Pathogens co-transported with invasive non-native aquatic species: implications for risk analysis and legislation

Rachel Foster,Louisa E Wood,Edmund Peeler,Hannah J Tidbury,David Morritt,David Bass,Helen E Roy,Jamie Bojko,Paul F Clark,Paul Stebbing

doi:10.3897/neobiota.69.71358

Rachel Foster, Louisa E Wood + Show 8 more

Open Access

https://doi.org/10.3897/neobiota.69.71358

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Abstract

Invasive Non-Native Species (INNS) can co-transport externally and internally other organisms including viruses, bacteria and other eukaryotes (including metazoan parasites), collectively referred to as the symbiome. These symbiotic organisms include pathogens, a small minority of which are subject to surveillance and regulatory control, but most of which are currently unscrutinized and/or unknown. These putatively pathogenetic symbionts can potentially pose diverse risks to other species, with implications for increased epidemiological risk to agriculture and aquaculture, wildlife/ecosystems, and human health (zoonotic diseases). The risks and impacts arising from co-transported known pathogens and other symbionts of unknown pathogenic virulence, remain largely unexplored, unlegislated, and difficult to identify and quantify. Here, we propose a workflow using PubMed and Google Scholar to systematically search existing literature to determine any known and potential pathogens of aquatic INNS. This workflow acts as a prerequisite for assessing the nature and risk posed by co-transported pathogens of INNS; of which a better understanding is necessary to inform policy and INNS risk assessments. Addressing this evidence gap will be instrumental to devise an appropriate set of statutory responsibilities with respect to these symbionts, and to underpin new and more effective legislative processes relating to the disease screening and risk assessment of INNS.

Highlights

Invasive Non-Native Species (INNS) are “species whose introduction by human activity outside their natural past or present distribution threatens biodiversity”, as defined by the Convention on Biological Diversity (CBD 2010), and are one of the greatest global threats to biodiversity (IPBES global assessment 2019)
Using PubMed; 34 of the 77 aquatic INNS were found to have no relevant literature relating to any known symbiotic species or pathogens
There were nine taxa for which species-level symbiont/pathogen data were published in 20+ papers; Neogobius melanostomus, Homarus americanus, Oncorhynchus gorbuscha, Carassius gibelio, Micropterus salmoides, Castor canadensis, Marsupenaeus japonicus, Myocaster coypus, and Ondatra zibethicus

Summary

Introduction

Invasive Non-Native Species (INNS) are “species whose introduction by human activity outside their natural past or present distribution threatens biodiversity”, as defined by the Convention on Biological Diversity (CBD 2010), and are one of the greatest global threats to biodiversity (IPBES global assessment 2019). It is increasingly recognized that invasions are not the product of single species introduction events but can be considered as holobionts (Skillings 2016): i.e., units of biological organisation including the host and all its symbionts (external and internal), including pathogenic species. Organisms such as viruses, bacteria, fungi, protists and other (micro-)eukaryotic parasites and pathogens may be introduced to new regions along with their invasive non-native host and can be important factors in the invasion process (Peeler et al 2011; Roy et al 2017). For the purposes of this paper, to avoid repetition of “parasites/pathogens” to refer to symbionts that take nutritional advantage of their hosts potentially causing disease, we use “pathogen” as a catch-all term

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