Is Fisheries & Oceans Canada ignoring Washington State research on chemical contamination from sewage treatment plants?
ARE THREE LARGE SEWAGE TREATMENT PLANTS located on the Fraser River estuary contributing to the decline of the Southern Resident Killer Whale population? Between them they discharge 1.1 billion litres of effluent every day of the year into the estuary and nearshore marine waters. The largest, Iona Island, provides only primary treatment and has been permitted by Fisheries and Oceans Canada to continue at that level until 2030.
We now know that the reproductive health of the orca population depends heavily on the availability of Fraser River chinook salmon, but, according to fisheries scientists, chinook runs on the Fraser are now only 25 percent of historic numbers. Recent research in Washington has found a strong link between the survival rate of juvenile chinook salmon and chemical contamination of their natal estuary. Is the survival rate of Fraser River juvenile chinook being similarly impacted by contamination from the Annacis Island, Lulu Island and Iona Island wastewater treatment plants? Currently, these three plants provide treatment for over 1.8 million people, and thatpopulation is not declining.
Vancouver’s three largest sewage treatment plants all discharge into critical chinook salmon habitat.
The physical processes involved in this chinook-sewage-orca death spiral have become better understood in recent years thanks to research by Dr James Meador, an environmental toxicologist with the Northwest Fisheries Science Center in Seattle, and Dr Samuel Wasser, a research professor of conservation biology at the University of Washington.
Since 2013, Meador and his team of researchers have published three studies that considered the impact of chemical contamination on juvenile chinook salmon during the period they reside in their natal estuary.
Meador’s first study found that the survival rate of juvenile chinook that smolted in contaminated estuaries of rivers flowing into Puget Sound was cut in half compared with juveniles coming from a relatively uncontaminated natal estuary. Let me repeat that: Survival rate is cut in half.
In his second study, Meador analyzed the discharge from secondary sewage treatment plants, located upstream from chinook estuaries, for the occurrence of 150 “chemicals of emerging concern,” or CECs. These are chemicals associated with pharmaceutical and personal care products, as well as industrial compounds. Many are known endocrine disruptors, which can affect hormonal balance and result in developmental and reproductive abnormalities.
The researchers also analyzed the tissue of juvenile chinook and resident sculpin in the estuary for the presence of the selected CECs.
That study became widely publicized in 2016 because cocaine and antidepressants—and many other chemicals—were found in both the treatment plants’ discharge and in fish tissue. Indeed, Meador’s team found unexpectedly high levels of certain CECs in the treated effluent.
The study’s findings suggested that chinook juveniles have a significant vulnerability to bioaccumulation of CECs. Many contaminants that were found in juvenile chinook tissue were at concentrations below detection limits in the estuary waters. The scientists also observed higher levels of contaminants in juvenile chinook than in resident sculpin, even though the latter were permanent residents of the estuary.
Meador’s team observed that the contaminants found in chinook tissue, although present in sub-lethal concentrations on a chemical-by-chemical basis, were, in some cases, present at levels that would be expected to cause detrimental physiological effects. The scientists noted the potential for a drug-cocktail effect: “The fact that we observed multiple pharmaceuticals capable of interacting with a variety of molecular targets in our two fish species, leads to the potential for mixture interactions on critical physiological processes. These interactions can be additive, synergistic, or inhibitory.”
Meador noted that these effects could be responsible for the two-fold reduction in survival rate found in his earlier study.
In a third study (click link below to download), released this past April, Meador’s team found that the contaminants were also causing metabolic dysfunction, which “may result in early mortality or an impaired ability to compete for limited resources.” Again, Meador noted that metabolic dysfunction induced by CEC contamination could contribute to the two-fold reduction in the survival rate of these juvenile chinook, compared with chinook migrating from the uncontaminated estuaries, that he had found in his first study.
Adverse metabolic effects in fish exposed to contaminants of emerging concern in the field and laboratory.pdf815.72 kB · 371 downloads
The US EPA has listed Puget Sound chinook as a “threatened” species, and the decline of those runs has been even more profound than the Fraser decline.
Historically, according to Jim Myers of the Northwest Fisheries Science Centre in Seattle, Puget Sound’s chinook runs were about 25 percent greater than the Fraser River’s. But by 2010, Puget Sound chinook returns had collapsed to only six percent of the size of the greatly-reduced Fraser River returns.
Although the link between the abundance of chinook salmon in the Salish Sea and the physical health of the Southern Resident Killer Whale population has been known for some time, Wasser’s seven-year-long study, published in 2017, provided the first confirmation that low availability of chinook is suppressing the population’s birth rate and endangering the health of reproductive female orca.
Wasser’s team collected orca poop and analyzed it for hormone measures of pregnancy occurrence and health. The scientists also looked for chemical indicators of nutritional and disturbance stress in the poop. By making the same measurements over time, they were able to distinguish between nutritional stress caused by low availability of chinook salmon, and disturbance stress caused by the presence of nearby boats.
Wasser’s team correlated periods of nutritional stress with the timing and strength of the two main chinook runs that are keeping the southern orca alive: the Columbia River early spring run and the Fraser River summer and fall runs. They found that—depending on the timing of those runs, and how many fish were in them—the southern resident orca experienced more or less intense famines through the winter months and between the spring and summer runs.
