Atlantic menhaden facts for kids
Quick facts for kids Atlantic menhaden |
|
|---|---|
 |
|
| Conservation status | |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Order: | |
| Family: | |
| Subfamily: | |
| Genus: |
Brevoortia
|
| Species: |
B. tyrannus
|
| Binomial name | |
| Brevoortia tyrannus (Latrobe, 1802)
|
|
The Atlantic menhaden (Brevoortia tyrannus) is a type of fish found in North America. It belongs to the herring family, called Clupeidae. These fish live in the coastal waters and bays of the North Atlantic Ocean. You can find them from Nova Scotia in Canada all the way south to northern Florida.
Atlantic menhaden often swim in huge groups called schools. The fish in these schools usually group together by their size and age. Younger and smaller fish tend to stay in places like the Chesapeake Bay and along the southern coast. Older and larger fish are more often found along the northern coast.
Contents
What Do Atlantic Menhaden Look Like?
Atlantic menhaden are shiny, silver-colored fish. Their bodies are somewhat flat from side to side. They have a clear black spot on their shoulder, right behind their gill openings. These fish can grow to be about 15 inches long.
How Do Atlantic Menhaden Live?
What Do Menhaden Eat?
Atlantic menhaden are special because they are filter feeders. This means they get their food by filtering water through their gills. Think of it like a strainer! What they eat changes as they grow.
When they are young, usually under one year old, their gill structures are small. At this age, they mostly eat tiny plant-like organisms called phytoplankton. As they get older, their gills grow larger. Then, their diet shifts to mostly eating tiny animal-like organisms called zooplankton.
The Menhaden Life Cycle
Atlantic menhaden can lay eggs all year long in the coastal waters of the Atlantic. The most eggs are laid near North Carolina in late fall. Their eggs hatch in the open ocean. The tiny young fish, called larvae, then float on ocean currents into calm bays and estuaries.
These young fish spend about a year growing in these sheltered areas. During this time, they are often called "peanut bunker." After a year, they return to the open ocean. Most Atlantic menhaden become ready to have babies when they are about two years old. A young female can produce around 38,000 eggs. A fully grown female can lay over 362,000 eggs!
The eggs float and hatch in 2 to 3 days, depending on the water temperature. The larvae stay in waters over the continental shelf for 1 to 3 months. The Chesapeake Bay is a very important nursery area for young menhaden. Larval fish enter the Bay in late winter and early summer. They move into less salty waters in rivers and streams. The slightly older, immature fish stay in the Bay until the fall. Atlantic menhaden can live for 10 to 12 years.
Who Eats Atlantic Menhaden?
Many animals prey on Atlantic menhaden. Other fish like striped bass, weakfish, and bluefish eat them. Birds such as ospreys and eagles also hunt them. Even large ocean animals like Humpback whales off the coast of New Jersey feed on menhaden. Other whales and dolphins also enjoy eating them. Dolphins can eat up to 20 pounds of Atlantic menhaden every day!
Menhaden Fishing and Protection
How Menhaden Were Used in the Past
For a long time, menhaden were used as a natural fertilizer for crops. It's thought that Squanto taught the Pilgrims to bury these fish with their seeds to help plants grow. People also used menhaden for animal feed, fishing bait, and to make oil. This oil was used for human food, in factories, and even as fuel.
In the early days of the United States, thousands of fishing boats caught Atlantic menhaden. Many factories lined the Atlantic coast. They quickly turned the fish into valuable products, mostly oil, and later fish meal. However, too many fish were caught, and the menhaden population started to shrink. Many small fishing companies closed, leaving only a few large ones.
Even though many people today say menhaden are not good to eat, they were once eaten like sardines or fried. For example, fishermen in Maine would eat fried "pogies" for breakfast. Fish that weren't sold for bait were often sold as food to poorer families.
Commercial Fishing Today
Today, Atlantic menhaden are caught by two main types of fisheries: one that processes them into products (reduction fishery) and one that sells them as bait (bait fishery). People also catch them for fun to use as bait for their own fishing trips.
The reduction fishery turns whole menhaden into fish meal, fish oil, and other liquid products. The bait fishery provides menhaden to other fishermen to use as bait for catching popular fish. Both fisheries use a method called purse seine fishing. This is where two boats use a very large net to surround a school of fish.
Purse seining is a very effective way to fish. It also has one of the lowest levels of bycatch, which means catching other unwanted animals. The UN Food and Agriculture Organization has said that the Atlantic and Gulf menhaden fisheries have some of the lowest bycatch rates in the world. The reduction fishery mainly operates in the Chesapeake Bay and nearby Atlantic waters. Its season runs from May through the fall.
