E. Titlyanov, T. Titlyanova, I. Yakovleva, O. Sergeeva
Regeneration of artificial injuries on scleractinian corals of massive colonies Porites lutea and branching Porites cylindrica and algal/coral competition on newly formed substrate are the subject of investigation. It was shown that the injured coral areas recovered at three stages (1) coral tissue recovery with the formation of a border between the regenerating live tissue and dead area, (2) growth and expansion of the live tissue on the substrate, and (3) new polyps development on the healed area. At the first stage of the regeneration, the rate of lesion healing was highest; it varied in respect to injury type and averaged 0.2-0.05 and 0.1-0.02mm day-1 for P. lutea and P. cylindrica, respectively. The regeneration rate mostly depended on morphology of corals and injury type. Coral entombed spores and thalli fragments of algae settled onto partially damaged live tissue and skeleton. At the second stage, the rate of lesion healing sharply decreased and varied from 0.1 to 0.03mm day-1 for P. lutea and from 0.05 to 0.02mm day-1 for P. cylindrica. Position of the injuries within the colony, light intensity, as well as the composition and abundance of algae and animals settled onto the damaged areas had a significant effect on the rate and duration of the recovery process. The algae growing on dead areas of the injuries acted as a physical and in rare cases as a chemical impediment for expansion of live tissue on the available substrate. At the second stage of healing, the live tissue overgrew twenty two algal species settled onto the lesions at winter and spring seasons. At the third stage of the regeneration, the recovery depended on external and internal conditions promoting the growth of coral polyps.
{"title":"Three stages of injuries regeneration on scleractinian corals","authors":"E. Titlyanov, T. Titlyanova, I. Yakovleva, O. Sergeeva","doi":"10.3755/JCRS.8.39","DOIUrl":"https://doi.org/10.3755/JCRS.8.39","url":null,"abstract":"Regeneration of artificial injuries on scleractinian corals of massive colonies Porites lutea and branching Porites cylindrica and algal/coral competition on newly formed substrate are the subject of investigation. It was shown that the injured coral areas recovered at three stages (1) coral tissue recovery with the formation of a border between the regenerating live tissue and dead area, (2) growth and expansion of the live tissue on the substrate, and (3) new polyps development on the healed area. At the first stage of the regeneration, the rate of lesion healing was highest; it varied in respect to injury type and averaged 0.2-0.05 and 0.1-0.02mm day-1 for P. lutea and P. cylindrica, respectively. The regeneration rate mostly depended on morphology of corals and injury type. Coral entombed spores and thalli fragments of algae settled onto partially damaged live tissue and skeleton. At the second stage, the rate of lesion healing sharply decreased and varied from 0.1 to 0.03mm day-1 for P. lutea and from 0.05 to 0.02mm day-1 for P. cylindrica. Position of the injuries within the colony, light intensity, as well as the composition and abundance of algae and animals settled onto the damaged areas had a significant effect on the rate and duration of the recovery process. The algae growing on dead areas of the injuries acted as a physical and in rare cases as a chemical impediment for expansion of live tissue on the available substrate. At the second stage of healing, the live tissue overgrew twenty two algal species settled onto the lesions at winter and spring seasons. At the third stage of the regeneration, the recovery depended on external and internal conditions promoting the growth of coral polyps.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129562969","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}
Hermatypic corals harbor symbiotic dinoflagellates (Symbiodinium spp.), which are generally referred to as zooxanthellae, in their gastrodermal cells. Zooxanthellate corals depend on photosynthetic products translocated by symbiotic algae as a nutrient source and a loss of zooxanthellae may lead to death of bleached corals. However, corals contain degraded zooxanthellae in their tissues and expel degraded zooxanthellae as well as healthy-looking zooxanthellae even under nonstressed conditions (Titlyanov et al. 1996). Brown et al. (1995) reported that degraded zooxanthellae were mainly observed in the mesentery and that they might be released from a certain part of the mesentery. These observations suggest that at least some zooxanthellae are partially digested by their hosts. It is, however, not understood whether these degraded zooxanthellae are produced by host digestion or represent aged algal cells undergoing auto-degradation. In order to examine the possibility of host partial digestion of zooxanthellae, we studied the distribution pattern of degraded zooxanthellae within polyps of Galaxea fascicularis. Polyps of G. fascicularis are large and can be easily isolated (Hidaka and Yamazato 1981), thus providing suitable material for comparison of zooxanthella morphology at various regions of a polyp. We also investigated whether the vacuoles containing degraded zooxanthellae are more acidic than those containing healthy-looking zooxanthellae, using a pH-sensitive fluorescent dye, LysoSensor, which accumulate in acidic compartments of the cell.
