| 1. |
- Hawkins, Stephen J., et al.
(author)
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The Intertidal Zone of the North-East Atlantic Region
- 2019
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In: Interactions in the Marine Benthos: Global Patterns and Processes (Systematics Association Special Volume Series, pp. 7-46). - : Cambridge university press. - 9781108416085
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Book chapter (peer-reviewed)abstract
- The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
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| 2. |
- Jenkins, S. R., et al.
(author)
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Population dynamics of the intertidal barnacle Semibalanus balanoides at three European locations: spatial scales of variability
- 2001
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In: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 217, s. 207-217
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Journal article (peer-reviewed)abstract
- Spatial variability in the population dynamics of the intertidal acorn barnacle Semibalanus balanoides was investigated using a hierarchical sampling programme. Variability in a number of population parameters (size distribution, density, % cover, absolute growth and instantaneous mortality) was determined separately for new recruits and adults over 3 spatial scales. Three locations, SW Ireland, the Isle of Man and the west coast of Sweden, which cover a large part of the European range of this species, were selected to investigate variability over a large spatial scale (100s of kilometres). Two smaller scales, shore (1000s of metres) and site (10s of metres) nested within each location were also used. In addition, temporal variation over two 6 mo periods was also examined in the Isle of Man and Ireland. Most variability for all population parameters occurred over the largest spatial scale (location). This was a direct result of differences between Sweden and the other 2 locations, the Isle of Man and Ireland, which showed highly similar levels of all population parameters. The population of S, balanoides at the Swedish location was characterised by high growth rates, large size, high levels of mortality and a large turnover of bare space. At the spatial scale 'shore', only 1 population parameter, the growth rate of recruits, showed variability. At the smallest scale of 'site', all parameters showed significant variability except growth rate of adults. Calculation of variance components showed that differences between replicates (spatial scale: <0.5 m) accounted for little of the overall variability, in general less than the scales of site and shore. Examination of temporal variability over two 6 mo periods revealed no difference between time periods and no significant interaction between temporal and spatial scales, Thus, there was consistency of spatial variability over time. The potential causes of variability in population parameters of S, balanoides at different spatial scales and the implications for future studies are discussed.
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| 3. |
- Jenkins, S. R., et al.
(author)
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Spatial and temporal variation in settlement and recruitment of the intertidal barnacle Semibalanus balanoides (L.) (Crustacea : Cirripedia) over a European scale
- 2000
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In: Journal of Experimental Marine Biology and Ecology. - 0022-0981. ; 243:2, s. 209-225
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Journal article (peer-reviewed)abstract
- Variation in the level of settlement and recruitment in the intertidal barnacle Semibalanus balanoides was studied using a hierarchical sampling programme. The effect of three spatial scales, 10s of metres (sites), 1000s of metres (shores) and 100s of kilometres (locations), was determined. The largest spatial scale represented the distance between four widely separated locations, Sweden, the Isle of Man, SW Ireland and SW England, covering a. large part of the range of S. balanoides in Europe. Temporal variation was determined by comparison between two years, 1997 and 1998. The settlement period of S. balanoides varied in length and timing, being earlier and shorter at the most northerly location, Sweden. The duration of settlement showed little difference among shores within locations, but the pattern of settlement did vary. Estimates of total settlement throughout the settlement period and of recruitment at the end of this period both showed substantial variation among locations which was dependent on the year of study. There was little consistency in the ranking of locations between the two years. Recruitment showed significant variation I the lower spatial scales of shore and site. In addition, examination of variance components showed a high degree of variation between replicates within sites in 1997. There was a significant relationship between settlement and recruitment at three of the four locations. Across all locations variation in settlement explained between 29 and 99% of variation in recruitment. However, locations showed distinct differences in the level of post-settlement survival. (C) 2000 Elsevier Science B.V. All rights reserved.
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| 4. |
- Coleman, Ross A., et al.
(author)
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A continental scale evaluation of the role of limpet grazing on rocky shores
- 2006
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In: OECOLOGIA. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 147:3, s. 556-564
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Journal article (peer-reviewed)abstract
- It is critical for our knowledge of biodiversity and ecosystem processes to understand how individual species contribute to ecosystem processes and how these contributions vary in space and time. We used a manipulative field experiment in five locations over 17 degrees of latitude [from southern Portugal to the Isle of Man (British Isles)] to determine the relative response of rocky intertidal algal assemblages released from control by the grazing of limpets. Response ratios showed that when limpets were removed there was a trend of effects from north to south. In the north, grazing had a strong effect on algal assemblages, but removing grazers reduced spatial variability in assemblages. In the south, the effect of limpet grazing was far weaker and removal of grazers had a much reduced impact on spatial variability. Here we show a clear trophic control of an ecosystem in that grazing by limpets not only determines macroalgal abundance overall but also modifies ecosystem stability via variability in cover of algae.
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