Abundant food supply is crucial for the survival of long-distance migratory birds.The continued population decline of the Spoon-billed Sandpiper(Calidris pygmeae),a critically endangered shorebird,is primarily attribu...Abundant food supply is crucial for the survival of long-distance migratory birds.The continued population decline of the Spoon-billed Sandpiper(Calidris pygmeae),a critically endangered shorebird,is primarily attributed to habitat loss and degradation.However,significant gaps remain in research on their diet and foraging habitat selection,limiting effective conservation and restoration efforts.In this study,we investigated the composition of macrobenthic communities,analyzing habitat and prey selection at the main foraging area of SBS in Tiaozini,Jiangsu Province of eastern China—their most critical staging site during southward migration.Our findings revealed 25 species of macrobenthos in foraging areas,with mobile epibenthos comprising the largest group by biomass,accounting for 73%,and having higher density and biomass nearshore.Observations of foraging Spoon-billed Sandpiper individuals indicated that shallow water habitats were their preferred foraging environments,where mobile epibenthos,which thrive in these habitats after the tide recedes,made up 81%of their biomass intake.We propose that shallow water habitats in intertidal mudflats serve as essential refuges for mobile epibenthos after tidal retreat,thereby providing Spoon-billed Sandpipers with access to high-quality food resources.Habitat protection efforts should prioritize habitats harboring extensive microhabitats with shallow water,especially the nearshore area,and further research is needed to explore the mechanisms underlying the formation of these microhabitats,with the ultimate goal of restoring more high-quality habitats for the Spoonbilled Sandpiper.展开更多
Despite the many submarine telecommunications and power cables laid world-wide there are fewer than ten published studies of their environmental effects in the refereed literature.This paper describes an investigation...Despite the many submarine telecommunications and power cables laid world-wide there are fewer than ten published studies of their environmental effects in the refereed literature.This paper describes an investigation into the effects of laying and operating the Basslink High Voltage Direct Current(HVDC)cable and its associated metallic return cable across Bass Strait in South East Australia.Over more than 95%of its length the cable was directly laid into a wet jetted trench given the predominantly soft sediments encountered.Underwater remote video investigations found that within two years all visible evidence of the cable and trench was gone at over a third of the transects at six deep water sites(32-72 m deep).At other deep water transects the residual trench trapped drift material providing habitat for the generally sparsely distributed benthic community.Diver surveys at both of the near shore sites(<15 m deep)on the northern side of the Strait also found the cable route was undetectable after a year.On the southern side,where the cable traversed hard basalt rock near shore,it was encased in a protective cast iron half shell.Ecological studies by divers over 3.5 years demonstrated the colonization of the hard shell by similar species occupying hard substrates elsewhere on the basalt reef.Magnetic field strengths associated with the operating cable were found to be within 0.8%of those predicted from theory with strength dropping rapidly with distance from the cable.Beyond 20 m the field was indistinguishable from background.展开更多
基金funded by the National Natural Science Foundation of China(No.42361144873)Yellow Sea Wetland Project(No.HHSDKT202312)the“Saving Spoon-billed Sandpiper”project of Shenzhen Mangrove Wetlands Conservation Foundation(MCF)。
文摘Abundant food supply is crucial for the survival of long-distance migratory birds.The continued population decline of the Spoon-billed Sandpiper(Calidris pygmeae),a critically endangered shorebird,is primarily attributed to habitat loss and degradation.However,significant gaps remain in research on their diet and foraging habitat selection,limiting effective conservation and restoration efforts.In this study,we investigated the composition of macrobenthic communities,analyzing habitat and prey selection at the main foraging area of SBS in Tiaozini,Jiangsu Province of eastern China—their most critical staging site during southward migration.Our findings revealed 25 species of macrobenthos in foraging areas,with mobile epibenthos comprising the largest group by biomass,accounting for 73%,and having higher density and biomass nearshore.Observations of foraging Spoon-billed Sandpiper individuals indicated that shallow water habitats were their preferred foraging environments,where mobile epibenthos,which thrive in these habitats after the tide recedes,made up 81%of their biomass intake.We propose that shallow water habitats in intertidal mudflats serve as essential refuges for mobile epibenthos after tidal retreat,thereby providing Spoon-billed Sandpipers with access to high-quality food resources.Habitat protection efforts should prioritize habitats harboring extensive microhabitats with shallow water,especially the nearshore area,and further research is needed to explore the mechanisms underlying the formation of these microhabitats,with the ultimate goal of restoring more high-quality habitats for the Spoonbilled Sandpiper.
文摘Despite the many submarine telecommunications and power cables laid world-wide there are fewer than ten published studies of their environmental effects in the refereed literature.This paper describes an investigation into the effects of laying and operating the Basslink High Voltage Direct Current(HVDC)cable and its associated metallic return cable across Bass Strait in South East Australia.Over more than 95%of its length the cable was directly laid into a wet jetted trench given the predominantly soft sediments encountered.Underwater remote video investigations found that within two years all visible evidence of the cable and trench was gone at over a third of the transects at six deep water sites(32-72 m deep).At other deep water transects the residual trench trapped drift material providing habitat for the generally sparsely distributed benthic community.Diver surveys at both of the near shore sites(<15 m deep)on the northern side of the Strait also found the cable route was undetectable after a year.On the southern side,where the cable traversed hard basalt rock near shore,it was encased in a protective cast iron half shell.Ecological studies by divers over 3.5 years demonstrated the colonization of the hard shell by similar species occupying hard substrates elsewhere on the basalt reef.Magnetic field strengths associated with the operating cable were found to be within 0.8%of those predicted from theory with strength dropping rapidly with distance from the cable.Beyond 20 m the field was indistinguishable from background.
