Pelagic red crabs seek warm shallow water to spawn. They are an indicator of el nino conditions, but ignore the people whining about radiation from japan or climate change.
this is a natural occurance every summer, though more noticeable during strong el nino conditions. They normally stay south of san diego, as our waters are normally too cold for them, but the warmth has allowed them to migrate up to socal.
just got back from 7 day trip omn excel and stopped and fish cedros for an afternoon and that place was full of red crabs. we went as far south as the ridge and i saw them everywhere. havent seen it this thick before. and they look like crawdads to me too