Text Size: A  A  A

Menhaden

Menhaden- This small, oily fish is a critical food source for many commercially and recreationally valuable predatory fish, including bluefish, weakfish and striped bass. (Brian Gratwicke/Wikimedia Commons)
{photos} {photo} {title} - {description} {/photo} {/photos}
This small, oily fish is a critical food source for many commercially and recreationally valuable predatory fish, including bluefish, weakfish and striped bass. (Brian Gratwicke/Wikimedia Commons)

Overview

Atlantic menhaden is an important fish species because it forms a critical link between the upper and lower levels of the Bay food web. While menhaden populations along the Atlantic coast appear to be healthy, there is concern about low regional abundance (also referred to as “localized depletion”), specifically in Chesapeake Bay. To prevent a possible future decline of this keystone species, a cap has been placed on the amount of menhaden that can be harvested from the Bay. In addition, scientists are currently studying the effects of predation and fishing on menhaden as part of a multi-species model of the coast-wide Atlantic menhaden stock.

Why are menhaden important?

Atlantic menhaden is a keystone species that forms a critical link between the lower and upper levels of the Bay food web. In addition, menhaden make up one of the oldest and largest commercial fisheries on the Atlantic coast.

Menhaden are vital to the food web

Atlantic menhaden are a significant link in the Bay food web. Like oysters, menhaden are filter feeders, grazing on algae and other planktonic organisms. This action helps cleanse the water of excess nutrients that contribute to the Bay's poor water quality.

In turn, the Bay's menhaden population is a key food supply for many commercially and recreationally valuable predatory fish, including bluefish, weakfish and striped bass. Fish-eating birds, such as ospreys and bald eagles, also rely on menhaden as a source of food.

Menhaden are economically important

The Bay's commercial Atlantic menhaden fishery is one of the most important and productive on the Atlantic coast. More pounds of menhaden are landed each year than any other fish in the Bay.

While this small, oily fish is not edible by humans, menhaden are used for a variety of other purposes, including:

  • Fish meal for poultry and livestock feed
  • Fish oil for foods, paints and cosmetics
  • Fertilizer
  • Bait for other fisheries

How is Atlantic menhaden harvested in the Bay?

Atlantic menhaden are typically caught using purse seines, then processed into oil or fish meal (called reduction). The Bay's major fishery and reduction industry for menhaden is located in the Virginia portion of the Chesapeake. Menhaden are also caught with pound nets in a bait fishery in the Potomac River and the Maryland portion of the Bay.

More pounds of menhaden are landed each year than any other fish in the Bay. Menhaden—along with blue crabs—have dominated the Bay's commercial fisheries during the past 60 years. In 2006, 376 million pounds of menhaden were caught in Maryland and Virginia waters (both Chesapeake Bay and Atlantic Ocean), valued at approximately $22.8 million.

Is the Bay's Atlantic menhaden population declining?

Chesapeake-specific population estimates for menhaden are not currently produced; estimates are only made for the entire Atlantic coast stock, which appears to be healthy. Still, scientists are concerned about what appears to be a low abundance of menhaden in the Bay, which is one of the fish's key nursery areas.

Fisheries-independent data from seine surveys in Maryland and Virginia through 2004 suggested that menhaden recruitment—the number of juveniles that grow to a “catchable” size—was possibly declining in the Bay. Coast-wide recruitment is considered to be at median historic levels.

The exact causes of the decline in recruitment remain unknown. While additional scientific knowledge is necessary to understand the variability of menhaden recruitment, scientists have cited several possible contributing factors, including:

  • Heavy fishing on the adult menhaden stock.
  • Possible increases in mortality by predators.
  • Changing environmental conditions, such as climate change or poor water quality, in menhaden nursery areas.

How would a decline in Atlantic menhaden affect the Bay?

The historical ecological functions of Atlantic menhaden may be diminished if populations decline in the Bay. Low menhaden abundance may create a reduced food supply for striped bass, bluefish, weakfish and other commercially and recreationally valuable predator species. Recent studies suggest that the Bay's striped bass are suffering from poor nutrition, which may be leading to slower growth rates and higher susceptibility to mycobacteriosis.

How is Atlantic menhaden managed?

The Atlantic menhaden fishery is managed by the Atlantic States Marine Fisheries Commission (ASMFC), which tracks and regulates how many menhaden are—and can be—caught each year, as defined in the ASMFC's Interstate Fishery Management Plan for Atlantic Menhaden.

In October 2006, the ASMFC approved Addendum III to Amendment 1 of the Interstate Fishery Management Plan for Atlantic Menhaden. Addendum III established a five-year annual cap of 109,020 metric tons—or approximately 240.3 million pounds—on menhaden reduction fishery harvests in the Bay. This harvest limit was based on the average landings from 2001-2005. The cap was implemented in 2006 and will extend through 2010.

In addition to the cap, a research program is being conducted to:

  • Determine menhaden abundance in the Bay.
  • Develop estimates of menhaden removal by predation.
  • Evaluate the rate of exchange of menhaden between the Bay and coastal systems.
  • Conduct larval studies to determine recruitment to the Bay.

Photos



 

Chesapeake Bay News

In The Headlines


Atlantic Menhaden Abundance

Atlantic menhaden are managed on a coastwide basis. Currently, Potomac River catch-per-unit effort (CPUE) data is used as a proxy for relative coastwide abundance. Catch-per-unit-effort is a measure of fishing success.


Publications

Suspension Feeders: A Workshop to Assess What We Know, Don't Know and Need to Know to Determine their Effects on Water Quality

Publication date: December 01, 2002 | Type of document: Report | Download: Electronic Version

Available in digital format and hardcopy. Phytoplankton standing stocks, production, and species composition are potentially influenced by both the supply of nutrients to the bottom of the food web and removal by suspension feeders higher…




From Around the Web

Bay FAQs

    Sorry no FAQs are currently available for this issue


 

Bay Terms

  • Filter feeder
  • Food chain/web
  • Keystone species
  • Predation
  • Prey

 

Bay-Friendly Tips

    Sorry no tips are currently available for this issue


 

410 Severn Avenue / Suite 112
Annapolis, Maryland 21403
Tel: (800) YOUR-BAY / Fax: (410) 267-5777
Directions to the Bay Program Office
Terms of Use | Privacy Policy
©2012 Chesapeake Bay Program | All Rights Reserved