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Monday, September 24, 2007

Commercial Salmon Fishing - what a wasted effort

Commercial salmon fishing has got to be the most wasteful industry you could imagine. The salmon when they are full size come back into their steam or river and you just have to harvest them. Instead we spend huge amounts of money, create masses of green house gases and waste the efforts of thousands of people going after them at sea. And we catch them before they are fully grown. No wonder salmon have become a luxury item rather than a delicious, reasonably priced product. No wonder the stocks have been decimated.

And ....... can someone tell me, why we are farming salmon. Could it be something to do with having destroyed the natural runs. Could it be all the other degradations in their environment we have caused. Salmon farming puts a quantity and quality of pollution into the oceans that wouldn't be allowed from a land based enterprise.

It requires the fishing of 10 kg of "trash fish"* to produce each kg of salmon. The other 9k** in the form of feces and excretion goes right into the sea by the farm. Salmon farming threatens our stocks of wild salmon by polluting migration routs with sea lice, and the fish from salmon farms are an order-of-magnitude richer in PCB's, pesticides and a cocktail of other carcinogenic compounds than wild salmon. Salmon farms use antibiotics which produce antibiotic resistant bacteria in the ocean. Fairly recently it has been found that quite a wide range of supposedly unrelated bacteria species exchange genetic material. Antibiotic resistance spreads from one bacteria to another along pathways we can't even begin to imagine.

*salmon farmers have spent considerable efforts to source some of the necessary protein from land crops rather than from fished anchovy.  So now we use lots of prime agricultural land to grow Soy beans to feed our salmon.

**A salmon farmer will tell you he gets a 2:1 conversion factor.  That is to say, two kg of food produces 1kg of fish.  You would be excussed in thinking that every kg of fish produced introduces 1kg of waste into the ocean.  However they are talking about dry food and wet salmon.  Salmon food is less than 7% water, the salmon, over 80% water.  The true figure is the 10% you learned in school.  ie 10% of the material from one trophic level goes into the next one.  90% back into the environment.

Salmon farming also introduces a range of arthropodicides into the sea to control sea lice, which then threatens food chains based on copepods and amphipods. These compounds are also toxic to commercial crustaceans such as crabs and lobsters which are also arthropods.

For that matter, I don't know why we call it salmon farming. There is no farming involved. Salmon cages are marine feed lots.

Why don't we simply let (or help) the runs to build up to what they once were and harvest them when they return to spawn. You can't even over-fish salmon if you harvest the returning fish correctly since all the fish you harvest would be dead in a month anyway. You have to harvest just below the point in their migration where the quality of the salmon meat begins to decrease and allow enough to get through to completely stock all natural and artificial redds. That's it. End of story. You can even selectively let salmon of superior characteristics through to spawn and improve the breed.

None of this is original or particularly startling. Lauren Donaldson of Washington University worked on salmon and trout from 1932 onward. He produced completely new "artificial" salmon runs at Portage Bay, Seattle and was getting 30 times better returns than found in natural runs. Through selective breeding his salmon were bigger, returned in less years and had more eggs that "natural" salmon. Incidentally, he supplied the majority of the eggs to the great lakes project, to control the alewife which had taken over those inland fresh water oceans. He also produced super-trout which are still the base of trout stocking in many countries of the world.

Although you can't harvest all the fish, depending on the location of your redd, hatchery or artificial spawning channel, you may be able to use the meat of fish which are artificially or naturally spawned. That is the beauty of the system. In addition to the still existing natural redds, you build hatcheries and artificial spawning redds such as exist in many parts of BC. In the hatchery, you choose the best fish to be the parents of the next generation. You only need a small portion of the returning salmon to fully stock hatchery and/or spawning channels and/or natural reds and the rest can be harvested. In a hatchery, if it is quite close to the sea, you can even eat the fish after stripping out the eggs and sperm.

