Welcome to FIS   Sponsored By
Subscribe to FIS | Register with FIS | Advertise with FIS | Newsletter | About FIS | Contact us
   


Marine biologist Dag L Aksnes. (Photo: FIS Stock)

Climate change darkens water, drives fish away

Click on the flag for more information about Norway NORWAY
Tuesday, November 20, 2012, 04:40 (GMT + 9)

Norwegian coastal waters are darkening due to changes in weather and climate, damaging optical conditions for marine animals.

Marine biologist Dag L Aksnes of the University of Bergen has analysed the impacts of these declining optical conditions with some funding from the Research Council of Norway's research programme on the Oceans and Coastal Areas (HAVKYST). He explained that this occurs when coloured matter from rivers and lakes flows into the sea and mixes with salt water.

"This fresh water contains far more coloured dissolved organic matter (CDOM) than marine water, so our coastal waters are darkening," explains Aksnes, the Research Cuncil reports.

Aksnes and his colleagues have been studying the Lurefjorden and Masfjorden fjords in northern Hordaland county on Norway's western coast for many years.

While the fjords are similar and close to each other, Masfjorden contains far more seawater than Lurefjorden, which contains lower-salinity coastal water all the way down to its seabed. Although Masfjorden still has an ecosystem dominated by fish, the darker Lurefjorden has a greater abundance of the jellyfish Periphylla periphylla.

"Periphylla periphylla is a very light-sensitive jellyfish that thrives best in the world's very deep marine waters," continued Aksnes. "But the water in Lurefjorden has now become so murky and dark that it is probably helping this jellyfish to thrive. At the same time, the fjord has become less hospitable as a habitat for important fish species."

Visibility conditions at Lurefjorden have made it more difficult for fish to find their prey, but not for the blind jellyfish. The jellyfish now have virtually no competition for the abundant prey organisms, Aksnes elaborated.

He highlighted that there is a clear correlation between poorer conditions for fish, the increase in jellyfish and the lasting changes in light conditions in the country’s coastal waters.

These conditions also affect algal photosynthesis and the production of organic compounds – which is why the researchers believe that light conditions impact most organisms.

The project demonstrates that changes normally linked to eutrophication (nutrient pollution) and human emissions of nutrients can also cause the water to become darker, reducing the abundance of attached algae such as seaweed and kelp while fueling the growth of planktonic algae.

Meanwhile, nutrient concentration climbs and oxygen saturation in the marine layers falls.

"More precipitation means that more murky fresh water mixes with the coastal water, making it less saline and murkier," explained Aksnes.

"Furthermore, studies done at the University of Oslo indicate that increased precipitation and rising temperatures lead to changes in vegetation on land, which in turn increases the concentration of CDOM in the fresh water that mixes with the coastal water. We don't know yet whether this leads to undesired changes in our coastal ecosystems, but if so, it will be hard to reverse," the professor added.

By Natalia Real
[email protected]
www.fis.com


 Print


Click to know how to advertise in FIS
MORE NEWS
Australia
Feb 25, 04:40 (GMT + 9):
IN BRIEF - Why does aquaculture matter in NSW?
Australia
Feb 25, 04:40 (GMT + 9):
IN BRIEF - Huon Aquaculture ‘not surprised’ Tassal sided with State Government on Macquarie Harbour fish farm
Norway
Feb 25, 04:00 (GMT + 9):
IN BRIEF - Marine Harvest completes the purchase of farming assets on the East Coast of Canada
Australia
Feb 25, 04:00 (GMT + 9):
IN BRIEF - Ocean Grown Abalone proposes trial near Port Lincoln
United States
Feb 25, 04:00 (GMT + 9):
IN BRIEF Environmental and fishing groups sue to save salmon
China
Feb 25, 04:00 (GMT + 9):
IN BRIEF - Is China’s Hands-Off Approach to Fisheries Producing More Fish?
United States
Feb 25, 04:00 (GMT + 9):
IN BRIEF - Council says ‘yes’ to fish tax, winter crab fishery
China
Feb 25, 01:50 (GMT + 9):
BioMar joint venture opens line of extruded feed
Viet Nam
Feb 25, 01:10 (GMT + 9):
Shrimp industry struggles to achieve ambitious export target
Spain
Feb 24, 23:50 (GMT + 9):
Cepesca questions 'laundering of illegal catches' in swordfish distribution
Norway
Feb 24, 23:00 (GMT + 9):
IN BRIEF - Marine Harvest ASA: Adjustment To Conversion Price Of Convertible Bond (ISIN NO0010710395)
Canada
Feb 24, 23:00 (GMT + 9):
IN BRIEF - Marine Harvest completes the purchase of farming assets on the East Coast of Canada
Spain
Feb 24, 22:50 (GMT + 9):
EU assigned 71pc of TAC for Mediterranean swordfish
Chile
Feb 24, 22:00 (GMT + 9):
Strengthened measures for transporting salmon
Spain
Feb 24, 21:50 (GMT + 9):
Galicia allocates EUR 8 million to promote sustainable aquaculture



