[DSRP Evidence](https://dsrpevidence.org/)

# Pacific Bluefin Tuna maintain trophic stability despite shifting diet composition over 12 years in the California Current Ecosystem

Richards et al., 2026, Scientific Reports — Ecology

Patterns: [Distinctions](https://dsrpevidence.org/pattern/distinctions), [Systems](https://dsrpevidence.org/pattern/systems)

## In short

A system-level relational property (trophic position) can stay invariant even as the specific parts composing it (prey species) are substantially swapped out, showing the whole's function is decoupled from its particular parts.

## What they found (results)

Stomach-content and isotope analysis over 12 years found tuna diet composition shifted markedly from cephalopod-dominated to anchovy- and deep-sea-fish-dominated, yet trophic position estimates (4.3-4.7) remained stable throughout.

These researchers were not testing DSRP. The finding is theirs; the correspondence to DSRP is drawn by this site.

[Source](https://doi.org/10.1038/s41598-026-66804-7)