Galaxea, Journal of Coral Reef Studies最新文献

{"title":"Dominant benthic mollusks in closed atolls, French Polynesia","authors":"B. Salvat","doi":"10.3755/GALAXEA.11.197","DOIUrl":"https://doi.org/10.3755/GALAXEA.11.197","url":null,"abstract":"We investigated the mollusk fauna of 53 closed lagoons (atolls without passes) among the 83 French Polynesian atolls. These confined lagoons of closed atolls reveal a limited diversity of mollusks but with wide distribution of some species. A few species occur in these lagoons but each lagoon is unique with a particular qualitative mollusk composition related to only 5 species: Tridacna maxima, Pinctada margaritifera, Pinctada maculata, Chama iostoma and Arca ventricosa. Due to the absence or poor data on 14 closed lagoons, our detailed study was limited to 39. We characterised the mollusk fauna of each closed lagoon and attempted to identify group of lagoons with the same dominant mollusk composition. T. maxima, the giant clam, appeared to be the most characteristic species of these confined lagoons with large densities and populations in 32 of the 39 lagoons. P. margaritifera, the mother-of-pearl oyster, also occurs as large populations in 18 lagoons; these two species are of economic importance now as they were in the past. The three other species mentioned above occurred respectively in 25, 28 and 20 lagoons. There are 11 lagoons with original and unique characteristics (their assemblages of dominant species do not occur in any other lagoon), 28 are grouped in 7 categories of assemblages. The most numerous groups contain all 5 species or at least 4 of them. Research topics are suggested in order to understand the ability of each mollusk species to colonize and maintain its dominance in a confined lagoon.","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130211211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fishing pressure occurs down to the lower mesophotic coral ecosystem in Lyudao, Taiwan","authors":"Ming-Jay Ho, C. Kuo, Hung-Yi Wu, M. Jeng, S. Shyue, Chaolun Allen Chen","doi":"10.3755/galaxea.22.1_29","DOIUrl":"https://doi.org/10.3755/galaxea.22.1_29","url":null,"abstract":"and Cirrhitichthys sp . ) and free-living invertebrates (e.g., Oligometra spp.) flourished as well, indicating that these outcrops found at 70 m act as an oasis MCE. Unfortunately, these isolated outcrops in sandy areas are likely to attract fish targeted by fishermen, therefore at risk to damage from fishing practices. We found evidence of disturbances by human activities, such as fishing lines entangled on corals (Fig. 1C, an ~50 cm Favites sp . colony) and coral colonies broken by fishing sinkers or boat anchors (Fig. 1D, an ~30 cm L. explanata colony). These findings suggest that fishing pressures remain strong, even at lower MCEs. Our findings reveal an urgent need to modify the existing regulation to extend the current marine protected areas to lower MCEs, and ensure that these potential refuges and seed banks for shallower coral communities in Lyudao survive (Smith et al. 2019).","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134197256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bird-view of the reef flat off Sesoko Station on the east coast of Sesoko Island, Okinawa, Japan obtained by aerial survey","authors":"I. Takeuchi, H. Yamashiro","doi":"10.3755/galaxea.g2021_s13pg","DOIUrl":"https://doi.org/10.3755/galaxea.g2021_s13pg","url":null,"abstract":"The use of small commercial drones (unmanned aerial vehicles, UAVs) for monitoring marine environments is increasing exponentially owing to their greater access to marine environments compared to in-water visual or photographic surveys by snorkel and/or SCUBA diving (Joyce et al. 2019). Structure for Motion (SfM) is an imaging technique used to reconstruct 3-D structures based on a series of 2-D images. It is widely used for terrestrial ecosystem mapping, and more recently it has been employed for creating high-resolution benthic complexity maps of coral reefs (Joyce et al. 2019). The orthophotos for coral reefs were created from a series of images taken by UAVs using SfM software (see Casella et al. 2017). While popular commercial 2-D stitching software, including Microsoft image composite editor (ICE) (Microsoft Corporation, Redmond, WA, USA), AutoStitch (Brown and Lowe 2007), Autopano Giga (Kolor SAS, Francion, France), are reported to introduce an error in the final composed image (Zhou et al. 2016), these inexpensive software have been commonly used in recent years for creating panorama images in various fields. We avoided the sun glint and subsurface illumination by conducting the aerial survey of the reef off Sesoko Station on the east coast of Sesoko