Browsing Irish Fisheries Investigations by Author "Briand, C."
Application of EDA (v 2.0) to Ireland: prediction of silver eel Anguilla anguilla escapementde Eyto, E.; Briand, C.; Poole, R.; O'Leary, C.; Kelly, F. (Marine Institute, 2016)Eel Density Analysis (EDA) is a modelling framework that can be used to estimate eel populations in aquatic habitats. Survey data (primarily electrofishing operations) are used to build predictive models describing the presence/absence and the density of eel. These models are then applied to the entire network of aquatic habitat in the area of interest to estimate the total population size. The fluvial (riverine) population of yellow eel in Ireland was estimated using the EDA (v2.0) model (Jouanin et al., 2012). A total fluvial population of 8,032,834 yellow eels and 200,821 silver eels (using a silvering rate of 2.5%) was estimated for 2011. Eel presence and abundance decreased as the distance to the sea increased, and the percentage of calcareous geology in the catchments decreased. Stock indictors (B0, Bbest and Bcurrent) were calculated from these yellow eel estimates to enable the display of precautionary diagrams for each EMU in Ireland. Lake production was also calculated for 2011, using empirical data from a small number of catchments. A precautionary diagram for this total production (fluvial and lacustrine habitat) is presented, and compared with previous estimates of stock indicators for Ireland.