Parasites as biological tags in aquatic ecosystems: present status and perspectives

TIMI, JUAN T.

Valencia

Simposio; IX International Symposium on Fish Parasites.; 2015

Universitat de Valencia

The first studies on parasite tags for host stock delineation were published nearly a century ago, when they were viewed as curiosities and it took many years before they were accepted and worthy of serious consideration. Nowadays, this methodology is widely applied and increasingly considered as a valuable tool for fisheries management. An analysis of more than 300 publications showed that, since its origins, there have been (i) a positive evolution in the publication rates, in the geographic distribution of investigations and in the quantitative methodologies; (ii) regular reviews along its history and actualizations of the guidelines for the selection of suitable tags and (iii) an overwhelming majority of papers dealing with parasites of teleosts, with very few studies on elasmobranchs, invertebrates and mammals. The main perspectives for parasite tags are also analysed, including (i) their integration in holistic approaches to stock studies utilising multiple techniques on the same samples and combining results across spatial and temporal scales to produce conclusive and reliable evidence and (ii) the use of molecular approaches for parasite genetic tagging, given that parasite genotypes often show an increased genetic variance relative to their hosts that could potentially be used to discriminate parasite (and host) populations with higher accuracy than by using the host?s genotypes alone. The possible extension of the study of parasite tags from a fishery to a zoogeographical context is also analysed and exemplified, which could help to delineate marine regions to strategically plan and prioritize new conservation measures and protected areas.