As humans continue to expand their range, the habitats of aquatic and terrestrial organisms are becoming increasingly lost or fragmented. Habitat fragmentation is detrimental to an ecosystem, as it hinders the organism from accessing certain parts of its habitat. Fragmentation can cut off an animal’s access to resources, such as shelter, food, and water. Additionally, terrestrial animals are more vulnerable to deadly interactions with vehicles as they attempt to cross the road.
Structures such as culverts and bridges allow organisms to safely move from one part of the ecosystem to another by going under roads rather than over them. However, these structures are not always well-maintained. Some culverts are old and clogged with debris, while others have caved in. Bridges and railroad crossings sometimes have structures that go down into the ground or stream, which could also inhibit the movement of the organisms.
Additionally, some of these structures can alter the function of the ecosystem. Culverts are often used to connect streams that cross roadway systems. If the culvert is too small compared to the width of the stream, it could slow water flow or cause erosion of the stream bed on the downstream side of the structure, which could ultimately impact the organisms living in the stream. What’s more, the structure may not be big enough for terrestrial animals, or may not even provide them with a passage to begin with.
There are thousands of these structures in New Jersey alone. How would we know which ones need to be restored?
In 2021, the Barnegat Bay Partnership (BBP), obtained a grant from the NJDEP’s Division of Fish and Wildlife’s Connecting Habitat Across New Jersey (CHANJ) program. Under this grant, the BBP is assessing over 150 priority road-stream crossings, using the North Atlantic Connectivity Collaborative (NAACC) guidelines. NAACC is a group of state and federal agencies, colleges, and other environmental organizations that strive to improve the connectivity of ecosystems. Using NAACC guidelines, the BBP is completing assessments at sites located within known wildlife corridors that connect core habitats where populations can thrive. These assessments will help identify road-stream crossings within these corridors that need restoration.
“We want to make sure that organisms small and large, terrestrial and aquatic, can still have a safe passage, regardless of human use of the area.”Kayla Racanelli- BBP Field and Lab Technician
The BBP stream-road crossing assessment field team, led by field technician Sammie Adamczyk, analyze the passability of aquatic and terrestrial crossings within the Barnegat Bay watershed. The team takes several measurements at the site including the height, width, and length of the crossing structure, as well as the width and depth of the stream. They also note whether there are any barriers blocking the passage that could potentially inhibit the crossing of wildlife.
When asked why this project is important, Kayla Racanelli, a field technician on the team, felt strongly about the road crossing assessments: “We want to make sure that organisms small and large, terrestrial and aquatic, can still have a safe passage, regardless of human use of the area.” The data that the team collects will be integral in the restoration process of these wildlife crossings.