Cleft, Crevice, or the Inner Thigh: ‘Another Place’ for the Establishment of the Invasive Barnacle Austrominius modestus (Darwin, 1854)

Abstract

The proliferation of anthropogenic infrastructure in the marine environment has aided the establishment and spread of invasive species. These structures can create novel habitats in areas normally characterised as void of suitable settlement sites. The habitat requirements of the invasive acorn barnacle Austrominius modestus (Darwin, 1854) were assessed using a novel sampling site at Crosby Beach, Liverpool. Austrominius modestus has spread rapidly around the UK since its initial introduction, becoming locally dominant in many estuarine areas including the Antony Gormley art installation, ‘Another Place’, at Crosby Beach. The installation consists of 100 replicate solid cast-iron life-size human figures, located at a range of heights on the shore. We recorded the distribution and abundance of A. modestus present on all of the statues at various positions during the summer of 2006. The positions varied in location, exposure, direction, and rugosity. Although parameters such as rugosity and exposure did influence patterns of recruitment, they were less important than interactions between shore height and direction, and specific location on the beach. The addition of a suitable substrate to a sheltered and estuarine region of Liverpool Bay has facilitated the establishment of A. modestus. Understanding the habitat requirements of invasive species is important if we are to make predictions about their spread and the likelihood of invasion success. Austrominius modestus has already become locally dominant in some regions of the UK and, with projections of favourable warming conditions and the global expansion of artificial structures, the continued spread of this species can be expected. The implications of this on the balance between native and invasive species dominance should be considered.

Explaining Ocean Warming: Causes, scale, effects and consequences

“…These artificial rocky habitats are not, however, the same as natural rocky shores. Although they are often colonized by common rocky shore organisms, they are frequently found to support less diverse communities Pinn et al, 2005;Firth et al, 2013bFirth et al, , 2016bAguilera et al, 2014), with opportunistic and invasive species taking advantage of the novel habitat Glasby et al, 2007;Vaselli et al, 2008;Bracewell et al, 2012;Firth et al, 2015). Nevertheless, in light of the predicted reduction in spatial extent, through loss of natural intertidal rocky habitats as sea levels rise ("coastal squeeze", e.g.…”

“…: Pollard and Hodgson (2016), which have all been involved in invasions worldwide). There is growing evidence that the proliferation of artificial hard structures in the marine environment has had an additive effect with climate warming, and facilitated range shifts in non-native species (Ruiz et al, 2009;Bracewell et al, 2012;Mineur et al, 2012;Spinuzzi et al, 2013;Airoldi et al, 2015). Artificial structures essentially act as stepping stones to aid the spread of species responding to climate-driven change.…”

Artificial structures in sediment-dominated estuaries and their possible influences on the ecosystem

“…Barbier et al, 2011). Though groynes and jetties represent artificial substrates, their structure is highly complex on a macro-scale (>10 cm) and provides a combination of hard substrate, crevices, pits, and rock pools which provide refuges for many species (Bracewell et al, 2012;Cartwright and Williams, 2012). Artificial reefs, for example, can facilitate and enhance marine communities in coastal and deep-sea environments and provide benefit for ecosystem services in sediment dominated environments (Macreadie et al, 2011).…”

Room for one more? Coexistence of native and non-indigenous barnacle species

“…Invasive species have been regarded as ''opportunistic'' (Occhipinti-Ambrogi and Savini 2003), in that they are capable of rapidly colonizing free space (Bracewell et al 2012). For example, non-indigenous barnacles have been recorded to initially colonise piers as opposed to shorelines (Barnes and Barnes 1961), likely due to the availability of space on novel structures.…”

“…This species is commonly found in sheltered areas and estuaries as opposed to exposed coastlines (Moore 1944;Southward 1955;Crisp 1958). While A. modestus has become dominant at many locations within its invaded range (Franke and Gutow 2004;Lawson et al 2004;Reichert and Buchholz 2006;Gomes-Filho et al 2010;Witte et al 2010;Bracewell et al 2012), native species have been recorded to persist along with this species (Stubbings and Houghton 1964;Bennell 1981;Kerckhoff and Cattrijsse 2001), and even remain the dominant species at some locations within this range (Southward 1991;Range and Paula 2001;Boaventura et al 2002;Burrows et al 2010;Gallagher et al 2015). Despite the long interval since its introduction to Europe, there have been no experimental studies investigating the competitive interactions between this alien and native barnacle species, though there have been anecdotal accounts of such competitive interactions (den Hartog 1953;Crisp 1958Crisp , 1960Barnes and Barnes 1962;Bennell 1981).…”