Long-Term Observation Program (LTOP) Seward Line CTD data, Gulf of Alaska (1997-2010)

This project is a component of the integrated Long-term Monitoring of Marine Conditions and Injured Resources and Services submitted by McCammon et. al. The ocean undergoes year-to-year variability in the physical environment, superimposed on longerterm cycles, and potential long-term trends. These variations influence ocean chemistry, and propagate through the lower trophic levels, ultimately influencing fish, seabirds and marine mammals. Over the past 50 years the Northern Pacific appears to have undergone at least one clear regime shift, while the last 12 years have seen multi-years shifts of major atmospheric indices, leaving uncertainty about what regime the coastal Gulf of Alaska is currently in. Regime shifts are often expressed as fundamental shifts in ecosystem structure and function, such as the 1976 regime shift that resulted in a change from a shrimp dominated fisheries to one dominated by pollock, salmon and halibut. Long-term observations are also critical to describe the current state, and natural variability inherent in an ecosystem at risk of significant anthropogenic impact. Given the potential for such profound impacts, this dataset continues a multidisciplinary observation program which began in 1997 along the Seward Line and in PWS and will continue to assess the current state of the Northern Gulf of Alaska, during 2012-2017. Such observations form critical indices of ecosystems status that help us understand some key aspects of the stability or change in upper ecosystems components for both the short and longerterm. By analogy, the weather has been for more than a hundred years, yet regular observations are still needed to know what is happening and what can be expected in the near future.

This data was collected by Dr. Tom Weingartner of the Institute of Marine Science, University of Alaska Fairbanks for the Gulf of Alaska LTOP (Long Term Observation Project) funded by various funders. The area of coverage is the Gulf of Alaska during 1997-2010.