Biology Reference
In-Depth Information
the oyster beds, such sturdy substrates are in short supply. The nooks and
crannies among and between oyster shells offer young crabs and fish
places to hide. Because some oyster species grow on top of one another,
they form shallow reefs that dampen wave action and reduce shoreline
erosion.
Olympia Oysters once played a major role in keeping bay waters clear and filled
with the light eelgrass needs to grow. One oyster can filter 30 liters of water per
hour. Scientists are analyzing oyster restoration opportunities in the bay by experi-
menting with hanging various substrates in the water and building new reefs, then
observing how many settle down and grow. (Jude Stalker)
In 2001, groups such as Save the Bay began assessing whether enough
wild oysters remained in the bay to replenish themselves, given the op-
portunity. They began by hanging out strings of clean Pacific Oyster shells
of bay piers, to see whether oyster spawn drawn to the chemical signal of
the shells might settle down. Resembling marine-themed Christmas tree
decor, these shell strings attracted a strong showing of infant Olympias in
places like Marin's Richardson Bay. Other efforts—ranging from stakes
topped with oyster shell clusters to bags of clean oyster shells stacked in
mounds and linear reefs—all drew baby oysters but proved very labor-in-
tensive.
Now scientists are exploring the idea of building temporary oyster
reefs. One idea is to coat squares of burlap with a mixture dubbed “sea-
ment”—pulverized fossil oyster shells mixed with bay sediments and small
amounts of Portland cement. The shells might help attract oyster spawn,
