Protecting Ocean Ecosystems
Protect Cashes Ledge, Protect Cod
The science is in and the survey says…Atlantic cod benefit from closed areas! Seems pretty self-explanatory, right? Fishing is prohibited in an area, so there will be more fish in that area. But, the Gulf of Maine Research Institute’s (GMRI) research show that closed areas don’t just promote cod populations, they are actually beneficial to the species’ overall health as well.
Since its closure in the early 2000s, Atlantic cod have benefited from protections of the Cashes Ledge Closed Area. Cashes Ledge is unique in that it hosts a resident cod population. This is in comparison to migrant cod that travel throughout the Gulf of Maine, as well as through Georges Bank, and are often the target of groundfishermen’s trawl nets. Researchers at GMRI have been able to study how the species vary inside and outside of a closed area.
The resident cod at Cashes Ledge are described as “red” cod, not your usual olive/brown cod. Although red cod are slightly smaller than olive cod, the cod within the closed areas proved to be fatter, larger, and more fecund (in the fish world, this means healthier).
In theory, a fatter and larger fish usually has had more time to grow, and the science showed just that: older cod were more plentiful inside the closed areas compared to outside.
In the Cashes Ledge Closed area, these old, fat fish are females. Larger female fish are proven to be productive than smaller ones and are essential to sustaining healthy fish populations. Since its fishing closure, the Cashes Ledge Closed Area has served as a refuge for these females and other large cod.
These protections yield benefits for fish populations throughout the Gulf of Maine as well. Dr. Jon Witman, Professor of Biology at Brown University said, “As the population builds up, it increases and spills over to other areas. So protection for Cashes is a win-win because it leads to higher populations in adjacent areas that can be fished even though the core area is protected from fishing.”
Further literature analysis shows that in order to be effective marine protected areas should be large and exist over a diversity of habitat types, isolated from heavy fishing areas. Research indicates that these conditions improve fish productivity due to the greater abundance of larger fish. While the Cashes Ledge Closed Area is certainly not an overly large area, Cashes Ledge possesses all the preconditions to be an effective protected area.
These benefits are originally the result of a proper fishery management decision. However, fishery closures do not stay closed forever, and we cannot gamble with the progress that has been made or the future of these fish populations. Now is the time to protect the Cashes Ledge Closed Area, from all types of commercial fishing, forever.