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Inhabitants of Oregon's Tidepools: Sea Lettuce

Nearly see-through, sea lettuce can seem to be extremely delicate.

Sea lettuce thrives on the upper beach, an area frequently exposed to air and hot sun. Their thin blades can get quite warm and a bit dry and stiff at low tide, especially in the summer. But sea lettuces are amazingly resilient: they’ll usually rehydrate and recover when the tide returns.Smooth, ultra thin, and bright green, delicate sea lettuce covers the rocks in the upper intertidal.  Two major shapes of sea lettuce are found on Oregon shores:  broad (usually about the size of your palm or your whole hand) and narrow (usually about the size of your finger).  Although sea lettuce starts out flat, it gently ruffles as it grows; older specimens often sport small holes and tears.  Wet sea lettuce can look like limp cellophane cast about the beach—only much more slippery.  Dry sea lettuce is pale green to dull brown and stiff, tightly papering the rocks.

And what if it rains at low tide? Or if it freezes? Sea lettuce is also remarkably tolerant of exposure to fresh water and to cold.

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