"We don't look at it as sustainability. It's about responsibility," Senior Buying Manager at US retail giant Walmart Trevyr Lester told IntraFish in the wings of the Seaweb Seafood Summit in Bangkok.

As one of the world's largest seafood buyers, the responsibility, needless to say, is huge, with all issues on the radar.

"We look at everything. Surety of supply as well as social, environmental and ethical issues.