Marine debris — An emerging threat to the reef areas of Gulf of Mannar, India.

Underwater survey was conducted to assess the accumulation and impact of marine debris in the reef areas of Gulf of Mannar in southeast India. A combination of roving diver technique and belt transect method was applied for the assessment, which was conducted during the period between February 2018 and March 2019. An estimated total reef area of 1152 m² has been affected by marine debris. Abandoned fishing nets were found to constitute the major portion of 43.17 ± 5.48% of the marine debris. Live corals were found to be dominant substrates for marine debris with 39.11%. The average prevalence of coral colonies in contact with marine debris was 3.28 ± 0.27%. Prevalence of corals in contact with debris was very high in genus Acropora with 8.23 ± 1.29% followed by Montipora with 4.63 ± 1.29% due to their complex growth form. Of the corals in contact with debris, 47.56% were fragmented and 34% were found with tissue loss. Unlabelled Image • Focusing on the underwater accumulation of marine debris in the reef areas of GOM. • Debris composed of nets, ropes, lines and traps made of non-biodegradable plastics. • Live corals have been found to be the dominant substrate for marine debris. • Reef area of 1,152 m² has been affected by marine debris • Acropora and Montipora are the common coral genera most affected by marine debris. [ABSTRACT FROM AUTHOR]