The bait fishery works all along the Atlantic coastline, from North Carolina to New England. People also use cast nets to catch menhaden for bait when they fish for fun. Independent groups have even certified that these fisheries are sustainable. Friend of the Sea, a program for sustainable seafood, has recognized both the Atlantic and Gulf menhaden fisheries as sustainable. This is because the fish population is healthy and they catch very few unwanted animals.
How Menhaden Are Protected
Atlantic menhaden are managed by the Atlantic States Marine Fisheries Commission (ASMFC). This is a group formed by 15 Atlantic coast states. The ASMFC works to prevent catching too many fish (overfishing) and to make sure the fish population stays healthy (not overfished). There's a small difference between these two ideas. Overfishing means too many fish are being taken out of the water. A stock is "overfished" when there aren't enough fish left to have enough babies to keep the population strong.
The ASMFC uses two main ways to check the health of the menhaden population. To see if the stock is overfished, they look at the number of mature eggs in the population. This shows how well the fish can reproduce. To check for overfishing, they watch how many fish are being removed from the water. In 2010, the ASMFC found that too many fish were being caught, but the population itself was not yet overfished.
Because of the 2010 findings, some groups asked the Commission to limit how many fish could be caught. The ASMFC then created new catch limits. They set a total allowable catch (TAC) of 170,800 metric tons. This cut the amount of fish caught along the coast by 20 percent compared to earlier years.
This decision came after environmental groups, like the Chesapeake Bay Foundation, asked for limits. Some people who worked in the menhaden fishery disagreed. They felt the cuts were not needed and would hurt their businesses. The TAC was the first time a catch limit was set for the entire coast. However, the ASMFC had already limited how many menhaden could be caught in the Chesapeake Bay. This was to stop too many fish from being caught in one area. Recent reports say that the menhaden population in the Chesapeake Bay is not overfished.
A new assessment in 2015 showed that the menhaden population was not being overfished. It also showed that the population had not been "overfished" since the 1990s. In May 2015, the ASMFC agreed to use this new assessment for management. They also increased the total allowable catch to 187,880 metric tons. They also started planning for new changes to how fish are divided among states. They also want to study the menhaden's role in the ocean's ecosystem.
Environmental Concerns in the Chesapeake Bay
Dead Zones and Menhaden
Some people believe that menhaden help clean the water by eating too much algae and nutrients. However, studies suggest that menhaden do not greatly improve water quality. Adult menhaden mostly eat zooplankton, not the phytoplankton that cause too much growth of algae. This excessive algae growth can lead to "dead zones" where there is not enough oxygen for other sea life. There is even some evidence that menhaden might actually add to phytoplankton growth because they release nitrogen.
Sometimes, many fish, including menhaden, die in one area. This is called a fish kill. The Virginia Institute of Marine Sciences studies these fish kills in the Chesapeake Bay. They found that fish kills have many causes. Often, they are related to environmental factors. These include low oxygen in the water, too many algae (algal blooms), or water temperatures that are too hot or too cold. Other things, like harmful materials being dumped or too much bycatch, can also cause fish kills.
Striped Bass and Menhaden
Some people think that changes in the striped bass population are due to too many menhaden being caught. They claim that menhaden are a very important food for striped bass. However, other studies show that striped bass eat many different kinds of sea creatures. They don't rely only on menhaden. In fact, menhaden have been found to make up as little as 8% of a striped bass's diet.
Names for Atlantic Menhaden
Atlantic menhaden have had many different names over time:
- Menhaden - This name comes from a Native American word, munnawhatteaug. It means "that which manures," referring to how Native Americans used the fish to fertilize their crops.
- American sardine - In the 1800s, Americans would prepare and eat menhaden much like European sardines.
- Bunker - This is a slang term used by fishermen in the Northeastern United States.
- Pogy - This name also comes from a Native American word, pauhagen or pookagan, which means the same as Munnawhatteaug.
- Bony-fish, hard-head - These names describe the fish's bone structure.
- White-fish - This term was used to describe North American freshwater fish.
- Mossbunker - This comes from the Dutch word Marsbanker, which means horse mackerel. This is a similar-looking fish found in the Netherlands. Dutch settlers started using this name for menhaden.
- Bug-fish, bug-head - These names come from a tiny parasitic crustacean (Cymothoa pregustator) that is sometimes found in the mouth of menhaden. Menhaden often swim with their mouths open.
- Fat-back - This name describes the oily flesh of the menhaden.
- Yellow-tail, yellow-tailed shad, green-tail - These names describe the color of the fish's tail fin.
- Shad, alewife, and herring - These are general terms for fish in the herring family that have also been used to describe menhaden.
See also
In Spanish: Sábalo atlántico para niños
