Fish longitudinal continuity assessment

Fish longitudinal continuity assessment

Type

Hydromorphological assessment methods

Brief description

Methods for fish longitudinal continuity assessment aim to assess the impact that cross-sectional structures (i.e. barriers) have on the movement and migration of fish communities. While early methods simply aim to obtain a database inventory of the location of barriers, more recent methods also attempt to assess the passability of barriers (mainly at the single barrier scale) both in terms of their structural characteristics and of the biological capacities of fish communities to pass them (e.g. swimming/jumping abilities, life history). We reviewed 20 methods in total (13 for European countries and 7 for non-European countries).

Strengths, limitations and gaps

Methods for longitudinal continuity assessment mainly consists of an inventory of features or on an assessment of barrier passability at the single barrier scale, rather than on the effective assessment of river longitudinal continuity at the catchment scale. Despite recent progress, efforts are still needed to combine small scale assessment and large scale inventories, species biology, spatial/regional environmental diversity and river processes.