Have you ever wanted to sell everything you own and just "take off?" Travel the country's back roads, paddle down a meandering stream, experience breath-taking mountain views, walk among 100-year old trees, and just marvel at America's beauty? That is the dream that my partner, Betsy, and I decided to make a reality. This blog describes our adventure. The food we eat, people we meet, sights we see, and the enjoyment we find in traveling.

Tuesday, April 30, 2013

The Dam Fish

Animal migration is a remarkable feat that absolutely baffles my mind and exhibits one of the truly beautiful acts of nature.  The fact that seabirds can fly over thousands of miles of open ocean with seemingly no cues or that monarch butterflies can flap their delicate wings for over 2,000 miles without feeding and end up in the same cypress grove as years past is astonishing.  We were fortunate to see the monarch migration in Pismo Beach, California and the thousands of butterflies that were gently gliding around entertaining onlookers in the warm winter air of coastal California.

Steelhead trout appear gray and silver when
they live in the ocean but take on a pronounced
red color when they migrate back to their
spawning grounds.
So fast forward to our location in North-central Idaho where we are surrounded by gorgeous streams and rivers that are bubbling with the mystiful migration of anadramous fish.  This fish tale of the steelhead trout starts way upsteam in the shallow inland waters of the North Fork of the Clearwater River where they are hatched – far away from the Pacific Ocean that they will call "home" for three or four years before swimming back to their birthplace.  (“Anadramous” is the fancy term used to describe fish that are born in fresh water, migrate to salt water, and return as adults to their natal grounds to spawn.)  Nature has provided an enormity of challenges for these creatures to survive a 600-mile journey.  Young fish imprint (through smell of all senses) on the rivers they swim through on their journey to the ocean and undergo physiologic changes allowing them to survive in salt water. 

A few posts ago when I introduced you to the Dworshak Dam and Reservoir (our work camping location for the next two months), I mentioned that the dam was not without controversy.  The Dworshak Dam provides flood protection, hydroelectric power, and recreational opportunities but what it DOES NOT provide is access for native salmon and steelhead trout to reach their historic natural spawning grounds.  The towering 717- foot dam rises from the base of the North Fork of the Clearwater River and, as you can see below, abruptly blocks the migrating fish.  

How would you like to face this dam as you are swimming to your spawning grounds - a journey that takes
 nearly two weeks and in which you don't eat and loose 30-50% of your body weight?

So enter into this interesting environmental picture a multitude of fish hatcheries that replenish juvenile fish that would have been hatched naturally if the dam did not exist.  There are two huge fish hatcheries in our new town of Orofino - The Dworshak National Fish Hatchery (NFH, run by the U.S.  Fish and Wildlife Service and the Nez Perce Tribe) and their sister hatchery - The Clearwater Hatchery (run by the Idaho Game and Fish Dept.).  So last Tuesday during our big day in town, and in between lunch and grocery shopping, we decided to visit the hatcheries.     


We were lucky enough to get a first-hand look at how the egg and sperm collection works from the viewing platform at the Dworshak NFH.  I must confess that I find hatcheries to be fairly boring as it usually just entails walking around outdoor ponds and looking at fish of varying sizes.  But this experience was much different and both hatcheries where a buzz with activity.  At the Clearwater Hatchery young fish were being moved from the hatchery for release into nearby rivers and at Dworshak NFH they were collecting sperm and eggs from returning steelhead trout who came home to spawn. When we visited the Dworshak NFH, they were well on their way to achieving their lofty goal of collecting 2.5 million eggs.

It all starts outside with the fish honing in on the fish ladder (as seen below in the picture) and swimming up it until they reach outdoor holding tanks.


Fish are moved to the processing location via a large basket that dumps the fish onto the sorting table.  Steelhead are sorted according to sex and machine-scanned for implanted microchips that were placed in hatchery-raised fish received as youngsters (that's the blue machine on the left the man in the black shirt is feeding them into). 


Now they are moved down the line for milking of sperm and retrieval of eggs.  


Eggs from females are collected into individual containers and will be mixed with sperm. Remarkably individual steelhead females produce an average of 6,500 eggs.  


Males are milked and the sperm is collected in a small cup.


Eggs and sperm are mixed and placed in these incubation trays for one to three months before being moved to nursery tanks.


In early summer, the young fish will be moved outside to rearing ponds where they will stay for nearly a year.


When juvenile fish are ready to be released they are "vacuumed" up into transport trucks and moved to a nearby river or stream.


Once released, the fish start their migration to the Pacific Ocean which is a much richer and productive feeding ground than the inland rivers and streams.  The journey to the ocean is a difficult one for the young fish.  There are eight dams that must be navigated (or the lucky ones get barged or trucked around the dams) and they must reach the ocean in a timely manner.  Life for the steelhead is difficult and only an estimated 1% of those released make it back to the hatchery.

2 comments:

  1. So what happens to adult fish after milking and collecting? I know they die after spawning but what do they do with them?

    ReplyDelete
    Replies
    1. The fish are given away to those visiting the hatchery and to the Nez Perce Tribe. The Chinook meat is pretty nasty by the time they reach their spawning grounds so it is discarded.

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