Seabirds as monitors of marine plastic pollution
type: CreativeWork
description: Small buoyant plastic items are one of the most pervasive and abundant marine pollutants. They pose significant environmental impacts, including threatening the health of marine life through plastic ingestion, necessitating efforts to reduce plastic leakage into the sea. To evaluate the effectiveness of mitigation strategies, it is essential to understand trends in marine plastic densities, types, and sources, which requires a reliable baseline for repeated assessments. While sea-surface net trawls are commonly used to monitor trends in small floating plastics at sea, they face several challenges. Seabirds, particularly petrels and albatrosses (order Procellariiformes), offer a practical alternative to net sampling as they often ingest and retain buoyant plastics encountered while foraging at sea, making them valuable indicators of this type of plastic pollution. However, few studies have thoroughly tested their utility. Larger species, such as albatrosses and giant petrels, typically ingest macroplastics items like bags, bottle lids, and fishery-related debris, which can often be traced back to specific sources. In contrast, smaller petrels, including storm petrels, prions, and shearwaters, tend to ingest smaller items like industrial pellets and fragments of larger plastic objects, whose sources are more challenging to identify. Due to their high propensity for ingesting plastics and their tendency to consume larger volumes, these smaller petrels may be particularly well- suited for monitoring ingested plastic loads over time. In Chapter 2, I assess trends in litter items collected at the nests of albatrosses and giant petrels breeding on Marion Island in the southwestern Indian Ocean, from 1996 to 2018. Temporal variation in litter composition and amounts were compared to data on Patagonian toothfish Dissostichus eleginoides fishing intensity in the area. Fishery-related litter abundance peaked during industry's height, declining in the following two decades. Oth…
abstract: Small buoyant plastic items are one of the most pervasive and abundant marine pollutants. They pose significant environmental impacts, including threatening the health of marine life through plastic ingestion, necessitating efforts to reduce plastic leakage into the sea. To evaluate the effectiveness of mitigation strategies, it is essential to understand trends in marine plastic densities, types, and sources, which requires a reliable baseline for repeated assessments. While sea-surface net trawls are commonly used to monitor trends in small floating plastics at sea, they face several challenges. Seabirds, particularly petrels and albatrosses (order Procellariiformes), offer a practical alternative to net sampling as they often ingest and retain buoyant plastics encountered while foraging at sea, making them valuable indicators of this type of plastic pollution. However, few studies have thoroughly tested their utility. Larger species, such as albatrosses and giant petrels, typically ingest macroplastics items like bags, bottle lids, and fishery-related debris, which can often be traced back to specific sources. In contrast, smaller petrels, including storm petrels, prions, and shearwaters, tend to ingest smaller items like industrial pellets and fragments of larger plastic objects, whose sources are more challenging to identify. Due to their high propensity for ingesting plastics and their tendency to consume larger volumes, these smaller petrels may be particularly well- suited for monitoring ingested plastic loads over time. In Chapter 2, I assess trends in litter items collected at the nests of albatrosses and giant petrels breeding on Marion Island in the southwestern Indian Ocean, from 1996 to 2018. Temporal variation in litter composition and amounts were compared to data on Patagonian toothfish Dissostichus eleginoides fishing intensity in the area. Fishery-related litter abundance peaked during industry's height, declining in the following two decades. Oth…
author: Perold, Vonica
language: en
keywords: Seabirds, Marine plant, Pollution
date published: 2025
date modified: 2026-07-22T22:22:50Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Biological Sciences

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/41897