Even as customs workers in Chile planned a second strike in mid-June, farmed salmon prices remain steady, buyers say. And, since the projected high Alaska salmon run has not yet come to fruition, fresh, wild sockeye prices are still strong.

However, buyers expect Chilean prices to soften as U.S. retail chains such as Costco drop Chilean salmon because of concerns over antibiotic use in production. “Chile is problematic, especially with antibiotic concerns. Retailers [in addition to Costco] ar…