Annapolis, Maryland – Maryland Department of Natural Resources biologists, in partnership with the U.S. Fish and Wildlife Service and other collaborators, released captive-bred blackbanded sunfish into a Wildlife Management Area pond on a mid-September Monday in 2025, marking the first time the state has reintroduced this rarest freshwater fish species into the wild.
The release occurred at the edge of a small, tea-colored blackwater pond after staff from Maryland DNR’s Fishing and Boating Services and the U.S. Fish and Wildlife Service gathered around five-gallon tanks holding quarter-sized fish with yellow-green bodies and dark vertical stripes. Biologists scooped the fish into buckets and placed them into the pond, where they quickly disappeared into the acidic, tannin-stained water.
The milestone resulted from nearly 20 years of conservation work, supported by State Wildlife Grants through the U.S. Fish and Wildlife Service’s Office of Conservation Investments and a 2024 grant from the Chesapeake WILD Program. Launched in 2022 by the Service in partnership with the National Fish and Wildlife Foundation, Chesapeake WILD funds efforts to sustain the Chesapeake Bay watershed’s health, including species like the blackbanded sunfish.
Jay Kilian, a Maryland DNR natural resource biologist involved for much of his career, described the release as the culmination of long-term efforts. “Where we are now — with successful propagation and release to augment a population, and more — is the culmination of nearly 20 years of work,” Kilian said.
Blackbanded sunfish require blackwater habitats—acidic, nutrient-poor wetlands stained dark by organic leachates from soil. Once common in Maryland’s coastal plain, these swamps were largely drained over centuries for agriculture and development, fragmenting remaining pockets and isolating populations. “What we are left with is pockets of blackwater in Maryland, as well as in Delaware, but without the connectivity between them to sustain populations,” Kilian explained. “Everything that remains here is highly isolated — and vulnerable for that reason.”
Surveys since 2008, part of an interstate conservation strategy for the Chesapeake Bay region, confirmed the species’ near absence in Maryland. One remaining site showed highly inbred fish. Partners then shifted to captive propagation to augment the existing population and establish new ones in suitable habitat.
New Jersey’s Pinelands, protected under state law, provided a source population. “In our last comprehensive review, we documented blackbanded sunfish in over 100 distinct locations, where they were fairly abundant at most sites,” said Scott Collenburg, a New Jersey Fish and Wildlife biologist. “New Jersey plays a unique role in the long-term survival of this species because most individuals are found in the Pinelands Preserve. We feel a responsibility to support conservation across our border.”
In 2017, Maryland collected 50 fish from New Jersey for a pilot at the National Aquarium in Baltimore. Initial attempts failed due to water chemistry mismatches; blackbanded sunfish need acidic, tannic conditions unlike typical aquarium setups. “We have clean water with perfect chemistry — but that’s not what blackbanded sunfish want,” said Ashleigh Clews, curator at the National Aquarium’s animal care and rescue center.
After setbacks, including a facility move in 2018 and COVID-19 delays, staff replicated pond conditions using natural materials, adjusted temperature, light cycles, and pH with CO2 dosing. In 2023, partners collected 40 fish from robust New Jersey ponds; 39 survived acclimation. In 2025, Maryland’s state hatchery successfully spawned and reared fish for the September release.
The Chesapeake WILD grant enabled redundancy: upgrades at the National Aquarium, a dedicated hatchery system and pond at Maryland DNR facilities, and habitat restoration. It funded planting 1,500 Atlantic white cedar trees at The Nature Conservancy’s Plum Creek Preserve near Sharptown, led by the National Aquarium’s Conservation Department with Maryland Conservation Corps assistance.
Deborah Landau, director of ecological management for The Nature Conservancy’s Maryland/DC chapter, described ongoing work at Nassawango Creek Preserve, where pine plantations have been converted to native oak, pine, Atlantic white cedar, and grasslands through hydrology restoration, controlled burns, and tree planting. “We’ve restored the physical properties and brought back native plant communities, now we’re excited to welcome back a species that has been lost for a long time,” Landau said.
Mike Slattery, Acting Deputy Assistant Director for Science Applications at the U.S. Fish and Wildlife Service, noted the grant’s catalytic role. “In addition to funding shovel-ready projects, the program provides grants for planning and technical assistance to support initiatives that simply need a catalyst,” Slattery said.
Jason Cessna, a Maryland DNR biologist, credited hatchery staff for the 2025 spawning success. “Given past difficulties, we weren’t sure we would have success in 2025, but because of the dedication of our hatchery staff they spawned successfully in captivity, and we had a high survival rate,” he said.
The release represents progress for a species once widespread in Eastern Shore blackwater systems but now confined to isolated pockets. Future steps include building robust populations in ponds before expanding to streams and rivers in the Chesapeake Bay watershed.