As highly social animals,Indo-Pacific humpback dolphins(Sousa chinensis)exhibit community differentiation.Nevertheless,our understanding of the external and internal factors influencing these dynamics,as well as their...As highly social animals,Indo-Pacific humpback dolphins(Sousa chinensis)exhibit community differentiation.Nevertheless,our understanding of the external and internal factors influencing these dynamics,as well as their spatiotemporal variations,is still limited.In the present study,variations in the social structure of an endangered Indo-Pacific humpback dolphin population in Xiamen Bay,China,were monitored over two distinct periods(2007–2010 and 2017–2019)to analyze the effects of habitat utilization and the composition of individuals within the population.In both periods,the population demonstrated a strikingly similar pattern of social differentiation,characterized by the division of individuals into two main clusters and one small cluster.Spatially,the two primary clusters occupied the eastern and western waters,respectively,although the core distribution area of the eastern cluster shifted further eastward between the two periods.Despite this distribution shift,the temporal stability of the social structure and inter-associations within the eastern cluster remained unaffected.A subset of 16individuals observed in both periods,comprising 51.6%and 43.2%of the population in each respective period,emerged as a foundational element of the social structure and may be responsible for sustaining social structure stability,especially during the 2007–2010 period.These observations suggest that the composition of dominant individuals,an internal factor,had a more substantial influence on the formation of the social network than changes in habitat use,an external factor.Consequently,the study proposes distinct conservation measures tailored to each of the two main clusters.展开更多
In this study, the mitochondrial DNA (mtDNA) control region and the mitochondrial cytochrome b gene of stranded Indo-Pacific humpback dolphin (Sousa chinensis) samples from the Pearl River Estuary and Xiamen water...In this study, the mitochondrial DNA (mtDNA) control region and the mitochondrial cytochrome b gene of stranded Indo-Pacific humpback dolphin (Sousa chinensis) samples from the Pearl River Estuary and Xiamen waters were sequenced and analyzed. The result of mtDNA control region revealed 34 variable sites and four unique haplotypes (named as A, B, C and D) identified among the total samples from these two water areas, and the most common haplotype (A) was shared by 75% of the dolphins sampled from the two water areas. The haplotypic diversity (h) was 0.455 and the nucleodde diversity (π) was 0.0088. The phylogenetic analysis showed that the haplotype A, C, and D were closely related, but the haplotype B (unique for XM01 from Xiamen) was far from the other three. By scanning cytochrome b fragments, two haplotypes (A and B) were identified in these two water areas, and the most common haplotype (A) was shared by 91.67% individuals, while XM01 from Xiamen as the only exception. The data suggest that there is a possibility of gene exchange between the two populations in the Pearl River Estuary and Xiamen waters, and there possibly exists a unique maternal lineage in Xiamen waters.展开更多
Ecological compensation plays an important role in implementing the social responsibility of infrastructure mega-projects. Based on the results of a field study, an in-depth interview, and archive data, this paper int...Ecological compensation plays an important role in implementing the social responsibility of infrastructure mega-projects. Based on the results of a field study, an in-depth interview, and archive data, this paper introduces the ecological compensation for Sousa chinensis(the Indo-Pacific humpbacked dolphin) during the construction of the Hong Kong-Zhuhai-Macao Bridge. It studies the concrete measures, decision-making processes,and organizational collaboration of the ecological compensation, using the method of a case study. The present study not only enriches our understanding of the ecological compensation practice during the construction of infrastructure mega-projects, but also extends the literature on the social responsibility of infrastructure mega-projects.This sheds light on the protection of the environment as well as biodiversity in the construction of future infrastructure mega-projects.展开更多
The Indo–Pacific humpback dolphin(Sousa chinensis Osbeck,1765)is a threatened species inhabiting the waters of China.Despite being of conservation concern,the distribution and abundance of this species has not been c...The Indo–Pacific humpback dolphin(Sousa chinensis Osbeck,1765)is a threatened species inhabiting the waters of China.Despite being of conservation concern,the distribution and abundance of this species has not been comprehensively evaluated.From 1994 to 2008 we performed over 14000 km of line-transect surveys and adminis-tered over 700 questionnaires to collect basic information on the geographic range and likely abundance of Indo–Pacific humpback dolphins along the southern and eastern coasts of China.Through our study we were able to establish a reporting network of stranding and incidental catches for this species.Our quantitative data suggests that only 76 animals remain around Xiamen,39 in the Hepu Nature Reserve and 114 in the estuary of the Dafengjiang River.Qualitative data from local fishing people and government officials suggests that dolphins may exist year-round in waters off Ningde and Shantou.We found that wild populations of Sousa chinensis in this important region are clearly being affected by human disturbance and habitat deterioration,including underwater blasting,vessel collision,fishing,aquaculture and water pollution.Although some protected areas have been established and this species is protected under Chinese law,there remains virtually no protection for this animal.展开更多
