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Risk of invasion predicted with support vector machines: a case study on northern pike (Esox Lucius, L.) and bleak (Alburnus alburnus, L.)

Risk of invasion predicted with support vector machines: a case study on northern pike (Esox Lucius, L.) and bleak (Alburnus alburnus, L.)
Risk of invasion predicted with support vector machines: a case study on northern pike (Esox Lucius, L.) and bleak (Alburnus alburnus, L.)
The impacts of invasive species are recognised as a major threat to global freshwater biodiversity. The risk of invasion (probability of presence) of two avowed invasive species, the northern pike (Esox Lucius, L.) and bleak (Alburnus alburnus, L.), was evaluated in the upper part of the Cabriel River (eastern Iberian Peninsula). Habitat suitability models for these invasive species were developed with Support Vector Machines (SVMs), which were trained with data collected downstream the Contreras dam (the last barrier impeding the invasion of the upper river segment). Although SVMs gained visibility in habitat suitability modelling, they cannot be considered widespread in ecology. Thus, with this technique, there is certain controversy about the necessity of performing variable selection procedures. In this study, the parameters tuning and the variable selection for the SVMs was simultaneously performed with a genetic algorithm and, contradicting previous studies in freshwater ecology, the variable selection proved necessary to achieve almost perfect accuracy. Further, the development of partial dependence plots allowed unveiling the relationship between the selected input variables and the probability of presence. Results revealed the preference of northern pike for large and wide mesohabitats with vegetated shores and abundant prey whereas bleak preferred deep and slightly fast flow mesohabitats with fine substrate. Both species proved able to colonize the upper part of the Cabriel River but the habitat suitability for bleak indicated a slightly higher risk of invasion. Altogether may threaten the endemic species that actually inhabit that stretch, especially the Júcar nase (Parachondrostoma arrigonis; Steindachner), which is one of the most critically endangered Iberian freshwater fish species.
0304-3800
123-134
Munoz-Mas, Rafael
6108fb3e-707c-484c-969f-c7d2de61cea6
Vezza, Paolo
feba4aab-3d89-4d3e-826d-ca439261a285
Alcarez-Hernandez, Juan Diego
0d35d089-2df8-4c9e-b3df-0336730a4c3a
Martinez-Capel, Francisco
3139b31c-0efb-4a91-a9b5-555a5ec9b8e4
Munoz-Mas, Rafael
6108fb3e-707c-484c-969f-c7d2de61cea6
Vezza, Paolo
feba4aab-3d89-4d3e-826d-ca439261a285
Alcarez-Hernandez, Juan Diego
0d35d089-2df8-4c9e-b3df-0336730a4c3a
Martinez-Capel, Francisco
3139b31c-0efb-4a91-a9b5-555a5ec9b8e4

Munoz-Mas, Rafael, Vezza, Paolo, Alcarez-Hernandez, Juan Diego and Martinez-Capel, Francisco (2016) Risk of invasion predicted with support vector machines: a case study on northern pike (Esox Lucius, L.) and bleak (Alburnus alburnus, L.). Ecological Modelling, 342, 123-134. (doi:10.1016/j.ecolmodel.2016.10.006).

Record type: Article

Abstract

The impacts of invasive species are recognised as a major threat to global freshwater biodiversity. The risk of invasion (probability of presence) of two avowed invasive species, the northern pike (Esox Lucius, L.) and bleak (Alburnus alburnus, L.), was evaluated in the upper part of the Cabriel River (eastern Iberian Peninsula). Habitat suitability models for these invasive species were developed with Support Vector Machines (SVMs), which were trained with data collected downstream the Contreras dam (the last barrier impeding the invasion of the upper river segment). Although SVMs gained visibility in habitat suitability modelling, they cannot be considered widespread in ecology. Thus, with this technique, there is certain controversy about the necessity of performing variable selection procedures. In this study, the parameters tuning and the variable selection for the SVMs was simultaneously performed with a genetic algorithm and, contradicting previous studies in freshwater ecology, the variable selection proved necessary to achieve almost perfect accuracy. Further, the development of partial dependence plots allowed unveiling the relationship between the selected input variables and the probability of presence. Results revealed the preference of northern pike for large and wide mesohabitats with vegetated shores and abundant prey whereas bleak preferred deep and slightly fast flow mesohabitats with fine substrate. Both species proved able to colonize the upper part of the Cabriel River but the habitat suitability for bleak indicated a slightly higher risk of invasion. Altogether may threaten the endemic species that actually inhabit that stretch, especially the Júcar nase (Parachondrostoma arrigonis; Steindachner), which is one of the most critically endangered Iberian freshwater fish species.

Text
Ecological Modelling vol 342, 24 Dec 2016, pages 123 to134.pdf - Version of Record
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More information

Accepted/In Press date: 6 October 2016
e-pub ahead of print date: 14 October 2016
Published date: 24 December 2016
Organisations: Water & Environmental Engineering Group

Identifiers

Local EPrints ID: 402306
URI: https://eprints.soton.ac.uk/id/eprint/402306
ISSN: 0304-3800
PURE UUID: 3f8c3441-85a3-458f-be0c-9a212e0a3627

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Date deposited: 07 Nov 2016 12:13
Last modified: 02 Dec 2019 19:51

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