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Project Description

Changes in the distribution and/or abundance of ecosystem engineers can have dramatic impacts on primary production and biodiversity. Nowhere may this be as dramatic as in the coastal zones of the Aleutian Archipelago where large declines in forest-forming kelps have occurred in recent decades due to sea urchin overgrazing. While the Aleutian coastal habitats are now dominated by urchin barrens, small patchy forests persist in some areas, which provide excellent opportunities for comparison. What remains unclear are the larger consequences of this loss to ecosystem services. Here, we ask two integrated questions: 1) How do the widespread losses of kelp forests impact benthic primary production across the Aleutian Archipelago? and 2) How do these kelp forest losses impact both onshore and offshore benthic biodiversity and community structure? To examine these questions, in situ and shipboard incubations will be conducted in both kelp forests and urchin barrens to examine both whole community and individual species rates of photosynthesis and respiration. Shipboard experiments for each species will be scaled by their ecosystem biomass and combined with in situ benthic chamber experiments of whole communities to estimate net ecosystem production. Benthic biodiversity and community structure within and offshore of each of these habitats will be assessed using diver surveys and shipboard benthic trawls. Along with these activities, remote sensing (satellite imagery) of the kelp canopies and historical data on benthic macroalgal abundances at these and other islands will be used to estimate the temporal and spatial patterns of these changes across the Archipelago.

Project Funding

National Science Foundation
Start Date: 2015-09-01
End Date: 0000-08-31

 

 

Research Team