Category: Neobiota

Dr Giovanni Vimercati gave the Best Talk at NEOBIOTA 2022

The invasion scientist and NEOBIOTA 2022 awardee shares more about his research on the impact assessment of biological invasions.

Giovanni Vimercati is a postdoctoral researcher at the University of Fribourg, Switzerland, and most recently recipient of the Best Talk award (Early Career Researcher) at the 2022 NEOBIOTA conference held in mid-September in Tartu, Estonia. 

As a sponsor of the event and publisher of the NeoBiota journal, Pensoft granted a complimentary publication in it to the awardee. 

NeoBiota readers might already be familiar with Vimercati, whose name first appeared on its pages in a 2017 paper that used alien amphibians as a case study to identify the differences and potential difficulties with two impact assessment scoring tools: the Environmental Impact Classification of Alien Taxa (EICAT) and the Generic Impact Scoring System (GISS). 

Then, in 2020 and 2021, the researcher had two research articles published in NeoBiota as lead author. The 2020 paper provided a summary of the frameworks assessing beneficial impacts of alien species, while in the 2021 study his team used a spatially-explicit stage-structured model to assess efficacy of past, present and alternative control strategies for invasive guttural toads (Sclerophrys gutturalis) in Cape Town.

Giovanni Vimercati being awarded at NEOBIOTA 2022. Photo by Ana Novoa.

In anticipation of Vimercati claiming the Best Talk award with a forthcoming submission to the journal, we asked him to join us for an interview and share his thoughts on his research.  

Going back to the beginning, what sparked your interest in the study of invasive species in particular? What are the unique aspects of your research?

Like the episodic nature of many biological invasions, my first contact with the study of alien species was quite “unexpected”. Having a strong interest in herpetology, I had the luck to pursue my doctoral research at the Center of Excellence for Invasion Biology (CIB) in Stellenbosch, South Africa, where I studied the invasion of an alien amphibian species. My PhD study, and the highly stimulating community of researchers that characterized the CIB, made me realize not only that invasive species provide an invaluable opportunity to address ecological and evolutionary questions, but also how important it is to study their impact on biodiversity and human communities. 

One unique aspect of my research since then has been its multidisciplinary character, as I have studied biological invasions from multiple angles simultaneously, by using mathematical models, physiological experiments, field surveys, remote sensing, literature reviews, meta analysis, and questionnaires. It seems a paradox, but the uniqueness of my research on biological invasions is that it has never really been unique! 

Are there recent developments in the field that you find particularly interesting to explore?

As many other scientific disciplines, the field of invasion science is highly dynamic, and novel developments emerge every year. However, I find of particular interest the development of new approaches and tools to explore the links between biological invasions and the various socio-economic contexts. The use of online structured and semi-structured interviews, or the development of standardized socio-economic indicators are, for example, particularly promising for future studies. 

In addition, the emergence of novel technological tools, for instance, linked to remote sensing, eDNA, stable isotopes and camera trapping, or the rapid increase in the computational power of modern CPUs, are allowing invasion scientists to collect and analyze data that used to be unaffordable, or simply unavailable. It is certainly an exciting moment to be an invasion scientist. 

What do you find to be the biggest challenges as a researcher in your field?

I find that the proliferation of hypotheses and frameworks that characterize the field of invasion biology are particularly intriguing and challenging. Many of them work extremely well in certain conditions or across specific taxonomic groups, but they often lack generality or are marred by context dependence, which may limit their predictive power. 

Addressing such a context dependence and finding ways to integrate various hypotheses and frameworks in invasion biology will be highly beneficial for understanding and forecasting biological invasions in the next decades. 

Another challenge is to communicate the implications of our research to non-experts. I often wonder how stakeholders and policymakers from different cultural backgrounds or geographic regions perceive alien species and their impacts.  

The theme of this year’s NEOBIOTA conference was “Biological Invasions in a Changing World”. To what extent can changes be anticipated and forecasted in order to make the work of assessing their impacts and mitigating damage easier?

I think that a key point would be to focus on specific indicators or proxies to measure these changes, so that different impacts and species can be quantified, both transparently and consistently. 

