Departmentof Fish and Wildlife Have Back Up Generators for Fish Farms
Lake sturgeon
Acipenser fulvescens
- Taxon: Freshwater Fish
- Range: Freshwater systems of North America from the Hudson Bay through the Mississippi River drainages
- Status: Not listed under the Endangered Species Act (ESA). Lake sturgeon is listed as threatened at the state level in 19 of the 20 states it inhabits.
Lake sturgeon (Acipenser fulvescens) is a temperate fish occurring in freshwater systems of North America from the Hudson Bay through the Mississippi River drainages. Lake sturgeon prefer sand or gravel habitat on the bottom of a riverbed or lake. Populations are declining throughout the species' native range and are listed as threatened in 19 out of the 20 states it inhabits. There are several reasons for this decline including over-harvesting and habitat loss due to dam construction.
Lake sturgeon are slow-moving fish but will migrate up rivers during spawning season. Female sturgeons reproduce between the ages of 20 and 26 years old. Males usually mature between 8 and 12 years old. While the male sturgeon's typical lifespan is 50 to 60 years, the female sturgeon can live up to 150 years.
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Appearance
The lake sturgeon is a docile fish despite its intimidating look and size. This species can grow to nine feet in length and weigh more than 300 pounds. Like its prehistoric ancestors, Lake sturgeon have a distinct shark-like tail and rows of armored plates called "scutes" for protection. Its skeleton consists of bone and cartilage.
Habitat
Lake sturgeon prefer sand or gravel habitat on the bottom of a riverbed or lake.
Diet
Lake sturgeon spend most of their time grubbing on the lake or river bottom for food. This species does not have teeth but has a small mouth with thick, sucking lips beneath the projecting snout. Lake sturgeon have four barbels (whiskers) in front of the mouth that are used to detect food like insects, worms, snails, crayfish, small fishes and other organisms. As soon as the sensitive whiskers pass over food, the mouth drops down with an elevator-like motion and rapidly sucks in its meal.
Current range
This species occurs in the Mississippi River drainage basin south to Alabama and Mississippi. It occurs in the Great Lakes and the Detroit River, east down the St. Lawrence River to the limits of fresh water. In the west, it reaches Lake Winnipeg and the North Saskatchewan and South Saskatchewan Rivers. In the north, it is found in the Hudson Bay Lowland. In the east, the species lives in Lake Champlain and several Vermont rivers, including the Winooski, Lamoille, and Missisquoi rivers, and Otter Creek
Conservation challenges
These fish were once killed as a nuisance bycatch because they damaged fishing gear. When their meat and eggs became prized, commercial fishers targeted them. Between 1879 and 1900, the Great Lakes commercial sturgeon fishery brought in an average of 4 million pounds (1800 metric tons) per year. Such unsustainable catch rates were coupled with environmental challenges such as pollution and the construction of dams and other flood control measures. Sturgeon, which return each spring to spawn in the streams and rivers in which they were born, found tributaries blocked and spawning shoals destroyed by silt from agriculture and lumbering. In the 20th century, drastic drops in sturgeon caught increased regulations, and the closure of viable fisheries occurred.
The sturgeon has also been negatively affected by pollution and loss of migratory waterways. It is vulnerable to population declines through overfishing due to its extremely slow reproductive cycle; most individuals caught before 20 years of age have never bred, and females spawn only once every four or five years.
Conservation measures
Egg collection
Warm Springs National Fish Hatchery staff travel every year to collect eggs from lake sturgeon caught in Wisconsin's Wolf River. Eggs from a minimum of five females are crossed with sperm collected from 30 males. These pairings ensure up to 25 family groups will be produced each year, which will assist in maximizing the genetic diversity of the founding population. The hatchery partners with the Wisconsin Department of Natural Resources to collect broodfish for pairings. Wisconsin DNR staff collect male and female lake sturgeon using a large dip net. Length, weight, sex, tissue (fin clip about the size of a pencil eraser), and other data are collected from each fish. When a ripe female is sampled, eggs are collected, divided into five groups, and each group is fertilized with sperm from one male. After fertilization, the eggs are rinsed, and a mixture of Fuller's earth is added to de-adhese the eggs.
Fertilized eggs are transported from the Wolf River collecting site to Warm Spring's hatchery in a trailer that is equipped with a tank, hatching jars, water pump, cooling unit, oxygen, and generator.
Rearing
After arriving at Warm Springs NFH in Georgia, eggs are disinfected with iodine, and placed into the hatching jar system until they hatch. It can take approximately 4 to 8 days for the eggs to hatch. During the first 30 days of culture, fish are quarantined in a re-circulation system.
By mid-June, the fish have grown to approximately 1 to 1.5 inches long. At this size, the fish need more room to grow and are distributed to different hatcheries, including Private John Allen National Fish Hatchery in Tupelo, Mississippi; Mammoth Spring National Fish Hatchery in Mammoth Spring, Arkansas; Orangeburg National Fish Hatchery in Orangeburg, South Carolina; and the Tennessee Aquarium Research Institute's Hatchery in Cohutta, Georgia. The sturgeon are reared in these five facilities until October-November. At this time, Lake Sturgeon are graded, marked, and stocked into the French Broad, Holston, and Cumberland rivers.
Reintroduction process
The hatchery prepares to release lake sturgeon when a batch reaches stockable size. It can take several days to prepare the batch of fish for its final river destination. The stockable size for this species of sturgeon is usually six inches; fish size is important to ensure the fish can survive the tagging procedure and stocking bigger fish into a river will hopefully reduce predation. The hatchery's first stocking is approximately 1,000 fish that have reached stockable size.
Partnerships, research, and projects
Warm Springs NFH has been rearing lake sturgeon since 2000 to reintroduce in two areas where the species was previously found. The hatchery works closely with the Tennessee Wildlife Resource Agency, Georgia Department of Natural Resources and Wisconsin Department of Natural Resources and reintroduction efforts are concentrated in the Lower French Broad River in Tennessee and the Coosa River in Georgia.
How you can help
You can help the lake sturgeon stage a comeback. If you catch a lake sturgeon, and local fishing regulations allow you to possess it, gently measure and release the fish. If the fish has a tag, record the agency, number, and color of the tag and then contact that agency. Report sightings of lake sturgeon to your nearest U.S. Fish & Wildlife Service Fishery Resources Office.
Federal Register notices
The following Federal Register documents were automatically gathered by searching the Federal Register Official API with this species' scientific name ordered by relevance. You can conduct your own search on the Federal Register website.
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Departmentof Fish and Wildlife Have Back Up Generators for Fish Farms
Source: https://www.fws.gov/southeast/wildlife/fishes/lake-sturgeon/
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