This article discusses some subjects which would
probably be considered heretical by most of the people involved in - and
responsible for - managing our fisheries. The idea that all it takes to
restore our fisheries is a cessation of pollution and overfishing is one
that our managers are comfortable with, in spite of mounting evidence to
the contrary. [Of particular significance, we feel, is the authors' suggestion
that all of the factors that impact on fish production be evaluated to
determine their relative importance ] |
July 19, 1998
SPECIAL TO THE TIMES
Puget Sound is approaching a diverse, healthier, but less-abundant fish
community. Scientists who in the past suggested that some amount of nutrient
and organic input might be beneficial to the Sound, or at least not harmful,
were discredited by the media, regulatory agencies and public-advocacy
groups. Is it time to take another look at the relationship between organic
matter and fish habitat?
Puget Sound is cleaner but where are the fish? This contradiction is
not a surprise. Years ago some of us aging scientists tried to encourage
agencies to look at connections between harvesting, pollution sources,
water quality, and climate change. That hasn't happened. But it looks like
we're getting close! Now, according to a just-released report, the Puget
Sound Water Quality Action Team promises to do something about it: relate
monitoring to models of how the Sound really works and be more rapidly
responsive to what it learns.
Much of the past focus of Puget Sound has been on sewage treatment,
chemical contaminants, dredging and bacteria. The public sees that we have
spent billions to control pollution and the result is fewer fish. This
contradiction must be frustrating. But it can be resolved by a more open,
flexible, "ecosystem-based" monitoring and assessment program. Such a program
will give managers and the public new alternatives for management and most
importantly, give us more realistic expectations about what "clean water"
means and "how clean is clean enough."
How does an "ecosystem" approach work? It looks at everything that might
affect the fish, not just pollutants. It explores contradictory ideas,
such as those highlighted in the recent articles by Ross Anderson, ("Voyage
of Discovery," July 12 and 15.)
For example, protection and enhancement of marine mammals may be cropping
resident fish and shellfish; ocean climate changes may be favoring certain
species at the expense of others and "advanced" treatment of sewage and
pulp-mill wastes may have reduced inputs of organic material to the Sound,
and therefore, reduced the amount of food. Let's see what unrestricted
consideration of these possibilities might lead to.
Is Herschel Godzilla?
We are all familiar with Herschel and his gang of California sea lions
who pillaged steelhead and salmon at the Ballard Locks. The "Herschels"
were sent to Florida but their friends are still consuming large numbers
of fish along the coast. Herschel is not alone.
During the past quarter century, the Sound has been home to fast-growing
populations of harbor seals. The Sound's seals have been reproducing at
record rates, even fouling shellfish beds with their fecal material. What
we don't know - but ought to - is what their food habits really are. How
much of the Sound's fish and shellfish production are they consuming each
year? Which species? We don't know if any agency is answering this question:
if they are, the answer is not being used to address the "clean Sound,
no fish" contradiction.
What about ocean change? El Ni centsno aside, the North Pacific Ocean
has been switching back and forth between several regimes. Each regime
lasts several decades. The last big switch was around 1976-77. We're overdue
for another (and there are signs it is coming!) These regime shifts result
in changing water clarity, water temperature and abundance of plankton
- the basic food of baby fish, shellfish and herring. The regime shift
has affected the entire Pacific Coast where plankton and fish abundance
have been especially low during the past 20 years. Presumably, this is
also the case in Puget Sound. Or is it?
To our knowledge, there is no program in place to compare plankton and
fish production in Puget Sound with that in the North Pacific Ocean, to
see if our local problem is actually oceanwide. Ironically, there are such
programs for Alaska's Prince William Sound and the California coast.
Did we stop feeding the fish?
The correlation between clean water and declining fish implies that
past pollution may have been a good thing. . .at least for fish abundance.
How do you explain - or get around - the fact that the Sound's fisheries
were more productive 30 to 40 years ago when we were discharging hundreds
of times more organic material than today?
During the 1950s and 1960s, when Seattle, Everett and Tacoma outfalls
were daily releasing tons of organic wastes into the Sound, bottom-trawlers
were reaping a bounty of fish - cod, sole, hake, rockfish and herring.
(Fish do not eat the organic matter directly, but do consume the worms,
clams and crustaceans that thrive on it).
Salmon were returning in acceptable numbers. To be certain, resident
fish in the Duwamish Waterway and other so-called "hot spots" were plagued
with fin rot and other diseases caused by chemicals. But fish were abundant,
even there. Is it possible the historically high fish production may be
due, in part, to the organic material that used to go into the Sound (and
now, at considerable public cost, has been renamed "biosolids" and landfilled
or purveyed as fertilizer)?
Did that organic wasteload function like the organic matter (called
detritus) that used to runoff from the once more-abundant coastal wetlands?
