Spiny Dogfish Welfare in Commercial Fisheries

The spiny dogfish is among the most heavily fished shark species in the world. Its welfare in trawl fisheries and as a food and oil source is largely unregulated.

Key Facts

Spiny dogfish are the most abundant shark species in the North Atlantic
They have one of the longest gestation periods of any vertebrate at up to 24 months
Females do not reach sexual maturity until 12-20 years of age
They were historically overfished to near collapse in the North Atlantic
Spiny dogfish are the primary source of fish and chips in the UK, sold as rock salmon
Their liver oil was widely used in cosmetics and machinery before synthetic alternatives

Welfare Considerations

Spiny dogfish are caught in enormous quantities by bottom trawls — a fishing method that causes significant trauma through net abrasion, pressure changes, and prolonged confinement. Their slow reproductive rate means populations are slow to recover from fishing pressure. Fish caught in bottom trawls experience severe crowding and barotrauma during retrieval. Spiny dogfish are often discarded as bycatch when quota species are targeted, dying from injuries sustained in the trawl. Their low fecundity makes population-level welfare harms especially persistent.

What You Can Do

Ask your fish and chip shop what species they use and whether it is sustainably sourced
Support campaigns for stronger shark fishing regulations in the North Atlantic
Avoid cosmetics containing shark liver oil (squalane from shark sources)
Choose plant-based squalane sourced from sugarcane or olives instead