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Diel and seasonal variations in the population dynamics of Hemimysis anomala, a non-indigenous mysid: implications for surveillance and management

Nunn, Andy; Cowx, Ian G.

Authors

Ian G. Cowx I.G.Cowx@hull.ac.uk



Abstract

This study investigated diel and seasonal variations in the population dynamics of Hemimysis anomala, a non-indigenous mysid originating from the Ponto-Caspian region. There were strong diel variations in the abundance (catch-per-unit-effort; CPUE) of H. anomala, with CPUE being low during the day but increasing by up to an order of magnitude at night. Abundance also varied seasonally, with CPUE increasing from mid-May to a peak in late June/early July, followed by a crash in mid-July. However, the seasonal variations in abundance were apparent only in nocturnal surveys, with CPUE during the day being low throughout the study. There were also seasonal variations in population structure (life stages, length distributions, sex ratios, reproductive state, fecundity). The nocturnal behaviour of H. anomala renders it difficult to assess its geographical distribution or population dynamics using only diurnal surveys or inappropriate sampling methods, which could underestimate the size, structure, reproductive potential and sustainability of non-indigenous populations of this invasive species. Surveillance programmes for H. anomala should therefore be conducted at night, at intervals throughout the year and targeting likely habitats using site-specific methods of proven effectiveness. © 2012 The Author(s).

Journal Article Type Article
Publication Date Aug 14, 2012
Print ISSN 1798-6540
Electronic ISSN 1818-5487
Peer Reviewed Peer Reviewed
Volume 7
Issue 3
Pages 357-365
APA6 Citation Nunn, A., & Cowx, I. G. (2012). Diel and seasonal variations in the population dynamics of Hemimysis anomala, a non-indigenous mysid: implications for surveillance and management. Aquatic Invasions, 7(3), 357-365. https://doi.org/10.3391/ai.2012.7.3.007
DOI https://doi.org/10.3391/ai.2012.7.3.007
Keywords diel variation; Hemimysis; invasive; population dynamics; seasonal abundance
Publisher URL http://www.aquaticinvasions.net/2012/issue3.html
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