A shark expert known for unusual research methods and "pushing the envelope" in his study of the feared marine predator’s behavior was badly bitten by a shark in the Bahamas, colleagues said on Thursday. ...A shark expert known for unusual research methods and "pushing the envelope" in his study of the feared marine predator’s behavior was badly bitten by a shark in the Bahamas, colleagues said on Thursday. 一位鲨鱼专家不仅以超常的研究方式闻名,而且在研究可怕的海洋食肉动物时喜欢“豁出去”。星期二他的同事称。展开更多
A reception for the 20th anniversary of the establishment of diplomatic relations between China and the Bahamas was held in Beijing on May 25. Zhang Ping, vice-chairman of the Standing Committee of the National People...A reception for the 20th anniversary of the establishment of diplomatic relations between China and the Bahamas was held in Beijing on May 25. Zhang Ping, vice-chairman of the Standing Committee of the National People’s Congress; Li Xikui, secretary-general of the CPAFFC; and Paul Andrew Gomez, ambassador of the Bahamas to China, were present. Zhang met Ambassador展开更多
Aims Nestedness is a characteristic of insular metacommunity structure.Relatively few studies,however,have attempted to evaluate temporal changes in nestedness,or elucidate the mechanisms underlying nestedness.I evalu...Aims Nestedness is a characteristic of insular metacommunity structure.Relatively few studies,however,have attempted to evaluate temporal changes in nestedness,or elucidate the mechanisms underlying nestedness.I evaluated both spatial and temporal patterns of nestedness in the insular floras of four archipelagoes of small islands in the Bahamas and the potential underlying environmental gradients.Methods The NODF(a nestedness metric based on overlap and decreasing fill)and the matrix temperature measure,T,were used to quantify nestedness in insular floras on small islands near Abaco,Andros,Great Exuma and the Exuma Cays,Bahamas.Two different null models were employed for each nestedness measure.Six environmental variables were evaluated in relation to nestedness by ordering islands according to gradients and recalculating NODF scores.Important Findings All archipelagoes were significantly nested.Nestedness among sites contributed more to overall nestedness than did nestedness among species.NODF scores varied among archipelagoes,but were surprisingly constant over time.Ordering islands by vegetated area yielded the highest nestedness scores for three archipelagoes;ordering islands by protection from exposure yielded the highest nestedness score for one archipelago.Nestedness scores varied little over time even though species compositions changed,indicating that extinctions occurred in a deterministic manner.The relative importance of area suggests extinction is an important mechanism in producing nestedness.Attempting to determine the relative importance of immigrations or extinctions requires some assumptions,however,and both processes are likely cumulative in most cases.展开更多
Seagrass and mangrove habitats have long been established as critical for diverse species at various life-stages,particularly as nursery grounds.However,despite their intrinsic and environmental value,these ecosystems...Seagrass and mangrove habitats have long been established as critical for diverse species at various life-stages,particularly as nursery grounds.However,despite their intrinsic and environmental value,these ecosystems are increasingly threatened by anthropogenic activities.In Bimini,Bahamas,where ongoing development threatens ecosystem integrity,baited remote underwater video surveys(BRUVs)were used to examine faunal communities in both nearshore habitat and a shallow water central lagoon(average depth 1 m).The study assessed species abundances and spatial distribution in a currently unperturbed of the North Bimini Marine Reserve(NBMR).A total of 140 BRUVs,conducted over a 13-month period,recorded 62 species from 27 different families.MaxN was used to assess relative abundances and multivariate analyses(i.e.nMDS,PCA,PERMANOVA)investigated differences in community composition across discrete factors and environmental variables.Boosted Regression Trees(BRTs)were used to explore environmental variables for their uncorrelated influences on recorded species diversity.Findings evidenced the importance of habitat diversity and particularly mangroveadjacent habitat for teleost fishes in Bimini with species diversity and abundance being significantly greater in the mangrove-adjacentdge habitat.Further,the study highlighted differences in environmental conditions between habitat types and the association this had with species diversity,abundance and distribution.Despite the shallow water environment,BRUVs served as a scalable,non-invasive technique to assess community structures within the study site.Results from this study should inform ongoing decision-making processes regarding the protection of the Bimini Islands ecosystem.展开更多
文摘A shark expert known for unusual research methods and "pushing the envelope" in his study of the feared marine predator’s behavior was badly bitten by a shark in the Bahamas, colleagues said on Thursday. 一位鲨鱼专家不仅以超常的研究方式闻名,而且在研究可怕的海洋食肉动物时喜欢“豁出去”。星期二他的同事称。
文摘A reception for the 20th anniversary of the establishment of diplomatic relations between China and the Bahamas was held in Beijing on May 25. Zhang Ping, vice-chairman of the Standing Committee of the National People’s Congress; Li Xikui, secretary-general of the CPAFFC; and Paul Andrew Gomez, ambassador of the Bahamas to China, were present. Zhang met Ambassador
基金This work was supported by National Geographic Society grants(7447-03 and 8137-06)to the author.
