Maryland Researchers Test Heat-Resistant Clam Breeding

The project aims to re-establish a local soft-shell clam industry after decades of decline in the Chesapeake Bay.

Updated on Oct. 29, 2026 in Environmental

Bold flat-color editorial illustration of a wire-mesh tray containing stylized shell fragments, representing aquaculture research. — Researchers at Morgan State University are utilizing selective breeding to reintroduce heat-resistant soft-shell clam aquaculture to Maryland’s Chesapeake Bay. AI Illustration. Upload story photo >

Live Poll

Do you support local efforts to expand aquaculture to protect regional industries from environmental change?

Researchers at Morgan State University are testing selective breeding to reintroduce soft-shell clam aquaculture to the Chesapeake Bay. This research-stage project aims to overcome high mortality rates caused by rising water temperatures that have historically decimated local stocks.

Why it matters

Maryland growers require a secondary aquaculture option to maintain business resilience as oyster production faces ongoing threats from disease and salinity fluctuations. The effort seeks to revive a fishery that largely disappeared from the region following the 1970s.

Lab-bred clams exhibit a lethal temperature threshold of 84 degrees. Future trials aim to scale operations to 100 seeds per mat, an increase from the 40 seeds utilized in previous configurations.

The players

Morgan State University

A public research university operating the Patuxent Environmental and Aquatic Research Laboratory.

Patuxent Environmental and Aquatic Research Laboratory

A research facility conducting studies on aquatic species and environmental stressors in the Chesapeake Bay.

The details

Researchers use selective breeding to isolate genes that confer tolerance to warming water conditions. To mitigate heat stress, scientists also employ protective shading by planting seeds beneath nets with oyster shells woven into the strands. This method provides physical cover for the juvenile clams, which are intended to reach a market size of 2 inches within one year.

Commercial wild clam fisheries in the Bay largely disappeared in the 1970s.
Last year, a trial of 350 adult clams resulted in total mortality during a summer heat wave.
In June and July, researchers tested planting clam seeds beneath shaded nets.
In early October 2026, researchers assessed the results of the net trial.

The Tech Race

This project seeks to challenge the dominance of Maine, which currently accounts for 60% of the U.S. soft-shell clam supply. By developing heat-resistant strains, Maryland researchers aim to establish a viable competitor in the mid-Atlantic market.

This research remains in the experimental stage and is not currently available for commercial application. If successful, the program could eventually provide local oyster farmers in St. Mary's County with a secondary, climate-resilient crop for their operations.

The takeaway

While heat-tolerant genetics show promise for juvenile survival, growers must watch for future trials to see if adult clams can reach maturity without total loss. Establishing a consistent cultivation method is the next hurdle for expanding this nascent industry in Maryland.