Salmon Life Cycle and Its Future in Pemberton Waterways
Growing Future Salmon - Gillian Steele
Even though there is not much evidence of salmon left in some of the local Pemberton streams, these waterways hold the beginnings of life within the salmon cycle. Pemberton rivers and streams see salmon migrations from June right through until October. Chinook will migrate from early summer until August, Sockeye from July through September, and Coho in September and October. With their vibrant red bodies and green heads, sockeye are the most obvious and can be observed in large numbers during the mid to late summer in the Birkenhead River. Larger carcasses you may find on the Lillooet are typically those of chinook and dark-coloured fish you see darting around in smaller tributaries are usually the later run coho.
Although we may not see evidence of the salmon as we enter the winter, their eggs lay beneath the gravel and streams become nature’s nursery for the next few months.
Salmon nests or ‘redds’ are gravel patches with consistent flow and small, round pebbles. Pemberton Creek is a good example of this smaller-sized stone, with consistent, clean water flow. Salmon eggs need enough flow to have water constantly moving over or around them, but not too much as to roll or damage the eggs. These areas are extremely specific thus the importance of spawning grounds is paramount. Eggs can be damaged as people, pets, livestock, or other animals move within the stream so being aware of these areas and staying out of the water in the winter months is paramount to helping our salmon friends!
How do salmon even get to Pemberton? Salmon in our local streams travel an exceptionally long way to get here, so it is important that we make sure their spawning is as successful as possible. All Pemberton salmon travel up the Fraser. Salmon found in the Birkenhead, Lillooet, Miller, and Green River travel up the Fraser to the Harrison River, through Harrison Lake, into the Lillooet River, through Lillooet Lake, and then into the Birkenhead or upper Lillooet Rivers and beyond. Coho and Sockeye found in Gates Creek near D’Arcy travel up the Fraser to Lillooet, into the Seton River and Seton Lake, through Seton Portage, into Anderson Lake and finally into Gates Creek. These migrations take marine-derived nutrients from the ocean and deposit them hundreds of kilometres inland as salmon die or are carried away by scavengers into the forest or surrounding areas. Many other species depend on this influx of food each year including plants, animals, insects, and the entire ecosystem.
All this is affected by climate change
Climate change is critically important to not only the longevity of our time on this planet, but also the health and wellness of the systems around us both locally and regionally. Many climate change impacts are obvious, measurable, and overt, however, recognizing some of the smaller impacts at the local level can put into perspective changes that are right under our feet. The consequences of these more subtle changes could lead to much greater problems for our ecosystems at large but still may be at the point of slowing rapid change or turning it around.
Through their long journeys and anadromous life cycles, salmon are at the mercy of numerous effects of climate change. Flooding and droughts are the most discussed and impactful events occurring as of late. Longer, hotter, and dryer summers are causing streams to dry up or become subterranean. Juvenile salmon may get stranded in pools and adults can have added stress as they migrate upstream through warmer or lower water conditions. Torrential rains, or delayed and severe winters with unprecedented rainfall events, after a summer of drought conditions, have incurred flooding or scouring of streams. These increasingly severe or flashy conditions can impact recently deposited eggs and destroy redds. Flooding in urban areas can transport harmful chemicals or pollutants into the waterways further impacting salmon or other species downstream.
There is no question that our forest fire seasons have gotten more severe. Weakened stream banks and the removal of vegetation from riparian areas can mean streams are more susceptible to erosion, flooding, and temperature increases. A rise in water temperature reduces the stream’s ability to hold oxygen, puts fish at a higher stress level during migration, can alter migration times, makes fish more prone to infection, and impacts spawning success rates. Depleted snowpacks and melting glaciers are reducing the longevity and cooling properties of freshet (melting of snow in spring) which can result in water temperature increases earlier than historical averages.
For many streams and their surrounding ecosystems, the dependence on salmon is key to their existence. If the salmon are gone, the dependent species around them are also at risk. Nutrients from salmon are critical to the health of countless regions or systems within this province and BC would not be the paradise it is without them. The good news is that salmon can and are adapting to these changes if we do not get too far ahead of them. Nature does find a way, and if we continue to recognize, protect, and mitigate impacts at the local level we still have hope in protecting our finned friends.
As salmon allies concerned about climate change, we do have tools to help our streams:
Stay out of waterways during the late summer/fall when adults are migrating, and fall/winter while the eggs are in the gravel and sensitive to people and animals being in waterways.
Stop the removal of gravel from streambeds.
Plant and protect native plant species along the shores of our waterways and limit livestock from grazing or animals from entering/ playing in streams when salmon are present.
Preventing pollutants from entering drains or streams and advocating for policies that protect local ecosystems and our water systems
Gillian Steele works for the Department of Fisheries and Oceans Canada within the Salmon Enhancement Program. Her position is Community Advisor, and her role is working with community stewardship groups as a liaison, providing operational support, education, and engagement with small hatcheries or volunteer groups.
