Abstract:

The increase of non-native species is a pervasive phenomenon associated with global change. Unfortunately, some of these “exotic” species can become invasive when they negatively impact native species and natural resources. However, although invasive species (IS) are often viewed as one of the main threats to biodiversity, substantial disagreement exists among researchers on the extent to which:
(i) non-nativism is a scientific concept;
(ii) the negative ecological impacts of many IS are empirically substantiated, and
(iii) many IS could, in balance, generate net positive effects in the ecosystem.

The first criticism is especially cogent as there are no clear-cut criteria to separate native vs. non-native species. Therefore, decisions to eradicate non-native, invasive species may lack theoretical support. So, what should the educational approach be to deal with IS in biology and environmental science careers?

In the present study, we investigated how the frame of information could influence students’ intuitive perceptions and attitudes on IS. In doing so, we wished to explore how specific discourses on IS could predispose students in their intuitive view of species. A sample of 334 students enrolled in careers on social and basic sciences at the University of Valencia, Spain, were given a test in which pictures of 5 species legally considered as invasive in Spain, i.e., the American vison, Neovison vison; the ruddy duck, Oxyura jamaicensis; the common bleak, Alburnus alburnus; the signal crayfish, Pacifastacus leniusculus, and the Asian clam, Corbicula fluminea, were presented for assessment, along with combinations of 10 pictures of other protected and unprotected animal species. Information on the goal of the study or the name of species was not disclosed. For each species, students were requested to answer three questions using a 5-point Likert scale:
(i) How much do you like this species?
(ii) How much would you regret if it becomes extinct? and
(iii) How beautiful is it?

Half of the students were randomly given a test with pictures and a short text (4 lines) providing factual information on each species, including the fact (when applicable) that the species was invasive in Spain (test A); half of the students were given a test with pictures only (test B).

Previous knowledge of the species identity could not substantially affect the results of the test, as the vast majority of students (over 95%) could not identify correctly any species, including the 5 IS under scrutiny. Not surprisingly, in both tests, A and B, the American vison and the ruddy duck scored significantly higher than the fish and the invertebrates in all questions. However, scores for the 5 IS were significantly lower in test B than in test A for questions (i) and (ii), with a similar rate of decrease regardless of species. Scores for question (iii) did not significantly differ between tests A and B. Results therefore suggest that, irrespective of taxonomic affiliation, dubbing a species as “invasive” influences the perception and attitudes of students about it. A proper framing of information on IS is thus relevant and important in all education contexts (e.g. in lectures of university teachers) given the lack of consensus on the concept of IS and the policies to manage them.

Keywords:

Invasive species, information framing, higher education, management measures, ethics.