Arctic benthos in the Anthropocene: Distribution and drivers of epifauna in West Greenland

Sandra R. Maier*, Nanette Hammeken Arboe, Henrik Christiansen, Diana W. Krawczyk, Lorenz Meire, John Mortensen, Koen Planken, Kirstin Schulz, Anna Selma van der Kaaden, Tobias Reiner Vonnahme, Nadescha Zwerschke, Martin Blicher

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Albeit remote, Arctic benthic ecosystems are impacted by fisheries and climate change. Yet, anthropogenic impacts are poorly understood, as benthic ecosystems and their drivers have not been mapped over large areas. We disentangle spatial patterns and drivers of benthic epifauna (animals living on the seabed surface) in West Greenland, by integrating an extensive beam-trawl dataset (326 stations, 59–75°N, 30–1400 m water depth) with environmental data. We find high variability at different spatial scales: (1) Epifauna biomass decreases with increasing latitude, sea-ice cover and water depth, related to food limitation. (2) In Greenland, the Labrador Sea in the south shows higher epifauna taxon richness compared to Baffin Bay in the north. Τhe interjacent Davis Strait forms a permeable boundary for epifauna dispersal and a mixing zone for Arctic and Atlantic taxa, featuring regional biodiversity hotspots. (3) The Labrador Sea and Davis Strait provide suitable habitats for filter-feeding epifauna communities of high biomass e.g., sponges on the steep continental slope and sea cucumbers on shallow banks. In Baffin Bay, the deeper continental shelf, more gentle continental slope, lower current speed and lower phytoplankton biomass promote low-biomass epifauna communities, predominated by sea stars, anemones, or shrimp. (4) Bottom trawling reduces epifauna biomass and taxon richness throughout the study area, where sessile filter feeders are particularly vulnerable. Climate change with diminished sea ice cover in Baffin Bay may amplify food availability to epifauna, thereby increasing their biomass. While more species might expand northward due to the general permeability of Davis Strait, an extensive colonization of Baffin Bay by high-biomass filter-feeding epifauna remains unlikely, given the lack of suitable habitats. The pronounced vulnerability of diverse and biomass-rich epifauna communities to bottom trawling emphasizes the necessity for an informed and sustainable ecosystem-based management in the face of rapid climate change.

Original languageEnglish
Article number175001
Number of pages17
JournalScience of the Total Environment
Volume951
DOIs
Publication statusPublished - 15 Nov 2024

Keywords

  • Biodiversity
  • Biogeography
  • Biomass
  • Bottom trawling
  • Sea ice
  • Spatial heterogeneity

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