Welcome   Sponsored By
Subscribe | Register | Advertise | Newsletter | About us | Contact us
   


Image: HI - INSTITUTE OF MARINE RESEARCH

Salmon do not become immune to salmon lice

Click on the flag for more information about Norway NORWAY
Friday, November 25, 2022, 07:00 (GMT + 9)

It is known that salmon get lice and react to it. Now the researchers have taken a closer look at what happens when the same fish is repeatedly attacked by lice.
 
"We clearly see that the salmon's immune system reacts when the fish gets lice, but it is not activated enough to prevent the same fish from getting lice several times", says Sussie Dalvin.
 
She is the project manager for a project where the researchers have specifically examined the salmon's immune response to salmon lice.

"The fish's response is very local, mostly only in the skin directly below the louse".
 
Important basic research
 
In the project, the researchers have worked on studies of basic mechanisms in the interaction between salmon and salmon lice. Such basic research does not provide solutions to problems such as how to avoid infection with salmon lice, but builds up the necessary basic knowledge of how the two species react to each other.
 
"Such research often confirms facts that many people think they know, but this is knowledge that we need to have scientifically confirmed or disproved so that we do not drag consequential errors into other parts of the research", says Dalvin.
 
 
Photo of several adult salmon lice, both females and males.  There is a clear size difference between the two sexes, the females being the largest.
This is what adult salmon lice look like. In the pictures there are both females and males.Photo: Sussie Dalvin / HI
 
A natural parasite
 
Salmon louse is a parasite that attaches itself to salmon, sea trout and char. Here it eats on the skin. If the fish is heavily attacked, it can get wounded and in the worst case die.
 
"Salmon lice are found naturally in our sea areas, but the amount has increased sharply as a result of the large number of farmed salmon that act as hosts for the parasite", says Dalvin.
 
Since farmed salmon are treated against lice, lice in themselves usually do not pose a major problem for the salmon in the cages, but the methods used to remove lice present major challenges with fish welfare. For the wild fish, salmon lice can pose a threat.

"Salmon lice are a problem especially for small salmon migrating from the rivers to the sea in spring/early summer and for sea trout that stay in coastal areas with high levels of salmon lice all summer", she says.
 
 
Picture of a salmon where a skin sample is taken from the back. Photographer: Sussie Dalvin / HI
 
Infected the salmon with lice repeatedly
 
In the past, experiments have been carried out to show how salmon react when they get salmon lice on them once. In this experiment, the researchers looked at what happens when it is repeatedly infected.
 
"Both in the wild and in farms, salmon are often repeatedly infected with lice. That is why we have carried out several rounds of lice infestation in different combinations on the same fish to see if previous infestation can have any effect"says Dalvin.
 
The researchers clearly see that the immune system of the fish reacts:
 
"We also see that the response changes over time, but not enough to prevent new infections with lice", she says.
 
 
To investigate how the salmon react to salmon lice, skin samples were taken where the lice had attached to the fish.Photographer: Sussie Dalvin / HI
 
The temperature matters
 
The researchers have also investigated whether different temperatures have an effect on the fish's reaction:
 
"It is clear that lower temperatures limit the fish's ability to respond to lice attacks, but at the same time the fish are infected with fewer lice at low temperatures", says Dalvin.
 
The results fit well with observations where areas/seasons with lower temperatures present fewer challenges in dealing with salmon lice.
 
"Although it looks like the salmon's immune system reacts worse at low temperatures, we see that low temperatures have the greatest negative consequences for the salmon lice", says Dalvin.
 
