fish – Ogeechee Riverkeeper

Blog Post, Creature Feature acipenser brevirostrum, creature feature, fauna, fish, shortnose sturgeon, sturgeon

Fauna: Acipenser brevirostrum

by Ogeechee Riverkeeper October 4, 2021

Shortnose sturgeon
Acipenser brevirostrum

The shortnose sturgeon is a hefty freshwater fish that can be nearly five feet long, weigh upwards of 60 pounds, and generally live about 30 years — some females have been known to live 70 years! Though they can be found feeding in saltwater environments, they live, and spawn, entirely in coastal, freshwater rivers, including the Ogeechee.. Because of this, their survival depends on two types of healthy ecosystems. Shortnose sturgeon are currently listed on the Endangered Species List.

Native Americans fishing, John White, 1530. Public domain.

Sometimes called a ‘living fossil,’ the shortnose sturgeon has been thriving in coastal areas for millions of years. There is evidence that the species has been fished by humans for at least 4,000 years. However, overfishing contributed to a swift decline in the late 1800s. According to NOAA, In 1890, more than 7 million pounds of sturgeon were caught in that year alone. In 1920, only 23,000 pounds of sturgeon were caught.

Their trademark ridged back is formed by bony plates called ‘scutes,’ giving them the appearance of armor. They lack teeth but have bony plates in their esophagus which serve to crush their food. They use their barbels — sort of like fish antennae — to find insects, crustaceans, and bivalves on the ocean floor or river bottom.

Due to their low numbers, protecting their habitat and spawning ability is crucial to the species population. Sturgeon require free flowing, unobstructed rivers and streams in order to swim upstream and spawn. They also need healthy intertidal zones to feed and rest.

Blog Post endangered, fauna, fish, robust redhorse

Fauna: Moxostoma robustum

by Ogeechee Riverkeeper June 23, 2021

Moxostoma robustum
Robust redhorse

Once thought to be extinct, the robust redhorse has been rediscovered and stocked in a few waterways, including the Ogeechee River. Missing from the scientific record for 122 years, it was conclusively identified again in 1991.

A sizable fish, they can be up to 17 pounds and live nearly 30 years. They are in the sucker family and eat bivalves, using strong teeth for crushing and grinding. This is especially helpful to natural populations as they will consume the invasive species of Asiatic clam. However, the fish will also consume aquatic insects.

With such a gap in the known history of the animal, scientists are still learning about the species. They seem to require still or slow-moving areas with gravel or silty beds for spawning. Once they reach adulthood, they prefer to live in riverbanks with woody treefall or branches. The health of the population is threatened by habitat loss, primarily from sedimentation.

Since its rediscovery, there has been a current Memorandum of Understanding (MOU) recognizing the importance of the robust redhorse and its delicate situation. The MOU includes the GA Department of Natural Resources, NC Wildlife Resources Commission, SC Department of Natural Resources, US Fish and Wildlife Service, US Geological Survey, US Forest Service, Duke Power Company, Georgia Power Company, Georgia Wildlife Federation, South Carolina Aquarium, and South Carolina Electric and Gas Company. The parties agree to be actively committed to the restoration of the species.

The Ogeechee River was chosen as a site to stock because of a lack of invasive predators, some gravel spawning areas, and a lack of major impoundments. From 1997 to 2004, about 43,000 young robust redhorse, were released into the Ogeechee River at three different locations.

Followup research in 2008 and 2011 found that the stocked fish were growing and reaching maturity, but that spawning has only been successful in one location near Louisville. Work still needs to be done to make sure this rare species can thrive in the Ogeechee River and throughout the southeast.

Blog Post, Creature Feature catfish, creature feature, fauna, fish, georgia, invasive species, lepomis auritis, ogeechee river, redbreast sunfish

Fauna: Lepomis auritis

by Ogeechee Riverkeeper April 24, 2020

Redbreast sunfish
Lepomis auritis

The redbreast sunfish is native to eastern North America and makes its home in freshwater rivers. A relatively small fish, it is considered full grown by the time it is two inches long. The largest one on record measured just 12 inches. They primarily eat immature insects.

Usually olive colored with dark fins, the male’s breast and belly will turn bright orange when spawning. The male makes a nest in sandy material, then guards the eggs and fry after the female lays. Auritis means “big-eared” in Latin and refers to the long tabs that extend behind their eyes.

Redbreast sunfish, caught in Georgia. Shared via Wikimedia Commons.

The redbreast sunfish thrive in waters with flowing current and a stable pH. They like to live in natural structures near riverbanks, like overhanging branches which offer shade and protected habitats. Clearing bank debris, lack of current, or a change in pH levels quickly and dramatically affect the population.

Flathead catfish, an invasive species, is a predator and decimated the redbreast sunfish in other nearby watersheds. Thus far, the Ogeechee and Canoochee Rivers have not been infested with flathead catfish.

Citizens are asked to report sightings of these detrimental catfish to Ogeechee Riverkeeper or the Georgia Environmental Protection Division immediately. Snap a photo and email to info@ogeecheeriverkeeper.org with the approximate location of the sighting.