The scientists observed: “Low availability of chinook salmon appears to be an important stressor among these fish-eating whales as well as a significant cause of late pregnancy failure, including unobserved perinatal loss.” The scientists surmised that “release of lipophilic toxicants during fat metabolism in the nutritionally deprived animals may also provide a contributor to these cumulative effects.”
Not only are the orca being periodically starved, but when a starved, pregnant orca begins burning off her fat reserves in response to the lack of food, toxins bioaccumulated in her fat reserves—such as PCBs and PBDEs—begin to have more of an impact on her health, such as a reduced ability to fight infections. This could contribute to the demise of the fetus and increase the risk to the mother’s life.
As a consequence of these conditions, the study noted, “the 31 potentially reproductive females in the Southern Resident Killer Whale population should have had 48 births between 2008–2015. Yet, only 28 births were recorded during that period. The 7 adult females in K pod have not had a birth since 2011, and just two births since 2007. The 24 females in the remaining two pods (J and L) have averaged less than 1 birth per pod since 2011, with no births in 2013, but had 7 births in 2015. One of the two offspring born in 2014 died.”
As of this writing, with the presumed death of “Crewser,” the population has dwindled to 75 whales. As recently as 1996 there were 98 orca in the 3 pods.
Wasser noted, “Results of the Southern Resident Killer Whale study strongly suggest that recovering Fraser River and Columbia River chinook runs should be among the highest priorities for managers aiming to recover this endangered population of killer whales.”
Let’s make the obvious connection between Meador’s and Wasser’s findings.
Meador’s research strongly suggests that the chemical contamination in Puget Sound rivers that’s quickly bioaccumulating in juvenile chinook is coming from sewage treatment plants discharging into their natal estuary. Removing that contamination could double the number of chinook returning to those rivers as adults.
Wasser’s study shows the Southern Resident Killer Whale population’s decline is strongly correlated with the availability of chinook and he recommends, for one thing, that managers of the Fraser River fishery make chinook recovery amongst their highest priorities.
A rational conclusion, based on the two groups of scientists’ extensive research, would be that Fraser River fisheries managers should be determining whether the impacts Meador measured in Washington estuaries are at play in the Fraser estuary. But that’s not happening.
DFO recently published “A science based review of recovery actions for three at-risk whale populations” that listed 98 specific actions. DFO acknowledges that only 2 of the 98 measures are “specifically directed toward recovery of chinook salmon stocks in Canada.” None of those 98 actions include examination, let alone reduction, of the impacts of chemical contaminants on chinook juveniles in the Fraser River estuary.
DFO paper on SRKW recovery efforts.pdf1.36 MB · 594 downloads
DFO has been caught flat-footed on chemical contamination of the Fraser River estuary in the past. The Cohen Commission of Inquiry into the decline of sockeye salmon in the Fraser River produced a technical report in 2011 that stated: “There is a strong possibility that exposure to contaminants of concern, endocrine disrupting chemicals, and/or contaminants of emerging concern has contributed to the decline of sockeye salmon abundance in the Fraser River.” Despite that, the technical report noted, “Due to limitations on the availability of exposure data and/or toxicity thresholds” it could provide only a “qualitative evaluation.”
Cohen Comm report on chemical contaminants re sockeye decline.pdf15.57 MB · 120 downloads
That was in 2011 and the information gap was related to sockeye. With chinook runs on the verge of collapse, you would think that Meador’s published research on chinook estuary contamination, only 200 kilometres away, would have prompted DFO to narrow the gap in their knowledge. We contacted DFO, but as of our press deadline a spokesperson had been unable to confirm whether or not any DFO-affiliated scientist was investigating the impact of the Fraser River estuary wastewater treatment plants, or other sources of chemical contaminants, on the survival rate of juvenile chinook.
The presumption may be that because sewage effluent is being discharged into the Fraser River estuary through outfalls that achieve legally required dilution ratios, no further consideration is required. But the rivers Meador considered in Puget Sound are meeting similar if not higher requirements, and he found chinook survival rate is being cut in half.
Meador has said it’s unlikely these contaminants can be effectively filtered out of the huge volume of wastewater that’s being flushed into Puget Sound. In the case of the Fraser River it seems possible that the three plants could be connected to a super outfall that diverts the discharge away from the estuary and into deeper marine waters. But without any examination of chemical loading of Fraser chinook juveniles being conducted by DFO, there will be no public pressure mounted for such a measure. Mr Floatie ought to find a new costume (Cocaine Man?) and relocate to Vancouver.
Victoria’s deepwater marine outfalls, by the way, are located about 70 kilometres away from the nearest chinook estuary.
While DFO wasn’t certain about what research is being done, it’s more certain about the magnitude of the chinook decline. In its 2018 outlook for the six different populations of chinook in the Fraser Basin, fisheries managers found that only one was at a level considered necessary to maintain a healthy population.
David Broadland is the publisher of Focus.
The orca famine and Puget Sound's poisoned rivers
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