Harvests of marine-spawning fish, which depend on the ocean rather thatn the Bay, are relatively good. Shellfish harvests remain at all-time lows due to poor reproduction and larval survival rates, plus increased demand and harvesting, weather, and disease. Crab harvests remain variable but high. Temperatures of Bay waters fluctuate greatly, from 0 deg. The Bay's salinity levels vary, are graduated vertically and horizontally due to freshwater flows, and are higher along the Bay's easter shore.
Salinity generally reaches a yearly low in the spring.
Freshwater flows drive most circulation in the Bay and tidal tributaries. The opposing movement of these two wedges affects circulation. It enters Bay waters from the atmosphere and as a byproduct of plankton and aquatic plant photosyntheses. Surface water is at or near saturation all year, while deep bottom waters go from saturation to nearly zero.