Identification and mapping of bottom fish assemblages in Davis Strait and southern Baffin Bay

Abstract

The bathymetry of Baffin Bay, with shallow sills both to the north and south, creates a relatively isolated body of deep polar water, unique among the Arctic Seas. During 263 trawl hauls completed during October 1999 and September to November 2001, 116 fish species were collected in Davis Strait and the southern Baffin Bay (61°44.1′ N–73°52.8′ N, depths of 145–1484 m). The abundance data for the 80 benthic species were used for analyses of the fish fauna diversity and fish assemblages. As a first step, seven assemblages were found by a standard type of cluster analysis. A Bayesian multinomial logit model was then applied to calculate vectors of probabilities defining the likelihood of each haul belonging to each of the seven clusters. The spatial distribution of the conditional probabilities for each cluster (assemblage) was mapped by means of a geostatistical tool. Each assemblage was further defined by indicator species, depth, and temperature. Four of the assemblages were found in Baffin Bay, two in Davis Strait and one mainly in Davis Strait but scattered into Baffin Bay.