Lenguaje
FEATURED EVENTS
  
TOP STORIES
EP Fisheries Commission visits Anfaco-Cecopesca
Spain Anfaco-Cecopesca was visited by a delegation of the EP's Fisheries Committee, led by its Vice-President, Werner Kuhn, of the European People's Party.
Thai Union records higher sales, despite difficult environment
Thailand Thai Union Group reported that its revenue grew by 7.3 per cent in 2016, driven by an adjustment of its prices and the acquisitions of Rügen Fisch and Chez Nous.
SNI asks to expand anchovy fishing zone for DHC in Tacna
Peru The National Industry Society has asked the Ministry of Production to expand the area in which small-scale purse seiners are authorized to catch anchovy in Tacna, due to problems of supply of this resource.
Half of 'suspicious' transhipments occur in Russian waters, a report says
Indonesia Fish transshipping at sea can mask illegal fishing practices and hide human rights abuses, stated Oceana in a report released at the Economist’s World Ocean Summit in Bali, Indonesia.
 
Maruha Nichiro Corporation
Nichirei Corporation -Headquarter-
Pesquera El Golfo S.A.
Ventisqueros - Productos del Mar Ventisqueros S.A
Wärtsilä Corporation -Wartsila Group Headquarter-
ITOCHU Corporation -Headquarter-
BAADER - Nordischer Maschinenbau Rud. Baader GmbH+Co.KG (Head Office)
Inmarsat plc - Global Headquarters
Marks & Spencer
Tesco PLC (Supermarket) - Headquarters
Nueva Pescanova, S.L. - Group Headquarters
Sea Harvest Corporation (PTY) Ltd.
I&J - Irvin & Johnson Holding Company (Pty) Ltd.
Blue Continent Products (Pty) Ltd - (Oceana Group Limited)
Pesquera San Jose S.A.
Nutreco N.V. - Head Office
CNFC China National Fisheries Corporation - Group Headquarters
W. van der Zwan & Zn. B.V.
SMMI - Sunderland Marine Mutual Insurance Co., Ltd. - Headquarters
Icicle Seafoods Inc. -Headquarter-
Starkist Seafood Co. - Headquearters
Trident Seafoods Corp.
American Seafoods Group LLC - Head Office
Marel - Group Headquarters
SalMar ASA - Group Headquarters
Sajo Industries Co., Ltd
Hansung Enterprise Co.,Ltd.
BIM - Irish Sea Fisheries Board (An Bord Iascaigh Mhara)
CEFAS - Centre for Environment, Fisheries & Aquaculture Science
COPEINCA ASA - Corporacion Pesquera Inca S.A.C.
Chun Cheng Fishery Enterprise Pte Ltd.
Food Project (Siam) Co., Ltd.
VASEP - Vietnam Association of Seafood Exporters & Producers
Gomes da Costa
Furuno Electric Co., Ltd. (Headquarters)
NISSUI - Nippon Suisan Kaisha, Ltd. - Group Headquarters
FAO -Food and Agriculture Organization- Fisheries and Aquaculture Department (Headquarter)
Hagoromo Foods Co., Ltd.
Koden Electronics Co., Ltd. (Headquarters)
A.P. Møller - Maersk A/S - Headquarters
BVQI - Bureau Veritas Quality International (Head Office)
UPS - United Parcel Service, Inc. - Headquarters
Hamburg Süd Group - (Headquearters)
Armadora Pereira S.A. - Group Headquarters
NOAA - National Oceanic and Atmospheric Administration (Headquarters)
Omega Protein Corporation -Headquarter-
Marona S.A.
Marine Harvest ASA - Headquarters
Marubeni Europe Plc -UK-
Findus Ltd
Icom Inc. (Headquarter)
WWF Centroamerica
Oceana Group Limited
The David and Lucile Packard Foundation
Ajinomoto Co., Inc. -Headquarter-
Friosur S.A. - Headquarters
Cargill, Incorporated - Global Headquarters
Benihana Inc.
Leardini Pescados Ltda
Mitsubishi Corporation Marine Products Depts. D.Team
CJ Corporation  -Holding Headquarter-
Greenpeace International - The Netherlands
David Suzuki Foundation
Fisheries and Oceans Canada -Communications Branch-
Mitsui & Co.,Ltd - Headquarters
Ocean Trawlers Group - Ocean Trawlers HK Ltd.
Natori Co., Ltd.
Carrefour Supermarket - Headquarters
FedEx Corporation -Headquarter-
AKBM - Aker BioMarine ASA
Seafood Choices Alliance -Headquarter-
Austevoll Seafood ASA
Walmart / Wal-Mart Stores, Inc. (Supermarket) -Headquarter-
New Japan Radio Co.Ltd (JRC) -Head Office-
Gulfstream JSC
INVE Group - Head Office
Marine Stewardship Council - MSC Worldwide Headquarters
Royal Dutch Shell plc (Headquarter)
Genki Sushi Co.,Ltd -Headquarter-
Iceland Pelagic ehf
AXA Assistance Argentina S.A.
Caterpillar Inc. - Headquarters
Tiger Brands Limited
Morpol ASA - Group Headquarters
SeaChoice
National Geographic Society
AmazonFresh, LLC - AmazonFresh

Copyright 1995 - 2017 Fish Info & Services Co.Ltd| All Rights Reserved.   DISCLAIMER