Diet of the southern opah Lampris immaculatus on the Patagonian Shelf; thesignificance of the squid Moroteuthis ingens and anthropogenic plastic

The diet of the large pelagic fish, the southern opah Lampris immaculatus w as examined along the Patagonian Shelf in the Falkland Islands region. Stom achs were available for 69 fish collected in 1993 and 1994. Surprisingly, t his fish had a relatively narrow range of prey items. The single most frequ ent prey item was the onychoteuthid squid Moroteuthis ingens (predominantly juveniles) which was eaten by 93% of the fish. The other important prey we re the loliginid squid Loligo gahi, the myctophid fish Gymnoscopelus nichol si and the southern blue whiting Micromesistius australis. There was no evi dence of larger individuals of L. immaculatus ingesting larger individuals of any of the 4 main prey species. An unexpected finding was the relatively high incidence of plastic ingestion (14 % of fish). The plastic came from a variety of sources including food, napkin and cigarette wrappers and vari ous pieces of plastic line and straps used in securing boxes. In several in stances, there was evidence of feeding on fishing boat discards. The findin gs reveal a significant impact of plastic pollution in this region of the S outhwest Atlantic.