The beloved fish that feed killer whales and humans depend on the unique sea otter kelp forests.
Threat to Kelp Forests Due to Climate Change
Kelp forests off the California coast have been suffering significant decline in recent years. This problem began in 2013 with the mysterious “blob” phenomenon. Elevated ocean temperatures led to the die-off of sea stars, which normally control the numbers of sea urchins. Sea urchins eat kelp. Thus, the “blob” phenomenon resulted in an explosion in sea urchin populations. These creatures embarked on a feeding frenzy that, according to some estimates, has cleared 96 percent of kelp from beneath the California coast.
Benefits of Kelp Forests
Kelp forests provide complex habitat for hundreds of species, including benthic invertebrates, small fish, and animals that exist on the food chain up to gray whales. Sea otters wrap their bodies in kelp to sleep without drifting away and wake up to breakfast as soon as they catch it with their forepaws.
Kelp forests reduce wave energy and create a physical refuge for marine life. They also store carbon in such large quantities that scientists refer to them as the “redwoods of the sea.”
Like terrestrial forests, kelp forests also enhance oxygen through photosynthesis and absorb carbon dioxide. In the ocean, this reduces acidification that threatens the most vulnerable marine animals.
Salmon Use of Kelp Forests
Salmon, considered a symbol of the Pacific Northwest, also utilize kelp forests. Fishermen had previously stated that this was the case, and Anne Shaffer, a marine biologist at the Coastal Watershed Institute in Washington, affirmed this. She has been studying kelp forests for over three decades.
A few years ago, she decided to prove it. I met her about 10 miles from her base in Port Angeles, Washington, on the shores of the Strait of Juan de Fuca. We headed to the mouth of the Hoh River, where Anne conducts some of her research on kelp forests.
More than 10 years ago, the Hoh River had two dams that blocked salmon from migrating. But now the river flows freely, and it has created new beaches and enriched underwater ecosystems as well.
Anne and her team, including undergraduate students, have conducted diving surveys for over seven years to determine who uses the kelp forest here.
She found that it varies seasonally. Her research, published this year, showed that several endangered salmon species, including Chinook, Coho, Chum, and pink salmon, definitely use kelp – in multiple ways.
Kelp forests provide shelter for young salmon and small fish as they migrate along the coast. They also provide a nursery ground for these animals to rest, feed, grow, and prepare to move to larger and different marine environments.
Specifically, certain types of living habitats that salmon found in kelp were different.
As they grow, salmon can also use kelp to ambush small fish.
Salmon are very important in the Pacific Northwest. Northwest tribes have had a practical and spiritual relationship with them for thousands of years. They feed people and populations of threatened killer whales. This genetically distinct group includes about 75 killer whales that only eat fish. These whales often struggle to find enough to eat in local waters.
If you live in the Pacific Northwest, you know that when it comes to killer whales and salmon, the law, government agencies, tribes, and many others pay close attention.
This is why it was essential for Anne to prove that salmon utilize kelp forests.
It was
There is already some interest dedicated to protecting the habitat of the sea dog for many other ways in which it is crucial, but now with the involvement of salmon, more people will pay attention to its protection.
Ann believes that there is a lot of research that needs to be done.
Ann says: “When I returned to Washington, I was really puzzled by the fact that no one was looking at the sea dog forests. People were largely looking at the seagrass at that time, and the sea dog was just a secondary idea. This is what really drove me to study this topic for a long time. Now things have really changed and people are starting to look at it, so now is really the right time.”
There are many ongoing studies. The Puget Sound Restoration Fund is currently running the most detailed sea dog forest monitoring program in the world. We hope that understanding the specific factors causing the variation in the health of sea dog forests here will help prevent what happened in California.
When I return to the rocky shore of Puget Sound at the end of fall, the sun encourages me to dive into the water with a temperature of 50 degrees Fahrenheit. As I glide over the surface of the sound, I imagine the forests below, with the sun shimmering on their brown-green blades, and fish and microorganisms settling into their tidal homes. I hope they remain healthy for everyone’s sake.
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