Ocean Creatures

by Carol Georgi

Hello Ocean Lovers Every Other Breath is From the Ocean
Here are some critters from our San Luis Obispo County coastal waters for you to enjoy
Thank you for your interest in the Central Coast Extension of the Monterey Bay National Marine Sanctuary.
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Western Gull Larus occidentalis

The Western Gulls have a small population along the west coast of North America, and they are often seen as common local birds living in coastal waters on the Pacific coast from British Columbia to Baja. These gulls have spectacular white plumage with a dark slate-gray mantle and grow to about 24-35 inches (61-70 cm). These gulls are commonly seen on wharves, jetties and docks.

The Western Gull's diet consists of fish, marine invertebrates, carrion, refuse, small mammals and both eggs and young of other birds. They catch fish by diving or wading. They feed largely on small, surface-feeding fish of no use to sport fishermen, and are often seen following fishing boats, commonly feeding on scraps thrown overboard by fish cleaners.

To break open the shells of their prey—like sea urchins and clams—Western Gulls drop them from high in the air to hard surfaces below. They also harass cormorants and pelicans, forcing them to regurgitate their catch, which the gulls quickly gobble up.

The gulls are subject to contaminants in their food, especially when eating human refuse. Feeding gulls or any other birds your picnic or snack leftovers is harmful to the birds’ health. Western Gulls feed on refuse only when natural prey is scarce. Birds that feed on refuse sometimes have lower breeding success.

Black Oystercatcher Haematopus bachmani

The Black Oystercatcher is a brownish black bird with a long, bright-red beak, large pink feet and yellow eyes. This coastal bird forages along rocky shorelines at low tide, looking for molluscs—mostly limpets and mussels and seldom eats oysters.The long, bright-red beak is useful in eating bivalves, because, like limpets and mussels, they have a strong muscle that holds the two shells tightly together—yet an oystercatcher can easily and quickly pry them open. The birds also sneak up on open mussels, quickly stab their beaks between the shells, sever the muscle, shake the mussel free and swallow it.

With sharp jabs of their bill tips, oystercatchers dislodge limpets and chitons from rocks, turn them over and eat the soft tissue. Breeding pairs of Black Oystercatcher make their nests by tossing rock flakes, pebbles or shell fragments toward their nest bowl with a sideways or backward flip of their bills. These nesting sites are above the high tide level and are used year after year. Since oystercatchers breed and forage near the shoreline, they’re highly vulnerable to oil spills.

(Photographers note on Black Oystercatcher image: "We don't really get an idea of what "laterally compressed" or "chisel-shaped" means in regard to the Oystercatcher's bill until we see the bird head on, as here. Shots like this suffer from lack of depth of field, but it does show the bill pretty well.")

Submitted by Carol Georgi, Volunteer Santa Lucia Sierra Club, Slo Surf Rider, Save Our Seas

Images and information provided by the Central Coast Extension of the Monterey Bay National Marine Sanctuary. Unless otherwise indicated, photos are by Terry Lilley with Sue Sloan doing the lighting. Terry is sharing his photos to encourage interest in the marine sanctuary effort.