BETHANY BEACH, Del. (Delmarva Now) -- Think back to those summer nights at the beach. In the dunes by the shore, did you ever spot a firefly?
When you saw it, did it look different than the others, with a bright green light instead of a warm yellow glow? Did it flash twice, not once?
If so, you saw one of the rarest creatures on earth, the Bethany Beach firefly, which only occurs along the coast of Delaware, mostly from the Indian River Bridge and south, according to Delaware State University Associate Professor Christopher Heckscher. He helped rediscover the firefly back in 1998, after it went more than four decades unseen by scientists.
It looks a lot like the bug people are most familiar with, the common Eastern firefly, except it is half the size.
With the recent completion of Delaware's Wildlife Action Plan for 2015 through 2025, there is now a guide for how to protect the endangered firefly, along with other species of concern in Delaware. Right now the bugs are facing four major threats, according to Heckscher: impacts from past development, sea-level rise, invasive species and future development.
The bugs are only found in wetlands that are formed in the depressions between dunes called interdunal swales. Unlike other dune wetlands, the ones along Delaware's coast are unique because they are freshwater — some even meet fresh groundwater sources.
"It is my suspicion the reason the species is so rare is that they're associated with these freshwater interdunal wetlands," Heckscher said.
Because of Route 1, the dunes are unable to move. That's good, because it allows them to remain freshwater, but in some ways it is bad because instead of interdunal wetlands, spots are becoming more heavily wooded and swamp-like.
"That's not real good for the fireflies," Heckscher said. "By controlling the seas during storm events we've created a system where we're losing interdunal swales."
Then there is the threat of future development — though because most of the firefly's habitat is on state-owned land that's less of a concern, according to state program manager for biodiversity Anthony Gonzon.
Because the swales are freshwater, salt water intrusion from things such as sea-level rise or storm events are also a major threat.
"If we get sea-level rise to a certain point, we're going to lose the freshwater aquifer that occurs under the dunes," Heckscher said.
Invasive species such as phragmites can also out-compete and kill native vegetation, another threat to the dune habitat.
In the wildlife action plan the state identifies actions to take moving forward, including creating a habitat and species management plan just for the firefly, planning for habitat movement and law enforcement to protect interdunal swales from disturbance. Gonzon said a part of that would be surveying the population.
"It's trying to create some resiliency in habitats," Gonzon said. "There's going to be things you can stop and there's going to be things you can't."
The state will work with partners to look at the habitat and multiple species in it on a range of scales, from how the species interact with the worldwide ecosystem to how they interact with grains of sand.
"Knowing what was there also gives us the opportunity to restore it after the fact," he said.
And the plan does that for all of Delaware, not just the coast. It is a guiding document for anyone's use, stating which species the state is most concerned about, what issues impact them and how to protect them. The state's last wildlife plan allowed them to get funding that contributed to the restoration of osprey populations in the area, Gonzon said.
The plan can be found online at www.dnrec.delaware.gov.
