Researchers in Maryland measure juvenile menhaden abundance by casting nets and recording the percentage of hauls with menhaden present. These are called “positive hauls.” The 2010 data show that menhaden were caught in 25 percent of the hauls
Menhaden play an important ecological role in the Bay. They are food for top predators such as striped bass and they filter the water while feeding.
The menhaden stock is managed under the Atlantic States Marine Fisheries Commission (ASMFC) using abundance targets and thresholds. In 2006, the ASMFC placed a cap of 109,020 metric tons on commercial menhaden harvest from the Bay. A coast-wide stock assessment was completed in 2009.
There is no specific Chesapeake Bay target for menhaden because there is no estimate of the menhaden population in the Bay.
Long-term trend (1959-2010)
After a decade of record high abundance beginning in the mid 1970s and a sharp decline through the 1990s, juvenile menhaden abundance in Maryland has stabilized at a level below the long-term average. Between 1959 and 2009, the proportion of positive hauls (PPH) decreased from 24 to 22.
The long-term trend has been inconsistent.
Short-term trend (10-year trend, 2001-2010)
The current 10-year trend shows that juvenile menhaden abundance in Maryland (as measured by PPH) has stabilized, although at a level lower than the long-term average.
Change from previous year (2009-2010)
Increased from 22 PPH to 25 PPH.
The menhaden stock assessment concluded that the stock is not overfished relative to biological reference points that are set to ensure its sustainability. However, scientists are concerned that Atlantic menhaden abundance in Chesapeake Bay may be declining, at least relative to the ecological demand for menhaden as a forage fish and filter feeder.
In 2006, Virginia placed a cap on the amount of menhaden that the commercial fishing industry can annually harvest from the Bay. Maryland currently prohibits the commercial industry from harvesting menhaden from its waters.
Since menhaden are an important forage species in the Bay food web, a number of studies are underway to assess their status in the Bay.
Atlantic Menhaden Historic Population Trends
Atlantic menhaden stocks were drastically reduced in the 1960s, leading to the closure of many menhaden reduction factories. As population size decreased, the age structure also changed. Fish older than age 3 were scarce or non-existent in many areas along the Atlantic coast.
The population began to recover in the early 1970s, and catches continued to improve into the early 1980s.
National Oceanic and Atmospheric Administration (NOAA)