A Report to the Oyster Industry of Virginia on the Biology and Management of the Cownose Ray ('Rhinoptera bonasus', Mitchill) in Lower Chesapeake Bay

摘要

In recent years (1972-1977) several Rappahannock River oyster growers reported substantial losses to seed and harvestable beds due to cownose ray predation. Concurrently, feeding cownose rays were observed to have a detrimental impact on eelgrass beds. The destruction of eelgrass habitat by rays is often considerable, resulting in reduced biological productivity of shoal areas, reduced sediment stability and localized erosion. The purpose of this report is to suggest reasons for the recently observed cownose ray predation on Rappahannock River oyster beds and the apparent increased abundance of the ray, and recommend short- and long-term methods to control and/or manage cownose ray predation on commercially important shellfish beds.