Advancing marine conservation
My thesis examined the implications of life history and ecology for population-level responses of the European long-snouted seahorse (Hippocampus guttulatus Cuvier 1829) to habitat alteration, exploitation and a recommended minimum size limit for seahorse management. The research employed a mark-recapture study, underwater visual censuses (UVCs) and catch data from an unrelated experimental sampling program in …
This thesis investigates the potential role of historical isolation of ocean basins in promoting diversification among marine organisms in Southeast Asia. It also questions the possible effects of Pleistocene exposure of the Sunda Shelf on present day marine distributions and genetic diversity. Four species of exploited seahorses (genus Hippocampus), with differing ecological parameters, are used …
Biogeographic information has great potential to enhance systematic conservation planning, although it has yet to be routinely incorporated in marine situations. Fundamental differences between marine and terrestrial environments (physical, biological, and sociopolitical) mean that biogeographic data are harder to obtain for marine systems, biogeographic boundaries more difficult to define, and the outcomes of similar conservation …
We present the first synthesis of the life history and ecology of seahorses, compare relationships for seahorses with other marine teleosts and identify research needs. Seahorses occurred primarily amidst temperate seagrasses and tropical coral reefs. Population densities were generally low, ranging from 0 to 0·51 individuals m−2, but reached 10 m−2 in some patches. Inferred life spans …
Overexploitation and habitat degradation threaten small-scale, artisanal fisheries around the world. Management of these fisheries is often inadequate or absent, partly because they are data poor. We here present the development of management options for such a fishery, using collaborative input from a variety of interested groups. Qualitative and semi-quantitative assessments of seahorse populations in …
1. Seahorses (Hippocampus spp.), many of which are listed as Vulnerable or Endangered on the IUCN Red List, are traded worldwide as souvenirs, aquarium fish and, primarily, for use in traditional medicines. Given concern over the sustainability of this trade, the genus was added to Appendix II of the Convention on International Trade in Endangered …
Wild and captive management of seahorses often requires individual or batch identification. In seahorses this has proven difficult in the past because of the seahorses’ rigid body structure, reduced size of fins and susceptibility to infection. We investigated the suitability of visible implant fluorescent elastomer (VIFE) for tagging the big-bellied seahorse, Hippocampus abdominalis, Leeson 1827. Thirty-six …
The sex with the higher potential reproductive rate is expected to mate polygamously unless there are temporal or spatial constraints on mate availability. We investigated whether such constraints were evident in a population of the monogamous seahorse Hippocampus whitei (family Syngnathidae). Across the whole study site, breeding was more asynchronous than expected by chance. Our …
Phylogenetic relationships among 93 specimens of 22 species of seahorses (genus Hippocampus) from the Atlantic and Indo-Pacific Oceans were analysed using cytochrome b gene sequence data. A maximum sequence divergence of 23.2% (Kimura 2-parameter model) suggests a pre-Tethyan origin for the genus. Despite a greater number of seahorse species in the Indo-Pacific than in the Atlantic Ocean, there was no …
1. Introduction 1.1. Why Is It Important To Assess Populations of Seahorses? Apart from their intrinsic worth, these fishes are unusual and valuable for a number of reasons including their unusual biology, economic value, medicinal properties and conservation importance. • Reproductive Behaviour: Seahorses (genus Hippocampus) exhibit the most highly specialized paternal care of any animal: …