雌雄同体珊瑚的腹真皮细胞中含有共生鞭毛藻(共生鞭毛藻属)，通常被称为虫黄藻。虫黄藻珊瑚依靠共生藻类转运的光合产物作为营养来源，虫黄藻的丧失可能导致白化珊瑚的死亡。然而，珊瑚在其组织中含有降解的虫黄藻，即使在非应激条件下，也会排出降解的虫黄藻和看起来健康的虫黄藻(Titlyanov et al. 1996)。Brown et al.(1995)报道降解虫黄藻主要在肠系膜中观察到，它们可能从肠系膜的某一部分释放出来。这些观察结果表明，至少有一些虫黄藻被它们的宿主部分消化。然而，目前尚不清楚这些降解的虫黄藻是由宿主消化产生的，还是代表老化的藻类细胞进行自降解。为了探讨寄主部分消化虫黄藻的可能性，研究了虫黄藻降解后在束状星系(Galaxea fascularis)息肉内的分布规律。G. fascularis的珊瑚虫体积大，易于分离(Hidaka and Yamazato 1981)，因此为比较珊瑚虫不同区域的虫黄藻形态提供了合适的材料。我们还研究了含有降解虫黄藻的液泡是否比含有健康虫黄藻的液泡更酸，使用ph敏感的荧光染料LysoSensor，它积聚在细胞的酸性区室中。
{"title":"Degradation of zooxanthellae in the coral Galaxea fascicularis","authors":"Mise Takeshi, M. Hidaka","doi":"10.3755/JCRS.2005.49","DOIUrl":"https://doi.org/10.3755/JCRS.2005.49","url":null,"abstract":"Hermatypic corals harbor symbiotic dinoflagellates (Symbiodinium spp.), which are generally referred to as zooxanthellae, in their gastrodermal cells. Zooxanthellate corals depend on photosynthetic products translocated by symbiotic algae as a nutrient source and a loss of zooxanthellae may lead to death of bleached corals. However, corals contain degraded zooxanthellae in their tissues and expel degraded zooxanthellae as well as healthy-looking zooxanthellae even under nonstressed conditions (Titlyanov et al. 1996). Brown et al. (1995) reported that degraded zooxanthellae were mainly observed in the mesentery and that they might be released from a certain part of the mesentery. These observations suggest that at least some zooxanthellae are partially digested by their hosts. It is, however, not understood whether these degraded zooxanthellae are produced by host digestion or represent aged algal cells undergoing auto-degradation. In order to examine the possibility of host partial digestion of zooxanthellae, we studied the distribution pattern of degraded zooxanthellae within polyps of Galaxea fascicularis. Polyps of G. fascicularis are large and can be easily isolated (Hidaka and Yamazato 1981), thus providing suitable material for comparison of zooxanthella morphology at various regions of a polyp. We also investigated whether the vacuoles containing degraded zooxanthellae are more acidic than those containing healthy-looking zooxanthellae, using a pH-sensitive fluorescent dye, LysoSensor, which accumulate in acidic compartments of the cell.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114987132","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}
Y. Takada, O. Abe, M. Nagao, A. Suzuki, M. Kobayashi, R. Oi, K. Hashimoto, T. Shibuno
Degradation of coral reef ecosystems are recognized in many areas around the world. Increase of seawater turbidity due to terrigenous sediments is regarded as one of the major cause of the degradation. We investigated levels and temporal variability of the turbidity during a two-year period at Urasoko Bay, a fringing coral reef of Ishigaki Island, Japan. At the near shore station, the median value of the turbidity was 2.26 NTU with the maximum of 92.9 NTU. At the two stations, 150m and 370m offshore, the median values of the turbidity were 0.58 NTU and 0.36 NTU, respectively. Correlation of the turbidity with the precipitation was weak, but wind showed significant correlation with the turbidity. Especially, the wind of the northwestern direction tended to increase the turbidity. These observations suggested that re-suspension of the bottom sediments by the wind driven turbulence and the wind-current with high turbidity and low salinity affected the variability of the turbidity in the Urasoko Bay.
