Increased spreading potential of the invasive Pacific oyster (Crassostrea gigas) at its northern distribution limit in Europe due to warmer climate

Abstract

The Pacific oyster, Crassostrea gigas, is an invasive species with a large increase in prevalence globally, and with potential of spreading even more because of climate-change effects. We examined how future climate might affect its potential for spread at its northern distribution limit in a temperate ecoregion, by simulating spawning, larval dispersal, larvae settlement and adult survival, given different climate scenarios. The simulations were performed using a three-dimensional current model (GEMSS) and a specially designed oyster module, applied at the study site in the Oslofjord, Norway. The simulations showed that the expected climate in the middle and latter part of this century, with warmer summers and winters, very likely will lead to increased prevalence of the species within northern Europe. The warmer summers will more often provide favourable temperature conditions for oyster spawning and settlement, and warmer winters will more seldom cause high winter mortality. The simulations gave a realistic picture of the relative frequency and the main distribution pattern observed, given the current climate. The future climate-scenario simulations indicated influence of local differences in temperature on the dispersal pattern. The study indicated increased dispersal and successful establishment at the outer edge of the species present distribution in the future and, hence, an increased risk to native species and habitats in temperate regions.

Rapid expansion of the invasive oyster Crassostrea gigas at its northern distribution limit in Europe: Naturally dispersed or introduced?

“…Future climate change with rising summer temperatures is likely to increase the risk of C . gigas larvae dispersal [ 62 ]. Analysis of sea surface temperature data along the Swedish Skagerrak coast [ 50 ] suggests a 125 km northwards displacement of the 19°C temperature isocline in August.…”

Indications of future performance of native and non-native adult oysters under acidification and warming

“…Nevertheless, the negative perception of wild M. gigas populations has led to management measures being introduced to prevent its further proliferation, and to promote the recovery of O. edulis (Harding et al, 2016;Herbert et al, 2012;Laing et al, 2006;Sawusdee, 2015;Woolmer et al, 2011). Since its introduction to Europe, M. gigas has been spreading northward across European shores (Shelmerdine et al, 2017) facilitated by increasing average sea surface temperatures (SST) (Angles d'Auriac et al, 2017;Rinde et al, 2016;Thomas et al, 2016;Townhill et al, 2017). In contrast, the extent of O. edulis is continuing to decline, and native oyster reefs are considered some of the most endangered coastal habitats in Europe (Airoldi & Beck, 2007;Beck et al, 2011).…”

Co-occurrence of nativeOstrea edulisand non-nativeCrassostrea gigasrevealed by monitoring of intertidal oyster populations

“…In Australia, wild C. gigas compete with native oyster populations in the mid and low intertidal zone (Krassoi et al , 2008; Wilkie et al , 2013). In Europe, introduced C. gigas populations produced viable spatfall and have spread extensively, possibly aided more recently by increasing sea temperatures (Dutertre et al , 2010; Rinde et al , 2016; Thomas et al , 2016), or adaptation of the oyster to colder water temperatures (Rohfritsch et al , 2010, 2013). For example, C. gigas has spread over 640 ha in parts of the Dutch Wadden Sea (Kater & Baars, 2004).…”