title: The use of a non-invasive tool for capture-recapture studies on a seahorse Hippocampus guttulatus population.
abstract: In this study, the spot pattern in Hippocampus guttulatus was analysed using a computer programme algorithm that allowed individual comparison. This methodology was first tested in a controlled environment using 51 adult and 55 juvenile H. guttulatus. Positive matches were obtained in 86·3 and 83·6% of the adults and juveniles, respectively. In a second experiment, monthly surveys were carried out in five selected locations in the Ria Formosa Lagoon, south Portugal, over the course of a year and a total of 980 photographs were analysed. Photographed H. guttulatus were re-sighted one to nine times during the course of the survey period with an overall re-sight record of over 30%. Photo-identification was therefore shown to be a useful tool for non-invasive mark-recapture studies that can be successfully used to survey the population abundance of H. guttulatus aged 6 months or older in consecutive years. This could be of great value when considering the assessment of H. guttulatus populations and understanding changes over time.
authors: CCMar, Universidade do Algarve, F.C.T., Edificio 7, Campus de Gambelas, 8005-139 Faro, Portugal.
authors: M
authors: M
authors: Correia
authors: J
authors: J
authors: Palma
authors: H
authors: H
authors: Koldewey
authors: J P
authors: JP
authors: Andrade
mesh_terms: D000465:Algorithms; D000823:Animal Identification Systems; D000818:Animals; D003247:Conservation of Natural Resources / Q000379:methods; D007091:Image Processing, Computer-Assisted; D010781:Photography; D011156:Population Density; D011174:Portugal; D023701:Smegmamorpha; D012984:Software
keywords: long-snouted seahorse; mark-recapture; photo-identification; population abundance