Mesophotic coral reef

Mesophotic coral ecosystem in the Marshall Islands. Photo by Luiz A. Rocha.

A mesophotic coral reef or mesophotic coral ecosystem (MCE), originally from the Latin word meso (meaning middle) and photic (meaning light), is characterized by the presence of both light-dependent coral and algae, and organisms that can be found in water with low light penetration. Mesophotic coral ecosystems occur at depths beyond those typically associated with coral reefs as the mesophotic ranges from brightly lit to some areas where light does not reach.[1] Mesophotic coral ecosystem (MCEs) is a new, widely-adopted term used to refer to mesophotic coral reefs, as opposed to other similar terms like "deep coral reef communities" and "twilight zone", since those terms sometimes are confused due to their unclear, interchangeable nature.[2][3][4] Many species of fish and corals are endemic to the MCEs making these ecosystems a crucial component in maintaining global diversity.[1] Recently, there has been increased focus on the MCEs as these reefs are a crucial part of the coral reef systems serving as a potential refuge area for shallow coral reef taxa such as coral and sponges. Advances in recent technologies such as remotely operated underwater vehicles (ROVs) and autonomous underwater vehicles (AUVs) have enabled humans to conduct further research on these ecosystems and monitor these marine environments.[1]

Mesophotic coral reefs also serve as a transition zone between shallow and deep-sea environments which creates a specialized and unique biodiversity for the MCEs.[5] They normally occur between 30 meters (130 ft) and up to 150 meters (490 ft) in tropical and subtropical water. The upper mesophotic is 30m to 60m in depth while the lower mesophotic is 60m to 150m. In some areas such as the American Samoa mesophotic reefs contain 80% of corals while the rest inhabits the shallow reefs (30m to 0m).[6] They are distributed globally but remain mostly understudied.[5] Basic information on the taxonomic composition, depth range, habitat preferences, and abundance and distribution of the mesophotic coral ecosystem is limited.[7]

  1. ^ a b c Turner, Joseph A; Babcock, Russell C; Hovey, Renae; Kendrick, Gary A (2017-12-01). Degraer, Steven (ed.). "Deep thinking: a systematic review of mesophotic coral ecosystems". ICES Journal of Marine Science. 74 (9): 2309–20. doi:10.1093/icesjms/fsx085. ISSN 1054-3139.
  2. ^ Sellanes J, Gorny M, Zapata-Hernández G, Alvarez G, Muñoz P, Tala F (2021). "A new threat to local marine biodiversity: filamentous mats proliferating at mesophotic depths off Rapa Nui". PeerJ. 9: e12052. doi:10.7717/peerj.12052. PMC 8395573. PMID 34513338.
  3. ^ Loya, Yossi; Puglise, Kimberly A.; Bridge, Tom C.L., eds. (2019). Mesophotic Coral Ecosystems. Coral Reefs of the World. Vol. 12. doi:10.1007/978-3-319-92735-0. ISBN 978-3-319-92734-3. ISSN 2213-719X. S2CID 199492314.
  4. ^ Baker E, Puglise KA, Colin PL, Harris PT, Kahng SE, Rooney JJ, Sherman C, Slattery M, Spalding HL (2016). "What are mesophotic coral ecosystems?". In Baker EK, Puglise KA, Harris PT (eds.). Mesophotic coral ecosystems—A lifeboat for coral reefs?. Nairobi and Arendal: The United Nations Environment Programme and GRID-Arendal. p. 98. ISBN 978-82-7701-150-9. OCLC 950914195.
  5. ^ a b Lesser, Michael P.; Slattery, Marc; Mobley, Curtis D. (2018-11-02). "Biodiversity and Functional Ecology of Mesophotic Coral Reefs". Annual Review of Ecology, Evolution, and Systematics. 49 (1): 49–71. doi:10.1146/annurev-ecolsys-110617-062423. ISSN 1543-592X.
  6. ^ Cite error: The named reference :8 was invoked but never defined (see the help page).
  7. ^ Kahng, S. E.; Garcia-Sais, J. R.; Spalding, H. L.; Brokovich, E.; Wagner, D.; Weil, E.; Hinderstein, L.; Toonen, R. J. (2010-06-01). "Community ecology of mesophotic coral reef ecosystems". Coral Reefs. 29 (2): 255–275. doi:10.1007/s00338-010-0593-6. ISSN 1432-0975.