Assessment of marine litter interactions with urban coral reefs in Okinawa, Japan

Ifenna Ilechukwu; Rocktim Ramen Das; Jue Alef Avanzado Lalas; Emmeline A Jamodiong; Anže Abram; Stéphane De Palmas; James Davis Reimer

doi:10.1016/j.marpolbul.2024.117248

Assessment of marine litter interactions with urban coral reefs in Okinawa, Japan

Mar Pollut Bull. 2024 Dec;209(Pt B):117248. doi: 10.1016/j.marpolbul.2024.117248. Epub 2024 Nov 11.

Authors

Ifenna Ilechukwu¹, Rocktim Ramen Das², Jue Alef Avanzado Lalas², Emmeline A Jamodiong², Anže Abram³, Stéphane De Palmas², James Davis Reimer⁴

Affiliations

¹ Molecular Invertebrate Systematics and Ecology (MISE) Laboratory, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa 903-0123, Japan. Electronic address: [email protected].
² Molecular Invertebrate Systematics and Ecology (MISE) Laboratory, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa 903-0123, Japan.
³ Molecular Invertebrate Systematics and Ecology (MISE) Laboratory, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa 903-0123, Japan; Department for Nanostructured Materials, Jozef Stefan Institute, 1000 Ljubljana, Slovenia.
⁴ Molecular Invertebrate Systematics and Ecology (MISE) Laboratory, Graduate School of Engineering and Science, University of the Ryukyus, Nishihara, Okinawa 903-0123, Japan; Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Okinawa 903-0123, Japan.

PMID: 39531831
DOI: 10.1016/j.marpolbul.2024.117248

Abstract

This study assessed different reef zones (lagoon, reef crest, reef slope) in three urban locations around Okinawa Island (Mizugama, Ginowan, Sunabe) and two marine protected areas around nearby Aka Island (Hizushi, Sakubaru) for marine litter pollution and litter interactions with reef organisms. A total reef area of 2250 m² was surveyed by scuba diving, and 46 marine litter items were recorded. Litter density ranged from 0.01 to 0.05 items/m², and plastics (76.09 %) and metals (15.22 %) were the most common litter types. The substrates for litter items were live corals (52.17 %), followed by dead corals and algae (26.09 %), sand (13.04 %), and rocks (8.70 %). Litter items on live corals were entangled exclusively with branching Acropora spp. (95.83 %) and Pocillopora spp. (4.17 %). This study highlights the need to protect coral reef ecosystems from the impacts of urbanisation in order to conserve and sustain their ecological and economic benefits.

Keywords: Acropora; Ghost fishing gears; Marine debris; Plastic pollution; Pocillopora; Seafloor.

MeSH terms

Animals
Anthozoa*
Coral Reefs*
Environmental Monitoring*
Japan
Plastics / analysis
Urbanization

Substances

Plastics