The use of a non-invasive tool for capture-recapture studies on a seahorse Hippocampus guttulatus population
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.
Correia, M., J. Palma, H.J. Koldewey and J.P. Andrade. 2014. The use of a non-invasive tool for capture-recapture studies on a seahorse Hippocampus guttulatus population. Journal of Fish Biology 84(4):872-884. https://doi.org/10.1111/jfb.12304