The skeleton of massive reef-building corals records the past tropical-temperate environmental conditions in which they grow. Coral skeletal luminescence bands and/or lines irradiated by ultraviolet light have been used to investigate past precipitation and river flood. In pioneer studies involving investigation of coral luminescent bands, it was found that the distinct luminescent bands observed in coral annual bands were formed by coral aragonite, organic matters in coral skeletons especially humic substances, skeletal structure such as skeletal cavities. The results of several studies confirm that coral luminescent bands are derived from humic substances because the luminescent bands were more abundant in areas where humic substances were concentrated than in other skeletal parts and seawater. On the other hand, several studies have been shown that the coral luminescent bands correspond to the skeletal parts of low skeletal density. However, the cause of the formation of the luminescent bands still remains a controversial topic. Elucidating coral luminescent bands is essential for establishing reliable environmental proxies for reconstructing past precipitation and river flood events.

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Morphological classification of zooxanthellate (hermatypic) corals (hereafter corals) in the Screlactinia is currently based on skeletal features of the corallite and colony forms. These corals, however, have few taxonomically significant morphological characteristics because such characters show polymorphism, intraspecific variation, and phenotypic plasticity in response to environmental factors. Quantitative description of taxonomic features that comprise differences between morphologically similar genera and/or species is challenging. Recently in Japan, picture books and identification guides of the corals that focus mainly on their living features have become popular. These publications promote awareness of the corals, but they have decreased attention to the skeletal features of corals. A number of these publications do not adhere to the International Code of Zoological Nomenclature, especially with regard to scientific names, thereby reducing the current stability of coral taxonomy. This complicates the effort to obtain a consensus on the taxonomic identification of coral species, which is important for comparing results of studies, past and present. Application of molecular phylogenetic analyses to corals has provided useful information for understanding the relationships among closely related families and/or genera as well as neighboring species in the same genus. These analyses should be used to revise the traditional taxonomic scheme, which is based only on morphological characteristics. Compounding the difficulty, past studies may also have used misidentified coral species. To establish greater taxonomic consistency among coral species, the morphological characteristics used for traditional taxonomy should be quantitatively compared among closely related species. Identification of new morphological characteristics of the external or internal skeletal structures of colony and/or corallite that are consistent with available phylogenetic evidence is also necessary. Because of the possibility of misidentification, efforts should be taken to retain samples of soft tissues of these species as well as skeletal specimens of their corallite and/or colonies.

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The content of suspended particles in coastal surficial sediments from Ishigaki and Iriomote Islands, Okinawa, Japan were monitored. Sediment samplings were carried out from June 2008 to May 2009 and in June, October, and December 2008 on Ishigaki (11 sites) and Iriomote (8 sites) Islands, respectively. The contents of suspended particles tended to fluctuate widely seasonally from site to site in the range from 1kg/m³ to 800kg/m³. Obtained results were compared with those of 1985 survey carried out by Okinawa Ppefecture.

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Conservation of the blue coral Heliopora coerulea in Oura Bay is desired due to its size and peculiar shape, and its being representative of the coral reef ecosystem of the bay. The bleaching of H. coerulea in 2009 is believed to have occurred as a result of the thick growth of diatom Licmophora sp. on the surface of the coral, causing damages and health hazards. In this time, algal masses different from Licmophora sp. were discovered on H. coerulea. The algal masses were thought to be cyanobacteria because those masses resembled the genus Lyngbya which twisted around a gorgonian coral Annella reticulata around the Kerama Islands. In the coral reef, such cases are known that corals were killed due to cyanobacterial overgrowth on colonies in response to increase of nutrients and that a fatal sickness of coral was caused by cyanobacteria belonging to multiple genera. In this study, we aimed to observe the form of the algal mass specimens collected from the surface of the H. coerulea colonies and a surrounding bedrock under a microscope, examine the 16SrDNA sequences, clarify the algal species by comparing them with known cyanobacterial sequences, and presume influence of the algae on H. coerulea. As a result of the analyses, each of the algal masses collected from H. coerulea and the bedrock turned out to form a consortium of cyanobacteria consisting of several genera, including the genus Leptolyngbya. In those consortia, Lyngbya majuscula and Hydrocoleum lyngbyaceum, those might occur in outbreaks when the concentration of nutrients in seawater rises, were included. Although the influence of cyanobacteria on the H. coerulea colonies is thought to be small at the present stage, continuous survey on cyanobacteria growth is needed.