In recent years, the field has produced a huge body of literature regarding impacts caused by alien species, but the results of these studies have not always been comparable. I feel that the development of the EICAT framework and its recent adoption by the IUCN as a global standard for measuring the magnitude of environmental impacts of alien species were two very important steps in this direction. 

Your talk at the NEOBIOTA conference focused on the positive socio-economic impacts of invasive species. Why is this important for different stakeholders, including policy makers, but also local communities and individuals?

In my opinion, invasive species, and more generally alien species, can have various positive socio-economic impacts that should be identified and assessed rigorously. These impacts are often anecdotally reported or vaguely stated in the literature, a tendency that hampers our capacity to identify (and forecast) conflicts of interest among different stakeholders or understand their perceptions toward alien species. 

In my talk, I presented the preliminary version of a framework that assesses positive socio-economic impacts. The framework is based on the capability approach, and aims to quantify the degree to which the well-being of certain human communities increases after the introduction of alien species. Of course, the scheme won’t be used in isolation, but rather in combination with other frameworks that assess the negative socio-economic and environmental impacts of alien species, so that their effects can be understood in their full complexity.

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Assessments of alien species impacts are reliable to prioritize resources

Experts are consistent when assessing the economic, health and ecological impacts of alien species, find the scientists.

Original post by EBD-CSIC

An international collaboration led by the Doñana Biological Station (EBD-CSIC) has shown that experts are consistent when assessing the economic, health and ecological impacts of alien species. These assessments are therefore reliable to guide the prioritization of resources invested against biological invasions.

You can find the scientific article published in the open-access, peer-reviewed scholarly journal NeoBiota.

These results have a great impact on the management by national and international institutions, which have limited resources to fight against the growing and worrying increase of alien species invasions and the damage they caused to society and environment. 

Biological invasions annually cause huge food losses, disease transmissions, species extinctions and ecosystem perturbations. For these reasons, it is one of the biggest problems that humankind currently faces, and its relevance will alarmingly increase due to the extreme situations that climate change will expose society to.

The seriousness of this problem lies in the limited human resources available to fight against it, that force to prioritize its management. Here is where tools such as impact assessments play a key role. Assessments report the impact of invasive species in different areas, including economy, health and environment, and allow us to rank the most harmful species.

For instance, in aquatic ecosystems like the Ebro Delta in Spain, there are dozens of invasive alien co-occurring species that cause millions of economic losses and irreparable ecological damage.

Such is the case of the Zebra mussel, which affects irrigation; the apple snail that devours rice fields; and the blue crab causing the local extinction and declines of many native species.

“That’s why it is crucial to ensure that the results are not dependent on the assessors and to understand what factors affect discrepancies among experts,”

explains RubĂ©n Bernardo-Madrid, lead author and researcher at Doñana Biological Station – CSIC.

One of the relevant aspects of this study is the quantification of the consistency of responses across assessors for a large number of invasive species of vertebrates, invertebrates and plants. In addition, the researchers have studied multiple protocols focused on different aspects, providing a global view of this problem.

“The study has shown that the great majority of assessments are consistent and therefore valid to aid in decision-making. These results are encouraging as they suggest that these protocols may be useful when facing the worrying forecasts of increasing biological invasions and their damages,” 

explains Rubén.

On the other hand, the researchers have observed that discrepancies across assessments might be due to multiple factors, such as the type of impact asked or the linguistic formulation used in the protocols.

The results suggest that there is room for improvement in assessments, but it will require more funding for research, and more multidisciplinary collaborations between ecologists and linguists to develop less ambiguous protocols.

As always, the most effective measure against biological invasions turns out to be prevention.

However, given the incapacity to control every voluntary and involuntary introduction, other tools such as impact assessments are essential to reduce as far as possible the damage caused by these species on human welfare and environment. Its continuous improvement and evaluation, such as the one made in this study, are decisive.

