September is Coastal Cleanup Month, and as anyone who has ever participated in a cleanup event knows, fascinating things wash up on the local coastline among the bits of kelp, shards of glass and plastic and broken shells that are the usual detritus on the shore. Mermaid’s purses—the leathery egg cases of skates and small sharks are an amazing thing to find, so are drift seeds—plant seed pods that are long-distance travelers turning up on the beach after southern swell events and winter storms. 

 Kelp wrack, including a mussel shell and a tunicate—a strange animal that is surprisingly more closely related to mammals—both belong to the phylum Chordata—than it is to other marine invertebrates.
A mermaid’s purse is really the egg case of a species of skate. Each leathery pouch contains a single skate embryo. The tendrils at the corners of the case anchor it to the kelp it resembles, providing safety for its occupant. The empty purse washes up on the beach after the skate has hatched. Photo by Suzanne Guldimann

A colorful array of common finds include blue mussel shells, purple urchin spines, turquoise chiton shell segments, and coral-colored colonies of bryozoans that coating rocks and even attached to the kelp. One of the strangest things to wash up locally are oarfish, a sea-serpent-like fish from tropical waters. This ocean giant can grow to be 20 feet long, but only turns up once or twice a century, and usually its appearance is connected to El Niño weather conditions. Less pleasant discoveries include dead birds, fish, and marine mammals. A 40-foot-long juvenile fin whale, killed by a boat strike, caused a stink—literally and figuratively—when it washed up on the beach in Malibu in 2012. That tragic death led to calls for slowing speeds in the shipping lanes offshore. 

 It may look like a shard of glass, but this is the shell of a pteropod—a planktonic sea slug—known as sea butterfly. Photo by Suzanne Guldimann

When the tide and the wind align sometimes small transparent shells that resemble glass ornaments wash up the sand along local beaches. Easily mistaken for jellyfish or shards of glass at first glance, these delicate shells are made by several species of pteropod—planktonic sea slugs—known as sea butterflies.

Velella velella, the by-the-wind-sailor, is a small jellyfish-like Hydrozoan that floats on the surface of the water, carried by the wind over vast distances. It is one of the strangest looking things that turn up on local beaches. Photo by Suzanne Guldimann

There is another small glass-like animal that occasionally appears in large numbers: Velella velella. These raft-like colonies of hydrozoas have no means of self-propulsion and can only go where the currents and winds drive them. This explains their common name: by-the-wind sailor, and their Latin name, which is derived from the word vela, a ship’s sail. 

Velella lives its entire life on the surface of the water and appears to be a popular food item for some species of fish. According to a Monterey Bay Aquarium factsheet, “The angle of the sail may determine where they land. Those whose sails angle to the left are blown to our coast, while right-angled ones sail toward Japan.”

Raucous, beautiful royal terns are one of several local tern species. They came perilously close to extinction in the 19th century and are still not common in California, but they are regarded as a conservation success story, one that has made a strong comeback, despite the odds. Photo by Suzanne Guldimann

Although this year’s coastal clean up is a solo event, here’s a good chance you won’t be walking alone. This time of year, a host of birds make the beach their home, running ahead of human visitors, racing the tide in the hunt for kelp flies and sand crabs. 

The tiny sanderling races the waves to forage for invertebrates at the edge of the water. This charismatic bird has a distinctive cry that is part of the soundtrack of autumn on the beach. Photo by Suzanne Guldimann
 A Western gull takes advantage of low tide to eat a purple sea urchin, washed up on the beach. Photo by Suzanne Guldimann

Look for a variety of seabirds: California brown pelicans; Western, California, glaucous, ring-billed, and Heermann’s gulls; royal and elegant terns. There are also an abundance of shorebirds this time of year: marbled godwits—their long bills turn slightly upward; long-billed curlews—largest of all the shorebirds, with a huge curved bill and a sorrowful call; whimbrels, the curlew’s little cousin; and willets—smaller, grayer, and shorter-beaked. These larger birds are joined by sandpipers, turnstones, tattlers, plovers, and sanderlings.

The beach is a busy place in the fall and winter, once the summer crowds of humans have gone. That there is still room for such a spectacular variety of birds on popular local beaches and habitat to support them is one of the things that make this stretch of coast so special and so worth visiting and protecting.

Curlews, whimbrels and willets are the only company on this stretch of beach. September marks the end of summer beach crowds and the return of winter seabirds on local beaches. For solitude seekers, birdwatchers, and beachcombers, this is the start of the best time of the year. Photo by Suzanne Guldimann