While seeing a not insignificant year-over-year decline, the population of adult crabs in the Chesapeake Bay remains at sustainable levels and the crab population is not being overfished, according to new data.
Between 2019 and 2020, the abundance of adult female blue crabs in the Bay decreased 26 percent to 141 million based on a variety of factors, according to estimates released April 6 by the Chesapeake Bay Program.
“Despite the decrease, this number remains above the 70-million threshold which is considered a sustainable level,” the organization said in its annual “Bay Barometer” report.
According to the estimates, approximately 17 percent of female blue crabs were harvested in 2019, the most recent year for which data are available. That figure is well below the rate of 34 percent that would be considered overfishing.
“The blue-crab stock in the Bay is not being depleted,” the organization said.
The annual report contains updates on a number of factors related to overall Chesapeake Bay health, and “continues to show an ecosystem in recovery from short-term weather impacts and long-term water-quality degradation occurring from excess nutrients and sediment.”
Among some of the other findings, positive and negative:
• Thirty-eight percent of the Chesapeake Bay and its tidal tributaries met water-quality standards during the most recent assessment period, down 4 percent from the previous assessment.
• In 2019, nearly 66,700 acres of underwater grasses were found in the Bay, down 38 percent from a year before. The target is 185,000 acres.
• Nearly 1.35 million acres of land in the Chesapeake Bay watershed has been permanently protected from development since 2010, bringing the total amount of land in that category to 9.2 million acres.
• In the decade ending in 2019, a total of nearly 200 boat ramps, fishing piers and other public-access sites were opened on or around the Bay, two-thirds of the way to the goal of 300 new access sites by 2025.
• Conservation practices to reduce pollution are in place that will achieve 39 percent of planned nitrogen reductions, 49 percent of phosphorus reductions and 100 percent of sediment reductions needed to hit water-quality goals.
“Determining the health of the Chesapeake Bay is as complex as the ecosystem itself,” noted the Chesapeake Bay Program, a regional partnership of governments, academic institutions and non-governmental groups that works to direct the restoration and protection of the Bay.
The organization noted that record rainfall in 2018 continued to impact Bay health in 2019 and 2020. Increasing human encroachment also plays a role.
“As the population of the watershed grows, urban and suburban development can fragment habitat, harden shorelines, increase impervious surfaces and push pollution into rivers and streams,” the organization’s report noted.