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Research article:

Bernardo-Madrid R, GonzĂĄlez-Moreno P, Gallardo B, Bacher S, VilĂ  M (2022) Consistency in impact assessments of invasive species is generally high and depends on protocols and impact types. In: Giannetto D, Piria M, Tarkan AS, Zięba G (Eds) Recent advancements in the risk screening of freshwater and terrestrial non-native species. NeoBiota 76: 163-190. https://doi.org/10.3897/neobiota.76.83028

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Pensoft’s ARPHA Publishing Platform integrates with OA Switchboard to streamline reporting to funders of open research

By the time authors open their inboxes to the message their work is online, a similar notification will have also reached their research funder.

Image credit: OA Switchboard.

By the time authors – who have acknowledged third-party financial support in their research papers submitted to a journal using the Pensoft-developed publishing platform: ARPHA – open their inboxes to the congratulatory message that their work has just been published and made available to the wide world, a similar notification will have also reached their research funder.

This automated workflow is already in effect at all journals (co-)published by Pensoft and those published under their own imprint on the ARPHA Platform, as a result of the new partnership with the OA Switchboard: a community-driven initiative with the mission to serve as a central information exchange hub between stakeholders about open access publications, while making things simpler for everyone involved.

All the submitting author needs to do to ensure that their research funder receives a notification about the publication is to select the supporting agency or the scientific project (e.g. a project supported by Horizon Europe) in the manuscript submission form, using a handy drop-down menu. In either case, the message will be sent to the funding body as soon as the paper is published in the respective journal.

“At Pensoft, we are delighted to announce our integration with the OA Switchboard, as this workflow is yet another excellent practice in scholarly publishing that supports transparency in research. Needless to say, funding and financing are cornerstones in scientific work and scholarship, so it is equally important to ensure funding bodies are provided with full, prompt and convenient reports about their own input.”

comments Prof Lyubomir Penev, CEO and founder of Pensoft and ARPHA.

 

“Research funders are one of the three key stakeholder groups in OA Switchboard and are represented in our founding partners. They seek support in demonstrating the extent and impact of their research funding and delivering on their commitment to OA. It is great to see Pensoft has started their integration with OA Switchboard with a focus on this specific group, fulfilling an important need,”

adds Yvonne Campfens, Executive Director of the OA Switchboard.

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About the OA Switchboard:

A global not-for-profit and independent intermediary established in 2020, the OA Switchboard provides a central hub for research funders, institutions and publishers to exchange OA-related publication-level information. Connecting parties and systems, and streamlining communication and the neutral exchange of metadata, the OA Switchboard provides direct, indirect and community benefits: simplicity and transparency, collaboration and interoperability, and efficiency and cost-effectiveness.

About Pensoft:

Pensoft is an independent academic publishing company, well known worldwide for its novel cutting-edge publishing tools, workflows and methods for text and data publishing of journals, books and conference materials.

All journals (co-)published by Pensoft are hosted on Pensoft’s full-featured ARPHA Publishing Platform and published in a way that ensures their content is as FAIR as possible, meaning that it is effortlessly readable, discoverable, harvestable, citable and reusable by both humans and machines.

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Invasive species denialism: what is it, and what can we do about it?

Even when there is agreement on the impacts of invasive species on ecosystems, some stakeholders nevertheless deny the need for, or benefit of managing invasive species.

Guest blog post by Noelle G. Stratton, Nicholas E. Mandrak, and Nicole Klenk

Invasive species denialism (ISD) is a hot topic in recent invasion ecology discourse. Many of us are familiar with the concept of science denialism, particularly during recent discussions about climate change and the ongoing COVID-19 pandemic. Essentially, a person who exhibits science denialism is skeptical of, or refuses to believe, the scientific facts about a topic. Much of the discussion about ISD has focused on characterising it as a form of science denialism. However, while science denialism may be one form of ISD, it is not the only one.

Understanding the different forms of ISD is an important step in learning more about what drives ISD positions, and how those positions can be overcome to improve invasive species management. Recently, researchers at the University of Toronto outlined these ISD forms in a new paper in NeoBiota. While these framings are not the only ways to characterize invasive species denialism, they demonstrate that there are multiple framings to the ways that people deny the imperative to manage all invasive species as prescribed by early detection and rapid response.

