Nature Watch: The Beach Buffet

About the author: Steve Ellis is a naturalist and Land Trust member who enjoys sharing his love of the natural world. His blog series, “Nature Watch,” will appear each month in “Habitchat,” chronicling native plants and wildlife you can expect to see during that particular time of year. We thank Steve for sharing his passion, illustrating the importance of island conservation.

Overview

Winter is a difficult time of year for a naturalist wanting to explore beaches at low tide. Beyond coping with the blowing rain is the problem of timing: winter’s low tides happen at night.

By late February, a few low tides occur during the daylight hours. Beach watching can be particularly rewarding this month not only because of the presence of ambient light. There’s still the possibility of storms bringing fresh material to the beachscape.

Veteran beachcombers know to walk the strand line, the area where the most recent high tide reached the farthest up the beach. When the water retreats, it leaves material along the strand line. I call these leavings “the beach buffet” for the variety of life in and on the debris. All sorts of food opportunities are lined up for exploitation.

Small crabs hiding under nearby rocks come out to feed on the detritus found on stranded kelp, while other invertebrates work through the algae, plants and driftwood. This results in nutrients being returned to the sea.

Some creatures to watch for are beach hoppers, kelp flies and beetles. These are sought out by shorebirds such as turnstones and sandpipers and even passerines like robins, working the buffet line to feast on the invertebrates. The chain doesn’t end there; falcons are a daily threat and are quite skilled at taking plump sandpipers.

Another animal attracted to the buffet is the raccoon, often leaving its distinctive tracks in the sand or mud.

Cruising cutthroat trout snap up larger invertebrate specimens when the tide is in. The trout leave no tracks but they may make their presence known by leaping from the water.

Many types of shells are mixed in with strand line detritus, the species corresponding with the particular beach substrate. Rocky beaches feature mussels, limpets, whelks, top snails and tiny periwinkles. Cockles, gapers and tellins, along with butter and littleneck clams are found on sandy and mud beaches.

You may come across a clam with a round hole in its shell. This is evidence of predation by a moon snail, large gastropods (the word means stomach-footed) that drill into their victims in order to gain a meal. A mussel or barnacle with a hole was probably attacked by a whelk, which is a type of sea snail. There are several whelk species along these island shores, and their empty shells often become homes for hermit crabs.

These islands have a number of beach access points. In addition to state and county parks, there are several Whidbey Camano Land Trust properties with beach access. The Land Trust’s website has an interactive map that will lead you to a beach buffet.

Eelgrass by Martha Ellis.

Flora: Eelgrass (Zostera marina & japonica)

Eelgrass beds are one of the most significant habitats in offshore waters.

The dull green leaves of eelgrass can be just a quarter of an inch wide and reach a length of 10 feet. Male pollen-bearing flowers and female seed-producing flowers grow on separate plants. Careful observation will reveal yellowish, more rounded leaves among the more numerous flat stems. These are the reproductive leaves. Pollination is accomplished underwater and seed capsules are formed. These eventually break away and seeds are pushed by currents to new areas. Most reproduction, however, is through the spreading of rhizomes in the substrate.

A list of organisms that shelter in eelgrass would fill several pages. Invertebrates range from jellyfish, snails, nudibranchs, anemones, sea slugs and shrimp to clams and sea stars.

Many fish also inhabit eelgrass including sculpins, gunnels, sticklebacks and the bizarre bay pipefish. The latter hides among the leaves and sways its elongated body in rhythm with the eelgrass.

Pacific herring adhere their eggs to eelgrass leaves during their spawning season, and juvenile salmon – recently arrived from their natal rivers – hide in the beds.

The two species of eelgrass grow in the intertidal zone and are only exposed by very low tides. The beds do best in the sand or mud of protected bays.

Eelgrass beds have contracted around many parts of Island County. You can help by not anchoring your boat in a bed. Anchors can create open patches when dragged through the mud.

Look for ribbons of eelgrass as you next walk a strand line. Many beds are located in the more protected places around our islands.

Northern Sea Lion. Photo by Jill Hein.

Fauna: Northern Sea Lion (Eumetopia jubetus), a.k.a Steller’s Sea Lion

A person looking seaward from a beach may be startled to find a large creature staring back. I once was leading a birding field trip when a line of eight or nine sea lions came to look us over. Each of them was three times the size of the average harbor seal.

Northern sea lions are the largest member of the eared seal family in this region. The only pinniped (seals, sea lions, elephant seals and walrus) here that is bigger is the titanic northern elephant seal.

Bull northern sea lions may be nearly four times the weight of females. They have huge necks and a mane of dense fur. A large bull can be 12 feet in length and weigh up to 2,500 pounds. Females average 600 pounds.

The bodies of northern sea lions are blond-colored with dark brown flippers and underbellies. They keep a pale tan color when wet.

Individuals seen off these beaches come from a breeding colony near Vancouver Island. Pups are born there in summer.

Fish and squid are the mainstay of their diet. Sculpin, hake, herring, skate, rockfish, lamprey and salmon are some of the species taken. To catch their prey, dives to 1,600 feet have been recorded. These remarkable mammals can hold their breath for 15 minutes.

Northern sea lions can be found off many local beaches. Perhaps the most reliable spot is the lane buoy off Fort Ebey State Park. Binoculars or a spotting scope will give you a good look at them as they’re hauled out on the buoy.

California sea lions are sometimes confused with their larger cousins. Any sea lion in the waters surrounding the islands from April through August is a northern, as the Californias will be in their breeding colonies well south of here. Bull California sea lions have a prominent brow projecting over their face. Northerns are lighter in color than the brown Californias. The former roar, while the latter growl.

How fortunate we are to have these incredible mammals near us virtually year round! They are a sign the Salish Sea is healthy enough to support large life forms.

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