● Landscape fragmentation & barriers to movement. Loss of habitat, changes in land use, and human infrastructure barriers such as roads and walls prevent turtles from moving between different habitat resources. These structures may block routes between wetlands and nesting sites or other habitat patches.
● Agriculture, logging, & ranching. These land use practices can result in a loss or degradation of wetlands and other habitat turtles inhabit, sedimentation and nutrient runoff into waterways, and changes to the local microclimate.
● Urban sprawl. Urban development results in loss of wetlands and degradation of water quality. Shorelines become too altered and disturbed for nesting and other turtle uses. Urban infrastructures are barriers to turtle movement and urban areas also subsidize populations of turtle predators, such as raccoons.
● Wetland loss and degradation. Many turtles inhabit wetlands, and wetland loss has been substantial in the Northeastern US. Water quality is poor in many wetlands due to residential, agricultural, and urban runoff. Invasive plant species such as common reed (Phragmites) and purple loosestrife lower habit quality of wetlands for turtles.
● River degradation, diversion, & dams. Shoreline hardening and loss of riparian vegetation and/or invasion of non-native plants make riverbanks less suitable for nesting and other turtle uses. Water quality in many rivers is impaired due to nutrient and chemical pollution. Dams inhibit movement of riverine turtle species.
● Road mortality. Turtles die from collision with vehicles while attempting to crossroads to access nesting sites or other habitats. These linear features also make it easier for turtle predators to find nesting females.
● Solar & wind energy installations and rights-of-way. Energy installations create access roads that increase road mortality and when fenced present movement barriers for turtles. They may reduce habitat quality and affect microclimate of nearby turtle habitat, particularly nesting habitat.
● Pollutants. Residential and agricultural nutrient runoff degrades water quality. Salt runoff from roadways also impairs water quality near roads. Snapping turtles and others near the top of the food chain accumulate pollutants that biomagnify such as methylmercury and PCBs. Water bodies inhabited by turtles are frequently places where illegal dumping of hazardous wastes takes place.