Gulf of Alaska

The Gulf of Alaska marine ecosystem supports Alaska's communities, valuable fisheries, and tourism. Climate change and ocean acidification threaten to disrupt marine life in the region. Shorter term extreme events, such as marine heat waves additionally exert pressure and push certain organisms temporarily beyond their ecological niche. If several extreme events happen at the same time, for example, the organisms are even more stressed. Our group collects and analyzes data, and conducts regional high resolution model simulations to better understand the Gulf of Alaska climate-ocean-ecosystem to develop adaptation strategies. Take a tour through our various Gulf of Alaska efforts. For example, we developed local climate indices, which describe past and predict future physical and chemical ocean conditions based on sea surface height. We provide past year's modeled ocean conditions as recommended by fishers and tribal organizations. We are also maintaining pH and pCO2 sensors at the Gulf of Alaska Observatory and collect and analyze discrete seawater samples for dissolved inorganic carbon, pH, and total alkalinity during the Northern Gulf of Alaska Long Term Ecological Research (NGA LTER) spatial surveys.

Our recent publication in AGU Advances indicates that compound heat, acidity and low oxygen extreme events have become more frequent and intense with time in the Gulf of Alaska, raising concerns for vulnerable parts of the ecosystem. We are working on model forecasts to provide advanced warning of compound extreme events, which will be useful to subsistence and commercial fisheries and marine resource managers as they develop climate adaptation strategies.

Timing of marine heat, acidification, and low oxygen extreme and compound extreme events at the shelf seafloor

 Area (%) affected by (a) marine heat (red), (b) positive [H+] (blue), (c) negative Ωarag (blue), (d) negative oxygen (green), (e) positive salinity (orange), and (f) triple (orange: negative oxygen, positive [H+], negative Ωarag, purple: negative oxygen, positive [H+], heat), and quadruple compound extreme events (negative oxygen, positive [H+], heat, negative Ωarag). The color bars indicate the intensities of the marine heat, acidification, and low oxygen extreme events in red, blue, purple, and green, respectively. The benthic area on the shelf is defined as the area with a bottom depth between 50 and 250 m depth. The intensity of the events was normalized to the maximum occurring intensity. From Hauri et al. 2024.