, Western Cape, by smallmouth bass Micropterus dolomieu has resulted in the extinction of several native fish species in the lower reaches of the river. In an attempt to rehabilitate aquatic environments for not only fish, but also amphibians and invertebrates, the piscicide rotenone is being implemented in this and other rivers by Cape Nature.

Clanwilliam yellowfish (Darragh Woodford, SAIAB)
Clanwilliam yellowfish (Olaf Weyl, SAIAB)
The fish team was led by Dr Olaf Weyl (SAIAB) and Bruce Ellender (Rhodes University), assisted by two MSc and nine Honours students. Dr Darrragh Woodford (SAIAB/Centre for Invasion Biology) was part of the invertebrate team.

    "Juvenile yellowfish were recorded in the first pool of the treatment area just three days after the operation, and two month later both yellowfish and redfin minnow Barbus callidus were recorded (the latter for the first time in probably 70 years)."

Read more about the preliminary surveys, the pilot project, and ongoing monitoring, in
Water Wheel Volume 11 No 6 November/December 2012.