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NorthCoast's Regional Information
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NATURESea, land, river ECONOMYRegional PLACEBooks+ PEOPLESCommunity |
Conference
was seen by organizers as emphasizing the biology and wanted to have low
visibility --- too bad there was a lot of interesting speakers present from Oregon
to SE Alaska though BC researchers were in majority
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Who Eats Eulachon?? Not only first Nations it seems, some see this “forage” fish as critical to coastal ecosystems – providing seabirds, marine mammals (whales, sea lions, and seals etc) with years 1st dose of carbohydrates (see very recent scientific article quoted below) ------------------------------------------Predator abundance rose rapidly at the beginning of the runs and
was significantly correlated with an index of eulachon abundance within
years. Gulls were
the most abundant predators, with a daily average peak of 40000 during the
1996 run--. A daily average peak of over 250 Steller sea lions --fed on eulachon early in
the run in both years. Daily average counts of bald eagles approached 600 on the lower reaches
of the rivers, and many others foraged upstream. Eulachon are unusually high in lipid content,
and many of the prodigious spawning runs in Alaska and British Columbia occur
in spring, when predator energy demands are high |
The good news is that many runs seemed to have bottomed
out
and are increasing once again
The “commercial landing graph above from the Columbia River
gives some impression of what was wrong—during the 1990s the Eulachon seemed to
have been on way to extinction
Oregan, and BC have been considering if Eulachon could be listed as by Federal governments
as “at risk”
What Happened??
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Alarm
bells were ringing in mid 1990s |
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Shrimp Trawling has a bad reputation
globally for being a “dirty fishery” with high bycatch. When the BC shrimp landings
increased in the 1990s, the Eulachon numbers plummeted. Butler estimated the
fleet was taking 150 Tonnes Eulachon; DFO suggested
140 tonnes in 1997. Otter trawls were fingered and the industry responded
with “better designed nets”. At the PR Conference evidence was given the new
design worked and fewer Eulachon intercepted |
How many different populations of Eulachons
are there??
Not an easy question—DFO scientist and First Nations don’t
agree. DFO has both the “power” and the current scientific paradigms behind
them. Using mitochondrial DNA (see my
previous story) found little differentiation. Beachem gave unpublished
results at the Conference (using micro-satellite DNA) to eek out a few more
genetic distinctions. --- These sort of things “genetically separate stocks”
are crucial if either COSEWIC or US to
declare some rivers “endangered” --- Even Beachem’s DNA work needs another
year of sampling to convince skeptics that it is not “chance” that makes the
small differences found so far.
The Conference decided its purpose was to conserve all 15+
BC populations – precautionary principle?
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Uriah Orr long time PR
DFO habitat specialist showed the way |
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Uriah doggedly explored the Nass River
in the early 1980s trying to quantify the Eulachon run. The methods he worked
out then |
“Ocean Conditions”
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We just don’t know |
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Are the Eulachon rebounding? Wait a
couple more months till March and see if the trend remains positive says Doug
Hay. While a regime shift might have taken place in the Pacific it is hard to
see how that correlates with Eulachon decline. Plus we have very little understanding
of where Eulachon larvae go after hatch see image left where blue = larvae and red
= none. (here is good biology of what is known, and similar for ‘kids’.) Best
Science is still at FishBase Eulachon Thaleichthys pacificus |
Other links ---
Eulachon
Society; Google Images;
a neat account and
illustration from Lewis & Clarke expedition (1803) of “Hooligan” meal;
In the Great lakes Eulachon is an Invasive
species and threatens local smelt spp
Images of Eulachon scales
which might be found in archeological dig
Minutes (large
MS Word Document) from 1998 Eulachon Conference which are in some ways more
detailed than the 2002 meeting ‘
See also NorthCoast.Net
earlier Eulachon Biology & cultured food pages
While First
Nations viewed Eulachon ( name) as “the saviour fish”(translation of Tsimshian
word) – the 1st marine fish protein after the winter
Below are hatchlings recorded in North Coast river see DFO
Created by LG 12/8/02’ If any mistakes
let me know