So, what are the forms of ISD?

Venn diagram of the three forms of invasive species based on interviews and focus groups with invasive species community members in the Great Lakes region, including interested publics and decision-makers: 1) Invasive species denialism; 2) invasive species cynicism; and 3) invasive species nihilism. Each has different motivations and ways of talking about invasive species. Notably, all forms include an opposition to invasive species engagement or management efforts.

Invasive species denialism is the form that will typically come to mind when you picture a “science denialist”. Someone who does not believe in invasive species, or says that the existing scientific literature is all wrong, would fall within this framing. However, it is more complex than that. Invasive species practitioners also identified some of those who believed in invasive species and supported their management under this framing.

For example, folks who wanted management to happen immediately, be 100% effective, or have no risks to them or the environment whatsoever, were considered another form of denialist. This is because while these people supported invasive species management, they were still opposed to certain management efforts due to a lack of understanding of the science behind that management. Similarly, people who agree invasive species are a problem but say “this isn’t my problem, and I shouldn’t have to do anything about it” when shown evidence otherwise were also framed as denialists, as it again indicated a denial, or at least a lack of understanding of the scientific facts.

Invasive species cynicism is the form where someone may well understand what invasive species are and the science behind their management. However, they may still oppose management because they believe it will harm them in some way.

For example, someone who does not want to have to check and clean their boat to prevent an invasive species spread because it takes too much time would be categorized as an invasive species cynic. As well, someone who does not want to cooperate with management efforts because they personally like a particular invasive species and would like it to persist, despite knowing its potential for harms to the ecosystem or economy, is also an invasive species cynic. From these examples, it should be clear that this form of ISD is quite different from what we would think of as a “science denialist”. They understand the science, but it just does not motivate their beliefs or behaviour on this topic.

This research was also recently presented at the International Conference on Aquatic Invasive Species by co-author Noelle G. Stratton. Invasive species nihilism, in particular, prompted discussion both in-person and on social media.

Invasive species nihilism is the form that does not appear to take into account the science behind invasive species or their management at all. Rather, it revolves around the idea that invasive species research, management, or engagement are essentially a waste of time. The efforts were pointless and the results useless. This framing also differed from the other two forms in that the folks who expressed these beliefs often directly approached invasive species practitioners during the course of their work to inform them that their job was meaningless and to ask them why they bothered. This type of framing has the greatest potential to impact invasive species researchers and practitioners personally, and it is potentially the most difficult form of denialism to surmount during engagement and management efforts.

How can invasive species denialism impact management efforts?

ISD has the potential to hinder management efforts in a few different ways. Invasive species denialists may slow down decision-making by stalling or halting discussions with other stakeholders. In some cases, invasive species cynics have taken direct action to interfere with the implementation of policies that would aid with management efforts. Invasive species nihilism could make some stakeholders less likely to engage with managers because they have come to believe that management is pointless, and managers themselves may endure the stress of hearing that their work is not of value to people with this perspective. The effects that ISD may have on management are varied and depend largely on the type of framing of ISD being used. Similarly, the way that we respond to someone that we believe to be an invasive species denialist should be informed by the framing of ISD they are using.



“An understanding of these framings is also vital to respond to instances of ISD appropriately. Whether we are being confronted with anti-science contrarianism, environmental cynicism, or outbursts of nihilism, should inform our responses and our strategies to counter these positions.” (Stratton et al. 2022)

The framings of ISD explored in this research suggest that a diversity of interpretations of species movements, and value judgments about their impacts and the need for management, exist. This has the potential to problematize reductionist claims that all critiques of invasive species management are simply a denial of scientific facts. These results provide evidence that even when there is agreement on the impacts of invasive species on ecosystems, some stakeholders nevertheless deny the need for, or benefit of managing invasive species. This study further contributes to ongoing scholarly and practitioner conversations about the normative assumptions of invasive species biology and their implications for invasive species management and governance.

