Stingrays are common residents in the Chesapeake Bay, particularly during the warmer months. This dynamic estuary, fed by numerous rivers and opening to the Atlantic Ocean, provides a seasonal habitat for these cartilaginous fish. Understanding their presence, migratory timing, and how to safely interact with them is important for anyone enjoying the Bay’s waters. This article details the specific species found in the Bay, their seasonal habits, and safety measures water enthusiasts should know.
Confirmation and Primary Species
The dominant stingray species found in the Chesapeake Bay is the Cownose Ray (Rhinoptera bonasus). This ray is easily recognized by its distinct diamond-shaped body, which can reach a wingspan of up to three feet in adult specimens. It gets its name from its uniquely indented snout, which resembles a cow’s nose, an adaptation for feeding on the bottom.
Their coloration is typically brown or olive-green on the top, allowing them to blend with the muddy or sandy bottom, with a white underside. Like all rays, they possess a long, whip-like tail that carries one or two venomous spines near the base. While the Cownose Ray is the most abundant, other species like the Southern Stingray (Dasyatis americana) are only occasional visitors to the lower portions of the Bay.
Seasonal Presence and Habitat
Cownose Rays are highly migratory, using the Chesapeake Bay as a seasonal nursery and mating ground. They typically arrive in the lower and middle Bay areas in late spring, around May or early June, when water temperatures begin to rise. Females use the shallow, protected tributaries of the Bay to give birth to a single live young, called a pup.
These rays prefer the warmer, shallower waters, often concentrating in areas with higher salinity, such as the mouth and mid-Bay region. The rays remain in the estuary throughout the summer, with mating occurring in June or July. As autumn approaches and water temperatures cool, the Cownose Rays begin their southward migration, leaving the Chesapeake Bay by late September or October for warmer wintering grounds off the coast of Florida.
Safety and Interaction
The Cownose Ray is not an aggressive animal and uses its venomous barb only as a defensive mechanism. A sting usually occurs when a swimmer or wader accidentally steps directly onto a ray that is resting, often partially buried in the sandy bottom of the shallow water. The spine, located at the base of the tail, is thrust upward to inflict a painful puncture wound and inject venom.
To prevent this accidental encounter, individuals should employ the “Stingray Shuffle” when wading in shallow, warm Bay waters. This technique involves shuffling or sliding the feet along the bottom instead of lifting them and stepping down. The shuffling motion creates vibrations and disturbs the sand, which alerts the ray to a person’s presence, prompting the animal to swim away before contact is made.
If a sting does occur, the immediate first aid protocol is to exit the water and soak the injured area in water as hot as can be tolerated, ideally between 104°F and 113°F. The heat helps neutralize the protein-based venom and reduce the pain; soaking is recommended for 30 to 90 minutes. After the pain subsides, gently clean the wound with soap and fresh water, but do not attempt to remove any deeply embedded barb fragments. Medical attention is necessary to ensure the wound is properly cleaned, check for retained spine pieces, and assess the need for a tetanus booster or antibiotics.
Ecological Role in the Bay
The Cownose Ray plays a distinct role in the Chesapeake Bay food web as a benthic predator, meaning it feeds on organisms living on or in the bottom sediment. Their diet is primarily composed of hard-shelled, or durophagous, prey, which they crush using powerful dental plates. The main food items include thin-shelled bivalves and crustaceans, such as softshell clams, macoma clams, and razor clams.
They locate their prey by flapping their pectoral fins against the bottom, uncovering buried shellfish, and using electroreception to sense their presence. While they are opportunistic feeders that consume commercially important oysters and hard clams, studies suggest these species do not constitute a significant portion of their natural diet. Intensive feeding on oysters is generally localized to specific areas, such as commercial aquaculture sites.