- Predicting recruitment, which is dependent on parent stock size and climate, is vital for forecasting productivity of fish stocks. The effects of climate can be analyzed via the use of climate indices. Three climate indices, the Pacific Decadal Oscillation, the North Pacific Gyre Oscillation, and the Oceanic Niño Index, describe the main climate patterns of the Northeast Pacific Ocean. PDO was expected to be the most influential for the majority of fish stocks in the East Bering Sea region, NPGO for the Gulf of Alaska, and ONI for the West Coast. The data were split between 1988 and 1989 to account for the effects of a regime shift. Models were created with each climate index for each stock, then compared to find the index with the most influence. No region had a single climate index that best predicted the majority of stocks, either before or after the regime shift. The influence of the PDO was expected to decrease after the 1988/89 regime shift, which was confirmed. Understanding the effects of climate on recruitment, and recognizing how those effects change over time, will allow scientists and managers to better predict recruitment and maintain fish stocks at healthy levels.
- Key Words: Recruits per spawner ratio, climate indices, Northeast Pacific, regime shift