Don’t Mess with the Estuary: Skeena mouth threatened by development near and far

Don’t Mess with the Estuary: Skeena mouth threatened by development near and far

👤Frances Riley 🕔Dec 01, 2012

Over the past few years, protection of the Skeena River has received a lot of attention. For the most part, that activity and awareness has focused on the upper end of the watershed, with Tahltan elders blockading the road into the Skeena’s headwaters, Ali Howard’s epic swim from source to sea, and a vibrant movement of coalitions dedicated to preserving the sustainability of the river and its vital role in local communities.

What many people may not realize, however, is that the estuary of a river is equally as important to the river’s overall health as the headwaters. Although the Skeena River estuary has until now been relatively unscathed by the effects of industry and land development, it is also vulnerable, as little formal protection in the form of management plans or conservation designations currently exists either.

In general, estuaries are unique ecosystems because of the way fresh and salt water constantly intermingle. Some scientists have called them super-habitats because they support so much life; their productivity and diversity rivals that of tropical rainforests. In BC, estuaries make up only about three percent of the rocky and convoluted coastline, yet 80 percent of coastal wildlife species use them at one time or another.

“At certain times of the year, estuaries are critical to many different species,” says Dan Buffet from Ducks Unlimited Canada. “They’re a great source of nutrients—such a productive zone!” For example, driving along the lower reaches of the Skeena in late February, it’s impossible to miss how the waterway literally teems with the tiny silver eulachon, pursued by thousands of birds and sea mammals that show up for the first big feast of the spring. First Nations’ culture also benefits, as many traditional foods come from a healthy estuary ecosystem.

Nutrient trap Constantly being fertilized by sediments washing downstream, estuaries trap critical nutrients and disperse them to a wide variety of small creatures that in turn become food for bigger ones. “Forage fish in the estuary are fundamentally important to the diet composition of larger species,” says John Kelson, a conservation biologist who recently released a study of marine life within the Skeena estuary. Those larger fish are usually the ones that are important to humans; while a fisherman probably doesn’t get too excited about plankton and small fry, he will certainly appreciate the fat salmon on his hook that may have been nourished by those smaller organisms.

Estuaries are gateways and nurseries for baby salmon transitioning to the rigours of the ocean, rest stops for migrating birds, and grocery stores for foraging grizzly bears. The effect of an estuary’s health radiates far beyond its physical demarcation: into the forest with the well-fed bears, far upstream with spawning salmon, and out into the ocean.

But estuaries are also particularly sensitive to change. Their sheltered, gradual coastlines have traditionally made them popular with industrial operations and residential development, and hardening of the shoreline to build homes and docks often means the loss of mudflats and grasses. Dredging to make navigable channels for tugs and barges disrupts the river bed; all those fertile layers of sediment, built up over time, are displaced and scattered. Excessive debris, such as bark from log booms, can suffocate existing vegetation, and invasive species flushed from ships’ bilges can force out native plants. And the qualities that make estuaries so good at trapping nutrients, warns Kelson, also make them good at trapping pollutants. “They can become places of accumulated contaminants,” he says. Runoff and spills from on-shore industries can contain chemicals and toxins that may be concentrated here, potentially affecting all levels of life.

Complicated boundaries Delineating the boundaries of an estuary can be a complicated matter because ocean tides are constantly mixing and remixing the fresh water coming downstream with the salty water of the sea. “This creates different zones of salinity,” says Kelson, “and different species use different zones.” When it comes to the Skeena, tides introduce salt water as far inland as the confluence with the Kwinitsa River—about 75 km upstream from Rupert—and a plume of fresh water fans far out from the river mouth into Chatham Sound. During spring freshet, when rivers swell with melting snow, the Skeena estuary, defined as the zone within which fresh and salt water mix, expands to about five times its normal size, actually meeting the outflow of the Nass River to the north and creating a kind of mega-estuary. The boundary of Prince Rupert harbour overlaps the limits of the Skeena estuary even during usual flow periods; increased shipping and potential shoreline development in that area, especially on Kaien, Ridley, and Lelu Islands, will unquestionably have an impact. How much impact will that be? Clearly, more research is needed.

Kelson says estuaries haven’t attracted a lot of study because they’re so complex, adding that extensive inventories are needed to ascertain just what species exist within them. As part of his research Kelson sampled marine life at the upstream limit of salt water in the Skeena, and discovered that the water column was teeming with nutrient-rich organisms. “There were mind-blowing amounts of shrimp and long-fin smelt,” he says. Previously, no one had discovered spawning long-fin smelt here. It’s difficult to know how an area is going to be affected by changes if detailed knowledge about species distribution and abundance hasn’t been established. While some investigation is being done, there are still many gaps.

Making a plan Currently, there is no comprehensive blueprint for protecting the Skeena estuary by managing the increasing industrial activity within its boundaries. The Prince Rupert Port Authority, the body responsible for managing and developing port activities at the north coast city, recently released its 2020 Land Use Management Plan, which lays out a framework for port development over the next 10 years and also mentions the organization’s commitment to environmental stewardship. The port is also a member of Green Marine, a voluntary international program dedicated to reducing the carbon footprint of ports and curtailing the spread of invasive species.

However, the complexity of the Skeena River estuary suggests that strategies for ecological preservation and best practices for local industry should fall under a dedicated management plan, similar to the one that governs habitat management and water-related industrial activities within the Fraser River. The Fraser River Estuary Management Plan is an intergovernmental partnership that includes federal, provincial, and regional governments as well as local port authorities. A similar collaboration for the Skeena could facilitate concerted efforts toward goals such as environmental studies, habitat inventories, and dredge management guides that would ultimately benefit all stakeholders in the estuary.

The Skeena estuary is, all things considered, comparatively healthy at the moment. However, sandwiched between expanding shipping activity on the coast and potentially dangerous projects upstream, it remains to be seen how long its vitality can be maintained. While a patchwork of several small conservancies was designated by the BC government in 2008, nothing exists to protect the estuary as a whole.

A recent study by Ducks Unlimited Canada placed the Skeena in the top tier of importance when considering estuary size, important plants, shellfish beds and herring spawning grounds. “A lot of estuaries on the North Coast are unprotected,” says Buffet, “but you can’t just put up a fence and keep people out. This is an opportunity for government, industry, and NGOs to all work together to try and keep the ecosystem as resilient as possible.”