Featured Research

from universities, journals, and other organizations

Fish Scales From Norway Show Ocean Fate Of Atlantic Salmon

Date:
June 4, 2008
Source:
University of Massachusetts Amherst
Summary:
Since 1983, sports fishermen from the Drammen River in Norway have been saving the scales of Atlantic salmon, caught as they return from years at sea to spawn in fresh water. Researchers are using these scales to solve the mystery of why most of these endangered fish never survive their ocean stay. Climate change may be one of several factors affecting this temperature sensitive species, bringing warmer water to the nursery areas and decreasing the numbers of small fish that salmon depend on for food.

Since 1983, sports fishermen from the Drammen River in Norway have been saving the scales of Atlantic salmon, caught as they return from years at sea to spawn in fresh water. A team of researchers including Jennifer McCarthy of the University of Massachusetts Amherst is using these scales to solve the mystery of why most of these endangered fish never survive their ocean stay.

“North American populations of Atlantic salmon have crashed, and European stocks are also declining,” says McCarthy, a graduate student of natural resources conservation. “Growth rings on the scales of fish from European stocks indicate that late summer conditions in nursery areas in the Norwegian Sea are less favorable for the survival rate of young salmon.”

Climate change may be one of several factors affecting this temperature sensitive species, bringing warmer water to the nursery areas and decreasing the numbers of small fish that salmon depend on for food.

Additional researchers include Kevin Friedland of the National Marine Fisheries Service and Lars Hansen of the Norwegian Institute for Nature Research. Results were published in the May 2008 issue of the Journal of Fish Biology.

Atlantic salmon typically spend from one to five years in freshwater rivers before heading for the ocean, and McCarthy says they seem to be doing well during this phase of their life cycle. After entering salt water, a process known as smolting, they usually undergo a period of rapid growth and feeding, but tracking them is next to impossible in their new environment.

McCarthy used the salmon scales like the rings of a tree, analyzing a record of growth that shows how well the salmon are faring. After examining scales from over 2,850 individuals, McCarthy found a consistent record of narrow rings and slow growth occurring four to five months after smolting, corresponding to the late summer, when the young salmon would be living in ocean nursery areas.

“Scale records showed good growth in the freshwater environment and immediately after smolting in May or June, which was a surprise,” says McCarthy. “Conventional wisdom has held that the months immediately following the transition to salt water are the most difficult for young salmon, since they are smaller and more vulnerable to prey.”

According to McCarthy, growth patterns show that current efforts to increase salmon populations may not be enough. “Conservation efforts focused on improving the quality of rivers and stocking them with fish are working well in the fresh-water phase, and thousands of salmon tagged by researchers are making it out to sea,” says McCarthy. “Unfortunately, only a few of these fish ever return to spawn, pointing to ocean conditions as a major factor in declining European populations.”

Continued research by Kevin Friedland will analyze climate data, including ocean temperatures and currents, to determine how big a role climate change is playing in salmon mortality by altering conditions in the nurseries and affecting ocean plankton and populations of smaller fish.


Story Source:

The above story is based on materials provided by University of Massachusetts Amherst. Note: Materials may be edited for content and length.


Cite This Page:

University of Massachusetts Amherst. "Fish Scales From Norway Show Ocean Fate Of Atlantic Salmon." ScienceDaily. ScienceDaily, 4 June 2008. <www.sciencedaily.com/releases/2008/05/080531092343.htm>.
University of Massachusetts Amherst. (2008, June 4). Fish Scales From Norway Show Ocean Fate Of Atlantic Salmon. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2008/05/080531092343.htm
University of Massachusetts Amherst. "Fish Scales From Norway Show Ocean Fate Of Atlantic Salmon." ScienceDaily. www.sciencedaily.com/releases/2008/05/080531092343.htm (accessed October 21, 2014).

Share This



More Plants & Animals News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Adorable Video of Baby Rhino and Lamb Friend Playing

Adorable Video of Baby Rhino and Lamb Friend Playing

Buzz60 (Oct. 20, 2014) Gertjie the Rhino and Lammie the Lamb are teaching the world about animal conservation and friendship. TC Newman (@PurpleTCNewman) has the adorable video! Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins