Time-since-invasion increases native mesoherbivore feeding rates on the invasive alga, Sargassum muticum (Yendo) Fensholt

Abstract

Peer reviewed versionCyswllt i'r cyhoeddiad / Link to publication Dyfyniad o'r fersiwn a gyhoeddwyd / Citation for published version (APA): Kurr, M., & Davies, A. J. (2018). Time-since-invasion increases native mesoherbivore feeding rates on the invasive alga, Sargassum muticum (Yendo) Fensholt. Abstract 17 18Invasive algae can have substantial negative impacts in their invaded ranges. One widely-19 cited mechanism that attempts to explain how invasive plants and algae are often able to 20 spread quickly, and even become dominant in their invaded ranges, is the Enemy Release 21 Hypothesis. This study assessed the feeding behaviours of two species of gastropod herbivore 22 from populations exposed to the invasive alga Sargassum muticum for different lengths of 23 time. Feeding-trials, consisting of both choice and no-choice, showed that the herbivores 24 from older stands (35-40 years established) of S. muticum were more likely to feed upon it 25 than those taken from younger (10-19 years established) stands. These findings provide 26 evidence in support of the ERH, by showing that herbivores consumed less S. muticum if they 27 were not experienced with it. These findings are in accordance with the results of other 28 feeding-trials with S. muticum, but in contrast to research that utilises observations of 29 herbivore abundance and diversity to assess top-down pressure. The former tend to validate 30 the ERH, and the latter typically reject it. The potential causes of this disparity are discussed, 31 as are the importance of palatability, herbivore species, and time-since-invasion when 32 considering research into the ERH. This study takes an important, yet neglected, approach to 33 the study of invasive ecology. 34 35

Herbivores shape the seascape : Cascading effects of herbivores on the functioning of tropical seagrasses in a changing world

“…obs.). An increase in biotic resistance matches with the reports from other coastal ecosystems: for macroalgae in the Caribbean(Santamaría et al 2022), and sargassum in the UK(Kurr and Davies 2018).resilience Scheffer 2007, van de Leemput et al 2018). In addition, our study provides evidence that dynamic indicators (i.e.…”

Drivers of Sex-specific Trade-offs in the Macroalga <i>Ascophyllum nodosum</i>

“…Three known herbivores of A. nodosum were found to be present at all sites (Littorina littorea, Littorina fabalis, Littorina obtusata) and Patella vulgata was also present at Cemlyn and Bull on Anglesey. Littorina fabalis was included in surveys because although it has been previously shown to subsist primarily on algal films [34], it does also consume macroalgae including Sargassum muticum, Fucus serratus, and A. nodosum [35].…”

The chemical defences of the invasive alga Sargassum muticum (Yendo) Fensholt correlate to mesoherbivore diversity, but not to time-since-invasion

“…However, native grazers typically ignore it in feeding trials, preferring to consume native algal species (e.g. Norton & Benson, 1983;Critchley et al, 1986;Monteiro et al, 2009;Cacabelos et al, 2010a;Engelen et al, 2011;Schwartz et al, 2016) unless the grazers are highly generalist and presented with particularly tough or well-defended native algae (Pedersen et al, 2005;Strong et al, 2009), or have been exposed to S. muticum for many generations (Kurr & Davies, 2017a). The lack of interest native herbivores show in S. muticum is unusual because, according to the ecoevolutionary concept, most of these species should possess the necessary adaptations to consume S. muticum due to the presence of similar defences in native algae (Engelen et al, 2015).…”

“…Time-since-invasion is an understudied approach in ecology, and historically very few researchers have specifically incorporated it into tested hypotheses (discussed by Strayer et al, 2006). However, there is evidence to suggest that grazers from long-established stands of S. muticum are more likely to consume it than those from recentlyestablished stands (Kurr & Davies, 2017a). It remains unclear if the increased grazer preference shown in the laboratory manifests as increased top-down pressure in the field, and whether time-since-invasion is more or less important to top-down pressure on S. muticum than enemy diversity.…”