California sea otters face ongoing welfare threats from Toxoplasma gondii infection originating from land-based cat feces, pollution bioaccumulation, and the continuing recovery from historical near-extinction.
Sea otter welfare is affected by a constellation of threats that reflect the interconnection between terrestrial and marine ecosystems. Toxoplasma infection from domestic and feral cat feces illustrates how land-based animal management decisions directly affect marine wildlife welfare: responsible cat ownership including indoor keeping and proper waste disposal reduces the coastal T. gondii burden that kills sea otters. Pollution bioaccumulation demonstrates the welfare costs of chemical contamination at the ecosystem level. The sea otter population remains in a fragile recovery state where individual welfare events accumulate to affect population viability. Supporting the multiple aspects of sea otter welfare requires addressing land-based threats like cat management alongside marine threats like oil spill prevention and pollution reduction.