Photo: Gary Fish
Illegal stockings of invasive fishes are a continuing problem in Maine waters. Each and every invasive introduction forever alters both the native fish assemblage and the ecosystem as a whole. Fisheries managers utilize a number of options to target and remove invasive fish populations including liberalized regulations, direct removal efforts, and chemical reclamation. Often the best defense isn't a regulation, a reclamation, or a removal. It is public education. Once illegal fishes are introduced into Maine waters, many times there is no turning back.
The Department of Marine Resources is monitoring a number of marine invasive species, including the green crab, which can destroy eel grass beds and eats mussels and clams; Asian shore crab; Didemnum, a tunicate that looks like pancake batter and spreads over the bottom; and Codium, a spongy green algae that can completely cover and smother shellfish beds.
Invasive aquatic species are introduced exotic flora and fauna that displace native plant and animal communities. Infestations result in habitat disruption, loss of property values, diminished water quality, reduced fishing and water recreation opportunities and significant expense for mitigating these environmental costs. Maine DEP's Invasive Aquatic Species Program addresses invasive aquatic species - primarily plants - in three ways: prevention, early detection and control.
The goal of the program is to provide an early warning system for pest detection and response that is critical for safeguarding our nation's agricultural and natural resources. Typical surveys target exotic and invasive pests and pests of export significance.
The Maine Forest Service surveys for invasive forest insects and diseases in a variety of ways. There are specific surveys for specific pests using traps and standardized visual monitoring as well as general forest pest surveys. Reports from the public are an invaluable method of detecting invasives in a sparsely settled state. Detecting an invasive early can allow for mitigation that will reduce the impact of the pest on Maine's forests.
Invasive terrestrial and wetland plants are a threat to Maine's beautiful natural areas, working farms and forests, and our backyards and open spaces. As part of their mission to conserve Maine's natural heritage, the Maine Natural Areas Program provides scientific guidance on identification, management, and monitoring of invasive terrestrial and wetland plants, and coordinates a statewide invasive species mapping tool, iMapInvasives.
The Horticulture Program maintains a list of invasive terrestrial plant species that are prohibited from sale in Maine. The ban includes the listed species and all cultivars, varieties and hybrids. Variances may be applied and granted for scientific research and for varieties, cultivars or hybrids that are shown to not be invasive through scientific research. The invasive plant rule and prohibited plant list is reviewed every 5 years.