Why adopt double standards for alien fish and homoeothermic vertebrates? A reply to Fenoglio, Delmastro, and Boano (2018)

Abstract

In order to mitigate the ecological impact of alien species there is a need to control or eradicate those species that are causing a loss of biodiversity. However, such conservation actions can lack public support. In their editorial to The European Zoological Journal (Vol. 85, pp. 227–228), Fenoglio and co-authors observe that public opinion is little concerned about fish welfare and, therefore, is less likely to oppose alien fish than alien bird and mammal eradications. Alien fish management is presented as a science-driven model to which the management of alien birds and mammals should aspire, and public education is identified as a solution for the social conflicts inherent to alien species management. This reflects the authors’ opinion that a unitary, integrally scientific strategy would be the best one to counter biological invasions. However, a more flexible strategy including societal inclinations might be considered too, to avoid sabotage of the conservation actions by several predictable opponents, including animal rights movements. Moving from the latter opinion, the present reply aims at providing additional examples and argumentations on (i) why double or multiple management standards could be the only viable strategy to counter alien species, (ii) why alien fish management is not a good model, and (iii) why education cannot be the only solution for social conflicts inherent to alien species management.

Keywords:

• Biological invasions
• eradication
• risk management
• social conflict
• conservation strategy

In their editorial to The European Zoological Journal, Fenoglio et al. (2018) pose an interesting question: Why does alien species management adopt double standards for fish and homoeothermic vertebrates? This opinion paper is structured through a series of selected examples from Italy, which is the country of origin of the authors. The authors suggest that biological controls and eradications are less problematic (i) in other developed countries and (ii) for fish than for birds and mammals, referring, in particular, to the problems arising from the opposition of a sector of public opinion concerned by animal rights and welfare. The influence exerted by this sector can sometimes overcome scientific recommendations, affecting the feasibility and the chances of success of conservation projects. On the whole, Fenoglio et al. (2018) consider this situation “inacceptable”, endorse education as a possible solution, and propose the management of alien fish as a science-driven, virtuous model, in clear contrast to the management of alien homeothermic vertebrates.

In the limited space allowed for their opinion, Fenoglio et al. (2018) leave the readers thinking on several open topics, each one deserving an articulated discussion. With my reply, I would like to add a few considerations that I consider important and try to explain why – in my opinion – adopting double or multiple standards could be the only viable solution. Some of my observations will question part of the general argumentation by Fenoglio et al. (2018), but I would like to thank the authors and the editors of The European Zoological Journal for disclosing this debate to a broader scientific readership. In addition, I appreciate the attempt to address these issues from a national or even local perspective. Indeed, even if social conflicts inherent to invasive species management have a broad geographic extent, regional differences in the conflict do exist (Estévez et al. 2015), and, as suggested by Fenoglio et al. (2018), they could represent a stronger deterrent in Italy than in other countries for the fulfilment of several urgent control and eradication actions.

My first consideration is that the central question should be changed to “Why adopt double standards for charismatic and non-charismatic taxa”, to avoid falling into some relevant contradictions. Indeed, most of what we know about the possibility of eradicating alien vertebrates come from several eradication actions of mammals (mainly rats and mice) from islands (Clout & Veitch 2002; Howald et al. 2007), and several similar actions have been implemented also in the Italian Mediterranean within the EU LIFE programme (e.g. LIFE04 NAT/IT/000172 – ISOTOSCA, LIFE08 NAT/IT/000353 – MONTECRISTO 2010, LIFE11 NAT/IT/000093 – Pelagic Birds, LIFE12 NAT/IT/000416 – Puffinus Tavolara, LIFE14 NAT/IT/000544 – PonDerat). Moreover, there are some charismatic species also among poikilothermic vertebrates, e.g. many alien pond turtles have widespread popular appeal, often hindering control and eradication actions (to avoid social conflict the Trachemys scripta removed within the LIFE12 NAT/IT/000395 were not culled, producing an increase in the action costs).

