An integrated analysis of the marine social-ecological system of the Strait of Georgia, Canada, over the past four decades, and development of a regime shift index

作者：Perry R Ian^*; Masson Diane

来源：Progress in Oceanography, 2013, 115: 14-27.

DOI：10.1016/j.pocean.2013.05.021

A Driver-Pressure-State-Impact conceptual model of the Strait of Georgia, Canada, was developed as a framework to characterise the low frequency temporal (regime-like) patterns of variability in this system since 1970, and to identify suitable indicators of these changes. Thirty-seven time series, including both bio-physical ("natural") and human variables, were assembled with sufficiently few missing years to permit multivariate statistical analyses. Principal component analyses identified regime-like shifts that correspond to those generally accepted for the NE Pacific (late 1970s; mid-1990s), plus an additional shift in the mid-1980s. Redundancy analyses identified significant relationships in which the natural and human explanatory driver/pressure variables accounted for 72% of the variability of the state/impact response variables. Partitioning this variance among the natural and human drivers/pressures attributed 4% to the natural drivers/pressures alone and 16% to the human drivers/pressures alone, but 53% to the interactions between natural and human drivers and pressures. Both sets of driver and pressure variables (natural and human) are therefore necessary to account for the patterns of variability of the state and impact variables in the Strait of Georgia. Redundancy analysis was also used to identify a reduced set of driver/pressure variables which accounted for a large proportion of the variability in the state and impact response variables: sea surface temperature, wind speed, the North Pacific Gyre Oscillation index, human population surrounding the Strait of Georgia, recreational fishing effort, and the number of hatchery releases of Chinook salmon (Oncorhynchus tshawytscha) into the Strait. A structural change analysis was used to identify significant changes in these six explanatory variables, and to identify regime shift years (including their 95% confidence intervals). A regime shift index for the Strait of Georgia was then constructed using a probabilistic causal network model. This model predicted the observed regime shift behaviour with a success rate of >70%. These six explanatory variables are proposed as leading indicators for low frequency changes (regime shifts) in the Strait of Georgia marine social-ecological system for use within a broader monitoring program.

• 出版日期2013-8