Estuarine small fish including gobies and sticklebacks live in challenging tidal environments, with welfare shaped by pollution, habitat change, and the unique stresses of intertidal life.
Estuarine small fish welfare sits at the intersection of robust welfare science and practical conservation challenge. Three-spined sticklebacks have become a model species for fish welfare research precisely because of their tractability in laboratory settings: studies have demonstrated pain avoidance behaviour, the effectiveness of analgesics in reducing pain responses, and cognitive bias changes associated with negative welfare states. This research provides scientific grounding for taking stickleback welfare seriously. In their natural estuarine habitat, sticklebacks and gobies experience acute welfare challenges from hypoxia events, temperature extremes, and predator pressure that are intensified by pollution and habitat loss. The bycatch of small estuarine fish in trawl gear represents a welfare harm that is largely invisible because these species are discarded rather than landed commercially. Estuarine habitat restoration - including salt marsh restoration, pollution reduction, and removal of artificial barriers to tidal flow - benefits the full community of estuarine fish by restoring the habitat complexity that supports natural behavioural repertoires and reduces the physiological stress of habitat degradation.