This week on Moir’s Environmental Dialogues, Rob sits down with interns Dorothy and Dan to discuss what we are doing to save Atlantic herring in regards to the New England Fishery Management Council’s upcoming decision to implement ecosystem-based management. .
We are calling on the Council to go with their alternative that keeps the large mid-water trawlers fifty or more miles offshore. This is a good conservation practice because river herring mix with Atlantic herring in the inshore waters. Smaller fishing boats and fishing weirs operate in inshore waters. (For more information tune into Rob’s radio show: Fishing weirs and cooperative research with fishermen)
River and Atlantic herring are closely related, but have very different life-cycles, as river herring (alewife, blueback, and shad) swim up freshwater rivers to spawn, while Atlantic herring never leave the ocean.
Atlantic herring are silvery fish with blue-green backs that can grow up to 14 inches in length. They spawn August through November, and a school of Atlantic herring can produce so many eggs that they cover the ocean floor in a dense carpet of eggs several centimeters thick. As eggs, they are prey for many bottom-dwelling fish, and as juveniles they feed larger fish, sharks, marine mammals, and seabirds.
Alewife are smaller than Atlantic herring. They swim upstream to spawn in the spring and spend most of their lives in the ocean. Blueback herring, are often larger, with smaller eyes and thinner bodies. Bluebacks usually spawn later in the spring than Alewife. They are pickier eaters and lay their eggs in faster moving water than do Alewife. Bluebacks inhabit fewer rivers, mostly south of Cape Cod. Thus blueback herring are in more danger of extinction and probably should be classified as a threatened species. Shad are the largest of the river herring, reaching up to a foot and a half in length. Shad school as juveniles in rivers and only enter the ocean later as adults.
All three species of river herring like to school with the Atlantic herring at sea. This means that fishermen trawling for Atlantic herring may catch river herring. Because all herring look similar and because the market does not differentiate between species, fishermen can not fish for just Atlantic herring unless they are regulated to fish further offshore were only Atlantic herring dwell.
Bycatch is a big problem, especially when hotspots are fished. Hotspots are ecological oases in the ocean where large diversities of endemic species congregate. The large schools make these areas a prime target for herring fishermen. It is impossible for them to avoid bycatch due to the many other species swimming in close proximity.
Amendment 8 could create a year-round buffer zone for midwater trawl gear that extends 50 miles offshore. This reduces the chances of river herring bycatch. The midwater trawlers catch a massive amount of herring compared to the smaller vessels that operate closer to shore. Having these trawlers operate further out at sea helps smaller vessels and weirs. This is good for coastal economics and sustainable for herring.