California sea lions face complex welfare challenges from fisheries entanglement, shootings by fishermen, and disease, alongside remarkable population recovery successes.
California sea lions face welfare threats from multiple anthropogenic sources. Entanglement in fishing gear causes injuries including deep lacerations from monofilament line that constrict and cut into flesh as animals grow, and drowning of entangled animals unable to surface. Illegal shooting causes traumatic injuries, sometimes resulting in deaths days or weeks later. Domoic acid poisoning from harmful algal blooms causes disorientation, seizures, and cardiovascular damage that are intensely distressing. Rehabilitation programs treating entangled and poisoned sea lions directly address individual welfare while also providing data on population-level threats. The complex management tensions between sea lion welfare and endangered salmon conservation create difficult decisions about acceptable welfare trade-offs.