Roads and highways often present significant challenges, not only for wildlife, but also for landscape modeling to evaluate terrestrial connectivity. Many highways and high traffic roads are assumed to be significant or severe barriers to wildlife. However, roads and highways are perforated by numerous stream crossings that range from small culverts to large bridges. Efforts are well established in the Northeastern U.S. to assess road-stream crossings for passability by fish and aquatic organisms, and the North Atlantic Aquatic Connectivity Collaborative (NAACC) was created in 2015 to help facilitate and coordinate these efforts. In 2019, the NAACC added a protocol, including electronic data forms and a scoring system, for assessing the suitability of stream crossings for passage by terrestrial wildlife. This protocol is a rapid assessment methodology for use during typical low-flow conditions, and involves data collection on the dimensions of crossing structures, as well as the presence and suitability of dry passage and the presence and severity of physical barriers. Wildlife are divided into six groups for purposes of assessing and scoring crossings for terrestrial passability. The protocol is designed to provide a rough assessment of the barrier effects of culverts and bridges on passability for a variety of terrestrial wildlife. Results of these assessments are being used to set resistance values for calculating landscape conductance, a Designing Sustainable Landscapes (DSL) metric for identifying areas of highest importance for connecting areas of high ecological value. These data will also be available for use in other efforts, such as the Connecting Habitat Across New Jersey (CHANJ) project, to model landscape connectivity and identify high-priority corridors for protection or restoration.
Climate change: adaptation, mitigation, resilience