Recent impacts of anthropogenic climate change on a higher marine predator in western Britain

Abstract

Impacts of anthropogenic climate change on marine ecosystems are now widely acknowledged. In the NE Atlantic, abundant evidence from the partly enclosed waters of the North Sea indicates that recent climate-induced changes in primary and secondary productivity have been propagated up the food chain, with marked consequences for higher vertebrate predators such as seabirds. In contrast, however, there is much less indication of such impacts on higher predators in the more open Atlantic waters around the west coast of the British Isles. Through an annual comparison of chick growth and adult food provisioning behaviour of Manx shearwaters in SW Wales, we found that birds bred later and chicks attained lower peak and fledging masses in 2007 and 2008 than in any previous recorded year dating back to 1965. These changes were accompanied by a reduction in parental attendance at the colony, which was probably the result of parents switching to a dual foraging strategy in 2007 and 2008. These events were linked to higher sea surface temperature in the preceding winter and to a reduction in prey quality, as indicated by the mean body mass of 2 yr old herring. These are the first such findings for the west coast of Britain and indicate that within the NE Atlantic region, adverse impacts of climate change on higher marine predators are no longer restricted to the vicinity of the North Sea.

Responses of Marine Organisms to Climate Change across Oceans

“…These results are likely due to climate-driven changes in prey availability, although mechanisms differ among populations. For example, a reduction in fledging masses of manx shearwater chicks in the Celtic Sea was linked to higher sea surface temperatures in the preceding winter and a reduction in prey quality (Riou et al, 2011). A link between breeding productivity and winter sea surface temperatures in the preceding year was also shown for kittiwake breeding colonies in east Scotland and Orkney, but not for colonies in adjacent regions (west Scotland and east England) (Frederiksen et al, 2007).…”

“…Breeding success is negatively related to warming temperatures for fulmer, Fulmarus glacialis, (Lewis et al, 2009), manx shearwaters, Puffinus puffinus, (Riou et al, 2011), and black-legged kittiwakes, Rissa tridactyla, (Frederiksen et al, 2007) in the north-east Atlantic. These results are likely due to climate-driven changes in prey availability, although mechanisms differ among populations.…”

Observed and predicted effects of climate change on species abundance in protected areas

“…The apparent sensitivity of seabirds to warming matches empirical observations which describe how recent increases in sea-surface temperature have reduced the abundance and condition of fish prey species for many seabirds 26 . As a result, the productivity of seabirds has declined in relation to warmer temperatures 27,28 and they may also be vulnerable to more direct negative effects of warming through heat stress 29 . Positive effects of winter temperature upon waterbird abundance may reflect improved survival 30,31 , whilst negative effects of temperature may operate through variation in prey populations 32 .…”

Environmental Impacts—Coastal Ecosystems, Birds and Forests

“…Climate change has been shown to affect the populations of oceanic seabirds by diminishing their food resources (Montevecchi and Myers 1997;Barbraud and Weimerskirch 2003). In addition to food abundance, the quality of food items may change (Riou et al 2011). The low-energy value of fish was considered the cause of a major breeding failure of common guillemots Uria aalge in the North Sea (Wanless et al 2005).…”