The journey of hull-fouling mobile invaders: basibionts and boldness mediate dislodgement risk during transit

Abstract

Vessel hull-fouling is responsible for most bioinvasion events in the marine environment, yet it lacks regulation in most countries. Although experts advocate a preventative approach, research efforts on pre-arrival processes are limited. The performance of mobile epifauna during vessel transport was evaluated via laboratory simulations, using the well-known invasive Japanese skeleton shrimp (Caprella mutica), and its native congener C. laeviuscula as case study. The invader did not possess any advantage in terms of inherent resistance to drag. Instead, its performance was conditioned by the complexity of secondary substrate. Dislodgement risk was significantly reduced when sessile fouling basibionts were added, which provided refugia and boosted the probability of C. mutica remaining attached from 7 to 65% in flow exposure trials. Interestingly, the invader exhibited significantly higher exploratory tendency and motility than its native congener at zero-flow conditions. Implications in terms of en-route survivorship, invasion success and macrofouling management are discussed.

Keywords:

• Non-indigenous species
• recreational boating
• biomechanical impact
• hydrodynamics
• en-route survivorship
• basibiont-epifauna assemblage

Acknowledgements

The marina directors and staff from Royal Vancouver Yacht Club and Reed Point Marina who granted access and offered assistance for sampling during this study were thanked. The authors also thank Sandra Emry, who supported in fieldwork, and Em Lim for their valuable advice during sampling and assistance with laboratory work. The authors would like to acknowledge the Squamish, Tsleil-Waututh, and Musqueam nations as well, on whose traditional, unceded territory this work was conducted. Finally, the authors are deeply grateful to Professor Dr. James Carlton and an anonymous reviewer, for their input when reviewing our manuscript.

Author’s contributions

Conceptualization: GML, MR, CDGH and CDM. Data collection and laboratory work: GML, CDM, AVH and CAK. Data analysis: GML, MR. The first draft of the manuscript was written by GML and all authors commented on previous versions on the manuscript.

Disclosure statement

The authors report there are no competing interests to declare.

Consent to participate/consent for publication

All authors agreed with the content and all gave explicit consent to submit.

Data availability statement

The datasets generated during the current study are available from the corresponding author on reasonable request. Also, methodology is well detailed in this article to allow replication by other researchers.

Additional information

Funding

Financial support for this study was provided by a predoctoral grant from the Spanish Government to GM-L (Reference FPU15/02223) and the Ministerio de Economía y Competitividad (Project CGL2017-82739-P) co-financed by the ERDF, European Union. This study was carried out in the framework of an internship at University of British Columbia, funded by Ministerio de Ciencia, Innovación y Universidades (EST18/00253). Additional support was provided by a Natural Sciences and Engineering Research Council (Canada) Discovery Grant to CDGH.