 You have probably seen the pictures of salmon spawning way up the rivers and what bad shape they are in. You certainly wouldn't want to eat any of these. However further down the river nearer the mouth where you might locate your hatchery, (seaward of the first high dam) the fish are still in fine commercial condition. For each species, the exact point where condition begins to decrease, whether still in the estuary, or at the point of entering fresh water or somewhere up the river is where you harvest the excess to what is needed for spawning. Disintegrating fish from further up the river systems can even be used for compost if so desired.

There are a wide variety of salmon to choose from.  They vary from the pink and chum which head out to sea from streams near the mouth of the parent river as soon as they hatch to Sockeye that live for various periods in fresh water lakes before heading to sea.  The variety you choose depends on your local conditions and requirements.

However, the real trick - the key to making the system work - is in allowing the people who operate the salmon producing facilities get the economic benefit from the returning fish. Why should they go to all this effort only to see fishing boats take their salmon.
It is so logical and only needs a "stroke of the pen" to set up. Why do our governments find it so hard to do the necessary.

My favorite hatchery is the Capilano in North Vancouver. Not because it is any better than the other hatcheries in BC but I lived near it as a boy and visited it often.  It is situated just below Cleavland dam.

Link Historically there were natural runs of Steelhead and Coho.  After they built the dam, like Donaldson they started a new run of salmon, in this case Chinook, by hatching eggs of this species in the hatchery. This has resulted in having runs of salmon for about three quarters of the year and an extra very valued fish species. Initially, they truck some of the young salmon above the dam and they also truck some adult salmon above the dam to spawn naturally. I'm not sure if they still do this as it has been found that survival is pretty bad when the young fish pass the dam on their way back to the sea.

The production from the hatchery is allowed to make its way down to the sea when the fish reach the appropriate developmental stage. Their success has been beyond all initial expectations and the runs are now reported to be larger than before the dam was constructed.

Actually, depending on your location, you can often get away without a hatchery. In fact there are some definite advantages of doing so.  In many locations Spawning Channels have been build instead, which are just artificial spawning streams constructed parallel to an existing stream, with suitable gravel on the bottom and often with rip-rap (stone) sides. The spawning success in Spawning Channels in some locations has been found to be 10 times as good on a per-area basis as in natural redds due to the freedom from floods. In a bad year floods can wipe out natural redds. True, you have to clean out the gravel from time to time in the spawning channels since in nature, the very floods which destroy many eggs also clean the gravel. In some spawning channels, the water is first let into a pond where much of the silt settles out before it enters the spawning channel. You also may need to protect the spawning channels from bears, eagles and other predators but after the fish have spawned, the carcases can be distributed to feed these animals.

Why bother giving the spent salmon to the local fauna? The return of nutrients from the sea via the salmon is a vital part of the ecology of coastal forests in salmon country. Via the dung of the salmon-eating animals, these nutrients are spread far and wide.  This is one of the few systems in nature that returns nutrients from the sea to the land.

In a couple of ways, spawning channels may be preferable to hatcheries. There is, of course the issue of cost. It is less expensive to build and operate a spawning channel than to build a hatchery. Of more importance, though, may be the preservation of a robust stock. In a hatchery, there is always the temptation to use various "chemical helpers" such as malachite green or various antibiotics when you see a 'fungus amongus'. (yes I know antibiotics don't work against fungus but there is always the temptation to cover all your bases and avoid secondary infections). These and other measures taken to assure a good result neutralize some of the effects of natural selection which, unlike the popular characterization, does much more to keep a species robust than it does to produce new species.

A spawning channel is much closer to the natural situation than a hatchery and fish that do well in a spawning channel will likely do well in a natural redd. While the vast majority of fish return to their stream and redd of origin there is always some leakage of fish from location to location. Not every fish returns to its original birth place so a successful spawning channel is a source of fish for natural redds. Some species of salmon actually do better in spawning channels than in a hatchery.