Research article:

Stratton NG, Mandrak NE, Klenk N (2022) From anti-science to environmental nihilism: the Fata Morgana of invasive species denialism. NeoBiota 75: 39-56. https://doi.org/10.3897/neobiota.75.90631

Image credits: diagram by NG Stratton; comic panels by NG Stratton, via material from Flickr (ChrisA1995, CC BY 2.0; Mike, CC BY-NC-SA 2.0; the-difference CC BY-NC-SA 2.0) and Studio Alternativi (Esetefania Quevedo).

Naturalists can mediate silent plankton invasions

Plankton can easily spread between water bodies on hydrobiological instruments if naturalists use inadequate biosecurity treatments in their work.

Homo sapiens is not only a great (perhaps the best) candidate for the world’s most invasive species award. Humans, due to their actions and technological wonders, are also at the forefront of good vectors for organismal dispersion. Can we break this inglorious streak?

“Because humans will continue to interact with terrestrial and aquatic environments, it is impossible to stop the human-aided dispersal of organisms completely. The best we can do is minimise the risk of human-mediated organism dispersal events by implementing adequate biosecurity methods in our activity” explains Dr Wejnerowski from Adam Mickiewicz University (Poland). 

Plankton sampling using net. Photo by Sandra Wejnerowska

“We should be aware that all our activities can affect biodiversity, and adequate biosecurity treatments should be applied whenever the risk of inadvertent spreading of organisms is non-zero” adds Dr Marcin Krzysztof Dziuba from the University of Michigan (United States of America).

Recently, a team of researchers from Adam Mickiewicz University, Istanbul University (Turkey), Åbo Akademi University (Finland), and the University of Michigan empirically proved that plankton net – a basic hydrobiological instrument of almost every aquatic scientist and water manager – is a good vector for the dispersal of various phyto- and zooplankton taxa, including species of high invasive potential. Nuisance, bloom-forming, also toxic filamentous cyanobacteria are efficient hitch-hikers, and they are able to successfully compete with native residents in the new environment.

Instructions for US citizens to avoid spreading invasive species during lake recreation. Photo by Marcin Krzysztof Dziuba

Apart from identifying hitch-hiking plankton on the net and its fate in the new environment, the paper they published in the journal NeoBiota also describes the most commonly used biosecurity treatments that naturalists worldwide use to prevent plankton spread between water bodies via the net.

Their findings sound disturbing: naturalists use inadequate or questionable biosecurity treatments. As revealed by the survey data, only 9% of plankton samplers clean plankton nets using disinfectant liquids after sampling, while a majority of people either rinse the net with distilled or tap water, immerse the net with an open outflow in the water body and let it dry, or do not care about the cleanness of the net after sampling at all.

Exemplary photos of some phyto- (A – Limnothrix redekei, B – Planktothrix agardhii, C – Pseudanabaena limnetica, D – Melosira varians, E – Desmodesmus armatus, F – Asterionella formosa, G – Tetradesmus obliquus) and zooplankton ( H – Keratella cochlearis f. typica) hitch-hikers on the plankton net. Micrograph I shows the plankton biomass on the surface of the plankton net after immersing the net with an open outflow in the water body (inadequate biosecurity treatment). Photos by Tumer Orhun Aykut and Ɓukasz Wejnerowski. Identification of organisms by Aleksandra PeƂechata and Marcin Krzysztof Dziuba.

“Indeed, the reality presented in the paper is unsettling. It worries me when I think of how often I have accidentally facilitated dispersion of nuisance plankton and how much I contributed to the invasion of plankton taxa into new water bodies when using inappropriate biosecurity treatments in my fieldwork,” admits Dr Wejnerowski, and adds: “We do not mean to reinvent the wheel; the problem of aquatic organism dispersal through hydrobiological instruments is already known. For years, it was neglected despite some recalls from the scientific community. It comes back like a bad penny because it needs a complex solution from the society of aquatic naturalists. It should happen. After all, naturalists are a human line of defence, protection and rescue for nature.”

