S. J. Foster

Conservation and management of seahorses and other Syngnathidae

This article analyses the pressures on seahorses and explores conservation responses. It focuses on seahorses (Hippocampus spp.) but also considers pipefishes and seadragons, especially where they can fill gaps in seahorse knowledge. The charisma of many syngnathids can make them good flagship species for threats and solutions in marine conservation. The article combines a synthesis of published literature with new data on the trade in seahorses for traditional medicine, aquarium display and curiosities. Most traded seahorses come from trawl by-catch, although seahorses are also targeted. The total extraction is large, tens of millions of animals annually, and unsustainable. A first review of the effect of habitat change on syngnathids raises many questions, while suggesting that some species may cope better than others. The combination of pressures means that many species of syngnathid are now included in the IUCN Red List of Threatened Species or national equivalents. In addition, seahorse exports from 175 countries are limited to sustainable levels under the Convention on International Trade in Endangered Species (CITES) of Wild Fauna and Flora. Possible conservation measures include marine protected areas, fisheries management, select aquaculture ventures, trade regulation, improved governance (particularly) and consumer engagement.

A global revision of the Seahorses Hippocampus Rafinesque 1810 (Actinopterygii: Syngnathiformes): Taxonomy and biogeography with recommendations for further research.

Nomenclatural clarity is vital for the collection, dissemination, and retrieval of natural history information, which itself is necessary for effective conservation and management of species. Seahorses (genus Hippocampus) are small marine fishes that in many cases are heavily exploited and suffering severe population declines worldwide, leading to conservation concern and action. Here we provide a brief history of seahorse taxonomy, and attempt to clarify seahorse nomenclature by reducing redundancy and exposing areas of disagreement in need of further study. We provide an annotated list of the 41 species we currently recognize as valid, and describe their geographical distributions to offer a solid foundation for future research and conservation efforts. We base our conclusions on available morphological, genetic and distributional data, re-examination of the relevant literature, previous examination of almost all original type specimens, familiarity with many thousands of other live and dead specimens, and photographs of seahorses. This work should lead to greater taxonomic clarity by highlighting known research gaps and by ensuring that each species designation is justified by robust and defensible taxonomic protocols. Such clarity should facilitate greater efficacy in management and conservation.

Using life-history information to assess potential effects of shrimp trawling on small fishes.

The current study presents information on size distributions, size at recruitment to the fishery, size at maturity and patterns of reproduction for several small benthic fishes caught as by-catch in the southern Gulf of California (Mexico) shrimp trawl fishery: sand perch Diplectrum spp., lumptail searobin Prionotus stephanophrys, bigscale goatfish Pseudupeneus grandisquamis and silver stardrum Stellifer illecebrosus. Pseudupeneus grandisquamis, P. stephanophrys and S. illecebrosus populations were all sexually dimorphic in size. Total-length (L(T))-based analyses did not provide reliable information on survival and growth. The majority of sampled P. grandisquamis and S. illecebrosus were caught before reproductive maturity, whereas the majority of Diplectrum spp. and almost all P. stephanophrys were mature when caught. L(T) at 50% gear retention (L(Tc), mm) v. 50% maturity (L(Tm), mm): Diplectrum spp. 124.53 v. 131.43; P. grandisquamis 90.98 v. 135.20; S. illecebrosus 82.55 v. 137.30. L(Tc) for P. stephanophrys was 104.73, but L(Tm) could not be modelled for this species as almost all captured individuals were mature. Diplectrum spp., P. grandisquamis and S. illecebrosus were indeterminate spawners, whereas P. stephanophrys appeared to be a determinate spawner. Sex ratios were equal for each of the gonochoristic species. In general, the gonado-somatic index (I(G)) increased with increasing L(T) for all except P. stephanophrys, where I(G) decreased with increasing L(T) for both males and females. Mature individuals of all taxa were found throughout the sampling period (September to March), and I(G) increased with sample day for all except females of P. grandisquamis. The current data suggest the potential for fishery effects on sampled populations of P. grandisquamis and S. illecebrosus.

Low Bycatch Rates Add Up to Big Numbers for a Genus of Small Fishes

Nonselective fishing gears extract a great many small marine species, with limited documentation or assessment of their impacts. Among those species, seahorses (genus Hippocampus) are unusual because this genus has been the focus of scientific surveys and international trade regulation. Our review of published and unpublished data sources analyzed data on seahorse bycatch for five gear-type categories and 22 countries. The median catch per unit effort of seahorse bycatch across all five gear types was 0.96 seahorses per vessel−1 day−1. Nonetheless, fleet sizes were so large that annual catches were estimated at approximately 37 million seahorses across our sampled countries. Fisher interviews suggested that seahorse catches were declining (although information on changes in effort over time were not available). Furthermore, international export data did not capture the magnitude of seahorses in bycatch. Our work emphasizes the importance of evaluating bycatch, even for taxa where reported daily catch rate...

