“It’s not an exact science” is a phrase we throw around jokingly in the non-scientific world. We might use that phrase in the context of building a boat or trouble-shooting an engine. But what if an influential scientific report proves to be not so exact?
In 2007, a report from the journal Science stated that overfishing of sharks increased the cownose ray population which, in turn, decimated the oyster, scallop, and clam populations on the East Coast in a top-down “community restructuring” scenario. This study led to campaigns in Maryland and Virginia to promote ray fishing with the slogan “Save the Bay, Eat a Ray.” Last year, a bow-fishing tournament came into the media spotlight with its viral video footage of rays being shot at close range and beaten by fishermen (many of whom reportedly did not consume the rays); it provoked heated talk about rays and fisheries management.
Rona Kobell from the Bay Journal recently brought to light a new Scientific Reports study countering the nine-year-old study that placed blame on the rays. The author of the new study, Florida State University’s Dean Grubbs and his colleagues, claim that the 2007 study exaggerated both the shark decline and “the ability of cownose rays to reproduce enough to devastate shellfish populations,” writes Kobell.
“Rays mature slowly and do not reproduce until age six or seven. Females produce only one pup a year, in a live birth. Furthermore, Grubbs said, oysters declined long before sharks, victims of disease, over-harvesting, over-sedimentation, and habitat loss.”
Grubbs and colleagues hope that the new study will result in responsible fisheries regulation and harvest limits for this species with such low reproductive rates and “evidence-based management decisions” to prevent overfishing.
Last year’s much talked about video prompted Virginia, Maryland, and the Chesapeake Bay Program to review how to manage Chesapeake cownose ray fishing. They have not announced decisions yet.
More Resources:
Cownose rays not to blame for shellfish declines, study says by Rona Kobell, Bay Journal
2007 study: Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean, Science
2016 study: Critical assessment and ramifications of a purported marine trophic cascade, Scientific Reports
Monday, March 28, 2016 - 12:00
“It’s not an exact science” is a phrase we throw around jokingly in the non-scientific world. We might use that phrase in the context of building a boat or trouble-shooting an engine. But what if an influential scientific report proves to be not so exact?
In 2007, a report from the journal Science stated that overfishing of sharks increased the cownose ray population which, in turn, decimated the oyster, scallop, and clam populations on the East Coast in a top-down “community restructuring” scenario. This study led to campaigns in Maryland and Virginia to promote ray fishing with the slogan “Save the Bay, Eat a Ray.” Last year, a bow-fishing tournament came into the media spotlight with its viral video footage of rays being shot at close range and beaten by fishermen (many of whom reportedly did not consume the rays); it provoked heated talk about rays and fisheries management.
Rona Kobell from the Bay Journal recently brought to light a new Scientific Reports study countering the nine-year-old study that placed blame on the rays. The author of the new study, Florida State University’s Dean Grubbs and his colleagues, claim that the 2007 study exaggerated both the shark decline and “the ability of cownose rays to reproduce enough to devastate shellfish populations,” writes Kobell.
“Rays mature slowly and do not reproduce until age six or seven. Females produce only one pup a year, in a live birth. Furthermore, Grubbs said, oysters declined long before sharks, victims of disease, over-harvesting, over-sedimentation, and habitat loss.”
Grubbs and colleagues hope that the new study will result in responsible fisheries regulation and harvest limits for this species with such low reproductive rates and “evidence-based management decisions” to prevent overfishing.
Last year’s much talked about video prompted Virginia, Maryland, and the Chesapeake Bay Program to review how to manage Chesapeake cownose ray fishing. They have not announced decisions yet.
More Resources:
Cownose rays not to blame for shellfish declines, study says by Rona Kobell, Bay Journal
2007 study: Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean, Science
2016 study: Critical assessment and ramifications of a purported marine trophic cascade, Scientific Reports