Climate change impacts to foraging seascapes for a highly migratory top predator

Area of Science:

• Marine Ecology
• Climate Change Biology
• Fisheries Science

Background:

• Climate change alters marine species distribution and movement globally.
• Correlative models may fail under novel environmental conditions, omitting key habitat drivers.
• Highly migratory species like albacore tuna are particularly vulnerable to climate-driven habitat shifts.

Purpose of the Study:

• Investigate spatial variability in energetic seascapes for juvenile North Pacific albacore tuna.
• Understand mechanisms of energy gain/loss and their link to ocean conditions.
• Quantify future changes in thermal and foraging habitats under climate change.

Main Methods:

• Combined laboratory measurements, field observations, and environmental predictors.
• Developed Generalized Additive Models (GAMs) for energy dynamics.
• Applied GAMs to Earth system model projections for historical and future periods.

Main Results:

• Albacore seasonally migrate between California Current and offshore North Pacific feeding grounds.
• Thermal corridors align with minimum metabolic costs; future warming may reduce subtropical habitat.
• Forage availability may offset thermal habitat loss, with coastal areas becoming more favorable.

Conclusions:

• Energetic seascapes provide mechanistic insights into projected habitat changes for migratory species.
• Moving beyond temperature is crucial for understanding climate impacts on marine species.
• Further research on migration mechanisms, physiology, and plasticity is needed for pelagic ecosystem predictions.