Brewin P.E.,University of Otago |
Brewin P.E.,Shallow Marine Surveys Group |
Probert P.K.,University of Otago |
Barker M.F.,University of Otago
Marine Ecology Progress Series | Year: 2011
We examined the processes that maintain spatially subdivided deep-basin macrobenthic communities in a New Zealand fjord. Based on previously reported quantitative taxa distribution data, we measured physical and biological processes acting at the sample scale (physical and nutritional sediment characteristics, predation), basin scale (disturbance, productivity, local connectivity) and the fjord scale (connectivity to the regional species pool). Using partial redundancy analysis (RDA), we partitioned their effects on community variability. Direct gradient analysis revealed that previously reported high-, medium- and low-diversity communities are similarly grouped according to their position along measured biotic and abiotic gradients, where 36% of community variation in niche space (i.e. after effects of distance along the fjord were removed) was explained by the full model. Variance partitioning showed that basin-scale factors explained the highest amount of variation in basin communities, followed by sample-scale and fjord-scale factors. Sample- and basin-scale factors were correlated. Examination of the residual component of community variation showed that further investigation into basin-scale processes is warranted. These data support the notion of multiscaled control of community dynamics. Fjords may be unique in representing an 'ecotone' type habitat demonstrating processes at similar scales to those maintaining shallow soft-sediment communities, and those of deep-sea systems. Furthermore, this analysis may understate the importance of connectivity to the regional species pool (fjord-scale process) in such habitats where local extinctions may be relatively frequent. © Inter-Research 2011.
Barnes D.K.A.,British Antarctic Survey |
Collins M.A.,Government of South Georgia |
Brickle P.,Shallow Marine Surveys Group |
Fretwell P.,British Antarctic Survey |
And 4 more authors.
Antarctic Science | Year: 2011
Abstract The multilateral failure to apply the Convention on Biological Diversity (CBD) by the target year 2010 was headline news as are the accelerating climatic changes which dictate its urgency. Some ecosystems that are vulnerable to anthropogenic change have few species listed as endangered because too little is known about their biota. The highest vulnerability may correspond to where hotspots of species endemism, range limits and physiological sensitivity overlap with areas of most rapid physical change. The old, large and remote archipelago of South Georgia is one such location. Sea-surface temperatures around South Georgia are amongst the most rapidly warming reported. Furthermore oceanographic projections are highlighting the region as extremely vulnerable to ocean acidification. We outline the first polar Darwin Initiative project and the technical advances in generating an interactive and fully integrated georeferenced map of marine biodiversity, seabed topography and physical oceanography at South Georgia. Mapping marine mega and macro-faunal biodiversity onto multiple physical variables has rarely been attempted. This should provide a new tool in assessing the processes driving biological variability, the importance of marine areas in terms of ecosystem services, the threats and vulnerabilities of Polar Regions and should greatly aid implementation of the CBD. © 2011 Antarctic Science Ltd.
Darbyshire T.,Amgueddfa Cymru National Museum Wales |
Brewin P.E.,Shallow Marine Surveys Group
Zootaxa | Year: 2015
Three new species of Dysponetus (Polychaeta: Chrysopetalidae) are described from the South Atlantic and Southern Ocean: Dysponetus ovalisetosus n. sp. from the Falkland Islands, Dysponetus bricklei n. sp. from South Georgia and Dy-sponetus antarcticus n. sp. from Antarctica are all characterized by having notochaetae that are oval in cross-section in contrast to the D-shape described for seven of the other species of Dysponetus. Dysponetus antarcticus n. sp. is the most distinct due to the combination of both a ventral cirrus on segment 3 and four eyes. Formerly mis-identified as Dysponetus bulbosus Hartmann-Schröder, 1982, it was discovered while clarifying the contradictory descriptions of that species pub-lished by Hartmann-Schröder in 1982 and 1986. Dysponetus bulbosus is re-described and newly figured. Dysponetus bricklei n. sp. and Dysponetus ovalisetosus n. sp. can be determined by comparing several characters including position of the median antenna, shape of the palps and cirri, and the number and shape of both the noto- and neurochaetae. Copyright © 2015 Magnolia Press.
Goodwin C.,National Museums Northern Ireland |
Goodwin C.,Queens University |
Jones J.,National Museums Northern Ireland |
Neely K.,Shallow Marine Surveys Group |
Brickle P.,South Atlantic Environmental Research Institute
Journal of the Marine Biological Association of the United Kingdom | Year: 2016
Sponge samples were taken by scuba diving from six sites around Sea Lion Island (Sea Lion, Sea Lion Easterly and Brandy Islands), three sites south-east of East Falkland (Motley Island, Green Island and Triste Island) and six sites around Beauchêne Island. Nine new species are described: Iophon roseum sp. nov., Clathria (Microciona) tenebrosa sp. nov., Clathria (Microciona) cheeki sp. nov., Hymedesmia (Hymedesmia) laptikhovskyi sp. nov., Hymedesmia (Hymedesmia) croftsae sp. nov., Myxilla (Ectyomyxilla) beauchênensis sp. nov., Tedania (Tedania) livida sp. nov., Amphilectus fimbriatus sp. nov. and Isodictya cutisanserina sp nov. Additional information is provided on several species recently described from the Falkland Islands and Amphimedon marsei is newly reported. The biogeography of the sponge fauna of the southern Falkland Islands is discussed. © 2014 Marine Biological Association of the United Kingdom.
Volonterio O.,University of the Republic of Uruguay |
Brewin P.E.,Shallow Marine Surveys Group
Journal of the Marine Biological Association of the United Kingdom | Year: 2014
South Georgia is a remote sub-Antarctic island, considered a marine biodiversity 'hotspot' in the Southern Ocean. During a survey along the north coast of South Georgia several marine planarians were found. One of the specimens was a new species of Allogenus (Uteriporidae), which is described here as Allogenus sluysi sp. nov. The new species has the characteristics of the genus and can be distinguished from the type and only known species, Allogenus kerguelensis, by its smaller size, blackish-brown pigmentation, presence of three retinal cells in each eye cup, position of its testes half-way between the ventral and dorsal body surfaces or at a slightly more ventral position, and by having an ejaculatory duct that opens centrally at the tip of the penis papilla. The presently known geographical distribution of Allogenus, the heterogeneous marine planarian species composition in South Georgia, and the distribution of these species in this region are in agreement with a previously proposed vicariance hypothesis, albeit that dispersal cannot be ruled out. © Marine Biological Association of the United Kingdom, 2013.