{"title":"Seasonal Variation of Turbidity in a Fringing Reef Water in Urasoko Bay, Ishigaki Island: Re-suspension due to Northerly Winds","authors":"Y. Takada, O. Abe, M. Nagao, A. Suzuki, M. Kobayashi, R. Oi, K. Hashimoto, T. Shibuno","doi":"10.3755/JCRS.2005.37","DOIUrl":"https://doi.org/10.3755/JCRS.2005.37","url":null,"abstract":"Degradation of coral reef ecosystems are recognized in many areas around the world. Increase of seawater turbidity due to terrigenous sediments is regarded as one of the major cause of the degradation. We investigated levels and temporal variability of the turbidity during a two-year period at Urasoko Bay, a fringing coral reef of Ishigaki Island, Japan. At the near shore station, the median value of the turbidity was 2.26 NTU with the maximum of 92.9 NTU. At the two stations, 150m and 370m offshore, the median values of the turbidity were 0.58 NTU and 0.36 NTU, respectively. Correlation of the turbidity with the precipitation was weak, but wind showed significant correlation with the turbidity. Especially, the wind of the northwestern direction tended to increase the turbidity. These observations suggested that re-suspension of the bottom sediments by the wind driven turbulence and the wind-current with high turbidity and low salinity affected the variability of the turbidity in the Urasoko Bay.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129478915","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}
Effects of short-term sedimentation on common coastal coral species, Goniastrea aspera, Porites lobata and Pavona frondifera, from the reef flat southeast of the Ryukyu Islands, Okinawa, Japan were investigated in laboratory experiments using oxygen uptake respirometers. The O2 consumption rate was significantly different among species and between sediment treatments (20 and 200mg l-1 red soil suspension, P<0.05). In dark experiments, Goniastrea showed higher respiration rates (0.020±0.002ml O2 cm-2h-1) than did Pavona (0.017±0.003mL O2 cm-2h-1) and Porites (0.010±0.001ml O2 cm-2h-1). In light experiments, Goniastrea also showed higher O2 consumption rates (0.021±0.003ml O2 cm-2h-1) than did Porites (0.010±0.004ml O2 cm-2h-1) and Pavona (0.007±0.001ml O2 cm-2h-1). Zooxanthellae densities were 6.53±0.13, 3.12±0.05, and 4.37±0.07 (×106cells cm-2; mean±SE, n=8) in Goniastrea, Porites, and Pavona, respectively. Coral respiration rate increased proportionally with zooxanthellae density in Goniastrea and Pavona. High zooxanthellae density may increase the O2 production that contributes to colony respiration; however, in Porites, the relationship between zooxanthellae density and coral respiration rate was not clear. The massive corals, Goniastrea and Porites, are more resistant to sediment stress than is the plate-like coral, Pavona. Goniastrea showed high tolerance and adaptation to stress conditions in all experiments, at all times (12h), with similar trends in both dark and light conditions. Porites was affected only within the first 3h under light conditions, while Pavona was the most affected species. These results help us to understand coral damage caused by red soil sedimentation, as well as coral mortality and potential shifts in community structure related to prolonged or repeated elevated levels of sedimentation on coastal reefs.