Research article:

Wejnerowski  Ɓ, Aykut TO, PeƂechata A, Rybak M, Dulić T, Meriluoto J, Dziuba MK (2022) ï»żPlankton hitch-hikers on naturalists’ instruments as silent intruders of aquatic ecosystems: current risks and possible prevention. NeoBiota 73: 193-219. https://doi.org/10.3897/neobiota.73.82636

Genetically-enhanced biocontrols can help fight large invasive mammals

Genetic biocontrols could rapidly eradicate animals like rats, mice and rabbits. Others – like cats and foxes, would however take a lot longer.

But gene drives are not a one-size-fits-all solution

Invasive alien mammals can have catastrophic impacts on native flora and fauna, causing species extinctions and driving profound environmental change. Classical control methods such as poison baiting, trapping, or hunting are currently not feasible on a large scale, which is why researchers are looking for alternatives.

CRISPR-based genome engineering is often seen as a “silver bullet” for pest control. Despite the increasing interest in the development of this technology for invasive mammals like mice, rats, rabbits, feral cats, and foxes, studies have so far only focused on mice.

Scientists have been pondering whether genome editing technologies could help eradicate larger mammals, and if so, how long it would take.

Rabbit. Photo by Mark Philpott licensed under CC BY-NC 2.0.

In order to address these questions, a team of researchers from the University of Adelaide developed a mathematical model able to simulate the impact of gene drives on mammal populations at a landscape scale. Published in the open-access NeoBiota journal, their study is the first to estimate the time it would take to eradicate long-lived alien mammals.

Using CRISPR-Cas9 technology, the simulated gene drive relies on “molecular scissors” inserted into the Y-chromosome that target and slice up the X-chromosome at the right time during meiosis, so that only Y-chromosome carrying sperms are functional and can successfully fertilize the egg. In this way, the drive carrying males should only produce sons that also carry the molecular scissors on their Y-chromosome. Over multiple generations, females will become rarer and produce fewer offspring; as a result, the population size will fall.

Red fox. Photo by Rylee Isitt licensed under CC BY-SA 2.0.

This “X-shredder” drive has been successfully developed and demonstrated to suppress cage populations of malaria-carrying mosquitos, but has not yet been developed in mammals. The model shows that the X-shredder drive could potentially achieve landscape-scale eradication of mice, rats, rabbits, feral cats, and red foxes, but the probability of success and the time it would take to eradicate them vary greatly.

The researchers investigated the ability of the X-shredder drive to eradicate a population of 200,000 individuals of each species. “CRISPR-based gene drives offer novel solutions for controlling invasive alien species, which could ultimately extend eradication efforts to continental scales,” they concluded.

The method could be effective in small-sized pests, such as rodents and rabbits. The expected time to eradication is 18 years for mice, 19 years for rats, and 48 years for rabbits, with 90% population suppression achieved in around half those times.

However, the results suggest that gene drives are not a one-size-fits-all solution: they might not be so useful in larger species like cats and foxes.

“The probability of eradicating feral cats with gene drives is identical to flipping a coin, 50/50; and provided that the coin lands on the right side, it would take about 140 years to get rid of them,” says Dr. Aysegul Birand, part of the research team. “The probability of eradication is higher for foxes, but the wait is even longer.”

Original source: 

Birand A, Cassey P, Ross JV, Thomas PQ, Prowse TAA (2022) ï»żScalability of genetic biocontrols for eradicating invasive alien mammals. NeoBiota 74: 93-103. https://doi.org/10.3897/neobiota.74.82394

More and more people are becoming aware of the dangers posed by invasive hornets

A study published in the open access journal NeoBiota reveals that citizens and stakeholders are becoming more and more aware of the Asian yellow-legged hornet

Wasps and hornets have a remarkable capacity of surviving transportation and establishing invasive populations in new areas. In some cases, this can generate massive environmental and socio-economic impacts. Such is the case of the Asian yellow-legged hornet (Vespa velutina), which has been spreading throughout Europe and worldwide, threatening to seriously impact beekeeping.

However, research shows that such invasions do not go unnoticed. A team of researchers working on the Asian yellow-legged hornet in Italy (Dr Jacopo Cerri from the University of Primorska, Slovenia, and Dr Simone Lioy, Prof. Marco Porporato and Prof. Sandro Bertolino, from Turin University, Italy) discovered that citizen awareness about invasive hornets is increasing. 

