September 12, 2018 — In the early 1980s, a group of recreational fishermen dropping lines near the Hiram M. Chittenden Locks in Ballard, Washington, started complaining about a particularly large and wily California sea lion.
The shore anglers had good reason to be annoyed. Each time they hooked a fish, this sea lion would pop up and eat it off their line.
The sea lion, nicknamed Herschel by the fishermen, quickly moved on from taking fish off lines to gobbling up steelhead as they tried to make it over the ladder south of the locks. Here, water sluices down stair-stepped pools and migrating fish jump from pool to pool until they reach the Lake Union Ship Canal and spawning grounds beyond. Herschel found that by hanging out under the fish ladder he could gorge himself on steelhead trying to make it upstream.
Over the next few years, it became apparent that Herschel and a handful of other large male sea lions were seriously depleting the winter steelhead run, putting the population that spawns in Lake Washington’s tributaries at risk of extinction.
California sea lions spend part of the year at breeding sites on the Channel Islands. The bulls that feed at the bottom of fish ladders, where salmon practically swim down their gullets, have a distinct advantage in their battles for mates and territory.