Temporal changes in microalgal biomass and species composition on different plastic polymers in nutrient-enriched...

Area of Science:

• Marine Biology
• Environmental Science
• Ecotoxicology

Background:

• Marine plastic debris (MPD) poses a threat to marine ecosystems.
• The role of MPD as a vector for harmful microalgae is not well understood.
• Impacts on marine organism habitats are uncertain.

Purpose of the Study:

• To investigate the role of different plastic polymers in supporting microalgae growth.
• To determine if MPD facilitates the transport of harmful algal bloom (HAB) species.
• To assess the impact of MPD on microalgae communities in marine environments.

Main Methods:

• Month-long experiments were conducted in 30 L microcosms.
• Six different plastic polymer plates (PP, LDPE, HDPE, PVC, PET, PS) were used.
• Changes in planktonic and periphytic microalgae were monitored over time.

Main Results:

• No significant differences in periphytic microalgae composition or biomass were found among plastic types.
• Nutrient depletion reduced planktonic microalgae but increased periphytic microalgae biomass.
• Abundance of HAB-causing benthic species, like Amphidinium operculatum and Coolia monotis, significantly increased on plastics over time.

Conclusions:

• Periphyton, including HAB-causing microalgae, readily colonize various plastic types.
• MPD can act as a vector for spreading microalgae, including HABs, to new regions.
• The findings highlight the potential ecological risks of MPD in marine ecosystems.