Species aggregation models resolve essential foraging habitat: Implications for conservation and management

Area of Science:

• Marine ecology
• Oceanography
• Biodiversity modeling

Background:

• Predicting species aggregations is crucial for understanding marine biodiversity and ecosystem dynamics.
• Traditional species distribution models (SDMs) often fail to capture pelagic species aggregation patterns.
• Seabirds serve as valuable, quantifiable indicators of pelagic ecosystem health and distribution.

Purpose of the Study:

• To develop and apply species distribution models (SDMs) to predict seabird aggregation dynamics.
• To identify the physical oceanographic drivers influencing the location and intensity of seabird aggregations.
• To enhance the realism and utility of pelagic SDMs for ecological and conservation applications.

Main Methods:

• Utilized a 20-year seabird observation record and a regional ocean modeling system.
• Employed a two-step SDM approach: presence/absence modeling and binary aggregation modeling.
• Integrated a conceptual ecosystem model to organize environmental covariates related to habitat production.

Main Results:

• Developed realistic spatial distribution patterns for seabird aggregations, reflecting known habitat associations.
• Observed mixed temporal responses in aggregation indices, influenced by ocean-climate variations and mesoscale structures.
• Found that abundant species aggregated more during warmer years, suggesting reduced foraging habitat availability.

Conclusions:

• Seabird aggregation models can improve the realism of pelagic SDMs and assess trophic interactions.
• Aggregation occurrence models provide a potential early warning system for ecosystem shifts based on ocean-climate conditions.
• These models offer significant utility for conservation applications, including bycatch reduction and spatial planning for offshore activities.