Asian yellow-legged hornet (Vespa velutina) attacking a colony of honey bees (Apis mellifera) in Italy. Photo by Prof. Marco Porporato

Moreover, they found that the relevant stakeholders – such as beekeepers – are aware of the hornet’s impacts. They consider the Asian yellow-legged hornet as one of the major causes of honey bee decline in Italy, comparing its effects to those of pesticides, and believing it causes more damage than diseases or other native insects.

To evaluate public awareness of this invasive hornet,the researchers adopted an innovative methodology, which they describe in a paper in the open-access journal NeoBiota. In addition to surveying beekeepers, the authors also analysed Internet searches, focusing on Google queries and visits to relevant Wikipedia pages.

Honey bee. Photo by Andy Murray, CC BY-SA 2.0, via Wikimedia Commons

The team found that beekeepers stayed up to date with information on the Asian yellow-legged hornet thanks to a wide range of different channels, such as the Internet, specialized magazines, and activities with other members of their community. Interestingly, they found that conventional media and mailing lists seemed to be of little contribution to knowledge on this species.

With high reproductive potential and no specialized predators, the Asian yellow-legged hornet predates intensively upon the western honey bee, which could decrease pollination, undermine honey production and inflict consequences for the overwinter survival of colonies. It also limits the foraging activity of honey bees by determining a “foraging paralysis”, a state in which honey bees do not leave the colony, fearing its predation. On top of that, as the species builds its nests mainly in or near urban areas, it poses a risk of stings to people, which in some cases could lead to fatalities.

An increased consciousness in citizens and stakeholders will hopefully lead to a higher number of ‘aware eyes’ able to spot invasive hornets in different environments, the researchers explain. Timely reporting of their presence would allow the speedy activation of more appropriate management measures, containing any possible damages before it’s too late.

Research article:       

Cerri J, Lioy S, Porporato M, Bertolino S (2022) ï»żCombining surveys and on-line searching volumes to analyze public awareness about invasive alien species: a case study with the invasive Asian yellow-legged hornet (Vespa velutina) in Italy. NeoBiota 73: 177-192. https://doi.org/10.3897/neobiota.73.80359

Pets or threats? Goldfish might be harmful for biodiversity

Goldfish pose a triple threat: not only are they readily available, but they combine insatiable appetites with bold behaviour

Invasive species are one of the leading causes of global biodiversity loss, and the pet trade is responsible for a third of all aquatic invasive species. Pet owners releasing unwanted pets into the wild is a major problem. Whilst many believe this is a humane option, a new research suggests that attempting to ‘save’ the life of a goldfish could in fact lead to catastrophic outcomes for native biodiversity.

To better understand the ecological risks posed by species within the pet trade, the researchers focused on the two most commonly traded fish species in Northern Ireland: goldfish and the white cloud mountain minnow.

Photo by Jeff-o-matic under a CC BY-NC 2.0 license

The globally popular goldfish was first domesticated over a thousand years ago and has since established non-native populations around the world. The white cloud mountain minnow on the other hand is a species with a limited invasion history to date.

This study, published in NeoBiota, developed a new method for assessing the ecological impacts and risks of potential pet trade invaders, based on availability, feeding rates and behaviour. The research showed goldfish to be voracious, consuming much more than the white cloud mountain minnow or native species. In terms of behaviour patterns, goldfish were also found to be much braver, a trait linked with invasive spread.

Dr James Dickey.

Lead author, Dr James Dickey from Queen’s University Belfast, explains: “Our research suggests that goldfish pose a triple threat. Not only are they readily available, but they combine insatiable appetites with bold behaviour. While northern European climates are often a barrier to non-native species surviving in the wild, goldfish are known to be tolerant to such conditions, and could pose a real threat to native biodiversity in rivers and lakes, eating up the resources that other species depend on.

“Our research highlights that goldfish are high risk, but we hope that the methods developed here can be used to assess others in the pet trade across Ireland and further afield. Readily available species are most likely to be released, so limiting the availability of potentially impactful ones, alongside better education of pet owners, is a solution to preventing damaging invaders establishing in the future.”