{"title":"Oxygen consumption rate of the corals Goniastrea aspera, Porites lobata, and Pavona frondifera under red soil stress in the Ryukyu Islands, Okinawa, Japan","authors":"M. Ismail, M. Tsuchiya","doi":"10.3755/JCRS.2005.11","DOIUrl":"https://doi.org/10.3755/JCRS.2005.11","url":null,"abstract":"Effects of short-term sedimentation on common coastal coral species, Goniastrea aspera, Porites lobata and Pavona frondifera, from the reef flat southeast of the Ryukyu Islands, Okinawa, Japan were investigated in laboratory experiments using oxygen uptake respirometers. The O2 consumption rate was significantly different among species and between sediment treatments (20 and 200mg l-1 red soil suspension, P<0.05). In dark experiments, Goniastrea showed higher respiration rates (0.020±0.002ml O2 cm-2h-1) than did Pavona (0.017±0.003mL O2 cm-2h-1) and Porites (0.010±0.001ml O2 cm-2h-1). In light experiments, Goniastrea also showed higher O2 consumption rates (0.021±0.003ml O2 cm-2h-1) than did Porites (0.010±0.004ml O2 cm-2h-1) and Pavona (0.007±0.001ml O2 cm-2h-1). Zooxanthellae densities were 6.53±0.13, 3.12±0.05, and 4.37±0.07 (×106cells cm-2; mean±SE, n=8) in Goniastrea, Porites, and Pavona, respectively. Coral respiration rate increased proportionally with zooxanthellae density in Goniastrea and Pavona. High zooxanthellae density may increase the O2 production that contributes to colony respiration; however, in Porites, the relationship between zooxanthellae density and coral respiration rate was not clear. The massive corals, Goniastrea and Porites, are more resistant to sediment stress than is the plate-like coral, Pavona. Goniastrea showed high tolerance and adaptation to stress conditions in all experiments, at all times (12h), with similar trends in both dark and light conditions. Porites was affected only within the first 3h under light conditions, while Pavona was the most affected species. These results help us to understand coral damage caused by red soil sedimentation, as well as coral mortality and potential shifts in community structure related to prolonged or repeated elevated levels of sedimentation on coastal reefs.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128137662","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}
Atsuko Muraoka, Y. Iryu, K. Odawara, Tsutomu Yamada, Tokiyuki Sato
The Pleistocene Ryukyu Group consisting mainly of reef-complex deposits is exposed in Maeda-misaki area, central part of Okinawa-jima, Ryukyu Islands, southwestern Japan. The Pleistocene sequence, unconformably overlying pre-Tertiary phyllite of the Nago Formation, comprises the Quaternary Ryukyu Group and Holocene beach and alluvial deposits in this area. The Ryukyu Group consists of the Sobe Formation which is unconformably overlain by younger limestones. The Sobe Formation, the main body of the group, reaches 35m in thickness and crops out at elevations of up to 90m. Five lithologic units have been identified in the carbonate sequence of the Sobe Formation in the neighboring area Yomitan and are numbered sequentially from the base upwards (Units 1-5). Of these, four units (Units 2-5) extend in the study area. Unit 2 is composed chiefly of conglomerate and sandy to gravelly limestone. Each of Units 3 and 4 consists of shallow-water coral limestone grading upward into deep-water deposits (rhodolith, Cycloclypeus-Operculina, and detrital limestones). Unit 5 is composed exclusively of coral limestone. The younger limestones are less than 4m in thickness, rest unconformably on the Sobe Formation, and include detrital and coral limestones. These limestones are found at 3 sites at elevations of <-30m on the coast of the study area. The stratigraphic relationship between the detrital and coral limestones remains unknown due to their limited occurrences. Nannofossil biostratigraphy indicates the sandy limestone of Unit 2 of the Sobe Formation ranges in age from 0.41 to 1.65Ma.
{"title":"Stratigraphy of the Ryukyu Group in Maeda-misaki area, Okinawa jima, Ryukyu Islands, Japan","authors":"Atsuko Muraoka, Y. Iryu, K. Odawara, Tsutomu Yamada, Tokiyuki Sato","doi":"10.3755/JCRS.2005.23","DOIUrl":"https://doi.org/10.3755/JCRS.2005.23","url":null,"abstract":"The Pleistocene Ryukyu Group consisting mainly of reef-complex deposits is exposed in Maeda-misaki area, central part of Okinawa-jima, Ryukyu Islands, southwestern Japan. The Pleistocene sequence, unconformably overlying pre-Tertiary phyllite of the Nago Formation, comprises the Quaternary Ryukyu Group and Holocene beach and alluvial deposits in this area. The Ryukyu Group consists of the Sobe Formation which is unconformably overlain by younger limestones. The Sobe Formation, the main body of the group, reaches 35m in thickness and crops out at elevations of up to 90m. Five lithologic units have been identified in the carbonate sequence of the Sobe Formation in the neighboring area Yomitan and are numbered sequentially from the base upwards (Units 1-5). Of these, four units (Units 2-5) extend in the study area. Unit 2 is composed chiefly of conglomerate and sandy to gravelly limestone. Each of Units 3 and 4 consists of shallow-water coral limestone grading upward into deep-water deposits (rhodolith, Cycloclypeus-Operculina, and detrital limestones). Unit 5 is composed exclusively of coral limestone. The younger limestones are less than 4m in thickness, rest unconformably on the Sobe Formation, and include detrital and coral limestones. These limestones are found at 3 sites at elevations of <-30m on the coast of the study area. The stratigraphic relationship between the detrital and coral limestones remains unknown due to their limited occurrences. Nannofossil biostratigraphy indicates the sandy limestone of Unit 2 of the Sobe Formation ranges in age from 0.41 to 1.65Ma.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128153277","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}
A total of 279 specimens belonging to nine species of soft corals of the genus Sarcophyton were subjected to chemical study for the diversity of cembrane diterpenes. Following morphological identification, each specimen was examined for metabolites using gradient HPLC, NMR, and other tools. The S. glaucum and S. cinereum species complex was found to be the most abundant and to contain the most diverse metabolites in the Ryukyu Archipelago, Japan. S. trocheliophorum and S. ehrenbergi were moderately abundant and diverse in metabolites, while other all species seemed to be scarce and restricted in metabolites. During this research we encountered two new compounds (7, 12), whose structures are described in this report.