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[in Japanese]

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The deterioration of coral reefs is a serious environmental problem. Conventional conservation policies for terrestrial ecosystems are sometimes difficult to apply to coral reefs because of the large number of stakeholders. In an interesting attempt to solve this problem, some diving tours in Japan have begun to transplant coral fragments on to deteriorated coral reefs. However, the fragments used for transplantation are taken from natural coral colonies, causing potential problems. These include decreasing the fecundity of the donor colonies; having a negative effect on the surrounding environment of the exploited corals; and contributing to low species diversity of transplanted fragments. In this paper, we suggest that seedlings can be used for transplantation. This is costly but has a lower negative environmental effect. We show how to determine the optimal ratio of fragments and seedlings to produce the best environmental effect, depending on the cost and the environmental effect of each coral transplant.

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The concept of Marine Protected Areas (MPAs) has undergone many definition changes without reaching a general consensus. At the World Summit on Sustainable Development in 2002, it was adopted that every signatory will establish MPAs by 2012. Furthermore, at the 5th World Park Conference, it was recom-mended that every signatory will protect at least 20-30% of marine habitat by 2012, and maintain representative protected area networks: these recommendations constitute the so-called 2012 Agenda which every signatory is expected to comply.
In Japan, various interpretations about MPA vary in scope and detail, but none of these are definitive. We consider MPAs as areas provided with legal protection of whole populations or biological diversity in shallow waters including intertidal zone or other effective methods that protect them from unnatural changes or undue exploitation to promote resource sustainability, as a concept of “No-take Zone”. It might be difficult to imple-ment such MPA concept in many Japanese coastal waters in the near future, however, it is hoped that the area needed to maintain the fishing-target species will be determined first, and based on this evaluation, a temporary MPA will be set, and after some time, the multiple effects of such MPA will be investigated. If concentrated mainly on coral reef environments, the coexistence of biodiversity protection and regulated fishery may be feasible. Within MPAs not only artisanal fishing but also game fishing and research collecting should be regu-lated.
The Philippines has the longest history of legally established MPAs in Asia. In order to learn how successful MPAs are maintained and how local people are relating to MPAs, we visited the Visayan area in March 2010, and met with Dr. A.C. Alcala who is the pioneer of the Philippine type of MPA which are numerous and small and protect both fishery resource and biodiversity. We visited MPAs in Apo Island and surrounding areas and conducted interviews with the local people.
In order to protect the fishery and whole populations, MPAs must be large enough to sustain the target conservation species. MPAs should not follow a top-down governance model involving municipal officials down to fishermen but should be firmly grounded on the agreement and participation by the local people. Even if fishermen are not allowed to fish within the MPA, they will realize the goals of the MPA when the benefits of the ‘spillover’ effect are proven. The ‘spillover’ effect is realized when fish stocks from the MPA contribute towards increased productivity outside the restricted fishing grounds. If MPA entrance fees are collected from pleasure divers and tourists, some of the fees can be used to maintain the MPA or paid as compensation for fishermen. The key to success of MPAs is continuous education/capacity building of the local people and fisher-men, maintaining mutual trust, identifying competent leaders and promoting transparency of finances and governance. The Kerama Islands in Okinawa support few small-scale fishermen. The residents maintain good consensus in protecting the coral reefs because they are the basis of tourism in these islands and are revenue sources for local residents. We are therefore speculating that a desirable MPA model can be tested in this region. In this report, we will propose and discuss some ways and approaches to possibly establish and implement an MPA in Japanese waters based on the existing coral reef ecosystems in the Kerama Islands.

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