Roads, for better or worse, result from the human need to interact with the environment for commerce, resource management, or recreation. Historically, roads have often been located adjacent to rivers and may intersect them several times along their route, requiring the establishment of road crossings. These can alter the geomorphic processes of rivers and streams, and harm aquatic species. Rivers are dynamic and need to erode, transport sediments and stay connected with their floodplains. These fluvial processes may run counter to the long term stability of static structures such as roads, resulting in risk management issues. The adoption of river regulation and mitigation measures to address human concerns can alter aquatic habitats by increasing fine sediment load, modifying the thermal regime and reducing habitat diversity. For biota, the loss of connectivity can harm migratory species that need extensive access to rivers to complete their life cycle. Habitat homogenization and degradation resulting from human actions to mitigate risks from stream-road interactions affect not only migratory species, but those whose life cycles play out over smaller spatial scales.
The objective of the symposium is to bring together professionals from various disciplines in order to share ideas and science about the following issues:
- Effects of roads on physical characteristics of rivers and impacts on riverine habitats.
- Consequences of roads and road crossings on aquatic organisms and fish species.
- The concept of a freedom space for rivers and its challenges.
- Response of fish populations and communities to restored longitudinal connectivity
The symposium will bring an interdisciplinary perspective on the interactions between road and drainage networks in order to better understand the above processes, to develop an integrated approach to road and river management to minimize impacts on fish populations, and to understand how aquatic biota respond to restored connectivity.