Glacial recession and creation of new watersheds in coastal Alaska
University of Birmingham
Glacier recession in the mountains of coastal Alaska and to a lesser extent the Pacific northwest has created a large number of new stream systems that have been, and could continue to be with further glacier retreat, colonised by anadromous salmon species creating new stocks that contribute to both commercial and sport fisheries. Estimates from modelling approaches indicate potentially ~13,000 km of new river habitat will be created that can be colonized by Pacific Salmon by the year 2100 between southern British Columbia and Alaska. Southeast Alaska represents an area of significant potential gains in salmon habitat. In contrast, loss of alpine glaciers in southern British Columbia, and the lower 48 states may contribute to negative hydrological and temperature conditions that limit salmon populations. Studies in Glacier Bay southeast Alaska, where rapid glacial recession has created watersheds of different habitat complexities and successional states, provide indications of the key factors influencing the resilience of these systems to extreme events linked to climate change. The speaker, who was a lead author on the recent IPCC special report on oceans and the cryosphere in a changing climate, will weave in some of the key findings for the Pacific Northwest region from this report in relation to precipitation, runoff, hazards and ecosystem services.