Mind the gap – context dependency in invasive species impacts : a case study of the ascidian Ciona robusta
Date
2017-01-04
Journal Title
Journal ISSN
Volume Title
Publisher
Pensoft Publishers
Abstract
ENGLISH ABSTRACT: In the face of increasing invasions and limited resources, appropriate management of invasive species
requires prioritisation of species for management action. This process often relies on knowledge of species
specific impacts. However, as studies explicitly measuring impact of marine alien species are rare, prioritisation
of management actions is often based on studies from outside the geographic area of interest.
Further, few impact studies account for context dependency (e.g. seasonal variability or distinct environmental
regimes), raising the question of how transferrable knowledge about the impact of a species
is between invaded ranges. This study addressed this question by using the widespread invasive solitary
ascidian Ciona robusta as a case study for assessing impacts across two invaded regions: South Africa and
California, USA. We replicated a previously conducted experiment from California that showed that C.
robusta depresses local species richness in San Francisco Bay. Our South African experiment showed no
effect of C. robusta on species richness, the Shannon-Weiner diversity index or community composition,
despite experiments being carried out over two years and at two depths. While these results may reflect
strong density dependency in the impact of C. robusta, they serve to highlight context dependency in invasive
species impacts. This suggests that until studies of impact in marine systems become common place,
context dependency should be explicitly addressed as a source of uncertainty during the prioritisation of
species for management action.
Description
CITATION: Robinson, T. B., et al. 2017. Mind the gap – context dependency in invasive species impacts : a case study of the ascidian Ciona robusta. NeoBiota, 32:127-141, doi:10.3897/neobiota.32.9373.
The original publication is available at https://neobiota.pensoft.net
The original publication is available at https://neobiota.pensoft.net
Keywords
Invasive species -- Management, Ciona robusta, Biological invasions, Prioritisation of species
Citation
Robinson, T. B., et al. 2017. Mind the gap – context dependency in invasive species impacts : a case study of the ascidian Ciona robusta. NeoBiota, 32:127-141, doi:10.3897/neobiota.32.9373