By definition charismatic taxa have public appeal, and the public is often more concerned about eradication and control of mammals and birds rather than neglected fish (e.g. Bremner & Park 2007). Similar attitudes are observable in several societal contexts: there are “vegetarians” eating fish (i.e. pescetarians), there are large anti-hunting but almost no anti-angling movements, and there are even discriminatory laws, e.g. Italian legislation (i.e. Legge 11 febbraio 1992, no. 157) safeguards the homoeothermic fauna considering birds and mammals as a collective property (i.e. patrimonio indisponibile dello Stato), but the so-called fauna minore (including all the poikilothermic vertebrates) is considered ownerless property (i.e. res nullius). It is not surprising that the same attitudes are also present in the social conflicts inherent to wildlife management.

Incidentally, this general indifference to fish can facilitate alien fish management, but I see no merit placed by fish management authorities on such a circumstance and I do not think that they have made the best use of this greater freedom of action. There is a profound disconnect between science and fish management (see Figure 1 for a vivid example of this disconnect). Therefore, I found inappropriate the use of fish management as a good model as well as the idea that the scarce public appeal of fish can promote a science-driven management. However, Fenoglio et al. (2018) use two examples to show the scientific basis of fish management: a very recent eradication project of introduced brook trout Salvelinus fontinalis from four high mountain lakes (Tiberti et al. 2017, 2019) and the campaign of active removal of the European catfish Silurus glanis by anglers. However, the former example is an isolated and highly experimental conservation project (i.e. LIFE11/BIO/IT/000020 – BIOAQUAE) which is not representative of fish management in the Alps, Italy or Europe; the latter is a conservation measure aimed at reducing European catfish density, biomass and ecological impact, but its respect and efficacy is unclear. Taking into account the conservation outputs of fish management as a whole, the conclusion would be quite different. In Italy, fish are the vertebrate group with the largest proportion of invasive species, and many native fish have an unfavourable conservation state (e.g. Lanzoni et al. 2018), often due to interactions and hybridisation with aliens (Zerunian & Ruosi 2002). As a matter of fact, fish management is only partially responsible for this dramatic conservation framework, because the fragility of the Italian fish fauna can be attributed to the biogeographic history of the Italian Peninsula: the Alpine and Apennine orogenesis and the dramatic excursions of the Mediterranean Sea (i.e. during the Messinian Salinity Crisis and the Quaternary glaciations) created the conditions for the evolution of many endemic species (Bianco 1995), which are extremely sensitive to the introduction of their vicariant species, because of their similar ecological requirements and the absence of complete reproductive segregation (e.g. Caputo et al. 2009; Meraner et al. 2014; Gandolfi et al. 2017). While acknowledging such a complex context, fish management was unable to protect several native fish. The decline of most fish threatened by alien species is irreversible because of the impossibility of eradicating or controlling some invasive species. Additionally, several species are almost neglected by conservation policies and maybe condemned to extinction. Even popular species such as some native salmonids have strayed into a very bad conservation status, mainly due to stocking with alien fish (Meraner et al. 2014; Splendiani et al. 2016); this is a common detrimental practice in fish management which has no equivalent in any other animal group, because it involves the release of very large numbers of top predators. Stocking alien fish is in clear contradiction to any scientific or conservation principle and to most of the EU legislation on nature conservation (Ventura et al. 2017; UZI 2018). However, it is widely accepted as a necessary measure to promote recreational and professional fisheries and to satisfy angler requests for outdoor recreation opportunities. In this context, the above-mentioned facility of performing biological control and eradication actions is nevertheless placed within a contradictory regulatory framework (where legal removal and introductions are both possible), and a conflictive social context (where science-driven management practices are conditioned by utilitarian and recreational instances).

