Analysis of common trends in the feeding habits of main demersal fish species on the Flemish Cap

• Main Authors: Pérez-Rodríguez, Alfonso, Koen-Alonso, Mariano, González, Carlos, Saborido-Rey, Fran
• Format: Article in Journal/Newspaper
• Language: English
• Published: Northwest Atlantic Fisheries Organization 2011
• Subjects: Canada; Newfoundland; Labrador region
• Online Access: http://hdl.handle.net/10261/83589

30 páginas, 13 figuras, 10 tablas.-- SC WG on Ecosystem Approach to Fisheries Management This study describes the diet of core fish species in the Flemish Cap marine community, with emphasis in the changes observed between 1993 and 2008. The analysis was based on trophic species rather than biological ones; trophic species were defined within biological species on the base of diet homogeneity and fish size. Trophic species were divided into four trophic guilds; these guilds were characterized as benthic-pelagic invertebrate, benthic invertebrate, pelagic invertebrate, piscivorous feeders. The multi-year diet matrix for all trophic species was summarized using non-metric multidimensional scaling (MDS). The resulting 3D MDS plot representing the distribution of predators over time in trophic space provided the basic information for the study of common patterns in the diet within the trophic guilds. The MDS scores for each one of the first 3 MDS axes were use to describe the trajectories of the trophic species over time. These trajectories were analyzes using Dynamic factor analysis (DFA); these analyses also included proxy variables representing intra-guild competition, prey availability, and environmental drivers. Results indicate that diet overlap among species has increased in recent years as a consequence of generalized trends towards increasing shrimp and redfish consumption, as well as decreasing consumption of Hyperiidea, Ophiuroidea, Copepoda and Ctenophora. These changes in feeding habits appear to be related to changes in ecosystem availability of prey as well as variations in bottom temperature. The work was funded by the Spanish Government through an I3P PhD Fellowship, and partially by Fisheries and Oceans Canada (DFO) through the Ecosystem Research Initiative of the Newfoundland and Labrador Region, the NEREUS program. We Peer reviewed