The Pearl River Delta(PRD)region on the southeast coast of China has long been known as a highly productive fishing ground.Since the late 1980s,fishing pressure in the PRD has been intense,which warrants concerns of p...The Pearl River Delta(PRD)region on the southeast coast of China has long been known as a highly productive fishing ground.Since the late 1980s,fishing pressure in the PRD has been intense,which warrants concerns of potential fishery-related impacts on the food resources and foraging ecology of apex marine predators in this region,such as the Indo-Pacific humpback dolphin(Sousa chinensis).In this study,we examined 54 stomachs with food remains,collected from beached carcasses of humpback dolphins recovered during fifteen years between 2003 and 2017.The 6043 identified prey items represent 62 teleost taxa,primarily small estuarine fish,but also larger reef fish.The dolphins appear to be opportunistic foragers,hunting across the water-column,with preference for shoaling and meaty fishes(e.g.Collichthys lucidus IRI%=38.6%,Johnius belangerii IRI%=23.1%,Mugil cephalus IRI%=14.0%).Our findings suggest a dietary shift in recent years,from primarily demersal(as previously reported)to greater intake of neritic and pelagic fish.Dolphin foraging group size has decreased in recent years,which corresponds with declining size and numbers of prey items retrieved from dolphin stomachs.We suggest that these are indicators of declining food resources.Faced with a shortage of preferred prey,humpback dolphins may have broadened their dietary spectrum to maintain their daily energy intake,while their foraging group size decreased in response to the altered tradeoff between the costs and benefits of group foraging.展开更多
The currently recognized Indo-Pacific humpback dolphin occurs in estuaries and surrounding shallow waters from the South China Sea to the Asian coast of the Indian Ocean.However,a recent study suggested that the humpb...The currently recognized Indo-Pacific humpback dolphin occurs in estuaries and surrounding shallow waters from the South China Sea to the Asian coast of the Indian Ocean.However,a recent study suggested that the humpback dolphin from the Bay of Bengal may represent a distinct phylogenetic species.In this study,we sequenced 915-bp mtDNA segments from five geographic populations in both Chinese and Thai waters;together with previously published sequences,these data revealed that the ancestral Indo-Pacific humpback dolphin might have split during the transition from the Oligocene to Miocene(23.45 Mya,95%HPD:16.65–26.55 Mya),and then dispersed along the Pacific and Indian Ocean coasts of Asia.Genetic differentiation was detected between most of the examined populations,except for only a few pairwise populations in the northern South China Sea.Genetic differentiation/distance between the humpback dolphins from the northern and southern South China Sea met the sub-species threshold value proposed for marine mammals,whereas that between the humpback dolphins in the Pacific and the Indian Ocean was above the species threshold.Bayesian inference of historic gene flow indicated low but constant northward gene flow along the Indian Ocean coast;however,there was a recent abrupt increase in gene flow in the Pacific region,likely due to the shortening coastline at the low stand of sea level.Our results revealed that the current taxonomic classification of Indo-Pacific humpback dolphins may not reflect their phylogeography.展开更多
Indo-Pacific humpback dolphins(Sousa chinensis)inhabit shallow coastal waters of the Indo-Pacific region including southeast China,with at least 6 putative populations identified to date in Chinese waters.However,the ...Indo-Pacific humpback dolphins(Sousa chinensis)inhabit shallow coastal waters of the Indo-Pacific region including southeast China,with at least 6 putative populations identified to date in Chinese waters.However,the connectivity among these populations has not yet been fully investigated.In the present study,we compared and crossmatched photographic catalogs of individual dolphins collected to date in the Pearl River Delta region,Leizhou Bay,Sanniang Bay,and waters southwest of Hainan Island,a total of 3158 individuals,and found no re-sighting of individual dolphins among the 4 study areas.Furthermore,there was a notable difference in the pigmentation pattern displayed by individuals from these 4 regions.We suggest that this may be a phenotypical expression of fine-scale regional differentiation among humpback dolphin groups,possibly distinct populations.Given the considerable conservation management implications it may carry(e.g.definition of management units),further research is much needed.展开更多
基金supported by the National Natural Science Foundation of China (32030011,31630071)National Key Research and Development Program of China (2022YFF1301600)Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘As highly social animals,Indo-Pacific humpback dolphins(Sousa chinensis)exhibit community differentiation.Nevertheless,our understanding of the external and internal factors influencing these dynamics,as well as their spatiotemporal variations,is still limited.In the present study,variations in the social structure of an endangered Indo-Pacific humpback dolphin population in Xiamen Bay,China,were monitored over two distinct periods(2007–2010 and 2017–2019)to analyze the effects of habitat utilization and the composition of individuals within the population.In both periods,the population demonstrated a strikingly similar pattern of social differentiation,characterized by the division of individuals into two main clusters and one small cluster.Spatially,the two primary clusters occupied the eastern and western waters,respectively,although the core distribution area of the eastern cluster shifted further eastward between the two periods.Despite this distribution shift,the temporal stability of the social structure and inter-associations within the eastern cluster remained unaffected.A subset of 16individuals observed in both periods,comprising 51.6%and 43.2%of the population in each respective period,emerged as a foundational element of the social structure and may be responsible for sustaining social structure stability,especially during the 2007–2010 period.These observations suggest that the composition of dominant individuals,an internal factor,had a more substantial influence on the formation of the social network than changes in habitat use,an external factor.Consequently,the study proposes distinct conservation measures tailored to each of the two main clusters.
