Ten surprising facts about California sea otters – Sonoma County Gazette

Stuff you otter know as we celebrate National Sea Otter day in Sonoma County May 29.
May 29 is National Sea Otter Day. Here’s a toast to our California sea otters and ten things you might not know about these playful critters.
Sea otters spend their entire lives in the ocean, managing all essential activities such as eating, sleeping, mating, and birthing in the water.
They consume up to 25% of their body weight daily, primarily feasting on sea urchins, crabs, mussels, and clams.
Sea otters are adept divers, able to hold their breath for over five minutes while foraging on the seabed.
Unique among marine mammals, sea otters use rocks to break open tough shells and store these tools in a skin pouch under their arms.
With around 1 million hairs per square inch, sea otters have the densest fur in the animal kingdom, essential for insulation as they lack blubber.
They dedicate several hours each day to grooming, maintaining their fur’s insulating and buoyant properties.
To avoid drifting apart while sleeping, sea otters may wrap themselves in kelp or hold paws, forming large groups known as rafts.
As a keystone species, sea otters help maintain the balance of kelp forests by preying on sea urchins, thus supporting diverse marine life.
Once nearly extinct due to fur hunting, sea otters are now protected but remain endangered.
Thriving sea otter populations signal healthy coastal habitats.
We don’t see a lot of these critters north of San Mateo county, but some adventurous explorers are beginning to repopulate the Sonoma coast.
The few sea otters observed in Sonoma County are “Southern Sea Otters” (Enhydra lutris nereis). These otters are a subspecies of the sea otter, primarily found along the central coast of California, from San Mateo County to Santa Barbara County. Although their historical range extended much farther, they now inhabit only about 13% of it due to past extensive hunting and other threats.
Southern sea otters are currently listed as a threatened species under the Endangered Species Act, facing ongoing threats from shark predation, habitat loss, and environmental changes​.
Sea otters are crucial to maintaining the health of coastal ecosystems. As a keystone species, they play a significant role in the balance of kelp forests, which are vital habitats for many marine organisms. Sea otters help control the population of purple sea urchins, which can devastate kelp forests if left unchecked. One of the otters’ favorite foods is sea urchin, and they can eat a lot of them.
Brock Dolman from Occidental Arts and Environment Center highlights the profound impact of their absence in the past due to hunting and recent ecological challenges: “Sea otter is well known to be a keystone species in our nearshore areas, especially in our kelp forest zones… the loss of sea otters so long ago with the Russian trappers… allowed the purple urchins to grow out of balance and eat all of the kelp, creating these kelp barrens.”
Sea otters can be recolonized in estuaries, which provide high-quality habitats, ample food, limited predators, and protected haul-out opportunities.
Despite their increasing numbers, from a historic low of about 50 to several thousand, sea otters still face numerous threats. Predation by sharks, vulnerability to oil spills and chemical contaminants, loss of habitat due to coastal development, and the effects of climate change like warmer seas and acidification, disrupt their food sources and habitat. Human activities also pose significant risks, with dangers such as fishing gear entanglement and disturbances from human interaction leading to problematic behaviors.
The kelp forests need the sea otters. The fishery needs the kelp. The importance of kelp forests cannot be overstated, as they provide shelter and food for local marine life, which is crucial for the fishing industry. Conservation strategies in place include the creation of marine protected areas, strengthened laws and policies to reduce pollution, and dedicated facilities for the rescue and rehabilitation of injured or sick sea otters. Public education programs also play a vital role in raising awareness about the importance of sea otters in maintaining the health of marine ecosystems.
Local fishermen have mixed feelings about the reintroduction of sea otters. Dick Ogg, a fisherman from Bodega Bay, encapsulates this concern: “They’re cute, the sea otters, but they are going to eat whatever they can get their hands on.” The potential for sea otters to impact local fisheries is significant, as their diet includes several commercially valuable species.
Scientists point out that sea otter recovery in California does not negatively impact the Dungeness crab fishery, as crab is less than 2% of their total diet.
The California State Coastal Conservancy is proactive in supporting the recovery of the southern sea otter through grants and funding opportunities. These initiatives aim to improve the nearshore ecosystem and explore the feasibility of sea otter reintroduction as a potential recovery strategy.

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