Influence of recruitment and temperature on distribution of intertidal barnacles in the English Channel

Abstract

Many warm-water (Lusitanian) species reach their limits in the central English Channel, failing to penetrate to the North Sea. We re-surveyed the eastern limits of the Lusitanian intertidal barnacles Chthamalus montagui and C. stellatus, from 1994 to 2004, a decade of exceptionally high sea temperatures, and found range extensions on both sides of the Channel compared to the 1950s and 1970s. Annual recruitment of Chthamalus on the English coast was monitored. There was a consistent gradient of low recruitment to the east of Portland Bill, with significant reductions coinciding with prominent headlands. Highest recruitment occurred during the warmest years. Cluster analysis showed a high degree of similarity of annual recruitment within coastal cells suggesting that local processes are also important. In 1999 we compared recruitment in the other common intertidal barnacles, the boreal Semibalanus balanoides and the non-native Elminius modestus, with Chthamalus spp. All species showed low recruitment between Selsey Bill and Portland Bill, suggesting habitat limitations and/or hydrographic mechanisms. Annual recruitment of Chthamalus at existing limits on the Isle of Wight was positively correlated with the number of days of westerly and south-westerly winds during the summer, coinciding with the pelagic larval phase. A ‘pulse’ of high Chthamalus recruitment on the Isle of Wight, measured during the summer of 2000, reversed population decline. Only a higher frequency of such pulses will maintain populations at existing limits and increase the rate of range extension towards the North Sea. Such extension will be limited by lack of hard substrata, but proliferation of coastal defence schemes in recent years is increasing suitable habitat for barnacles.

Biogeography of Intertidal Barnacles in Different Marine Ecosystems of Taiwan - Potential Indicators of Climate Change?

“…There, the warm water species Chthamalus montagui and C. stellatus reach range limits in the Central English Channel and fail to enter the North Sea due to reduced water temperature. By comparing the distribution pattern of Chthamalus in the UK from 1950 to 2004, Chthamlaus showed range extension in the English Channel and with extensive recruitment in warmest years (Herbert et al, 2007). Under the effect of global warming, warm water barnacle species along the east coast of Taiwan can expand northwards.…”

“…Additionally, specific searching was conducted on shaded rocks and in cracks to detect stalked barnacles, including Capitulum and Ibla species, and the Tetraclitid barnacle Tetraclitella species. The abundance of each species of barnacles was scored using a semiquantitative scale, modified from Herbert et al, 2007 (Table 2).…”

“…Recent studies (e.g., Barber et al, 2000Barber et al, , 2006Zakas et al, 2009), however, showed that the interplay between larval supply, local oceanographic currents and geographical isolation can result in retention of larvae in both regional or local scales, leading to distinct assemblage structure and geographic distribution (see Scheltema, 1988;Kojima et al, 1997;Pannacciulli et al, 1997;Wethey, 2002;Dawson et al, 2010;Reece et al, 2010). In addition to the effects of ocean current on larval dispersal, temperature and recruitment also can affect the survival and sustainability of both cold and warm marine species, thus affecting their biogeography (Herbert et al, 2007;Jones et al, 2009). …”

“…Rocky intertidal species therefore are sensitive to environmental changes, and can show rapid responses (Thompson et al, 2002, Rivadeneira & Fernandez, 2005Helmuth et al, 2006;Hawkins et al, 2009). Increased seawater temperature has resulted in range shifts of intertidal species in northern temperate Atlantic waters (Southward et al 2005;Helmuth et al 2006;Lima et al, 2006Lima et al, , 2007aMieskowska et al, 2006Mieskowska et al, , 2007Herbert et al, 2007;Hawkins et al, 2008). In the northwestern Pacific at present there are no studies concerning the range shift of intertidal organisms, because the baseline biogeographic pattern species is still poorly known.…”

Status and trends in the structure of Arctic benthic food webs

“…It may influence growth, survival, reproduction, phenology and recruitment success of particular species (Lewis 1996;Walther et al 2002;Lewis 2005;Herbert et al 2007). Therefore, spatial distributions of organisms will likely change because of differential survival and recruitment of pelagic larval stages with varying water temperatures (Sirenko & Kolutin 1992;Blanchard et al 2010;Grebmeier 2012).…”