Invasive species denialism: Sorting out facts, beliefs, and definitions

Abstract

In the last decades, thousands of investigations confirmed the detrimental effects of species translocated by man outside of their native ranges (nonindigenous species, or NIS). However, results concluding that many NIS have null, neutral, or positive impacts on the biota and on human interests are as common in the scientific literature as those that point at baneful impacts. Recently, several scholars confronted the stand that origin per se is not a reliable indicator of negative effects, suggesting that such conclusions are the expression of scientific denialism, often led by spurious purposes, and that their numbers are increasing. When assessed in the context of the growing interest in introduced species, the proportion of academic publications claiming that NIS pose no threats to the environment and to social and economic interests is extremely low, and has not increased since 1990. The widely prevailing notion that many NIS are effectively or potentially harmful does not conflict with the fact that most have mixed (negative, neutral, and positive) impacts. When based on solid grounds, reports of positive or neutral impacts should not be labeled as manipulative or misleading unless proven otherwise, even if they may hamper interest in‐ and funding of research and control bioinvasion programs.

On allegations of invasive species denialism

“…; Davis & Chew ; Boltovskoy et al. ; Guiaşu & Tindale ; Sagoff ). The discipline of invasion biology needs to reflect on its values and engage with the diversity of perspectives held by the wider community that it must ultimately serve.…”

“…; Thomas ; Boltovskoy et al. ). Instead, different values and perspectives inside and outside the discipline of invasion biology, and in the wider population, are currently regarded as wrong, threatening to their discipline's legitimacy, and an impediment to progress (Courchamp et al.…”

“…Clearly, attempts to quantify science denialism and its trends cannot be achieved through the methods applied by Ricciardi and Ryan () (see also Boltovskoy et al. ). D.M.’s evaluations were likely not entirely free of bias or presupposition either, but we provide the evidence (Supporting Information) and justifications for decisions so that others can reevaluate our application of the criteria.…”

“…Moreover, a definition based on harm renders the interpretation of invasive species impacts a tautology (Boltovskoy et al. ).…”

A four‐component classification of uncertainties in biological invasions: implications for management

“…Regardless of the motives of the criticisms (Duffy , Collomb ), it is important to address conflicting views in a constructive fashion (Boltovskoy et al. ), and most of the issues raised have been repeatedly rebutted based on scientific evidence (Richardson and Ricciardi , Russell and Blackburn , Ricciardi and Ryan ). Nonetheless, these criticisms highlight several key problems of coherence, ambiguity, or lack of agreement even among invasion scientists.…”