The research led by Queen’s University Belfast was funded by the Alexander von Humboldt Foundation, Inland Fisheries Ireland and the Department of Agriculture, Environment and Rural Affairs (DAERA) NI. The study was presented at the International Conference on Aquatic Invasive Species in Oostende, Belgium along with a range of other leading research from Queen’s on alien species.

Research article:

Dickey JWE, Arnott G, McGlade CLO, Moore A, Riddell GE, Dick JTA (2022) Threats at home? Assessing the potential ecological impacts and risks of commonly traded pet fishes. NeoBiota 73: 109–136. https://doi.org/10.3897/neobiota.73.80542

Invasive crayfish can cause high fisheries damage

In Zambia and Zimbabwe, a single crayfish may cause annual fishery losses of as much as $6.15

Guest blog post by Josie South

Invasive crayfish have the potential to cause high economic cost to artisanal fisheries in southern Africa through scavenging behaviour and destroying fish fry habitat.

A recent study by C∙I∙B Research Associate Josie South (University of Leeds, UK) with scientists from the South African Institute for Aquatic Biodiversity (SAIAB) quantified the damage caused by two invasive crayfish compared to native crab species, at two temperatures, on tilapia catch and macrophytes.

Redclaw crayfish entangled in a gill net in the Kafue River. Photo by Bruce Ellender

Economic costs of invasive species are vital to prioritise and incentivise management spending to reduce and restrict invasive species. No economic costs have been published for the global invader – the redclaw crayfish (Cherax quadricarinatus), and none for the entire continent of Africa. Another prolifically invasive crayfish, the red swamp crayfish (Procambarus clarkii) is also invasive in various countries of southern Africa. Anecdotal reports of crayfish scavenging from artisanal gillnet fisheries are abundant across the invasive ranges but lacked quantification. Similarly anecdotal information about macrophyte stands being destroyed by crayfish has been reported.

For their study, Josie and colleagues compared the feeding rates per gram of crayfish to that of the native Potamonautid crabs at 19°C and 28°C on simulated fisheries catch and macrophytes to identify how much damage may be caused.

Gill net fish catch damaged by crayfish scavenging. Photo by Josie South

The red swamp crayfish consumed the most macrophytes regardless of temperature, at a higher rate than the redclaw crayfish or crabs. In contrast, redclaw crayfish consumed the most tilapia regardless of temperature, and targeted the tail, abdomen, and fins whereas the crab only consumed the head of the fish. The damage rates of redclaw crayfish were then combined with average mass of crayfish in three invasion cores in Zambia and Zimbabwe. It was found that the damage one crayfish may cause annual fishery losses from $6.15 (Kafue River); $5.42 (Lake Kariba); and $3.62 (Barotse floodplain).

Inland fisheries contribute substantially to the livelihoods and quality of life in Africa. The two invasive crayfish have different capacities for ecological and socio-economic impact depending on the resource and the temperature which means that impact assessments should not be generalised across species.

Redclaw crayfish capacity to damage fish catch was substantial but this should be caveated with two over/under estimation issues: 1) the potential for fisher behavioural change which may reduce crayfish damage and 2) small damage to the fish may render the catch unsaleable and therefore the cost of the whole fish is lost.

Dr Josie South states that while these data are a crucial first step in filling knowledge gaps in crayfish impacts in Africa, it also stresses the need to derive observed costs from fisheries dependent data to avoid misleading estimates.

Also of concern, is the capacity for ecological and socio-economic damage from the red swamp crayfish, which was recently removed from the NEM:BA regulations of prohibited species due to lack of impact evidence.

Read the paper published in NeoBiota

Madzivanzira TC, Weyl OLF, South J (2022) Ecological and potential socioeconomic impacts of two globally-invasive crayfish. NeoBiota 72: 25–43. https://doi.org/10.3897/neobiota.72.71868

This blog post was first published by DSI-NRF Centre for Invasion Biology, Stellenbosch University.

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