{"title":"Chemical diversity of Sarcophyton soft corals in Okinawa","authors":"J. Tanaka, Takumi Yoshida, Y. Benayahu","doi":"10.3755/JCRS.2005.1","DOIUrl":"https://doi.org/10.3755/JCRS.2005.1","url":null,"abstract":"A total of 279 specimens belonging to nine species of soft corals of the genus Sarcophyton were subjected to chemical study for the diversity of cembrane diterpenes. Following morphological identification, each specimen was examined for metabolites using gradient HPLC, NMR, and other tools. The S. glaucum and S. cinereum species complex was found to be the most abundant and to contain the most diverse metabolites in the Ryukyu Archipelago, Japan. S. trocheliophorum and S. ehrenbergi were moderately abundant and diverse in metabolites, while other all species seemed to be scarce and restricted in metabolites. During this research we encountered two new compounds (7, 12), whose structures are described in this report.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124635983","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}
The feeding habits of juvenile serranids, Cephalopholis urodeta, were examined on the basis of 104 specimens (≤100mm in total length, TL) collected from coral reef areas at Iriomote Island, Ryukyu Islands, Japan, from May to September between 1998 and 2001. Thirtyone (29.8%) of the specimens collected had empty stomachs, the overall mean stomach fullness index being low (0.94). The most important prey comprised small fishes and shrimps, food preferences not differing among three juvenile size classes (≤60, 61-80 and 81-100mm TL).
{"title":"Feeding habits of juvenile darkfin hind Cephalopholis urodeta (Serranidae) at Iriomote Island, southern Japan","authors":"T. Nakai, Y. Nakamura, M. Sano, H. Kurokura","doi":"10.3755/JCRS.2004.43","DOIUrl":"https://doi.org/10.3755/JCRS.2004.43","url":null,"abstract":"The feeding habits of juvenile serranids, Cephalopholis urodeta, were examined on the basis of 104 specimens (≤100mm in total length, TL) collected from coral reef areas at Iriomote Island, Ryukyu Islands, Japan, from May to September between 1998 and 2001. Thirtyone (29.8%) of the specimens collected had empty stomachs, the overall mean stomach fullness index being low (0.94). The most important prey comprised small fishes and shrimps, food preferences not differing among three juvenile size classes (≤60, 61-80 and 81-100mm TL).","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130634635","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}
Hiroshi Hata, S. Kudo, Akiko Muramoto, K. Nozaki, Ken Kato, A. Negishi, H. Saito, H. Yamano, A. Watanabe, H. Kayanne
In the present study, the applicability of the continuous monitoring of pH and partial pressure of CO2 (pCO2) to the investigations of coral reef community metabolism was examined. Of the four measurable parameters of the aquatic carbonate system, pH, pCO2, total alkalinity (TA), and total inorganic carbon (TIC), only pH and pCO2 could be continuously monitoring. Although the values of TA and TIC calculated from the pH and pCO2 data were not more precise than direct measurements, the continuous monitoring data with high time-resolution were shown to provide good estimations of the changes in CO2-related variables using the least-squares method. A new equation for estimating inorganic carbon metabolism (precipitation and dissolution of CaCO3: g) with an initial value of TA and a simplified equation for estimating organic carbon metabolism (photosynthesis and respiration: p) also helped to minimize the uncertainty. A simulation analysis showed that the standard errors for the calculations of the rates of g and p were less than ±5μmol kg-1 h-1 when pH (±0.005unit) and pCO2 (±2μatm) were monitored at 1-min intervals for 1h; this error is comparable to that of the calculations made using direct measurements of TA (±4μmol kg-1) and TIC (±2μmol kg-1) at the start and end of monitoring. The pH and pCO2 monitoring, tested in the present study at the Shiraho coral reef (Ishigaki Island, Japan), resulted in estimates for g and p that were equivalent to those calculated from TA-TIC direct measurements. The continuous monitoring of pH and pCO2 has been shown both theoretically and experimentally to be adequate for the estimation of coral reef community metabolism.
