The use of a non-invasive tool for capture-recapture studies on a seahorse Hippocampus guttulatus population

Publication Type: Journal Article

Year of Publication: 2014

Authors: Correia, M, Palma J, Koldewey H, Andrade JP

Journal: Journal of Fish Biology

Volume: 84

Issue: 4

Pagination: 872-884

Date Published: 02/2014

Keywords: long-snouted seahorse, mark–recapture, photo-identification, population abundance


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.

DOI: 10.1111/jfb.12304

Short Title: J Fish Biol