Research Document - 2012/003

Arctic Marine Biodiversity: Indicators for Monitoring Coral and Sponge Megafauna in the Eastern Arctic

By E. Kenchington, T. Siferd, and C. Lirette

Abstract

Cold-water corals and sponges are important to ecosystem function and biodiversity in polar environments. The general distribution of these taxa in the Eastern Arctic has been determined from the bycatch of research trawl surveys for shrimp and Greenland halibut. Trawl survey data are not ideal for quantifying biomass and abundance of these organisms. However, at this time trawl survey data are the only data that provide a broad spatial coverage and annual time series. Here we discuss nineteen potential indicators for monitoring coral beds and sponge grounds. We suggest the ecological and biological properties of these habitats that they reflect. Established state indicators are drawn from the Arctic Council Circumpolar Biodiversity Monitoring Marine Plan and the Gully MPA monitoring plan, while stressor indicators are drawn from the European Commission Marine Framework Strategy Directive. Novel indicators are proposed for each; specifically a suite of geospatial state indicators which reflect trends in habitat fragmentation, reproductive processes and distribution, and stressor indicators to capture likely threats from changes to ocean acidification, ocean circulation and food supply in addition to those of fishing with bottom contact gear. Geo-referenced biomass/abundance data by species allow for the calculation of nine of the twelve state indicators. Further information on the proportion of live:dead fauna, percent infestation with zoanthid anemones and size structure completes the data requirement for state indicators. For six of the indicators we construct a six year (2005-2010) time series using trawl survey data from a common area (Shrimp Fishing Area 2EX) in the Eastern Arctic. We evaluate their performance as useful indicators to monitor coral beds and sponge grounds in light of climate change projections for this area. The need to have both state and stressor indicators is discussed.

Complete document (PDF, 2372 KB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.