Dozens of bird corpses wash up on Monterey beach, California

Birds recently began washing up on Monterey Municipal Beach.

Over the past few days, the tide has brought in more than just kelp.

Recently, observant beachgoers have reported dozens of bird corpses along the high-water mark of several local beaches. On Wednesday morning, there were over four dozen dead seabirds along a 1.5-mile stretch of Monterey Municipal Beach, including Cassin's auklets, western grebes, northern fulmars and murres.

Seabirds can die during fall migration if they are too old, weak or malnourished. Also, warm near-shore waters may have decreased local populations of krill, a common food for seabirds, according to Raphael Kudela, professor of ocean sciences at UC Santa Cruz. Occasional algal blooms can also kill seabirds.

The causes of death of the birds spotted Wednesday were not known. But, dead seabirds are not an unusual feature of Monterey-area shorelines during autumn, experts with the Audubon Society and the Monterey County chapter of the Society for the Prevention of Cruelty to Animals said.

"This appears to be one of those things that can happen every year around this time," said Jessica Shipman, a spokeswoman with the Monterey County SPCA.