How does the widespread loss of kelp forests
impact subtidal ecosystems in the Aleutian archipelago?
The widespread loss of sea otters from the Aleutian Archipelago has lead to a dramatic increase in sea urchin abundance and subsequent declines in forest forming kelps in recent decades. While the Aleutian coastal habitats are now dominated by urchin barrens, small patchy forests persist in some areas, which provide excellent opportunities for comparison between the two habitats. What remains unclear are the larger consequences in ecosystem function such as benthic primary production, biodiversity and community structure, and ultimately net ecosystem production (NEP).
Benthic Primary Productivity
To estimate changes to NEP across islands with kelp loss we will use:
(1) Benthic primary production chambers and incubation bags
(2) Shipboard incubations experiments conducted on common flora and fauna to estimate individual rates of photosynthesis and respiration
(3) Remote sensing (satellite imagery) to estimate long-term and large-scale changes of kelp
To estimate community changes across islands with kelp loss we will compare:
(1) Nearshore benthic biodiversity
(2) Nearshore community structure (biomass, abundance, and size structure)
(3) Offshore benthic biodiversity
(4) Offshore benthic community structure (biomass, abundance, and size structure)