Mesoscale activity facilitates energy gain in a top predator

Area of Science:

• Marine ecology
• Behavioral ecology
• Biophysical oceanography

Background:

• Understanding the link between animal movement, resource distribution, and fitness is crucial in ecology.
• Mesoscale ocean features (fronts, eddies) aggregate prey, influencing marine vertebrate distribution.
• The role of these features in energy transfer to top predators remains unclear.

Purpose of the Study:

• To investigate how migrating northern elephant seals utilize mesoscale ocean features.
• To quantify the energetic gains derived from seal foraging within these features.
• To assess the influence of the physical environment on predator fitness and trophic dynamics.

Main Methods:

• Tracking migrating northern elephant seals.
• Analyzing diving behavior and habitat selection in relation to oceanographic data.
• Quantifying daily energy gain based on foraging patterns.

Main Results:

• Northern elephant seals modified diving behavior and actively selected mesoscale features for foraging.
• Daily energy gain significantly increased with higher mesoscale activity.
• Areas of high mesoscale activity serve as foraging hotspots, enhancing energy transfer to seals.

Conclusions:

• The physical ocean environment significantly influences top predator fitness by controlling resource availability.
• Mesoscale features facilitate energy transfer across trophic levels in the marine environment.
• Understanding these biophysical couplings is vital for predicting the effects of environmental change on food webs and individual fitness.