Editing Menhaden (section)

==Ecology==
Menhaden are [[filter feeder]]s that travel in large, slow-moving, and tightly packed [[Shoaling and schooling|schools]] with open mouths. Filter feeders typically take into their open mouths "materials in the same proportions as they occur in ambient waters".<ref>{{Cite report|url=https://www.gsmfc.org/publications/GSMFC%20Number%20099.pdf|title=The Menhaden Fishery of the Gulf of Mexico, United States: A Regional Management Plan|date=March 2002|publisher=[[Gulf States Marine Fisheries Commission]]|issue=99|pages=3–10|archive-url=https://web.archive.org/web/20190303234246/https://www.gsmfc.org/publications/GSMFC%20Number%20099.pdf|archive-date=3 March 2019|editor-last=VanderKooy|editor-first=Steven J.|editor2-last=Smith|editor2-first=Joseph W.|url-status=live}}</ref> Menhaden have two main sources of food: [[phytoplankton]] and [[zooplankton]]. A menhaden's diet varies considerably over the course of its lifetime, and is directly related to its size. The smallest menhaden, typically those under one year old, eat primarily phytoplankton. After that age, adult menhaden gradually shift to a diet comprised almost exclusively of zooplankton.<ref>{{Cite journal|last1=Friedland|first1=Kevin D.|last2=Lynch|first2=Patrick D.|last3=Gobler|first3=Christopher J.|date=November 2011|title=Time Series Mesoscale Response of Atlantic Menhaden ''Brevoortia tyrannus'' to Variation in Plankton Abundances|url=https://www.researchgate.net/publication/242329913|journal=[[Journal of Coastal Research]]|volume=27|issue=6|pages=1148–1158|doi=10.2112/JCOASTRES-D-10-00171.1|s2cid=131569331}}</ref>

Menhaden are omnivorous filter feeders, feeding by straining [[plankton]] and [[algae]] from water. Along with [[oyster]]s, which filter water on the seabed, menhaden play a key role in the [[food chain]] in estuaries and bays.<ref name=Discover/> Atlantic menhaden are an important link between plankton and upper level predators. Because of their filter feeding abilities, "menhaden consume and redistribute a significant amount of energy within and between [[Chesapeake Bay]] and other estuaries, and the coastal ocean."<ref>{{cite web|url=http://www.dnr.state.md.us |title=Maryland Department of Natural Resources |publisher=Dnr.state.md.us |date=2012-12-31 |access-date=2013-01-07}}</ref> Because they play this role, and their abundance, menhaden are an invaluable prey species for many predatory fish, such as [[striped bass]], [[bluefish]], [[mackerel]], [[flounder]], [[tuna]], [[Drum (fish)|drums]], and [[shark]]s. They are also a very important food source for many birds, including [[egret]]s, [[osprey]]s, [[seagull]]s, [[northern gannet]]s, [[pelican]]s, and [[heron]]s.

In 2012, the [[Atlantic States Marine Fisheries Commission]] declared that the [[Atlantic menhaden]] was [[Resource depletion|depleted]] due to [[overfishing]]. The decision was driven by issues with water quality in the [[Chesapeake Bay]] and failing efforts to re-introduce predator species, due to lack of menhaden on which they could feed.<ref name="conservationmagazine1"/>

Menhaden are crucial not only because of their keystone species-status in the food web, but also because of their ecological services. The way menhaden filter feed on phytoplankton helps to mitigate toxic algal blooms. These algal blooms, which are often detrimental to a number of fish, bird, and marine mammal species, create hypoxic conditions. The phytoplankton being preyed upon are photosynthetic organisms, converting sunlight into energy which is then transferred to menhaden and then to bigger species of fish or other larger marine organisms such as birds or mammals. The consequence of this behavior is that if menhaden are eliminated or significantly decreased, there are limited means of energy transfer among trophic levels – making menhaden a true keystone species with ecological services that are invaluable to humans.

=== Habitat ===
Menhaden are a pelagic schooling fish that migrate inshore during the summer and off-shore in the winter months. The juvenile and larval menhaden migrate to shore and inland waterways through currents during summer months to grow while feeding on the phytoplankton and eventually zooplankton once they have matured. Commercially caught menhaden have been recorded in waters of around 5 to 24 ‰, as well as in hypersaline waters around 60 ‰.<ref>{{Cite web|title=FAO Fisheries & Aquaculture – Aquatic species|url=http://www.fao.org/fishery/species/2899/en|access-date=2020-12-04|website=fao.org}}</ref>

=== Reproduction ===
Menhaden reproduce in open oceans externally, however, the female does not carry eggs with them during the process as they are released into the water column at the planktonic level as gametes and sperm. Currently, functional hermaphroditism is unknown to the species and identification of sex of the individual organism cannot be determined externally due to the lack of accessory reproductive organs.<ref name=":02">{{cite report|last=Reintjes|first=John W. |title=FAO Species Synopsis No. 42: Synopsis of Biological Data on the Atlantic Menhaden, ''Brevoortia tyrannus'' |publisher=U.S. Department of the Interior, U.S. Fish and Wildlife Service, Bureau of Commercial Fisheries|website=Food and Agriculture Organization of the United Nations|location=Washington, DC|date=November 1969 |url=https://www.fao.org/3/ap905e/ap905e.pdf |archive-url=https://web.archive.org/web/20201129101317/http://www.fao.org/3/ap905e/ap905e.pdf |archive-date=2020-11-29 |url-status=live|access-date=14 November 2022|id=Circular 320}}</ref> These fish breed during the winter months through December to March and the eggs and juveniles navigate towards estuaries and inland waterways through tides and currents.<ref name=":02" />