文摘Aims Nestedness is a characteristic of insular metacommunity structure.Relatively few studies,however,have attempted to evaluate temporal changes in nestedness,or elucidate the mechanisms underlying nestedness.I evaluated both spatial and temporal patterns of nestedness in the insular floras of four archipelagoes of small islands in the Bahamas and the potential underlying environmental gradients.Methods The NODF(a nestedness metric based on overlap and decreasing fill)and the matrix temperature measure,T,were used to quantify nestedness in insular floras on small islands near Abaco,Andros,Great Exuma and the Exuma Cays,Bahamas.Two different null models were employed for each nestedness measure.Six environmental variables were evaluated in relation to nestedness by ordering islands according to gradients and recalculating NODF scores.Important Findings All archipelagoes were significantly nested.Nestedness among sites contributed more to overall nestedness than did nestedness among species.NODF scores varied among archipelagoes,but were surprisingly constant over time.Ordering islands by vegetated area yielded the highest nestedness scores for three archipelagoes;ordering islands by protection from exposure yielded the highest nestedness score for one archipelago.Nestedness scores varied little over time even though species compositions changed,indicating that extinctions occurred in a deterministic manner.The relative importance of area suggests extinction is an important mechanism in producing nestedness.Attempting to determine the relative importance of immigrations or extinctions requires some assumptions,however,and both processes are likely cumulative in most cases.
基金This study was supported by a Keystone Grant to BBFSF from the Save Our Seas Foundation.
文摘Seagrass and mangrove habitats have long been established as critical for diverse species at various life-stages,particularly as nursery grounds.However,despite their intrinsic and environmental value,these ecosystems are increasingly threatened by anthropogenic activities.In Bimini,Bahamas,where ongoing development threatens ecosystem integrity,baited remote underwater video surveys(BRUVs)were used to examine faunal communities in both nearshore habitat and a shallow water central lagoon(average depth 1 m).The study assessed species abundances and spatial distribution in a currently unperturbed of the North Bimini Marine Reserve(NBMR).A total of 140 BRUVs,conducted over a 13-month period,recorded 62 species from 27 different families.MaxN was used to assess relative abundances and multivariate analyses(i.e.nMDS,PCA,PERMANOVA)investigated differences in community composition across discrete factors and environmental variables.Boosted Regression Trees(BRTs)were used to explore environmental variables for their uncorrelated influences on recorded species diversity.Findings evidenced the importance of habitat diversity and particularly mangroveadjacent habitat for teleost fishes in Bimini with species diversity and abundance being significantly greater in the mangrove-adjacentdge habitat.Further,the study highlighted differences in environmental conditions between habitat types and the association this had with species diversity,abundance and distribution.Despite the shallow water environment,BRUVs served as a scalable,non-invasive technique to assess community structures within the study site.Results from this study should inform ongoing decision-making processes regarding the protection of the Bimini Islands ecosystem.
