Desired Outcome: Fishability
(fish that are safe to eat)
SOLEC's overall subjective assessment of its indicator Chemical
Contaminants in Edible Fish Tissue is "Mixed, Improving." This assessment
is described in the SOLEC report as, "The ecosystem component displays
both good and degraded features, but overall, conditions are improving
toward an acceptable state."8
Basis for SOLEC Assessment
SOLEC reported on the results of a study that applied a uniform set
of health standards to historical data on polychlorinated biphenyls (PCBs)
in coho salmon in the Great Lakes.9 The results show a slight decline in
PCBs over time. Because of the risks they present and their persistence, PCBs
are a frequent basis for health-based fish consumption advisories in the
Great Lakes basin, and coho salmon is a popular sport fish.
The indicator for the desired outcome of Fishability is based on the
concentration of persistent toxic substances that bioaccumulate in the food
chain and can harm the health of humans who eat contaminated fish.
Under SOLEC, this is measured by using fish contaminant data and a
standardized fish advisory protocol. The Indicators Implementation Task Force
concluded that indicators for the desired outcome of Fishability could be
measured using trends in the chemical contaminants PCBs, DDT and mercury
in selected species of fish, such as walleye, lake trout, coho salmon, smelt
and alewife.10 The Task Force also concluded that trends could be measured
by the number of added, altered or lifted
advisories where changes in advisories reflected changes
in fish tissue concentrations, although not in
cases where changes were made based on contaminant concentrations
at which advisories were issued.
There continue to be restrictions on consumption of sport fish from
the Great Lakes, and the desired outcome of Fishability has not been
achieved for sport or subsistence fishers. All eight Great Lakes states and
the province of Ontario continue to have fish consumption advisories.
The analysis of PCBs in coho salmon using a uniform advisory is a good
initial effort that provides information over both space and time. However,
as recognized by the Parties, a single contaminant in a single species of fish
is not sufficient for a thorough assessment of this desired outcome.
The Indicators Implementation Task Force report states that trends
detected in fish contaminants could be corroborated by long-term trends of
contaminants in fish-eating wildlife species, such as otters, snapping turtles
and bald eagles as well as herring gull eggs. Bald eagles had PCB levels
that were stable or declining in the last decade, but no trends are apparent
for the entire Great Lakes.11 Real declines in the levels of PCBs over the last
20 years are evident from studies of Great Lakes biota, including herring
gull eggs, lake trout, coho salmon and bald eagles.
Commission-sponsored studies using several data sets for PCBs in
herring gull eggs, and a data set for PCBs in coho salmon, show continuing
decline in contaminant levels, but at dramatically slower rates than was observed
in the period immediately following controls on manufacturing and
point sources (1978-1980), and the rapid declines for the period of 1983-1989.
The presence of a plateau effect is possible but unknown. Recent trends
for PCB levels in lake trout also show a weak or very slow decline, which
also could indicate a plateau, but there is no solid
statistical evidence of such. The recent trends for PCBs in bald eagles are unclear because of huge
data scatter, but only some pollutants, notably DDE and oxychlorodane
show continuing declines in the bald eagle in all Great Lakes
The eight Great Lake states and the province of Ontario have
jurisdiction over sampling, measurement and analytical protocols and issue their
own advisories. Individually, each jurisdiction has compiled a great deal
of information on fish consumption advisories in the Great Lakes.
However, this information is not readily comparable or compatible
Using changes in fish consumption advisories as a measure for this
indicator would be effective if there were a uniform protocol for advisories in
all jurisdictions and the rationale behind any changes to the advisories
were clearly stated when issued. Given the number of jurisdictions
involved, devising such a uniform advisory is not an easy task.
As outlined later in this Eleventh Biennial
Report, studies show injury to human health. This is particularly so in fetuses and young children, and
at lower levels of exposure to contaminants in fish than had previously
been encountered. Exposure varies by type of fish, the parts of fish
consumed and frequency of consumption. Without major new initiatives to reduce
the sources of contaminants and ongoing human exposure, the desired
outcome of Fishability will not likely be achieved in the foreseeable future.
"There shall be no restrictions on the human consumption of
fish in the waters of the Great Lakes basin ecosystem as a result
of anthropogenic inputs of persistent toxic