April 9, 2020 — New research suggests that large-scale environmental factors influence the size of one of the ocean’s most abundant forage species. Recently, scientists from LSU, NOAA, the University of Southern Mississippi and the University of Maryland Center for Environmental Science evaluated large-scale ecosystem dynamics influencing growth of menhaden in the Gulf of Mexico and the Atlantic Ocean. They found that anthropogenic influences affected menhaden in the Atlantic more than in the Gulf, where environmental factors were the more dominant predictors of growth.
Menhaden are used primarily for the production of fishmeal and fish oil, and small quantities are used for bait. According to NOAA’s 2018 Fisheries of the United States report, menhaden ranked number two by volume, after Alaska pollock, on the list of major U.S. domestic species “landed,” or caught and brought to port. More than 1.5 billion pounds of menhaden were landed in that year. Menhaden ranked number 10 by value of the landings, totaling more than $160 million. In addition to their commercial value, menhaden are critically important components of their food webs.
According to Steve Midway, lead author and assistant professor in LSU’s Department of Oceanography & Coastal Sciences, “They’re sort of the classic forage species—meaning they provide a really important link in marine food webs. They are not exerting any kind of population pressure on any other fish species because they’re not eating any other fish species. But, other fish species eat them. So, they support the higher levels of the food web and ecosystem.”