Beyond Traditional Methods: Multi-Technique Approaches to Unlock the Trophic Secrets of Predatory Marine Fishes

The importance of predatory marine fishes, which play vital roles as apex and middle predators in food webs, is widely recognized. Among these, elasmobranch populations (sharks, rays, and skates) are of critical conservation concern. The IUCN considers many of these populations threatened globally, with basins like the Mediterranean Sea acting as hotspot threat zones. The primary risks they face, including overfishing, bycatch, habitat loss, and pollution, threaten the stability of marine ecosystems. Deepening our understanding of their diets and trophic interactions is vital to uncovering their ecological roles, migration patterns, and habitat use, which directly supports the definition of key feeding grounds and the establishment of Important Shark and Ray Areas (ISRAs).

However, our knowledge of the trophic ecology of predatory marine fishes remains highly fragmented. Traditional studies have often relied on a single methodology (e.g., stomach content analysis or stable isotope analysis), providing only a snapshot of feeding dynamics. To build a comprehensive picture, there is an urgent need to combine and integrate multiple methodologies that capture trophic dynamics across different spatial and temporal scales.

This Research Topic aims to address these data gaps by exploring the trophic ecology of predatory marine fishes, with a particular focus on elasmobranchs, through the lens of multidisciplinary and integrated approaches. By combining dietary, biogeochemical, and molecular techniques, we can achieve a high-resolution, long-term understanding of marine predator feeding habits, dietary preferences, resource partitioning, and broader food web dynamics.

We welcome original research, methods, reviews, and perspective articles addressing, but not limited to, the following core directions:
- Traditional and emerging approaches to diet reconstruction: The development, application, and comparison of methodologies including stomach content analysis, stable isotopes, fatty acid profiles, compound-specific stable isotope analysis (CSIA), and DNA metabarcoding (including non-lethal methods like anal swabs and gastric lavage).
- Trophic niche, resource partitioning, and food web dynamics: Studies investigating how predatory fishes partition resources, share habitats, or compete, and how these interactions shape overall marine food web structures.
- Ontogenetic, spatial, and temporal variation in feeding ecology: Unraveling how predator diets shift across life stages, habitats, geographical regions, and seasons.
- Comparative studies on teleost fishes and other marine predators: Research providing broader ecological insights relevant to marine food webs, facilitating comparisons between bony predatory fishes and cartilaginous species.
- Conservation and management applications: Using trophic data to identify key feeding grounds and predator aggregations to support marine management decisions and spatial planning, such as ISRAs.