Program on the Environment

Blue whale is an endangered species that plays a major role in maintaining healthy marine ecosystems as a top predator. However, studies have found that ship strike is a significant source of mortality for blue whale populations and thus limits their recovery. Recent advances in ocean modeling offer new opportunities for protecting marine species, and one such model is National Oceanic and Atmospheric Administration (NOAA)’s dynamic ensemble model, which predicts blue whale distributions in near real-time with a highly predictive accuracy. The model can decrease ship strikes by providing real-time whale location updates for shipping vessels. However, shipping vessels have to schedule their routes four days ahead, requiring only future blue whale predictions. The purpose of this study is to evaluate NOAA’s ensemble model’s predictive skill for estimating blue whale distributions 1-30 days into the future. To accomplish this task, I used the prediction maps from the ensemble model for the years 2000-2018 and calculated the average similarities between maps at 1-30-day lags. Findings show that NOAA’s model can predict blue whale distributions 30 days ahead with a 97.5% accuracy in the summer, and 4 days ahead with a 98% accuracy year-round. The existence of a large positive value of persistence over a range of a 30-day time scale illustrates that the blue whale habitat suitability trends are highly likely to be preserved over these time intervals. Hence, shipping vessels can use the model to reduce ship strikes and maintain marine ecosystems without compromising the economic productivity of shipping activities.