Diseases have plagued the bay oysters and harvests fell steadily during the 1980s. The harvest now is about 200,000 bushels per year. We think we could get back to something like a quarter or a third. Polluted runoff containing nitrogen and phosphorous has caused algae blooms in the bay, which block the sunlight needed for the growth of sea grasses on the bay floor. The sea grasses serve as nurseries for crabs and fish.
Oysters feed on the algae, essentially cleaning the bay.
An adult oyster can filter about 50 gallons of water a day. When the oyster population in the bay was at its original density, the entire volume of the estuary could have been filtered in a few days. Now, the bay oysters can filter the entire bay in about a year.