Physiological and biochemical effects of microplastics on corals: Environmental and ecological impacts and mitigation strategies and policy options

Microplastic pollution is a growing concern for coral reef ecosystems. It is adversely affecting coral health, biodiversity, and overall resilience. microplastics alter coral feeding behaviour which may reduce the food intake and energy depletion. The main objective of this paper is to discuss the altered physiological and biochemical behaviors of corals, related to bleaching, tissue necrosis, reproduction, occurred due to microplastic and microplastic-associated contaminants in marine ecosystems. The ingestion of microplastics induces oxidative stress in coral tissues by triggering the excessive production of reactive oxygen species (ROS) which may weaken the coral defense mechanisms and make them more vulnerable to diseases. Reproductive success is compromised as microplastic exposure reduces larval settlement and survival rates. microplastics also act as vectors for contaminants such as heavy metals, persistent organic pollutants (POPs), and pathogenic microorganisms. Moreover, the anthozoan-algae symbiotic relationship, fundamental to coral survival and reef building, is threatened by microplastic pollution, which can trigger coral bleaching. To mitigate the impacts of microplastic pollution in coral ecosystems, it is essential to develop and to use biodegradable alternatives of traditional plastics. Additionally, large-scale ocean clean-up initiatives related to plastic waste reduction, public awareness, and the international regulations on plastic waste management are also essential steps in this regard. • Microplastic pollution leads to reduced food intake and energy depletion in corals. • Microplastics induce oxidative stress in coral tissues, leading to diseases. • Microplastics also act as vectors for contaminants, affecting corals. • Anthozoan-algae symbiotic relationship is affected by microplastic pollution • International cooperation is required to mitigate microplastic pollution in coral ecosystems.