For all researches, please visit our "Peer-reviewed publications" page.
Lee-Yaw J, Kharouba H, Bontrager M, Mahony C, Csergő A, Noreen A et al. (2016)
A synthesis of transplant experiments and ecological niche models suggests that range limits are often niche limits
Global change has made it important to understand the factors that shape species' distributions. Central to this area of research is the question of whether species' range limits primarily reflect the distribution of suitable habitat (i.e. niche limits) or arise as a result of dispersal limitation. Over-the-edge transplant experiments and ecological niche models are commonly used to address this question, yet few studies have taken advantage of a combined approach for inferring the causes of range limits. Here, we synthesise results from existing transplant experiments with new information on the predicted suitability of sites based on niche models. We found that individual performance and habitat suitability independently decline beyond range limits across multiple species. Furthermore, inferences from transplant experiments and niche models were generally concordant within species, with 31 out of 40 cases fully supporting the hypothesis that range limits are niche limits. These results suggest that range limits are often niche limits and that the factors constraining species' ranges operate at scales detectable by both transplant experiments and niche models. In light of these findings, we outline an integrative framework for addressing the causes of range limits in individual species.
Keywords: Abiotic constraints, climate, dispersal limitation, fitness, geographical distribution, over the edge transplant, species distribution modelling
Trowbridge C, Little C, Ferrenburg L, Resk H, Kachmarik K, Plowman C et al. (2016)
Alcyonacean octocorals are anthozoans which are found in many coastal benthic habitats, where they can be sensitive to environmental and/or anthropogenic stress. As part of a two-decade monitoring study of Lough Hyne (Europe’s first marine reserve and Ireland’s only one), we documented benthic communities at rocky-shore sites. As a fully marine, semi-enclosed, tidal ‘lake’ connected to the Atlantic Ocean via tidal rapids, Lough Hyne has long been noted for its high species and habitat diversity. One of the noteworthy guilds we report here was the alcyonacean octocorals: (1) the soft coral Alcyonium hibernicum under shallow subtidal rocks at monitoring sites in the lough from 2002 to 2015 and (2) the first known records (2013 to present) of the red soft coral A. glomeratum inside the lough (above the rapids). Furthermore, in August/September 2014 and 2015, we rediscovered the stoloniferous octocoral Sarcodictyon catenatum, last reported in the lough in the 1930s. We documented the distribution and abundance of these species in shallow subtidal areas of the lough as a baseline in the face of rapidly degrading conditions due to extreme oxygen fluctuations from eutrophication.
Keywords: Alcyonium, Ireland, Lough Hyne, Marine protected area, Marine reserve, Octocorallia, Sarcodictyon
Glynn F, Houghton JDR, Bastian T, Doyle TK, Fuentes V L (2015)
High-resolution genetic analysis reveals extensive gene flow within the jellyfish Pelagia noctiluca (Scyphozoa) in the North Atlantic and Mediterranean Sea
Biological Journal of the Linnean Society.
Despite the importance of gela tinous zooplankton as component s of marine ecosystems, both ecologically and socio-economically, relatively little is known about population persistence or connectivity in jellyfish. In the present study, we employed a combination of nuclear microsatellite markers and sequence data from the mitochondrial cytoch rome oxidase I (COI) gene to determine levels and patterns of population genetic st ructuring in the holoplanktonic jellyfish Pelagia noctiluca across the northeast Atlantic Ocea n and Mediterranean Sea. Our results indicate a high de gree of connectivity in P. noctiluca , with little evidence of geographical structuring of gene tic variation. A small but si gnificant differentiation of Atlantic Ocean and Mediterranean stocks was de tected based on the micr osatellite data, but no evidence of differentiation was observed with the mtDNA, probably due to the higher power of the microsatellites to detect low levels of genetic structuring. Two clearly distinct groups of genotypes were observed within the mtDNA COI, which probably diverged in the early Pleistocene, but with no evidence of geographical structuri ng. Palaeodistribution modelling of P. noctiluca at the Last Glacial Maximum (LGM; ca . 21 KYA) indicated large areas of suitable habitat south of the species’ current-day distribution, with little reduction in area. The congruent evidence for minimal genetic differentiation from the nuclear microsatellites and the mtDNA, coupled with th e results of the palaeodistribution modelling, supports the idea of long-term population stab ility and connectivity, thus providing key insights into the population dynamics and de mography of this important species.
Keywords: Gelatinous zooplankton, jellyfish, microsatellites