Microplastic Pollution in Marine Environment: Occurrence, Fate …
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metabolism, development, and reproduction of phytoplankton are all influenced by
microplastic contamination. The toxicity increases significantly with the decrease of
microplastics size.
The relationship between microplastics and microalgae interacted, some studies
also reported that microplastics can also affect the photosynthesis of algae. The
chlorophyll content and photosynthetic efficiency of algae are reduced under the
exposure of microplastics [78].
Mao et al. have reported that exposure to polystyrene (PS) microplastics causes
an oxidative stress response, cell membrane damage, and decreased photosynthetic
activity of chlamydomonas nucleolus [79]. Ting et al. have also shown that micro
polyvinyl chloride has adverse effects on chlorophyll content and photosynthetic efficiency of phytoplankton (dinoflagellates) [80]. Besides, when exposed to microplastics, the photosynthetic efficiency of phytoplankton such as Dunaliella declined by
45% [80]. Bhattacharya et al. reported that the content of chlorophyll in algal cells
would reduce when low-concentration polystyrene microplastics were exposed to
chlorella and phyllostrella, thereby reducing the efficiency of photosynthesis [75].
It increases the production of ROS in algal cells and causes apoptosis. Other studies
reported that the chlorophyll synthesis content and photosynthetic efficiency are
significantly decreased when polystyrene is exposed to phytophthora [81].
As the primary consumer of phytoplankton, zooplankton is also threatened
by microplastic pollution. Microplastics might be mistakenly taken and ingested
by any zooplankton, including rotifers, copepods, and polychaete worms [82].
Once ingested, microplastics can be transferred through the food chain from small
zooplankton to larger zooplankton [83].
Besides, microplastics attached to phytoplankton could be eaten by zooplankton,
which would be eventually transported by fecal particles to deep seabed sediments.
However, some researches have shown that when fecal particles contain microplastics, the subsidence rate of fecal particles decreases by 1.35 times, and they are more
likely to be broken [84], which makes microplastics more likely to float in the upper
water and has an impact on the degradation process of microplastics.
3.2 Impacts on Marine Benthic Communities
Benthic organisms play a vital role in the sediment environment, and different
benthic organisms can maintain the geochemical cycling process in sediments such
as the nitrogen cycle, by modifying sediments and regulating microbial activity
[85]. Benthic organisms with different functional characteristics can participate in
the maintenance of ecosystem functions, thereby improving the resilience of the
ecosystem in the sediment environment [86]. Therefore, the effect of microplastics
on benthic organisms is of great significance to the marine ecological environment.
The toxicity of microplastics to benthic organisms depends on whether they can
be enriched in benthic organisms. According to documented studies, the excretion of
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metabolism, development, and reproduction of phytoplankton are all influenced by
microplastic contamination. The toxicity increases significantly with the decrease of
microplastics size.
The relationship between microplastics and microalgae interacted, some studies
also reported that microplastics can also affect the photosynthesis of algae. The
chlorophyll content and photosynthetic efficiency of algae are reduced under the
exposure of microplastics [78].
Mao et al. have reported that exposure to polystyrene (PS) microplastics causes
an oxidative stress response, cell membrane damage, and decreased photosynthetic
activity of chlamydomonas nucleolus [79]. Ting et al. have also shown that micro
polyvinyl chloride has adverse effects on chlorophyll content and photosynthetic efficiency of phytoplankton (dinoflagellates) [80]. Besides, when exposed to microplastics, the photosynthetic efficiency of phytoplankton such as Dunaliella declined by
45% [80]. Bhattacharya et al. reported that the content of chlorophyll in algal cells
would reduce when low-concentration polystyrene microplastics were exposed to
chlorella and phyllostrella, thereby reducing the efficiency of photosynthesis [75].
It increases the production of ROS in algal cells and causes apoptosis. Other studies
reported that the chlorophyll synthesis content and photosynthetic efficiency are
significantly decreased when polystyrene is exposed to phytophthora [81].
As the primary consumer of phytoplankton, zooplankton is also threatened
by microplastic pollution. Microplastics might be mistakenly taken and ingested
by any zooplankton, including rotifers, copepods, and polychaete worms [82].
Once ingested, microplastics can be transferred through the food chain from small
zooplankton to larger zooplankton [83].
Besides, microplastics attached to phytoplankton could be eaten by zooplankton,
which would be eventually transported by fecal particles to deep seabed sediments.
However, some researches have shown that when fecal particles contain microplastics, the subsidence rate of fecal particles decreases by 1.35 times, and they are more
likely to be broken [84], which makes microplastics more likely to float in the upper
water and has an impact on the degradation process of microplastics.
3.2 Impacts on Marine Benthic Communities
Benthic organisms play a vital role in the sediment environment, and different
benthic organisms can maintain the geochemical cycling process in sediments such
as the nitrogen cycle, by modifying sediments and regulating microbial activity
[85]. Benthic organisms with different functional characteristics can participate in
the maintenance of ecosystem functions, thereby improving the resilience of the
ecosystem in the sediment environment [86]. Therefore, the effect of microplastics
on benthic organisms is of great significance to the marine ecological environment.
The toxicity of microplastics to benthic organisms depends on whether they can
be enriched in benthic organisms. According to documented studies, the excretion of