Genoa National Fish Hatchery Grows Wings
September 15, 2016
Hine's emerald dragonfly naiad. Photo by Ryan Hagerty/USFWS.
With glowing green eyes and a metallic green body, the rare Hine’s emerald dragonfly (Somatochlora hineana) is found only in a few pockets of the Midwest. First discovered in Ohio, the dragonfly was thought to be extinct by the mid-1900s due to the negative impacts of urban sprawl in its home range. The dragonfly’s status changed when an adult Hine’s emerald dragonfly was identified in the Des Plaines River Valley, southwest of Chicago, Illinois in 1988. By 1995 the dragonfly was placed on the federal list of endangered species. The Hine’s is the only dragonfly in the country listed as federally endangered. Its story illuminates the unique role that a national fish hatchery can play in the captive rearing and recovery of an endangered species.
Within the U.S. Fish and Wildlife Service, Hine’s emerald dragonfly restoration and recovery efforts are led by the Chicago Ecological Services Field Office in close partnership with the University of South Dakota. Together, they developed a captive rearing protocol and monitored the species across its current range in Illinois, Missouri, Michigan and Wisconsin.
They recognized that Genoa National Fish Hatchery in Wisconsin had great potential to contribute to the endangered dragonfly’s recovery efforts. Genoa National Fish Hatchery is uniquely situated on the Mississippi River and is home to natural wetlands that are close to ideal Hine’s emerald dragonfly habitat. It’s also very well known for its innovations in aquaculture and rearing techniques in support of conservation efforts for a variety of freshwater species, including fish and endangered mussels. So the partners contacted the hatchery in 2013 to see if it would be possible to transform a small scale laboratory-based propagation into a larger production-scale operation.
As adults, Hine’s emerald dragonflies lay their eggs in small streams, spring fed marshes and sedge meadows. After hatching, the aquatic larvae, called naiads or nymphs, spend up to five years in wetlands before completely maturing and emerging as adult dragonflies. Dragonflies are critically important in a healthy ecosystem because they prey on small insects, including mosquitoes, biting flies, and gnats. In their larval stage, dragonflies are valuable as food items for larger aquatic animals such as fish. They also serve as excellent indicators of changes in water quality.
In the fall of 2013, staff from Genoa began working with partners from the University of South Dakota and the Chicago field office on a proposal to the Cooperative Recovery Initiative. The Initiative provides funding for projects working with threatened or endangered species on or near National Wildlife Refuge lands. In addition to Genoa having the natural environment preferred by the Hine’s dragonfly, the hatchery’s location allowed the project to be eligible for this Initiative funding. The Hine’s emerald dragonfly project was selected for funding in 2015 and work began to acquire a mobile rearing unit, start cage construction and hire additional hatchery staff to begin culturing the dragonfly. Funding also supported a coordinator position in the Chicago office and for the University of South Dakota to perform collection efforts and genetic sampling. Within a few months of receiving funding, Hine’s emerald dragonfly larvae were collected in the wild by experts from the University of South Dakota and the Chicago office, where they were in turn delivered to Genoa. Hatchery staff spent that first season with Hine’s on-station learning the complexities of the dragonfly’s life cycle. In a just a short time, Genoa hatchery staff were able to answer many questions about necessary rearing conditions including water quality, food availability, site-specific growth and suitable rearing units for the endangered species.
In the laboratory environment there was little to no risk of common dragonfly larvae entering rearing cages, growing faster and larger, and then preying upon the Hine’s naiads. But at the hatchery, in an outdoor pond, protection from predation while ensuring access to adequate food and optimum oxygen levels was a real concern. Through intense observation during the 2015 pilot rearing cycle this challenge and many others were identified and resolved. Now in their second season at Genoa, Hine’s eggs delivered in the spring have hatched and larvae have responded positively to the newest rearing practices, which include a mobile rearing trailer that circulates “predator free” filtered water from hatchery ponds for free roaming larvae reared in tanks. Also, improved rearing cages or “Hine’s Hotels” provide protection from predation while allowing naiads more freedom to access food items once they are transferred to outdoor ponds. In the controlled environment at the hatchery, dramatically improved survival rates are now expected for the dragonfly in its early life stages.
Other successes in 2016 include the emergence of the first hatchery raised Hine’s emerald dragonfly; a male, healthy and capable of foraging and reproduction in the wild. With the emergence of several other Genoa reared dragonflies off-site at the University of South Dakota’s Lockport Prairie location, the hatchery team continues to work with their partners on scaling up the operation to produce more dragonflies to bolster wild populations.