And how about expense. Well the Capilano hatchery cost some $3 million Can. to build(many many years ago) and employs about 10 people, some of them involved in tourism and education rather than in fish production. Compare this with operating a fleet of salmon boats and you will see it is cheap by comparison. Spawning channels cost even less to build and run than hatcheries. You are not even restricted to one commercial unit per river or stream. Since by far the majority of the salmon return to their patch of spawning gravel, within certain limits, it is possible to have a number of enterprises in one water-shed. Each business gets back its own fish. Whoever designed this fish was a genius. The limit on how many juveniles you can send down to the sea each year is probably related to the pollution load from feeding the young fish to the stage where they return to the sea. Since they are small and eating much less per fish than when they are older, this is a smaller problem and returning adults don't feed. However, if the legislation is ever set up so that this type of salmon ranching can occur, we will probably even reach this limit. Note, though that the carrying capacity of a stream can be greatly increased with very little cost.Link

Why do we still run fishing fleets. It is the usual story. Vested interest. The fishing companies with their boats already exist and they of course still want to continue to fish and make money. They lobby against anything that will interfere with their prerogatives. The same applies to the salmon farmers. Never mind that the fish stocks would be far better off if we let them all come back to their streams and ensured that enough were allowed/induced to spawn to fill all the natural and artificial redds available. Never mind that pollution from salmon farms is detrimental to wild salmon runs.

To get such a system of salmon ranching working, all rivers with dams or other man caused spawning-reducers such as excessive soil erosion have to be well supplied with hatcheries or spawning channels and the fish harvested when they return. Rivers that still have great spawning runs (there still are one or two) would be fished right by the sea but in a sustainable way, allowing the best fish to pass in sufficient numbers to completely stock all redds.

Since salmon get by far the greatest part of their life-time nutrition from the sea, there is a reasonable chance that with the man-caused demise of all the other sea-fish stocks, that there is a lot of feed left over for salmon. It is possible that we could even end up with greater runs of salmon that were present in pre-historic times as has occurred in the Capilano. Actually it is more likely that we have so degraded the sea that there is less feed available but that remains to be seen. Of most importance, though, the salmon must be allowed to return to the companies that spawned them. It is not fair to expect a business to go to all the expense of growing the juveniles only to have them harvested by boats at sea.

Think of the tourism potential. With great salmon runs on all our rivers, we can increase all aspects of tourism associated with this fish. As in Africa with their animal safaris, we can have fishing safaris both at sea and in our rivers with well heeled Americans coming to rod-fish our waters and bringing in lots of foreign currency. In case you think this goes against the above argument of every facility getting back its own fish, consider the following. A rod fisherman going after a salmon and especially one from overseas, puts so much money into the economy in transportation, guides, accommodation, fees and so forth that his value to the economy hugely exceeds the value of the salmon he catches. Of course a recompense should be directed to the hatcheries and spawning channels by the government, commensurate with their contribution to the economy through tourism. This could take the form of tax rebates.

As in Africa we can have camera safaris with people coming during the spawning season to wonder at our hatcheries, spawning channels and natural redds, and at salmon jumping water falls and digging nests in pristine streams. We can have safaris where they watch the bears and other predators taking their share and they can wonder at the Canadian people who live in harmony with their natural resources instead of fighting them.

If there ever was a fish designed by the creator or by evolution, depending on your point of view, to give us vast quantities of delicious food for ridiculously little effort, the salmon is it. Why do we work so hard to circumvent the obvious system and make life hard for ourselves. Why do we send expensive polluting fishing fleets after these fish when they swim right back to us. Why do we farm these fish at the cost of polluting our coastal water and imperilling our natural runs. Why do we fish 10 kg of "trash" fish to produce each kg of farmed fish when the wild fish don't cost us anything to feed once they have left the hatchery. Why do we farm these fish when it produces an inferior product laced with a cocktail of carcinogenic pollutants.

The latest buzz word is sustainability. If ever there was a species which can be utilized by us in a sustainable way, it is the salmon. Why are we fighting so hard against the obvious.


Anonymous said...

what a bunch lie's

William Hughes-Games said...

Hi Anonomous. Would you like to be more specific.
The author