Spring 2023 waters in the Chesapeake Bay were marked by early warming, low freshwater flows, and above-average salinities. This may be good news for some Bay critters—but not for others.
Spring 2023 water temperatures in some areas of the Chesapeake Bay were warmer than average. This graph shows how on some days in April, water temperatures were 5 degrees higher than average at the Potomac CBIBS buoy.
Following a winter that had warmer-than-average water temperatures, much of the Bay had an average spring for water temperatures. But some locations in the mid to upper Bay saw some periods with above-agerage water temperatures. This may have led some striped bass to spawn earlier in the spring than usual. Striped bass larvae feed on zooplankton. Whether zooplankton were available earlier in the season, to match potential earlier striped bass spawning, remains to be seen.
Warmer waters also spur growth and spawning of oysters in the Chesapeake Bay. In water temperatures of around 50 degrees, oysters start to feed again after being dormant over the winter. They start to spawn in water temperatures of around 60 degrees. The warm period in April may have initiated their feeding and growth earlier than usual. Oyster growth and survival may have been bolstered by higher-than-average salinity, too. But if salinity levels get too high, diseases can become more prevalent—potentially negating the other positive effects of saltier conditions.
For more information on spring 2023 conditions and how they may have affected living resources in the Chesapeake Bay, see the full spring 2023 scientific seasonal summary.