{"title":"The application of pH and pCO2 monitoring to estimating the rates of coral reef community metabolism","authors":"Hiroshi Hata, S. Kudo, Akiko Muramoto, K. Nozaki, Ken Kato, A. Negishi, H. Saito, H. Yamano, A. Watanabe, H. Kayanne","doi":"10.3755/JCRS.2004.21","DOIUrl":"https://doi.org/10.3755/JCRS.2004.21","url":null,"abstract":"In the present study, the applicability of the continuous monitoring of pH and partial pressure of CO2 (pCO2) to the investigations of coral reef community metabolism was examined. Of the four measurable parameters of the aquatic carbonate system, pH, pCO2, total alkalinity (TA), and total inorganic carbon (TIC), only pH and pCO2 could be continuously monitoring. Although the values of TA and TIC calculated from the pH and pCO2 data were not more precise than direct measurements, the continuous monitoring data with high time-resolution were shown to provide good estimations of the changes in CO2-related variables using the least-squares method. A new equation for estimating inorganic carbon metabolism (precipitation and dissolution of CaCO3: g) with an initial value of TA and a simplified equation for estimating organic carbon metabolism (photosynthesis and respiration: p) also helped to minimize the uncertainty. A simulation analysis showed that the standard errors for the calculations of the rates of g and p were less than ±5μmol kg-1 h-1 when pH (±0.005unit) and pCO2 (±2μatm) were monitored at 1-min intervals for 1h; this error is comparable to that of the calculations made using direct measurements of TA (±4μmol kg-1) and TIC (±2μmol kg-1) at the start and end of monitoring. The pH and pCO2 monitoring, tested in the present study at the Shiraho coral reef (Ishigaki Island, Japan), resulted in estimates for g and p that were equivalent to those calculated from TA-TIC direct measurements. The continuous monitoring of pH and pCO2 has been shown both theoretically and experimentally to be adequate for the estimation of coral reef community metabolism.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"564 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123921993","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}
K. Tottori, M. Nagao, N. Morimoto, M. Inoue, A. Iwase, T. Shibuno, Y. Fujioka, H. Ohba, H. Kan, A. Suzuki
The distributions of sediments and its relation to reef water turbidities were investigated in three fringing reefs along the east coast of Ishigaki Island and a patch reef named “Shimobishi” in the lagoon of Sekisei Reef. In order to quantify fine particles in sediments, we employed “SPSS (content of suspended particles in sea sediments)” method, which was originally proposed by Ohmija (1987) for quick assessment of land-derived soil distribution in reef sediments. We found highest SPSS values in a moat and channel bottom of the Miyara Bay and along the northern coast of the Todoroki River mouth in Ishigaki Island. In contrast, SPSS values were low in other three reefs including Yasurazaki, Shiraho and Shimobishi areas. Reef water turbidities showed significant correlation with SPSS values, which suggests that the major cause of reef water turbidities is resuspension of fine particles in the sediments. Accuracy and precision of the measurements can be increased by using a portable turbidimeter in the original SPSS method. The modified method has the potential for applying to a study of under-water light environment, which may influence coral-algal competitions in degrading reef conditions.