基金the National Natural Sci-ence Foundation of China (No. 30570255)
文摘In this study, the mitochondrial DNA (mtDNA) control region and the mitochondrial cytochrome b gene of stranded Indo-Pacific humpback dolphin (Sousa chinensis) samples from the Pearl River Estuary and Xiamen waters were sequenced and analyzed. The result of mtDNA control region revealed 34 variable sites and four unique haplotypes (named as A, B, C and D) identified among the total samples from these two water areas, and the most common haplotype (A) was shared by 75% of the dolphins sampled from the two water areas. The haplotypic diversity (h) was 0.455 and the nucleodde diversity (π) was 0.0088. The phylogenetic analysis showed that the haplotype A, C, and D were closely related, but the haplotype B (unique for XM01 from Xiamen) was far from the other three. By scanning cytochrome b fragments, two haplotypes (A and B) were identified in these two water areas, and the most common haplotype (A) was shared by 91.67% individuals, while XM01 from Xiamen as the only exception. The data suggest that there is a possibility of gene exchange between the two populations in the Pearl River Estuary and Xiamen waters, and there possibly exists a unique maternal lineage in Xiamen waters.
基金funded by National Natural Science Foundation of China:71390525,National Natural Science Foundation of China:71620107004Shanghai Excellent Academic Leaders Program:14XD1402200
文摘Ecological compensation plays an important role in implementing the social responsibility of infrastructure mega-projects. Based on the results of a field study, an in-depth interview, and archive data, this paper introduces the ecological compensation for Sousa chinensis(the Indo-Pacific humpbacked dolphin) during the construction of the Hong Kong-Zhuhai-Macao Bridge. It studies the concrete measures, decision-making processes,and organizational collaboration of the ecological compensation, using the method of a case study. The present study not only enriches our understanding of the ecological compensation practice during the construction of infrastructure mega-projects, but also extends the literature on the social responsibility of infrastructure mega-projects.This sheds light on the protection of the environment as well as biodiversity in the construction of future infrastructure mega-projects.
基金supported by a key project of the National Natural Science Foundation of China(Grant 30830016)the Program for New Century Excellent Talents in University(NCET-07-0445)+3 种基金the Ministry of Education of Chinathe Specialized Research Fund for the Doctoral Program of Higher Education(SRFDP 20060319002)the Ministry of Education of China,the Major Project for Basic Researches of Jiangsu Province University(07KJA18016)Key Project in the National Science&Technology Pillar Program during the Eleventh Five-Year Plan Period(2007BAC03A08).
文摘The Indo–Pacific humpback dolphin(Sousa chinensis Osbeck,1765)is a threatened species inhabiting the waters of China.Despite being of conservation concern,the distribution and abundance of this species has not been comprehensively evaluated.From 1994 to 2008 we performed over 14000 km of line-transect surveys and adminis-tered over 700 questionnaires to collect basic information on the geographic range and likely abundance of Indo–Pacific humpback dolphins along the southern and eastern coasts of China.Through our study we were able to establish a reporting network of stranding and incidental catches for this species.Our quantitative data suggests that only 76 animals remain around Xiamen,39 in the Hepu Nature Reserve and 114 in the estuary of the Dafengjiang River.Qualitative data from local fishing people and government officials suggests that dolphins may exist year-round in waters off Ningde and Shantou.We found that wild populations of Sousa chinensis in this important region are clearly being affected by human disturbance and habitat deterioration,including underwater blasting,vessel collision,fishing,aquaculture and water pollution.Although some protected areas have been established and this species is protected under Chinese law,there remains virtually no protection for this animal.
基金This study was funded by the National Natural Science Foundation of China(41576128)the Natural Science Foundation of Guangdong Province(2017A030308005)in China+3 种基金the Ocean Park Conservation Foundation Hong Kong(MM01.1920)Alashan Society of Entrepreneurs and Ecology(SEE)the General Research Fund of the Research Grants Council(RGC)of Hong Kong(HKU_17100015 to LK and CityU_160613 to TCW)Field-based observations were facilitated by ongoing photo-ID study supported primarily with LK’s Marine Ecology Enhancement Fund grants MEEF2017015,MEEF2017015A and MEEF2017015B.