Island, Okinawa, under calm oceanographic conditions and overcast cloudy skies during the early summer rainy season. These environmental factors should be considered when capturing images to ensure the success of drone photographic monitoring (Joyce et al. 2019). On 27 May 2017 four flights were conducted from 14:38 to 15:50 during the spring low tide using a Phantom 3 Professional (DJI Co. Ltd, Guangdong, China), which was improved to","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129400361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Size-dependent dispersal by Goniopora stokesi corals at Semporna, eastern Sabah, Malaysia","authors":"B. Hoeksema, Z. Waheed","doi":"10.3755/GALAXEA.13.9","DOIUrl":"https://doi.org/10.3755/GALAXEA.13.9","url":null,"abstract":"Free-living corals of Goniopora stokesi Milne Edwards &Haime, 1851 (Scleractinia: Poritidae) were observed at various sites during the Semporna Marine Ecological Expedition(SMEE 2010) in eastern Sabah, from 29 November to 18 December 2010. At two out of 63 sites, dense aggrega tions (75- 100% cover) with extended polyps had formed only on the sandy bottom of depressions (at 16-20 m depth). These corals could not leave, unlike scattered G. stokesi corals found on sandy slopes, which may migrate in downward direction (Hoeksema 1988). The largest coral patch (Fig. 1a) was c. 200 m2 (Denawan I.) and the other only c. 40 m2 (Larapan I.).Some colonies showed budding through the formation of polyp balls (Fig. 1b), which is a known trait in this species (Boschma 1923; Rosen and Taylor 1969). A few parent individuals had loose polyp balls around them, which had dropped and rolled to available space nearby. Most largespecimens were dome-shaped with their dead, fl attened baseon the sand or partly buried inside it (Fig. 1b). Only a fewwere found in upside-down position or laying on a side (Fig.1c). The heavy weight and fl at underside of these large corals would likely hinder any further migration and may render them practically immobile. Our observations suggest that free-living G. stokesi corals can disperse easily when they are small and may eventually form dense fi elds when they are physically entrapped by the surrounding reef.","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130794260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reefal microbial crusts found in Middle Holocene reef from Okinawa Island, the Ryukyu Archipelago","authors":"K. Fujita, Toru Sasaki, S. Koyano, M. Chinen, Chuki Hongo, J. Webster, Y. Iryu","doi":"10.3755/galaxea.22.1_9","DOIUrl":"https://doi.org/10.3755/galaxea.22.1_9","url":null,"abstract":"Reefal microbial crusts (RMCs) are fine-grained, non-skeletal carbonate crusts coating coralgal reef frameworks, and are locally common in late Quaternary reef deposits. They are interpreted as microbial carbonates produced by the growth and metabolism of benthic bacterial communities. Key questions remain concerning their uneven spatio-temporal distributions, formation process and controlling factors; the crusts have not yet been reported in the Ryukyu Archipelago. Here we report the first occurrence of brownish, few-centimeter-thick, fine-grained, non-skeletal crusts in a Middle Holocene reef core recovered at Naha New Port Pier, off the western coast of Okinawa Island, the Ryukyu Archipelago. The outer morphology of the crusts is either knobby or flat. The meso-scale fabric of the crusts is generally clotted and structureless, while a few crusts are weakly laminated or digitate. The slab core shows a biological succession from a bioeroded coral oriented upward, overlain by thin crusts of coralline algae and encrusting foraminifers, ending in a brownish, fine-grained, non-skeletal crust. Surface elemental mapping shows that the crusts are composed mainly of Ca and Mg (i.e., Mg-containing carbonate). X-ray diffraction analysis indicates that the crusts are composed predominantly of high-magnesium calcite, subordinate with aragonite and quartz. Petrographic observations show that the crusts are made mainly of peloidal micrite with irregular voids (cavities), associated with silt-sized bioclastic and siliciclastic grains. The crusts develop within a particular core depth and age range (4.6 - 6.1 m depth; ca. 7 ka), from which the crusts change downward and upward into encrusting bryozoan and foraminiferal crusts filled with micrite. Based on our observations, compared with previous studies, we conclude that brownish, non-skeletal carbonate crusts found in this study are RMCs, similar to those found in the last glacial, last deglacial and Holocene deposits other coral reef regions (e.g., Tahiti and Great Barrier Reef). The RMCs likely developed in a low light/darker, semi-enclosed