Marine debris from recreational fishing and plastic ingestion in two Australian fishes
Plastic is ubiquitous in our oceans and directly and indirectly threatens marine habitat and biota. Interactions such as entanglement and ingestion of plastics can cause serious health consequences and are thought to lead to stunted growth, reproductive abnormality and mortality in species. Surprisingly, however, there is little evidence to back up these claims in local Sydney fishes. This thesis, which assesses the impacts of plastics and other forms of debris on eastern Australian fishes, has two sections. The first reviews published literature marine debris associated with recreational fishing and its impacts. While the review is a global assessment, particular reference is made to temperate eastern Australian waters. The second section directly assesses the prevalence of plastic ingestion in two commercially and recreationally-important, wild-caught fish species in coastal eastern Australian waters: bluespotted flathead (Platycephalus caeruleopunctatus) and tailor (Pomatomus saltatrix). In this pilot study, individuals are assessed for the presence of plastics in the gastrointestinal tract, the liver and the muscle, and results considered in light of their feeding and life history strategies. Outcomes of this preliminary research are relevant for ecologists, managers, fishers, as well as food safety regulating bodies and consumers.