Author: Beate Hoddevik / HI - INSTITUTE OF MARINE RESEARCH
 


 Print


Click to know how to advertise in FIS
MORE NEWS
Japan
Mar 29, 18:30 (GMT + 9):
IN BRIEF - Frozen volume of salmon and trout, both lower than the previous year. Salmon coho Fall
China
Mar 29, 07:40 (GMT + 9):
Southeast Pacific Squid Index: Giant squid (dosidicus gigas)
Canada
Mar 29, 07:10 (GMT + 9):
Cooke Aquaculture Named One of Atlantic Canada’s Top Employers
France
Mar 29, 07:00 (GMT + 9):
Other Media | The Fishing Daily: French Minister Urges Dialogue Over UK Expansion of Marine Protected Areas
Thailand
Mar 29, 07:00 (GMT + 9):
Thai Union Collaborates to Achieve Zero Wastewater Discharge and Establish an Industry Learning Center
Russian Federation
Mar 29, 07:00 (GMT + 9):
Russia and China Combat Illegal Fishing: Electronic Certificates of Legality for Catches
United Kingdom
Mar 29, 07:00 (GMT + 9):
Brexit costs Scotland up to USD 126.09 million-a-year in lost salmon exports
Japan
Mar 29, 03:00 (GMT + 9):
Driftnet fishing for salmon and trout starts early. Agreement with Russia
Russian Federation
Mar 29, 01:00 (GMT + 9):
Will the Russian Far East be the country with the most snow crabs in 2025?
Viet Nam
Mar 29, 01:00 (GMT + 9):
Shrimp exports from Ecuador are facing many challenges
Japan
Mar 29, 00:50 (GMT + 9):
IN BRIEF - Faced with the Peruvian decline, fishmeal production in India and Oman is increasing rapidly
Australia
Mar 28, 21:10 (GMT + 9):
IN BRIEF - At WTO, Australia seeks details on India's fisheries plan
Croatia
Mar 28, 21:00 (GMT + 9):
IN BRIEF - Cromaris business results in 2023
United States
Mar 28, 07:20 (GMT + 9):
AQUA Cultured Foods Partners with Ginkgo Bioworks to Optimize Alt-Seafood Production
United States
Mar 28, 07:00 (GMT + 9):
Seafood Expo Global Announced Finalists of the 2024 Seafood Excellence Global Awards



Lenguaje
FEATURED EVENTS
  
TOP STORIES
Clipfish challenges in Brazil: Port bureaucracy stops millions worth
Brazil More and more clipfish containers are being stopped in Brazilian ports. - Complicated regulations make market access challenging, to say the least, say Norwegian exporters who risk large losses. Bra...
Catches in the Sea of Okhotsk and Bering Sea
Russia Fed. Situational update as of 03/24/2024 Source: Stockfile FIS Sea of Okhotsk (pollock) According to OSM data in the Sea of Okhotsk, pollock catch (industrial and coastal fisheries) as of March 24, 20...
Productive Development of the Fishing Activity
Peru Fishing Sector Bulletin - January 2024 The landing of hydrobiological resources registered a negative interannual variation of 62.7%, as a result of the lower landing of fishing resources for indirec...
NGO Sues UK Government Over International Fishing Quotas
United Kingdom Blue Marine Foundation, a charity dedicated to restoring the ocean to health, has launched legal proceedings over the government’s decision to set fishing opportunities, for more than half UK st...
 

Maruha Nichiro Corporation
Nichirei Corporation - Headquarters
Pesquera El Golfo S.A.
Ventisqueros - Productos del Mar Ventisqueros S.A
Wärtsilä Corporation - Wartsila Group Headquarters
ITOCHU Corporation - Headquarters
BAADER - Nordischer Maschinenbau Rud. Baader GmbH+Co.KG (Head Office)
Inmarsat plc - Global Headquarters
Marks & Spencer
Tesco PLC (Supermarket) - Headquarters
Sea Harvest Corporation (PTY) Ltd. - Group Headquarters
I&J - Irvin & Johnson Holding Company (Pty) Ltd.
AquaChile S.A. - Group Headquarters
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
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.
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
Brim ehf (formerly HB Grandi Ltd) - Headquarters
Hamburg Süd Group - (Headquearters)
Armadora Pereira S.A. - Grupo Pereira Headquarters
Costa Meeresspezialitäten GmbH & Co. KG
NOAA - National Oceanic and Atmospheric Administration (Headquarters)
Mowi ASA (formerly 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. - Headquarters
Friosur S.A. - Headquarters
Cargill, Incorporated - Global Headquarters
Benihana Inc.
Leardini Pescados Ltda
CJ Corporation  - Group Headquarters
Greenpeace International - The Netherlands | Headquarters
David Suzuki Foundation
Fisheries and Oceans Canada -Communications Branch-
Mitsui & Co.,Ltd - Headquarters
NOREBO Group (former Ocean Trawlers Group)
Natori Co., Ltd.
Carrefour Supermarket - Headquarters
FedEx Corporation - Headquarters
Cooke Inc. - Group Headquarters
AKBM - Aker BioMarine ASA
Seafood Choices Alliance -Headquarter-
Austevoll Seafood ASA
Walmart | Wal-Mart Stores, Inc. (Supermarket) - Headquarters
New Japan Radio Co.Ltd (JRC) -Head Office-
Gulfstream JSC
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
SeaChoice
National Geographic Society
AmazonFresh, LLC - AmazonFresh

Copyright 1995 - 2024 Seafood Media Group Ltd.| All Rights Reserved.   DISCLAIMER