Novel life‐history data for threatened seahorses provide insight into fishery effects

Life-history variables for three incidentally captured species of seahorse (Kelloggs seahorse Hippocampus kelloggi, the hedgehog seahorse Hippocampus spinosissimus and the three-spot seahorse Hippocampus trimaculatus) were established using specimens obtained from 33 fisheries landing sites in Peninsular Malaysia. When samples were pooled by species across the peninsula, sex ratios were not significantly different from unity, and height and mass relationships were significant for all species. For two of these species, height at physical maturity (HM ) was smaller than the height at which reproductive activity (HR ) commenced: H. spinosissimus (HM = 99·6 mm, HR = 123·2 mm) and H. trimaculatus (HM = 90·5 mm, HR = 121·8 mm). For H. kelloggi, HM could not be estimated as all individuals were physically mature, while HR = 167·4 mm. It appears that all three Hippocampus spp. were, on average, caught before reproducing; height at 50% capture (HC ) was ≥HM but ≤HR . The results from this study probe the effectiveness of assessment techniques for data-poor fisheries that rely heavily on estimates of length at maturity, especially if maturity is poorly defined. Findings also question the sustainability of H. trimaculatus catches in the south-west region of Peninsular Malaysia, where landed specimens had a notably smaller mean height (86·2 mm) and markedly skewed sex ratio (6% males) compared with samples from the south-east and north-west of the peninsula.

Trade in seahorses and other syngnathids in countries outside Asia (1998-2001)

Fourteen African countries were known to have participated in the seahorse trade by 2001, including Egypt, Gambia, Guinea, Kenya, Madagascar, Mali, Mozambique, Nigeria, Senegal, the Seychelles, South Africa, Tanzania, Togo, and Zimbabwe. Trade surveys were undertaken only in Kenya and Tanzania, which consequently are dealt with in most detail below. Correspondence with researchers in southern Africa provided reasonable information on Mozambique and South Africa. Information on other countries was largely gleaned from Customs records in the European Community, Hong Kong and the USA, and is correspondingly brief. Given the scarcity of information in most African countries, it is difficult to judge the relative importance of African seahorse trading countries. The information obtained, however, suggests Guinea, Senegal, and Tanzania are the major players in African seahorse trade. BACKGROUND FOR KENYA AND TANZANIA

Food and feeding habits of the seahorses Hippocampus spinosissimus and Hippocampus trimaculatus (Malaysia)

m.y. yip, a.c.o. lim, v.c. chong, j.m. lawson and s.j. foster Faculty of Science, Institute of Biological Science, University of Malaya, Kuala Lumpur 50603, Malaysia, Save Our Seahorses Malaysia, No. 2, Jalan 6/24, Seksyen 6, 46000 Petaling Jaya, Selangor Darul Ehsan, Malaysia, Institute of Ocean & Earth Sciences, C308, Institute of Postgraduate Studies Building, University of Malaya, 50603 Kuala Lumpur, Malaysia, Project Seahorse, Fisheries Centre, The University of British Columbia, 2204 Main Mall, Vancouver, BC V6T IZ4, Canada

A holistic investigation of the ecological correlates of abundance and body size for the endangered White's seahorse Hippocampus whitei

Analysing the associations between the endangered Whites seahorse Hippocampus whitei and characteristics of its environment (including habitat, prey and predator variables) in an estuary in New South Wales, Australia, revealed that seahorses had a greater number of significant associations with environmental correlates within a single seagrass bed than among seagrass beds. Predator abundance was negatively correlated with H. whitei abundances among seven seagrass beds (200-6,000 m apart) and no ecological correlate was associated with H. whitei body size distributions. Within the seagrass bed with the greatest number of H. whitei, individuals preferentially selected locations that were deeper, had denser seagrass, more epiphytic prey types and fewer predators. Smaller H. whitei were associated with greater depths within the bed. In this study, each class of ecological correlate (habitat, prey, predators) was found to have at least one significant relationship with H. whitei, depending on the scale, demonstrating that all three are important to H. whitei populations. As such, future studies that evaluate animal populations may benefit from holistic approaches that consider each of these together. For animals that are experiencing dramatic population declines due to habitat destruction, as H. whitei has over the last decade, a better understanding of its relationship to its environment is important to inform conservation action.

Changes in the trade of bycatch species corresponding to CITES regulations: the case of dried seahorse trade in Thailand

Exploitation for trade is one of the biggest threats to many species, especially for marine fishes. Trade regulations should, therefore, be effective in helping conserve marine fish populations. The Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITES), one of the few multilateral environmental agreements with enforcement capacity, has embraced a number of marine fishes in recent years. However, the impacts of such measures on wildlife trade have rarely been assessed. We conducted a case study of the dried seahorse (Hippocampus spp.) trade in Thailand to understand the trade of these species under CITES regulations. We carried out 203 semi-structured interviews with traders to estimate the economic scale of Thai seahorse trade, and compared perceived changes with official trade datasets. Even though most seahorses were incidentally caught, we estimated that dried seahorses could be worth US

Life history and ecology of seahorses: implications for conservation and management

26.5 million per year for Thai fishers. However, the total declared annual export value was only around US