Research

Aquatic Ecosystems

Key Findings

In its research on the relationship between climate and Pacific Northwest (PNW) aquatic ecosystems, the Climate Impacts Group (CIG) has:

Identified PDO Impacts on PNW Salmon Productivity and Abundance

• CIG research has found that during warm phases of the Pacific Decadal Oscillation (PDO), salmon are more plentiful than usual off the coast of Alaska but less plentiful off the Washington and Oregon coast. During cool phases of the PDO, the opposite is true. The findings have important implications for salmon management and recovery activities. (Mantua et al. 1997; Hare et al. 1999)

Developed an Empirical Model for Understanding and “Nowcasting” Oregon Coho Marine Survival

• The CIG has developed an empirical model for making skillful preseason run-size forecasts that can inform salmon resources managers and fishers up to six months prior to the harvest season. This simple environmental model relating observed Oregon coho salmon marine survival rates to changes in coastal ocean sea surface temperatures, winds, and sea level explains 75% of the variance in the model training period data (1969-1998). (Logerwell et al. 2003)

Identified North Pacific Ecosystem Regime Shifts

• A study jointly funded by the International Pacific Halibut Commission identified patterns of covariation among 69 biotic and 31 abiotic time series from the North Pacific and Bering Sea for the period 1965-1997. The leading pattern of covariability reproduced previously described features of the 1977 North Pacific climate and ecosystem regime shift. The second pattern of covariability identified sharp changes in about half the biotic variables taking place around 1989, with increases in Bering Sea Jellyfish and decreases in Bering Sea groundfish recruitment, Western Alaska chum salmon, west coast rockfish recruitment and coho salmon landing being among the prominent time series with strong 1989 changes. While the leading pattern had a strong association with large-scale climate changes in 1977, the 2nd pattern that suggested a 1989 ecosystem shift did not. (Hare and Mantua 2000)

Used Geoduck Shells to Reveal Climate Signals Over the Last 160 Years

• In an innovative study approach, the CIG used internal growth rings in geoduck shells (Figure 2) to identify climate signals since the 1840s. The research placed the 1990s as the warmest decade of the last 154 years for March through October sea surface temperatures in the Strait of Juan de Fuca (Figure 3). Other warm periods occurred during 1870s, the 1900s, and the years from 1926 to 1934. (Strom 2003)

Proposed Strategies for Coping with Climate Uncertainty in Fisheries Management

• The uncertainty associated with key global climate model-derived variables of interest to fishery scientists (sea surface temperatures, ENSO variability, coastal upwelling rates) is significant and unlikely to be significantly reduced in the near future. Rather than seeking predictive information, efforts to improve resource management should focus instead on explicit incorporation of environmental uncertainty in management frameworks and policies. (Mantua and Mote 2002; Mote and Mantua 2002)
• A review of the methods currently used to incorporate climate forecast information into salmon management and the potential for reducing fishery forecast errors with climate information, together with an examination of current fisheries management and research potential, suggests that stock/ecosystem monitoring offers many more immediate benefits to managing for sustainable fisheries than does a narrow focus on prediction (even with careful consideration of climate information). (Mantua and Francis, in review)