According to reports from the National Oceanic and Atmospheric Administration (NOAA), 2021 ocean conditions were optimal for salmon and steelhead in the Pacific and should continue through this winter. During 2021, the Pacific Ocean off the US west coast exhibited cold, nutrient-rich waters, which is expected to benefit salmon and steelhead in those marine environments. These ocean conditions were a welcomed departure from recent periods of unprecedented bodies of warm water in the Pacific and will hopefully assist the salmon and steelhead in the PNW which experienced dismal 2021 returns–again, hopefully.
“There is certainly some optimism all along the West Coast and in the Columbia basin given the conditions we are seeing out in the ocean,” said Lance Hebdon, fisheries bureau chief for the Idaho Department of Fish and Game at Lewiston. “We hit the bottom a year or two ago and we may have a little breathing room in the future. The proof will be in adult returns,” per an Idaho Statesman article.
In 2014 and 2019, a marine heatwave, congenially named the ‘Blob,’ brought warm waters to the US west coast. These Blob periods experienced sea surface temps as much as 7 degrees above average and fueled “unprecedented ocean change,” according to NOAA. Among other impacts, the 2014 Blob shifted fish migration routes, decreased the quality of forage for juvenile salmon and steelhead, reduced the size and survival of salmon and steelhead, harmful algal blooms, and contributed to drought.
The 2014 Blob was the biggest marine-warming event ever recorded, but the 2019 blob was the second longest and largest. Thankfully, the 2019 Blob aggregation dissipated due to several well-timed storms. Still, these marine-warming events took a toll on wild salmon and steelhead returns–many of these runs’ sizes are fractions of what they once were. It’s worth noting that salmon and steelhead numbers are influenced by many factors. And while we as humans cannot actively control the weather, we can, to a degree, control salmon and steelhead habitat and how we interact with these fish.
So, let’s look at 2021 ocean conditions and what that might mean for salmon and steelhead on the west coast. A return to La Niña weather conditions with strong upwelling currents brought cold, nutrient-rich water to the coastline. This phenomenon can have cascading effects on marine food webs. According to NOAA, the 2021 ocean conditions were the second best over a 24-year dataset. Notably, the ocean conditions last year fueled the highest annual biomass of Northern Copepods in the time series. Northern Copepods are a type of plankton that contain high levels of lipids, “fatty compounds that appear essential to the growth and survival of many pelagic fishes.”
The 2021 ocean conditions were only second to 2008, a period where many steelheaders do recall stronger runs. And these conditions, should they persist, will likely have a notable impact on salmon and steelhead survival both in the ocean and during their migrations to spawn. Juvenile salmon and steelhead, particularly, stand to benefit a lot, as copepods are foundational to their diets and survival.