{"title":"Relationship between sediments and water turbidity in coral reefs around Ishigaki Island, the Ryukyus","authors":"K. Tottori, M. Nagao, N. Morimoto, M. Inoue, A. Iwase, T. Shibuno, Y. Fujioka, H. Ohba, H. Kan, A. Suzuki","doi":"10.3755/JCRS.2004.1","DOIUrl":"https://doi.org/10.3755/JCRS.2004.1","url":null,"abstract":"The distributions of sediments and its relation to reef water turbidities were investigated in three fringing reefs along the east coast of Ishigaki Island and a patch reef named “Shimobishi” in the lagoon of Sekisei Reef. In order to quantify fine particles in sediments, we employed “SPSS (content of suspended particles in sea sediments)” method, which was originally proposed by Ohmija (1987) for quick assessment of land-derived soil distribution in reef sediments. We found highest SPSS values in a moat and channel bottom of the Miyara Bay and along the northern coast of the Todoroki River mouth in Ishigaki Island. In contrast, SPSS values were low in other three reefs including Yasurazaki, Shiraho and Shimobishi areas. Reef water turbidities showed significant correlation with SPSS values, which suggests that the major cause of reef water turbidities is resuspension of fine particles in the sediments. Accuracy and precision of the measurements can be increased by using a portable turbidimeter in the original SPSS method. The modified method has the potential for applying to a study of under-water light environment, which may influence coral-algal competitions in degrading reef conditions.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129994579","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}
T. Hayashibara, H. Shimizu, M. Tamaki, S. Nishihama, M. Minagawa
The 1998 bleaching event was the most extensive and severe one ever observed in the Ryukyu Islands, Japan. From late August to September, mass mortality of hermatypic corals, especially the genus Acropora, occurred in Urasoko Bay of Ishigaki Island (Fujioka 1999, 2002). On the outer reef flat, where the present study was conducted, the live coral coverage drastically decreased from 80.4 % (estimated) at the highest before bleaching to only 6.6 % at four months after the bleaching event (Fujioka 2002). It was reported that in the breeding season following the bleaching event of 1998 the reproduction of corals was severely affected by the high thermal stress that had caused the mass bleaching in Okinawa (Omori et al. 2000 Hirose and Hidaka 2001) and the Great Barrier Reef (Hoegh-Guldberg 1999 Baird and Marshall 2002), and a drastic reduction in recruitment was predicted. Contrary to these predictions, an unexpectedly rapid recovery was reported to have occurred in some coral reefs (Normile 2000). However, it is not been clear whether the recovery can be attributed to new recruits or to the survival of juveniles. In October 1998, we deployed several artificial reefs in Urasoko Bay, immediately after the bleaching event. At present, many juvenile coral colonies can be observed on these artificial reefs. This provides evidence that the sexual recruitment resulted in recovery from the mass mortality by the bleaching event of 1998.
{"title":"Mass coral settlement on the artificial reefs in Ishigaki Island, Okinawa, Japan","authors":"T. Hayashibara, H. Shimizu, M. Tamaki, S. Nishihama, M. Minagawa","doi":"10.3755/JCRS.2004.47","DOIUrl":"https://doi.org/10.3755/JCRS.2004.47","url":null,"abstract":"The 1998 bleaching event was the most extensive and severe one ever observed in the Ryukyu Islands, Japan. From late August to September, mass mortality of hermatypic corals, especially the genus Acropora, occurred in Urasoko Bay of Ishigaki Island (Fujioka 1999, 2002). On the outer reef flat, where the present study was conducted, the live coral coverage drastically decreased from 80.4 % (estimated) at the highest before bleaching to only 6.6 % at four months after the bleaching event (Fujioka 2002). It was reported that in the breeding season following the bleaching event of 1998 the reproduction of corals was severely affected by the high thermal stress that had caused the mass bleaching in Okinawa (Omori et al. 2000 Hirose and Hidaka 2001) and the Great Barrier Reef (Hoegh-Guldberg 1999 Baird and Marshall 2002), and a drastic reduction in recruitment was predicted. Contrary to these predictions, an unexpectedly rapid recovery was reported to have occurred in some coral reefs (Normile 2000). However, it is not been clear whether the recovery can be attributed to new recruits or to the survival of juveniles. In October 1998, we deployed several artificial reefs in Urasoko Bay, immediately after the bleaching event. At present, many juvenile coral colonies can be observed on these artificial reefs. This provides evidence that the sexual recruitment resulted in recovery from the mass mortality by the bleaching event of 1998.","PeriodicalId":432348,"journal":{"name":"Journal of The Japanese Coral Reef Society","volume":"25 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115997433","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}
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