Simply put, it promotes the consumption of plants or animals that are having a detrimental effect on native wildlife and habitats – thereby also supporting their decline in affected areas. It’s the reason you see blue catfish tacos on restaurant menus, garlic mustard festivals and lionfish cookbooks.
In the Chesapeake Bay, a similar promotion launched a few years ago entitled, “Save the Bay, Eat a Ray.” At the time, an interpretation of scientific data pointed to a growing cownose ray population as a significant source of oyster population decline. Because fisheries managers and restoration experts were not only promoting but also dedicating a significant amount of resources to restoring native oyster populations in the bay, the cownose ray was labeled one of the bad guys, and they began implementing innovative population control techniques.
Two recent publications however have shed new light on our understanding of the predator-prey relationship between cownose rays and oysters and should make us take a second look at how we protect and support our aquatic food webs.
The first is a final report from a Cownose Ray Scientific Workshop (convened on October 15 right here at the National Aquarium). Experts on cownose ray biology gathered to discuss the current state of knowledge of this species in the Bay and how to determine the status of the population to inform future fisheries management. The workshop’s findings state that, while cownose rays have been known to consume oysters, these rays are not an invasive species and oysters are not considered a high percentage of their diet.
Therefore, reducing the number of rays is not an effective solution for oyster predation concerns. Furthermore, due to their migratory patterns, slow growth rates, low reproductive rates and long gestation periods, a Chesapeake Bay fishery for cownose rays is easily susceptible to overfishing.
The second recently-published paper took a critical look at our general understanding of aquatic food webs and, in particular, the long-held misconception that growing ray populations caused bivalve population declines in the Chesapeake Bay. Instead, the report states that bivalve populations decreased more than a decade before ray numbers increased and was most likely the result of pollution, disease, overfishing and habitat loss.
If we are really interested in restoring the Chesapeake Bay and building the population numbers of our native fish and shellfish, we need to take a broader look at the real issues affecting our species. That starts with clean water and healthy habitats.
There are more than 17 million residents of the Chesapeake Bay watershed with the power to make that happen through everyday actions. It is up to us.
This blog was written by our Director of Conservation, Laura Bankey. Click here to follow @LauraBankey on Twitter.