Context : Researchers have discovered that the population of ospreys, a fish-eating bird, is facing a decline due to the decreasing numbers of Atlantic menhaden, their primary food source.
- The depletion of menhaden, a small silvery fish, is attributed to commercial fishing practices.
About the Species
- Atlantic menhaden support a significant commercial fishery along the Atlantic Coast of the United States.
- They are filter feeders, primarily consuming phytoplankton and zooplankton in the water column.
- They are harvest for use as fertilizers, animal feed, and bait for fisheries like blue crab and lobster.
- In estuaries like Chesapeake Bay, menhaden serve as food for striped bass, fish, osprey, and eagles.
Where They Live
- Menhaden live in coastal and estuarine waters from Nova Scotia to northern Florida.
- In the Chesapeake Bay, menhaden are common in all salinities. They swim in large schools close to the water’s surface during the spring, summer, and fall.
Appearance
- Menhaden are silvery in color with a distinct black shoulder spot behind their gill opening.
Biology
- Menhaden can live to be 10 to 12 years old and reach 15 inches in length. Fully grown, they weigh about a pound.
- Menhaden eat both phytoplankton and zooplankton. When well-fed, people refer to them as fatbacks or bunkers.
- Mature menhaden spawn in coastal waters off the East Coast of the United States. The peak of their spawning season is thought to be from December to February.
- Menhaden larvae drift into estuarine environments and metamorphosize into juveniles. The juveniles tend to stay in the estuarine environments—like the Chesapeake Bay and Delaware Bay—for approximately a year before leaving the estuary to join adult schools.
- While many menhaden are migratory, others do not migrate and stay resident in their area.
Importance of Atlantic Menhaden
- Role in Coastal Ecosystem: Menhaden are vital in coastal waters, providing sustenance for larger fish, marine mammals, and birds.
- Nutrient-Rich and Filtering Capacity: Nutrient-rich menhaden contain omega-3 fatty acids and filter large amounts of ocean water, consuming smaller organisms like plankton..
Commercial Fishing Impact
- Increased Catch Allowance: The Atlantic States Marine Fisheries Commission increased the menhaden catch limit to 233,550 metric tons, a 20% increase.
- Fishery Quota: The commission maintained a 51,000 metric ton quota for the Chesapeake Bay’s reduction fishery using menhaden.
- Ecological Concerns: Critics argue that the removal of significant menhaden quantities is degrading the ecosystem, negatively affecting species like ospreys and striped bass that rely on menhaden.
Low Reproductive Numbers and Menhaden Depletion
- Researchers found only three young ospreys in 84 nests checked in Mobjack Bay, Chesapeake Bay.
- Scientists at the College of William & Mary, monitoring the local osprey population for over 50 years, recorded the lowest reproductive number.
- The decline in breeding success is attributed to the depletion of Atlantic menhaden, the osprey’s primary food source.
Encouraging Developments Outside Chesapeake Bay
- Menhaden Recovery: Menhaden populations outside Chesapeake Bay increased after 2012 measures to address overfishing, recovering within two years.
- Ecological Impact: Menhaden population recovery attracts predators like humpback whales, tuna, sharks, and bald eagles in New York and New Jersey.
FAQs Related with Atlantic Menhaden
Ques 1: Where are Atlantic menhaden found?
Answer: Atlantic menhaden inhabit coastal and estuarine waters spanning from Nova Scotia to northern Florida.
Ques 2: What do Atlantic menhaden eat?
Answer: Atlantic menhaden are filter feeders, primarily consuming phytoplankton and zooplankton in the water column.
Ques 3: How are Atlantic menhaden utilized commercially?
Answer: Atlantic menhaden have significant commercial value. Harvested for fertilizers, feed, bait, and as a source of omega-3 fatty acids for supplements.
Atlantic Menhaden: Species in news,Atlantic Menhaden: Species in news
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