Sea Otters Help Restore Ecosystem Balance

A new study highlights how southern sea otters at the Elkhorn Slough National Estuarine Research Reserve in California are consuming 50,000–120,000 invasive green crabs annually, mitigating a significant ecological threat.

Key Points

Why Green Crabs Are a Problem: Native to Europe, green crabs arrived in North America in the 1800s through ship ballast water.
Since the late 1980s, they have damaged seagrass beds, outcompeted native species, and disrupted coastal ecosystems. Efforts to curb their proliferation had largely failed until now.
Comeback of Sea Otters: Once thought extinct, sea otters have rebounded due to conservation efforts. Currently, around 120 sea otters thrive at Elkhorn Slough, contributing to the ecosystem's restoration.
Sea Otters’ Unique Diet and Energy Needs: Unlike other marine mammals, sea otters lack blubber and rely on their high metabolism to stay warm, eating up to 25% of their body weight daily.
Their predation on green crabs and sea urchins helps maintain healthy seagrass beds and kelp forests, which are vital carbon sinks.
Wider Ecological Impact: By curbing sea urchin populations, sea otters also protect kelp forests, which play a crucial role in absorbing carbon dioxide and supporting marine biodiversity.