As ocean temperatures warm, in particular the shallow Chukchi Sea, many organisms may spread into Arctic waters. Some of these present significant threats to human and ecosystem health, such as harmful algal bloom (HAB) species (commonly called red tides). The potent neurotoxins that these species produce can affect marine mammals, seabirds, and other resources critical to subsistence harvesters.
At the same time, little is known about the present and future risk from toxic algae to humans in the Pacific Arctic region. This study will be the first to document the current distribution of highly toxic HAB species over large spatial scales within the Alaskan Arctic and will provide estimates of areas at high risk of toxicity now and in a warming future. The hypothesis underlying this project is that HABs in Alaskan Arctic waters are not only transported from the south through Bering Strait but are now originating locally on the Chukchi shelf due to warming temperatures, circulation dynamics, and water mass structure. These factors influence bloom magnitude, duration, toxicity, and recurrence. This will be addressed through a joint physical-biological field and laboratory program to study the relationship between HAB species distribution/dynamics and the physical environment of the Chukchi Sea region.
The distribution of HAB species on the Chukchi shelf will be mapped in relation to hydrography and circulation, including a comprehensive survey of the Alaskan Coastal Current which transports the warmest water in the Chukchi Sea. A range of molecular and physiological tools will be used to investigate the origin, connectivity, and fate of HAB populations in the region. Sediment profiling will establish a historical record of blooms along the major transport pathways to the western Arctic. This information will be used to generate conceptual models of the origin, transport, and fate of HABs in the Chukchi Sea region.