environment within primary cavities of high-energy, shallow-water coralgal frameworks. Since the study area is located adjacent to a river mouth and directly exposed to terrigenous sediment input from river runoff, multiple, local and global environmental factors associated with Holocene transgression and reef formation likely influenced the development of RMCs in the study area.","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132910820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphological and physiological studies on sex change in tropical fish: Sexual plasticity of the ovaries of hermaphroditic and gonochoristic fish","authors":"Masaru Nakamura, R. Nozu, Shigeo Nakamura, M. Higa, R. Bhandari, Yasuhisa Kobayashi, R. Horiguchi, T. Komatsu, Y. Kojima, R. Murata, K. Soyano, Satoshi Ogawa, T. Hirai, H. Matsubara, T. Tokumoto, Tohru Kobayashi, H. Kagawa, S. Adachi, K. Yamauchi, Y. Nagahama","doi":"10.3755/galaxea.g2021_s6r","DOIUrl":"https://doi.org/10.3755/galaxea.g2021_s6r","url":null,"abstract":"To clarify the role of estrogens in the onset of sex change in fish, estrogen levels were artificially reduced in hermaphroditic and gonochoristic female fish via the treatment with aromatase inhibitors (AIs). AI treatments caused depletion in blood estrogen levels and induced complete sex change from a female to a male in protogynous three-spotted wrasse and the honeycomb grouper. Opposite-direction sex change of the protandrous yellowtail anemonefish was also induced by AI treatments. Not only in hermaphrodites, AI treatments induced testicular differentiation and, in certain circumstances, a complete sex change in the developing ovaries of the gonochoristic fish: tilapia, medaka, zebrafish, carp and golden rabbitfish . We demonstrated that estrogen depletion induces the female to male sex change in both hermaphroditic and gonochoristic fish. Results suggested that some germ cells in the ovaries of both hermaphroditic and gonochoristic fish maintain sexual bipotentiality, which is the ability to differentiate into both female and male germ cells, throughout the life and that the fate of these germ cells’ differentiation depends on the level of endogenous estrogen. Higher levels of circulating estrogen maintain femaleness, while lower levels force their differentiation into males. These studies contribute to the progress of aquaculture.","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127652819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal patterns of reef macroinvertebrate communities Tawi-Tawi, Philippines","authors":"Genibeth E. Genito, W. Campos","doi":"10.3755/GALAXEA.15.143","DOIUrl":"https://doi.org/10.3755/GALAXEA.15.143","url":null,"abstract":"The inclusion of macroinvertebrates in the char­ acterization of coral reef community structures is a com­ mon practice in reef assessment. More often than not however, data on this component is relegated to rudi­ mentary analysis and poor utilization, as priority is given to the keystone species, the corals, or to the reef fish as­ semblage. Macroinvertebrates, being relatively sessile, are vulnerable to current fast­paced environmental changes and it is imperative for a more comprehensive and holistic approach to examine changes in the assemblages of this biota in relation to changes in habitat structure. In an at­ tempt to address this, temporal changes in the reef macro­ invertebrate communities of Tawi­Tawi, Philippines were examined in relation to changes in the benthic structure. Macroinvertebrates in Tawi­Tawi were consistently dominated by ascidians, mollusks and echinoderms which showed close affinity to changes in the reef structure. The shift in the reef framework from living coral structures to dead coral and algae were corresponded by a significant decrease in abundances of macroinvertebrates. The in­ crease in species richness however showed that macro­ invertebrates have the adaptive capacity to buffer impacts, and slow down the rate of community change by becoming generalists and opportunists, but only for a transitory period before species­specific impacts eventually sets in.","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116045397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fish aggregating devices in Indonesia: Past and present status on sustainable capture fisheries","authors":"R. Yusfiandayani","doi":"10.3755/GALAXEA.15.260","DOIUrl":"https://doi.org/10.3755/GALAXEA.15.260","url":null,"abstract":"","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116477479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coral transplantation in turbid waters at Rad Island, Phuket, Thailand","authors":"M. Yucharoen, Suppachai Thammachote, Anupong