Microplastic in a macro filter feeder: Humpback whale Megaptera novaeangliae

Area of Science:

• Marine Biology
• Environmental Science
• Ecotoxicology

Background:

• Marine filter feeders, including baleen whales, ingest small particles from large water volumes.
• Previous research documented macroplastic presence in baleen whales.
• The impact of microplastic on baleen whale health remains under-investigated.

Purpose of the Study:

• To investigate the presence and types of microplastics in the gastrointestinal tract of a baleen whale (Megaptera novaeangliae).
• To characterize the polymer composition and physical forms of ingested microplastics.
• To understand the implications of microplastic ingestion for baleen whale populations.

Main Methods:

• Gastrointestinal tract contents were sieved, dissolved in potassium hydroxide, and washed.
• Potential synthetic polymer particles were isolated based on density and appearance.
• Fourier transform infrared (FTIR) spectroscopy was used for polymer identification.

Main Results:

• Microplastics were identified in the intestines of Megaptera novaeangliae, marking the first such finding in this species.
• Multiple polymer types were detected, including polyethylene, polypropylene, polyvinylchloride, polyethylene terephthalate, and nylon.
• Ingested microplastics presented in various shapes, such as sheets, fragments, and threads, ranging from 1mm to 17cm.

Conclusions:

• This study provides the first evidence of microplastic contamination in baleen whale intestines.
• The diverse range of polymer types and particle shapes reflects the varied nature of marine plastic pollution.
• The findings suggest that baleen whales ingest microplastics due to their unselective filter-feeding mechanisms, posing a potential threat to their health.