November 1, 2019 at 3:57 pm
By Native Fish Conservation Biologist Merry Gallagher
Maine is home to two freshwater fish species that are listed under Maine’s Endangered Species Act.
The Swamp Darter (Etheostoma fusiforme) is listed as Threatened and received that designation in 1997. Darters are known to occur in seven locations within two river drainages in Southern Maine. It is very unlikely that you will ever encounter one!
These are tiny fish that are generally less than 2 inches in length and although they may be abundant in certain localized areas, they are very difficult to find due to their tiny size, camouflage coloring, and propensity to live within tiny cracks and crevices of their habitat’s sediments. Darters inhabit murky, sluggish waterbodies including lakes, ponds and slow backwaters of rivers and streams. Their habitats are often muddy with high levels of vegetation and detritus and when found, darters are often hiding within these cover elements.
Although they can tolerate wide-ranging water conditions related to thermal regime, pH or dissolved oxygen range, they are vulnerable and susceptible to water level fluctuations and drought. Although current darter populations in Maine appear to be secure, due to their limited geographic range in Maine, coupled with their relatively poor ability to disperse and colonize new habitats, we continue to monitor their presence whenever potential stressors arise.
Redfin Pickerel (Esox americanus americanus) are listed as Endangered in Maine and are only known to occur in two locations, both centered in the Merrymeeting Bay area of the lower Kennebec River system. Redfins were added to Maine’s list of endangered species in 2006.
Unlike the swamp darter, redfin pickerel are sometimes, although rarely, accidentally angled. They can sometimes be seen in clear, still waters hanging at the surface, usually within vegetation, as they hunt for their next meal. Being a pickerel, these fish are predators although insects, other invertebrates and small fish or fry tend to be their preferred targets.
Redfins max out at about 6 inches in length here in Maine, but they are readily discernable from chain pickerel by their small size, noticeably short snout, and dark coloration with a distinctive vertical bar pattern. Redfin pickerel tend to occur in low abundance, can disperse and occupy new habitats as conditions change, but are usually found in slow-flowing coastal streams with lots of vegetation and cover. Unlike most other pickerel and pikes, they do have a bit of a tolerance for saltwater or estuarine conditions, hence they are usually found in the upper reaches of small, coastal streams that drain directly into an estuary.
Due to its status as endangered in Maine, if you happen to accidentally angle up a redfin, please let the fish go, unharmed, as quickly as possible. In addition, if you think you have encountered a rare, Maine redfin pickerel, please let me know. I am always appreciative of any additional information we can get concerning these elusive fish!
Although we continue to monitor and conserve our rare, native fishes as best we can, if you are interested in this type of work (or native fish in general), there are ways you can help.
We often have opportunities for volunteer assistance in efforts such as rare fish population monitoring. You can also help spread the word and support on-going efforts to enhance funding mechanisms for rare, native fish conservation and management through the Recovering America’s Wildlife Act (RAWA). Click here to learn more.