Of All the Fish in the Sea
The Importance of Menhaden
The Fish
Menhaden are an oily, bony fish that can grow up to 15 inches in length and live in schools of thousands. Those schools feed on algae and zooplankton by swimming around with gaping mouths, filtering out water in the process. A single menhaden can filter more than four gallons of water per minute. Like oysters and other filter feeders, they play a pivotal role in maintaining a clean, healthy ecosystem.
They can be found along the coasts of both North and South America, in several varieties. The North American species span from the Gulf of Mexico to Nova Scotia, while the South American species can be found on either side of the continent.
Click the buttons below for individual ranges.
Menhaden begin their lives adrift at sea. Mothers become sexually mature between ages two and three and can produce more than 300,000 eggs over the course of a year. The larvae hatch 20-30 miles offshore before being swept by the currents into estuaries along the coast. There, the juvenile fish can develop with plenty of food and protection among the shallow, brackish waters and surrounding salt marsh.
For Atlantic menhaden, the Chesapeake Bay is a crucial nursery for young fish. They thrive among its many estuaries throughout the first year of life before moving into the deeper waters of the bay and eventually out into open sea, where schools of menhaden migrate up and down the Atlantic coast in search food and pleasant weather.
Throughout all their stages of life, menhaden serve as a critical source of food for just about anything that can swallow them. Tuna, swordfish, striped bass, ospreys, eagles, dolphins, whales, etc. all rely on menhaden as a part of their diet.
The Fishery
Humans have been using menhaden for centuries. The name itself comes from a Native American term meaning "that which fertilizes", referring to burying the fish alongside crops to promote growth; a tip which was shared with European settlers once they arrived in North America.
Menhaden were so prodigious in the Chesapeake then that in 1608, the famous John Smith noted:
"...an abundance of fish, lying so thick with their heads above the water, as for want of nets we attempted to catch them with a frying pan: but we found it a bad instrument to catch fish with.
An illustration depicted the sight on the title page of his 1624 work General History of Virginia, New England and the Summer Isles.
Though no good for eating, menhaden quickly became one of the largest fisheries in the United States, thanks to their industrial uses. At first, they were caught for fertilizer by farmers and their families. As settlements grew and more crops were needed, farmers worked together to drag entire schools of fish ashore, and eventually those partnerships evolved into the first fishing companies.
But menhaden weren't just good fertilizer. They're full of oil, too. After whales populations were decimated in the 1850s, menhaden became the nation's primary source of industrial oil. By 1870, the menhaden business was 50% greater than that of whaling, with half a billion fish wrung out annually for paints, lubricants, soaps, and more.
By 1955, there were more than 20 menhaden processing plants from Florida to Maine. Total catch for the reduction fishery peaked in 1956 at more than 700,000 metric tons (mt).
Then, like the whales before them, menhaden populations began to decline. Schools couldn't be found outside of the Chesapeake in profitable numbers, despite advances in technology, and cheaper sources of oil began to replace them on manufacturing lines.
Today, only one factory remains along the Atlantic coast. Total reduction catch in 2021 was just 136,690 mt.
And yet, menhaden are still the largest US fishery in the Atlantic, and second largest fishery overall behind Alaskan pollock. The industry survived by shifting its product to farm feed, pet food, and fish oil pills.
Data from the Atlantic States Marine Fisheries Commission
The Problem
Menhaden are currently listed as "Least Concern" on the IUCN Red List, based on a 2015 study by the Atlantic States Marine Fisheries Commission (ASMFC). The study concluded that, based on current population models, Atlantic Menhaden are not overfished, nor are they in the process of being overfished. A stock assessment in 2017 reaffirmed this conclusion.
Menhaden catch beneath buckets of blue crab - NOAA Photo Library
So what's the issue?
Conservation groups argue that this assessment doesn't take into account the role that menhaden play in the greater marine ecosystem. The species doesn't exist in a vacuum, and though they might be on track as a sustainable business model, there are other factors we have to consider when deciding how to manage them.
Menhaden populations are a shadow of what they once were when John Smith first sailed into the Chesapeake. Less menhaden means less food for other commercially, recreationally, and ecologically important species; and multiple studies have linked declines in the health of other species to the decline of their food source, menhaden.
There's also the problem of water quality. Algal blooms occur when excessive nutrients enter the environment through urban and industrial runoff . The rapid increase in algae uses up all of the oxygen in the water, forming "dead zones" which suffocate marine life. These conditions have plagued the Chesapeake Bay since at least the 1970s, when they were first identified.
Chesapeake Bay Dead Zones - Data from Maryland Department of Natural Resources
Menhaden are natural combatants to these dead zones, since they remove algae from the environment while filter feeding. The process also clears the water, allowing more sunlight to reach marine plants. This leads to increased photosynthesis, making even more oxygen available.
It seems like a no-brainer that protecting menhaden and allowing them to return to their historic numbers could not only help fix problems in the Chesapeake, but along the entire east coast. Yet we continue to grind them up, turning forage for wild fish into feed for pigs, dogs, and cats. We squeeze them into pills for the latest health craze, reduce them to lipstick and salad dressings, all the while wondering why our waters have become so empty.
The Waters Ahead
Though there is much work to do, things are slowly headed in a positive direction. Catch limits have been set by the ASMFC ( though the primary taker has openly exceeded them ). Acknowledging the need to manage the menhaden fishery in terms of a sustainable ecosystem, rather than a sustainable business, is a critical step. Polluted waters and habitat loss (the removal of the salt marsh which supports young fish) are additional, equally urgent threats in need of solutions.
As consumers, we can be more aware of what goes into the products we buy. On pet food, for example, check the ingredients for terms like "Ocean Fish", "Fish Meal", "Fish Oil" (and of course the obvious but rarely undisguised, "Menhaden"). The same can be said for fish oil pills, which can be replaced with plant-based alternatives like soy and algae. After all, menhaden don't produce the omega-3 fatty acids we so crave, they themselves get it from the algae we need them to consume.
Further Reading:
- Franklin, H. Bruce. The Most Important Fish in the Sea: Menhaden and America. Shearwater Books, 2008.
- Goode, G. Brown, and W. O Atwater. American Fisheries: A History of the Menhaden . New York, Orange Judd, 1880.
- SEDAR. 2015. SEDAR 40 – Atlantic Menhaden Stock Assessment Report . SEDAR, North Charleston SC. 643 pp
- Andre Buchheister, Thomas J. Miller, Edward D. Houde, David H. Secor, Robert J. Latour, Spatial and temporal dynamics of Atlantic menhaden (Brevoortia tyrannus) recruitment in the Northwest Atlantic Ocean , ICES Journal of Marine Science, Volume 73, Issue 4, March/April 2016, Pages 1147–1159
- Kurlansky, Mark. Cod: A Biography of the Fish That Changed the World. Penguin Books, 1998.
- Atlantic State Marine Fisheries Commission - Atlantic Menhaden Reports, Management Plans, FMP Reviews, & Stock Assessment Reports
Story Map by Aaron Koelker. Data sources found in "Further Reading" above, except where otherwise linked. Originally published Dec 15, 2019. Updated with 2022 catch data on July 24, 2024.