文摘The Pearl River Delta(PRD)region on the southeast coast of China has long been known as a highly productive fishing ground.Since the late 1980s,fishing pressure in the PRD has been intense,which warrants concerns of potential fishery-related impacts on the food resources and foraging ecology of apex marine predators in this region,such as the Indo-Pacific humpback dolphin(Sousa chinensis).In this study,we examined 54 stomachs with food remains,collected from beached carcasses of humpback dolphins recovered during fifteen years between 2003 and 2017.The 6043 identified prey items represent 62 teleost taxa,primarily small estuarine fish,but also larger reef fish.The dolphins appear to be opportunistic foragers,hunting across the water-column,with preference for shoaling and meaty fishes(e.g.Collichthys lucidus IRI%=38.6%,Johnius belangerii IRI%=23.1%,Mugil cephalus IRI%=14.0%).Our findings suggest a dietary shift in recent years,from primarily demersal(as previously reported)to greater intake of neritic and pelagic fish.Dolphin foraging group size has decreased in recent years,which corresponds with declining size and numbers of prey items retrieved from dolphin stomachs.We suggest that these are indicators of declining food resources.Faced with a shortage of preferred prey,humpback dolphins may have broadened their dietary spectrum to maintain their daily energy intake,while their foraging group size decreased in response to the altered tradeoff between the costs and benefits of group foraging.
基金supported by grants from the Fundamental Research Funds for Ministry of Natural Resources(No.2018015)the Natural Science Foundation of China(No.41506164,42076159,41806135)+3 种基金the Natural Science Foundation of Fujian Province,China(No.2017J05062)the China-ASEAN Maritime Cooperation fund(No.HX180701 and No.T190701)the Biodiversity Investigation,Observation and Assessment Program(2019-2023)of Ministry of Ecology and Environment of China(No.9-38-27-1)Ocean Park Conservation Foundation of Hong Kong(OPCFHK,#MM03-1415,MM02-1516).
文摘The currently recognized Indo-Pacific humpback dolphin occurs in estuaries and surrounding shallow waters from the South China Sea to the Asian coast of the Indian Ocean.However,a recent study suggested that the humpback dolphin from the Bay of Bengal may represent a distinct phylogenetic species.In this study,we sequenced 915-bp mtDNA segments from five geographic populations in both Chinese and Thai waters;together with previously published sequences,these data revealed that the ancestral Indo-Pacific humpback dolphin might have split during the transition from the Oligocene to Miocene(23.45 Mya,95%HPD:16.65–26.55 Mya),and then dispersed along the Pacific and Indian Ocean coasts of Asia.Genetic differentiation was detected between most of the examined populations,except for only a few pairwise populations in the northern South China Sea.Genetic differentiation/distance between the humpback dolphins from the northern and southern South China Sea met the sub-species threshold value proposed for marine mammals,whereas that between the humpback dolphins in the Pacific and the Indian Ocean was above the species threshold.Bayesian inference of historic gene flow indicated low but constant northward gene flow along the Indian Ocean coast;however,there was a recent abrupt increase in gene flow in the Pacific region,likely due to the shortening coastline at the low stand of sea level.Our results revealed that the current taxonomic classification of Indo-Pacific humpback dolphins may not reflect their phylogeography.
基金This research was financially supported by the National Natural Science Foundation of China(41406182,41306169,and 41422604)the biodiversity investigation,observation,and assessment program(2019-2023)of Ministry of Ecology and Environment of China+2 种基金Research Grants Council(RGC)of Hong Kong(General Research Fund HKU 768913M)Marine Ecology Enhancement Fund(MEEF2017015,MEEF2017015A,MEEF2017015B,and MEEF2017015C)Ocean Park Conservation Foundation Hong Kong(MM01-1415,MM02-1516,AW02-1920,AW04_1617,MM01_1920).
文摘Indo-Pacific humpback dolphins(Sousa chinensis)inhabit shallow coastal waters of the Indo-Pacific region including southeast China,with at least 6 putative populations identified to date in Chinese waters.However,the connectivity among these populations has not yet been fully investigated.In the present study,we compared and crossmatched photographic catalogs of individual dolphins collected to date in the Pearl River Delta region,Leizhou Bay,Sanniang Bay,and waters southwest of Hainan Island,a total of 3158 individuals,and found no re-sighting of individual dolphins among the 4 study areas.Furthermore,there was a notable difference in the pigmentation pattern displayed by individuals from these 4 regions.We suggest that this may be a phenotypical expression of fine-scale regional differentiation among humpback dolphin groups,possibly distinct populations.Given the considerable conservation management implications it may carry(e.g.definition of management units),further research is much needed.