Figure 1. Excerpt of an insert of the daily Italian newspaper La Stampa reporting the news from the Valle d’Aosta region (11 August 2011, p. 51). In a single page two items of “good news” are reported: (i) “Arctic crustacean discovered within the National Park” (large title on the left), and (ii) “Start of the fish stocking action of seventy alpine lakes” (title on the right). The former news talks about the finding of a very rare zooplanktonic crustacean (Daphnia middendorffiana, sensu Margaritora 1985; Daphnia pulicaria according to Bellati et al. 2014), which survived in a few mountain lakes of the Gran Paradiso National Park (Aosta, Italy) just because the lakes were conserved in their original fishless state, i.e. Daphnia pulicaria is a large zooplankton species, very sensitive to visual predation by introduced fish (Tiberti 2011); the latter is a report of a large fish stocking campaign involving 70 historically fishless high mountain lakes in the Western Italian Alps (Aosta).

At the end of their opinion paper, Fenoglio et al. (2018) entrust education with the task of informing public opinion on the problems related to some animal welfare issues, which can seriously damage important conservation actions (e.g. Bertolino & Genovesi 2003) and which currently condition wildlife management. There are at least two facts to consider when public education is proposed as the only solution to any social conflict: educating people could take a long time, and increased education levels may not be effective in reducing the conflicts. The long time needed to educate people through countless outreach actions could condemn the fight against invasive alien species to immobility until a sufficiently high level of consensus is reached. On the other hand, conflicts surrounding invasive species have arisen mainly in areas of developed countries with a relatively high education level, based largely on a clash between different value systems (e.g. utilitarian, moralistic, etc.; Estévez et al. 2015). Environmental education certainly deserves attention and participation by the scientific community, but to confront or to avoid such conflicts education is likely not sufficient.

Finally, recalling the central question of Fenoglio et al. (2018), I wonder if the only possible answer is: “Because we need it”, i.e. we need to adjust merely rational conservation strategies in order to avoid their sabotage. In many cases (if not always), alien species management should account for the likely appraisal of some contentions with several sectors of society (e.g. from the international trade industry to local communities, passing through animal rights movements; Courchamp et al. 2017). Individuals and organisations often demand greater consultation, and they have managed to be part of the decision process on environmental issues (Richardson & Razzaque 2006). Avoiding/managing the conflict with some stakeholders (e.g. hunting and angling associations, farmers) through dialogue is an established practice in wildlife management, while the request for participation by animal rights and welfare movements is relatively new and less obvious. The inclusion of new stakeholders could complicate the decision-making process and produce disappointing delays in the starting date of a conservation action, which is particularly relevant for urgent actions. However, each time an alien species needs to be managed, the risk of sabotage associated with any social contention should be considered as well (i.e. in a risk-management plan). My current opinion is that involving new stakeholders should be considered not a tribute to pluralism, but a pragmatic step to reach the final objective (prevention, control and eradication). Accordingly, if the risk of sabotage is negligible, the number of stakeholders should be kept as low as possible.

The social dimension inherent to invasive species management is becoming an integral part of the decision process and is likely to become more important in the near future (Estévez et al. 2015). Public participation in alien species management can be spontaneous (e.g. complaints, protests, sabotage actions, legal litigation and appeals), or can be mediated by environmental authorities (e.g. through public hearings and submissions). Through the second option, conservation authorities could take advantage of the debate to identify public concerns while formulating environmental policies. In general, integrating different value systems into the decision process seems a good idea, even if science-driven management and conservation authorities should be strengthened through the adoption of new regulations (e.g. limiting the possibility to use legal litigation and appeals to contrast conservation projects) and new shared rules (e.g. animal rights movements could be asked to take on the responsibility for and associated costs of avoiding animal culling; Perry & Perry 2008).

Acknowledgements

I would like to thank Stefano Fenoglio, Giovanni Boano and Giovanni Delmastro for their helpful comments on an early version of this letter and for their genuine desire to think about nature conservation.

Disclosure statement

No potential conflict of interest was reported by the author.