This article presents a novel application of the essential input welfare measure to valuing sportfishing harvest. The approach was suggested 30 years ago and has only been applied two other times with market data and has never been applied in the recreation context. We model boat fuel as an essential input in the production of sportfish harvested offshore and trace the value of changes in harvest quality with shifts in the demand for boat fuel. To implement the model we generate the first estimate of the demand for sportfishing boat fuel using the infrequent-purchases model. The estimate of boat fuel price elasticity is more than six times larger than typical estimates for the household demand for automobile fuel. Our estimates of the value of fishing quality are similar to estimates using stated preference and travel cost methods, but have the advantage of being based on market purchases.

JEL Codes: Q260, Q510, Q220.