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
Viet Nam
May 24, 22:30 (GMT + 9):
IN BRIEF - Shrimp export continues growing
Viet Nam
May 24, 22:30 (GMT + 9):
IN BRIEF - 81,000 hectares of shrimp breeding ponds damaged
United States
May 24, 22:30 (GMT + 9):
IN BRIEF - Future of Maine shrimp fishery up for discussion
United Kingdom
May 24, 22:10 (GMT + 9):
Scottish farmed shellfish production drops in 2015
Ecuador
May 24, 21:30 (GMT + 9):
Argentine fishermen and Manabi’s ones exchange marketing experiences
Thailand
May 24, 03:30 (GMT + 9):
EU puts off deadline for Thailand to address illegal fishing
United Kingdom
May 24, 03:00 (GMT + 9):
IN BRIEF - Man found guilty of marine licensing offences relating to salvage of shipwreck
United States
May 24, 03:00 (GMT + 9):
IN BRIEF - Porter farm's organic fish project raises mining concerns
Kuwait
May 24, 03:00 (GMT + 9):
IN BRIEF - Bureaucracy linked to hike in prices of fish
Worldwide
May 24, 02:50 (GMT + 9):
IN BRIEF - Tens of countries sign up to shut pirate fishers out of their ports
India
May 24, 02:50 (GMT + 9):
IN BRIEF - Fish prices rise due to scarcity
New Zealand
May 24, 02:50 (GMT + 9):
IN BRIEF - Sanford to take NZD 5m impairment charge in sale of last Tuna vessel
Canada
May 24, 02:50 (GMT + 9):
IN BRIEF - Fish processing plant planned for False Creek as community supported fisheries grow
New Zealand
May 24, 02:50 (GMT + 9):
IN BRIEF - Land all fish caught to stop dumping - NZ First
Namibia
May 24, 02:50 (GMT + 9):
IN BRIEF - Fish Farming Could Provide Jobs - Kashuupulwa



Lenguaje
FEATURED EVENTS
  
TOP STORIES
HSMI evidence detected in farmed salmon
Canada A team of international researchers has diagnosed a potential heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon samples collected from a BC aquaculture facility in 2013-2014. Th...
Is New Zealand's hoki McDonald’s sources from really sustainably?
New Zealand Environmentalists have urged McDonald's to stop sourcing its fish from New Zealand waters following the leak of a confidential report casting doubts on the sustainability of fish that are widely used by the fast food giant.
WWF urges IOTC to cut Indian Ocean yellowfin tuna catches
Worldwide Indian Ocean yellowfin tuna stocks may collapse without better regulation, warns WWF.
Electronic monitoring of tuna longliners proves successful
Fiji A recent series of pilot projects in Fiji deployed electronic monitoring systems on more than a dozen longline vessels fishing in the Western and Central Pacific Ocean.
 
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 - 2016 Fish Info & Services Co.Ltd| All Rights Reserved.   DISCLAIMER