As the coastal wetlands were filled (mostly many years ago), the important
detritus export diminished but may have been compensated for by societal
discharges of organic wastes. With advances in wastewater treatment did
we move - like the modern farmer - from organic manure and compost to just
chemical fertilizers that only provide the raw nutrients?
Unfortunately, scientists who suggested that some amount of nutrient
and organic input might be beneficial to the Sound, or at least not harmful,
were discounted by the media, regulatory agencies and public advocacy groups.
It was practically illegal to discuss the Sound's "assimilative capacity"
for nutrients and organic material and, indeed, any research smacking of
that issue was summarily ignored, with one notable exception - Lake Washington.
In his 1991 book, "The Uses of Ecology: Lake Washington and Beyond,"
University of Washington Professor Emeritus "Doc" Edmundson describes how
diversion of treated sewage in 1964 to Puget Sound transformed Lake Washington
from a "polluted" but highly productive water body into a clean-looking
but less-productive lake. As it got cleaner, it produced fewer fish, including
sockeye.
Actually the story is more complicated. Neither he nor the rest of us
advocate a return to those days. But to continue to ignore the role of
nutrients and organic matter as a factor in increasing native fish production
is akin to sticking our collective heads in the mud.
There is a provocative problem with this "sewage was good" idea: our
expectation about what is normal. If you accept that there were more fish
in the past when pollution was at its peak, the necessary implication is
that before industrialization - before the turn of the century - maybe,
just maybe, there were actually fewer fish in the Sound - at least marine
fish such as sole, flounder, rockfish and cod. Were we harvesting, during
the '40s and '50s, an excess of fish raised on waste discharges?
Maybe the normal situation is what we
are now approaching: a diverse, healthier (low disease), but less-abundant
fish community. We know this happened elsewhere. The abundance of fish
around California wastewater outfalls increased 10- to 100-fold during
discharge, then crashed as the effluent was cleaned up or outfalls relocated.
So, is more fish a realistic expectation for a cleaner Sound? Maybe not!
These are just a few of the possibilities that need to be considered
in a broader view of Puget Sound. There are more: we didn't discuss overfishing,
source control, sediment hot spots, waste sites, oil spills, red tides,
watershed development, etc. Together with marine mammal enhancement, ocean
climate change and organic and nutrient loading, we need to know not only
what roles all these factors play in fish production, but also, on a scale
of 1 to 10, their relative importance!
Look at all the factors
What has been missing from Puget Sound monitoring, research and management
is an ecosystem approach. The water quality team is moving in that direction
now, but it needs our collective support. We suggest our agencies stop
and take a broader look at all factors that may have been and may be affecting
the living resources of the Sound.
-- Start with the 1993 National Research Council Report, "Managing Wastewaters
in the Coastal Urban Areas," with the fishery-oceanography reports from
the California and Prince William Sound programs, "Doc" Edmundson's masterpiece
on Lake Washington and the advice from the team's own science advisers.
-- Look at existing conceptual and physical models of the Sound. Re-consider
what our ecological and fisheries expectations should be in light of pre-industrial
history and data.
-- Mine the "old timers" for their knowledge and their opinions before
it is too late to do that.
-- Look at century-long trends: marine mammals, marine birds, wastewater
inputs, fish landings, fishing effort, plankton abundance, rainfall, temperature,
runoff, El Ni centsno events, regime shifts, wastewater loading, etc.,
etc.
-- Then use the models to connect the pieces; spend some money testing
the new hypotheses and start modeling new alternative management scenarios.
Such a broad focus may not solve all the riddles, but it will greatly
reduce our uncertainties and the chance for future surprises. More importantly,
it will help make sure that we don't waste billions in public money on
false expectations or counterproductive management actions.
There will be a bureaucratic reluctance to admit that some of our management
actions may have been counterproductive, so a number of changes that should
happen probably still will not for many years to come. If the reader is
challenged by these comments, that is exactly our point.
The Puget Sound Water Quality Action Team is on the verge of important
discovery. The team deserves encouragement, support and a broader working
arena.
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THE AUTHORS
Alan Mearns is a marine ecologist with the Hazardous Materials Response
and Assessments Division, National Oceanic and Atmospheric Administration,
Seattle. Mearns' teams worked on wastewater management, long-term pollution
trends around the US.
Lincoln Loehr is an oceanographer working as an environmental analyst
for Heller, Ehrman, White and McAuliffe, Seattle. He has worked on conceptual
modeling of Pacific Northwest ecosystems and on issues associated with
wastewater discharges.
Herbert Curl Jr. is a biological oceanographer, now retired from service
with the National Oceanic and Atmospheric Administration. During the late
1970's and 1980's Curl's teams and associates helped develop and test models
for managing contaminants in Puget Sound.
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