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How a pulp mill killed commercial fisheries in New Brunswick’s St. Croix Estuary, and its lessons for the Northumberland Strait

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KJIPUKTUK (Halifax) – The planned release of treated effluents into the Northumberland Strait by Northern Pulp is a topic of much debate, with some arguing all will be fine, while others, many fishermen amongst them, fear that it will not be safe at all.

Folks engaged in that debate may find an early 2000s water quality study of the St. Croix Estuary of interest. The St Croix Estuary, a body of water separating Maine and New Brunswick, located at the western mouth of the Bay of Fundy, has been the recipient of effluents of a local paper mill since 1965.

Art MacKay, a now retired biologist, is one of the authors of the 2003 study of the relative environmental health of the St. Croix Estuary over the the last 400 years. The study is part historic research, and part data collected in the early 2000s through fieldwork.

No matter what creatures you look at, be they sponges, anemones, jellyfish, crustaceans, urchins, sand dollars, and what have you, the study concludes that by and large all have suffered a decline, although the exact extent and cause of that decline is often difficult to pinpoint.   

The report points to a pulp mill in Woodland, Maine, as one of the two main causes of ongoing water pollution in the estuary.

“During the 1960s, black liquor and other wastes from the Georgia- Pacific Pulp Mill in Woodland, Maine were dumped directly into the St. Croix River. The health of the Estuary declined dramatically and the commercial fishery of the Lower Estuary all but disappeared,” the report states.  

“The mudflats of the Upper Estuary became anoxic and virtually all of the plants and animals died. A commercial eel fishery came to an end and once thriving herring weir, handlining, longlining, and dragger fisheries ended in the Estuary and western Passamaquoddy Bay with an estimated loss of millions of dollars in revenues.”

Only when waste treatment at the mill was upgraded in the early seventies did the situation slowly begin to improve. But spills continue to this day, and altogether water quality, even with effluents treatment, continues to be a major issue, the report concludes.

“While it is clear that the St. Croix River Estuary has improved, inputs from industrial, domestic, and air-borne sources remain at levels that are dangerous to both desirable marine species as well as the human residents of the lower St. Croix River Valley. (…) the continued input of highly toxic chemicals and pathogenic bacteria represents a real risk. Until these conditions are changed, it is unlikely that any significant restoration can be accomplished and the economic benefits of tourism, recreational angling, and the commercial fishery will not be realized.”

MacKay fears that something similar to what happened to the St. Croix Estuary could happen to Caribou Harbour, the immediate location of Northern Pulp’s proposed effluent dump, and the Northumberland Strait altogether. That we’re assured that the new effluent treatment prior to release will be “state of the art” doesn’t take a away the need for a rigorous environmental assessment, MacKay believes.

“Since it is impossible to remove all toxic chemicals and physical alterations (pH, temperature, residual solids, etc.) the alterations in and of themselves will impose negative impacts on life forms, particularly on the planktonic level. That in turn impacts the organisms up the food chain, this is well known and understood on a general level,” MacKay writes in a message exchange with the Nova Scotia Advocate.

“It is essential for the effluents to be tested for lethal and sub-lethal effects in an independent laboratory. LC-50 concentration tests that we carried out showed “treated” effluents in the St. Croix killed Atlantic salmon parr starting in only 20 minutes, MacKay writes.

MacKay notes that another similarity between the St. Croix Estuary and the Northumberland Strait is that it multiple jurisdictions will be affected by a potentially deteriorating water quality.

“The impact of the mill is not just a problem for Nova Scotia. The effluent impacts  waters under federal jurisdiction and PEI waters as well, since the boundary is shared by two provinces,” Mackay writes.

There’s lots at stake, MacKay believes.

“With the St. Croix we were able to determine that the annual value of the fishery was between $10 and $20 million. The fisheries actually disappeared from the river, estuary and western Passamaquoddy Bay.

“How much is that Gulf fishery worth? That’s the potential loss in real dollars and jobs versus the mill. When you determine where mill profits go, I’m betting the marine losses will be much greater than the actual benefits to Nova Scotia,” MacKay writes


See also: John Collins: A letter on Northern Pulp, science and the clock that’s ticking

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