Evidence of an unreported negative effect of fisheries discards on seabirds: death by choking on the Atlantic Midshipman, Porichthys porosissimus, in southern Brazil

摘要

The effects of the fishing industry on the marine environment have been studied and described over the past two decades. Trawl-netting is a common but non-selective method of fishing that often captures non-target specimens of no commercial value that are discarded at sea. We discovered an unreported threat caused by fisheries discards on seabirds attending fishing activities in Brazilian waters: choking by feeding on discarded Atlantic Midshipman (Porichthys porosissimus). Over 6 years of monitoring (2007-13), we recorded five procellariiform species - Atlantic Yellow-nosed Albatross (Thalassarche chlororhynchos), Cory's Shearwater (Calonectris diomedea), Sooty Shearwater (Ardenna grisea), Great Shearwater (Ardenna gravis) and Manx Shearwater (Puffinus puffinus) - dead on beaches with Atlantic Midshipman stuck in their throats and showing evidence of death by suffocation as a result of blockage of the airways through choking. This phenomenon has not been consistently described, and the consequences of the consumption of fishery discards by seabirds in Brazilian waters remain poorly understood.