Jaroenpon, Suwit Lamka, N. Thongtham","doi":"10.3755/GALAXEA.15.343","DOIUrl":"https://doi.org/10.3755/GALAXEA.15.343","url":null,"abstract":"Dredging for marina construction has affected shallow water reef of Rad Island, Phuket. The experiments on coral transplantation were set up to select appropriate coral species for transplanting in turbid environment. Ten species of coral, Turbinaria peltata, Favia pallida, Favia speciosa, Favites abdita, Favites halicora, Favites pen­ tagona, Platygyran verweyi, Cyphastrea serailia, Porites lutea and Goniopora sp. were transplanted to shallow waters at the southeast side, and their survival and growth were monitored every 6 months. Two years after trans­ plantation, survival rates of transplanted species were as follows: F. pallida (70.1%), F. speciosa (56.5%), F. pen­ tagona (56%), T. peltata (54.8%), Goniopora sp. (50%), C. serailia (45.4%), F. abdita (42.8%), F. halicora (35.7 %), P. lutea (24.3%) and P. verweyi (22.6%). Growth rate of transplanted corals were measured from colony height increase that ranged from 0.8±0.8 cm・y to 1.4±1 cm・ y and approximate volume increase that ranged from 88.1±140.7 cm・y to 312±467.8 cm・y. In addition, colonies of Acropora pulchra, Acropora aspera and Acropora formosa, which were obtained from mid­water nursery at Cape Panwa were transplanted to the northern side for one year. After one year, survival and linear ex­ tension were 38.6% and 5.9±1.8 cm・y. A. formosa from local reef were also collected and transplanted in an adjacent area. After one year, survival and linear extension were 4.3 % and 1.1±0.5 cm・y. It is concluded, that all species can survive in high turbid environment and coral from mid­water nursery can be transplanted from less stress environment.","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123423735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First record of cuttlefish egg-deposition at an in situ coral nursery","authors":"Shu Qin Sam, D. Taira, C. L. Ng, T. Toh, L. Chou","doi":"10.3755/GALAXEA.20.1_9","DOIUrl":"https://doi.org/10.3755/GALAXEA.20.1_9","url":null,"abstract":"Coral nurseries provide a sheltered environment to enhance coral growth and survivorship (Afiq-Rosli et al. 2017). The role of in situ nurseries in supporting coral-associated organisms such as Chaetodon octofasciatus (Taira et al. 2016) and Trapezia cymodoce (Shafir and Rinkevich 2010) has been reported, but detailed documentation of such ecological services remains limited. We report the first observation of cuttlefish (Sepia sp.) eggs and juvenile recruitment in an in situ coral nursery. Nursery tables were established on a sandy seabed at 3 m depth off Lazarus Island (1°13.49′N, 103°51.14′E), Singapore in 2014 to culture scleractinian corals, such as Pocillopora acuta, Podabacia crustacea, Acropora aculeus and Platygyra sinesis (Chou et al. 2017). Adult Sepia sp. were seen hovering around the coral nursery on four occasions in early 2016 (Fig. 1A). From July to November 2016, cuttlefish eggs were observed among the branches of dead and live colonies of Acropora aculeus (n=1) and Pocillopora acuta (n=15). Geometric mean diameter of these coral colonies ranged 13.8429.68 cm. The ovoid eggs were deposited in dense clusters of 21.8±13.8 (mean±SD) eggs per coral colony (Fig. 1B). Most eggs were attached via their stalks between branches deep within each colony (Fig. 1C) while others were deposited between the base of the colony and the tops of the nursery tables. No eggs were seen on the exposed parts of the nursery tables. The average egg was 1.98±0.28 cm by 1.47±0.32 cm (length by breadth) (n=6). The eggs, white and opaque in July 2016, became more transparent as they matured over the next two months (Nabhitabhata and Nilaphat 1999). Between November 2016 and March 2017, juvenile Sepia sp. were observed swimming around the nursery (Fig 1D). As Sepia embryos develop in three to five months (Dupavillon and Gillanders 2009; Dan et al. 2012), the observed juveniles had most likely hatched from the eggs in the nursery. Although cuttlefishes have been reported to deposit eggs on the underside of rocks and within crevices (Cronin and Seymour 2000), we did not find any eggs on the granite seawall that was near the nursery tables. Our observations suggest that in situ coral nurseries can function as platforms for the recruitment of other reef fauna. Such contributions to ecosystem functioning should be documented to enhance as sessments on the overall effectiveness of habitat restoration efforts.","PeriodicalId":118057,"journal":{"name":"Galaxea, Journal of Coral Reef Studies","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124092165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}