Socialize

Facebook

Hatchery fish too slow for their own good

1:28 pm April 1st, 2014

HOOK AND FUR
By Bob Brown
It is a common conception that bigger is better. In some instances it might be true, but when it comes to hatchery-raised fish versus their wilder relatives, it may not be so.
In a study conducted by Washington State University, researchers said they have documented dramatic differences in the swimming ability of domesticated trout and their wild cousins.
Kristy Bellinger, who did the study for a Ph.D in zoology, said, “Traditional hatcheries commonly breed for large fish at the cost of speed the fish need to escape predators in the wild. The use of hatcheries to support declining salmon and steelhead is controversial. They have a role in both being part of the solution supplementing depleted fish stocks and being a hindrance to boosting natural populations. Hatcheries often produce fish that look and behave differently from their wild relatives.
Domesticated fish tend to grow faster, but while increased size is generally seen as a sign of fitness, researchers saw that wasn’t the case as far as speed is concerned. Domesticated fish have bigger body sizes, but slower swim speeds compared to smaller wild fish.
Bellinger said, “It is perceived the more you feed them, the more they are going to grow and the faster they are going to be, and that’s what we see within each cloned line. However, between the lines, domesticated fish were larger but slower when it comes to sprinting. Some hatchery managers tend to select for large fish because they want a bigger bang for their buck, but increased size is a tradeoff of sprint speed, as our data show, then we assume hatchery fish are picked off by predators due to their slower speed, which makes the process of supplementing native fish with hatchery fish an inefficient tool for conservation and a waste of money.”
An improvised speed trap was used for the study – a meter-long plastic tank filled with water and fitted with electronic sensors. Over 10 weeks, Bellinger repeatedly ran 100 genetically similar hatchery-raised and semi-wild trout through the tank, clocking their speed and monitoring their growth week to week.
Bellinger conducted the study with Gary Thorgaard, a fish geneticist and professor in WSU’s School of Biological Sciences, and her adviser, Patrick Carter, who is an associate professor. Their work is published in the journal Aquaculture.

Clam season opens

The Washington Department of Fish and Wildlife (WDFW) announced that a sports clam season will open at Sequim Bay State Park April 1. The beach is located in Clallam County, near Sequim.
Aports clam and oyster season will be delayed until June 1 at North Bay (Case Inlet). The beach is located in Mason County near Victor and Allyn. The department delayed the season due to increased and continuing harvesting of both clams and oysters. Recent surveys indicate the clam population has declined, and because the state clam share was overharvested in 2013 by more than 6,000 pounds, a much shorter season is required this year. The department noted the June-July season maximizes the number of good low tides available for harvesters.

Fishing report

Joe Hymer, of WDFW’s Vancouver office, reported that during March 1-16, anglers on the lower Columbia River made 7,200 trips, caught 63 chinook, released 23 and kept 40. Angler trips and steelhead catch are not currently available for February. There was no chinook catch that month. Hymer also reported during the week March 10-17, Tacoma Power recovered 156 winter steelhead, one spring chinook and one cutthroat at the Cowlitz Salmon Hatchery.

Who shot the wolf?

The reintroduction of gray wolves into Washington is and has been a complex social issue, difficult to accommodate and equally difficult to understand. It is also a known fact there is a segment of state citizenry who are not happy with the presence of wolves in the state. Last month, someone took their displeasure to a higher level by illegally shooting and killing a gray wolf in Stevens County. A 2-year-old black female wolf from the Smackout Pack was found dead Feb. 9 near Cedar Lake in northeast Stevens County. The female wolf was captured about a year ago and fitted it with a radio collar to track its movements and those of her pack members.
With the help of three non-profit organizations, WDFW is offering a reward up to $22,500 for information leading to the arrest and conviction of the perpetrator or perpetrators. Conservation Northwest, the Center for Biological Diversity, and The Humane Society of the United States have each pledged $7,500 to create the reward. The illegal killing of a wolf or other endangered wildlife species is a gross misdemeanor, punishable by up to one year in jail and a fine up to $5,000.

Bob Brown can be contacted at robertb1285@fairpoint.net

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>