Welcome to FIS   Sponsored By
United States
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
editorial@fis.com
www.fis.com


 Print


Click to know how to advertise in FIS
MORE NEWS
India
Aug 30, 03:10 (GMT + 9):
IN BRIEF - Banned pelagic trawling still prevalent in Kerala
United States
Aug 30, 03:00 (GMT + 9):
IN BRIEF - Alaska Crabbers Urge Obama to Impose Ban on Russian Crab Imports
United States
Aug 30, 03:00 (GMT + 9):
IN BRIEF - Warm waters divert sockeye salmon run to Canada instead of Washington
Canada
Aug 30, 03:00 (GMT + 9):
IN BRIEF - 'Walking fish' studied for clues about evolution of limbs
Australia
Aug 30, 03:00 (GMT + 9):
IN BRIEF - Black market fishing is killing off local stocks
United States
Aug 30, 03:00 (GMT + 9):
IN BRIEF - Commercial Fishing Winds Down In Lower Cook Inlet
Uganda
Aug 30, 03:00 (GMT + 9):
IN BRIEF - Masaka Factory Forced To Shut Over Lack Of Mature Fish
Russian Federation
Aug 30, 03:00 (GMT + 9):
IN BRIEF - Russian fish processors turn to domestic resource base
Spain
Aug 29, 23:50 (GMT + 9):
Galicia reopens some raft polygons and shellfish beds
European Union
Aug 29, 23:40 (GMT + 9):
Four-year fisheries protocol agreed with Cape Verde
European Union
Aug 29, 23:20 (GMT + 9):
Herring dispute with Faroe Islands 'is over', says Damanaki
United States
Aug 29, 23:10 (GMT + 9):
Louisiana shrimpers asked to report foreign tiger prawn
Peru
Aug 29, 23:00 (GMT + 9):
Hake reproductive ban starts
Argentina
Aug 29, 22:20 (GMT + 9):
Shrimp still leading seafood export volume growth
Norway
Aug 29, 21:40 (GMT + 9):
Salmon price status at week 35



Lenguaje
FEATURED EVENTS
  
TOP STORIES
Satellite localization and monitoring system rule modified
Mexico The Secretariat of Agriculture, Livestock, Rural Development, Fisheries and Food published the amendment draft to the Official Mexican Norm 062 for the use of the tracking system and satellite monitoring of fishing vessels.
High supply and low prices boost octopus fishing ban
Mauritania For three months octopus will not be allowed to be caught in Mauritanian waters, following the ban enacted by the Government of this country from 21 August.
Govt plans to limit Pacific bluefin tuna catch
Japan The Japanese Government intends to reduce the catch of immature Pacific bluefin tuna and prevent overfishing of the high-priced fish by implementing common regulations internationally, out of criteria currently adopted independently by Japan.
The European fleet must wait two further weeks to fish in Morocco
European Union The Ministry of Agriculture and Fisheries of Morocco considered rumors stating this country is trying to delay the adoption of the fisheries agreement signed with the EU as "ill-founded".
 
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 (Head Office)
Inmarsat plc - Global Headquarters
Marks & Spencer
Tesco PLC (Supermarket) - Headquarters
Pescanova, S.A. - Group Headquarters
Sea Harvest Corporation (PTY) Ltd.
I&J - Irvin & Johnson Limited
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 ehf - 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-
Grupo Calvo - Luis Calvo Sanz, S.A. (Group 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
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 - 2014 Fish Info & Services Co.Ltd| All Rights Reserved.   DISCLAIMER