Interaction of elasmobranchs with litter in South Brazil: ingestion and oviposition patterns

Abstract

Elasmobranchs, one of the most endangered animal groups, have been affected by different anthropogenic stressors, including marine litter. To better understand the interactions of elasmobranchs with litter we analyzed the gastrointestinal tract of sharks and examined skate nest composition in southern Brazil. Among 47 sharks caught in longline fisheries, three had ingested mesoplastic items (FO = 6.4 %); a subsample of 18 of these sharks was assessed for microplastic ingestion, revealing 34 microplastics in 12 individuals (FO = 66 %). Gillnet-captured sharks (n = 7) only ingested three microplastics (FO = 42.85 %). Sixteen skate nests examined for litter interaction presented a total of 269 egg capsules and 1676 litter items. The FO of litter in nests was 100 %, with plastic being the predominant material (96.71 %), mainly fishing lines (85.98 %). While litter ingestion by sharks was less frequent than other groups, litter prevalence in skate nests was high and primarily linked to fishing activities.

Keywords: Habitat alteration; Plastic ingestion; Plastic pollution; Shark; Skate.