Taxonomic notes: The 1996 and 2000 IUCN Red Lists included Hippocampus aimei, which is now a synonym of H. barbouri and H. spinosissimus (Lourie et al. 1999, 2004).

Hippocampus barbouri is recorded from Indonesia, Malaysia and the Philippines in shallow seagrass beds up to a maximum depth of 10 m (Lourie et al. 2004).

Population estimates for Hippocampus barbouri are currently unknown but trade surveys conducted by Project Seahorse have shown that this species is widely traded for traditional medicine, the aquarium trade and for curios (Vincent 1996, Perry et al. 2010, Evanson et al. 2011). There is also evidence from fisher surveys that there have been local declines in seahorse numbers generally in Malaysia and the Philippines (O'Donnell et al. 2010, Perry et al. 2010) and it can be suspected that similar reductions are occurring throughout this species' range where the same threats are found.

Respondents at various levels of trade (including fishers, buyers, wholesalers, retailers, exporters and officials)  in 1998 and 1999 in Malaysia reported declines in seahorse numbers and availability and that H. barbouri was one of the most common species traded (Perry et al. 2010). In the Philippines seahorse fishers also reported high levels of decline between 1970 and 2003 (O'Donnell et al. 2010). Although this study did not focus on H. barbouri, these trends are indicative of seahorse populations in the area where this species occurs. The fishers in the Philippines cited overfishing, the increasing population of fishers and indiscriminate catch of seahorses, including pregnant and immature seahorses, as causes of the observed decline in catch.

General seahorse population declines within H. barbouri'srange are suspected as a result of habitat degradation and declines in seagrasses (Marcus et al. 2007, Short et al. 2011), and mortality from intense trawling bycatch (Baum et al. 2003, Giles et al. 2006, Perry et al. 2010) — and indeed these threats are known to occur throughout this species’ range (FAO 2001, Perry et al. 2010). Declines in seagrasses are particularly concerning as this is H. barbouri'sprimary habitat. In addition, H. barbouri is reported in international trade in large volumes (Evanson et al. 2011, UNEP–WCMC 2012a). Trade in this species has been reported from as early as 1998 in Malaysia (Perry et al. 2010), and since the implementation of the listing of all Hippocampus species in 2004 on Appendix II of CITES (Evanson et al. 2011, UNEP-WCMC 2012a). The large and potentially unregulated numbers of H. barbouri in international trade led this species to be selected by the CITES Animals Committee for the Review of Significant Trade following COP15 (UNEP–WCMC 2012b). Thus, this major threat has been acting on this species for more than ten years, and it is reasonable to suspect that trade will continue into the future.

This seahorse occupies shallow seagrass beds up to a maximum depth of 10 m (Lourie et al. 2004). This species may be particularly susceptible to decline due to it occurring in this very vulnerable in-shore habitat (Short et al. 2011) and having ecological and life-history traits that are susceptible to exploitation (Foster and Vincent 2004).

All seahorse species have vital parental care, and many species studied to date have high site fidelity (Perante et al. 2002, Foster and Vincent 2004), highly structured social behaviour (Vincent and Sadler 1995), and relatively sparse distributions (Lourie et al. 1999); these traits make seahorses vulnerable to harvest. There are some traits, such as small body size, fast growth and high fecundity that may make seahorses more resilient to exploitation (Morgan 2007). However a specialised life-history coupled with a dependence on shallow habitats that are subject to extremely high fishing pressure, and the fact that seahorses do not move very much and are thus easily captured, means they are very vulnerable to over-exploitation. The importance of life history parameters in determining response to exploitation has been demonstrated for a number of species, including seahorses (Jennings et al. 1998, Foster and Vincent 2004).

Hippocampus barbouri has been widely reported in international trade for use in traditional medicine, curios and for the aquarium trade (Evanson et al. 2011, UNEP–WCMC 2012a). In Malaysia, the majority of seahorses, including H. barbouri, are caught as bycatch in other fisheries but some are caught in small-scale target fisheries where fishers catch them by hand or with nets (Perry et al. 2010).

Declines in seahorse availability have been reported for several countries where H. barbouri is known to occur. Surveys in 1998 and 1999 in Malaysia and Thailand reported trade in this species and that both fishers and traders noted the availability of seahorses had been decreasing (Perry et al. 2010). Surveys in the Philippines have also reported more recent and substantial declines in catch rates of seahorses generally (O'Donnell et al. 2010). There is, at present, a national ban on the capture and trade of seahorses in the Philippines (Philippine Department of Agriculture, 1998), however field research in the area revealed that fishing continued in spite of the ban (O'Donnell et al. 2010, UNEP–WCMC 2012b). 

Since the implementation of the CITES Appendix II listing of seahorses in 2004 this species has been one of the most traded seahorses and large volumes of both live and dry trade in H. barbouri, approximately 200,000 individuals per annum, have been recorded (Evanson et al. 2011, UNEP–WCMC 2012a). And given that a large proportion of the trade reported to CITES is only reported to the genus level, it is possible this volume underestimates the true extent of trade in this species (Evanson et al. 2011). Taken together this information suggests continued exploitation of this species throughout its range.

The main threat to Hippocampus barbouri is exploitation for trade for traditional medicine and aquaria display. Although this seahorse has spines on its body, which is traditionally an undesirable trait in the traditional medicine trade (Vincent 1996), it is still heavily traded (Evanson et al. 2011). This seahorse is a bycatch in multiple fisheries in its shallow seagrass habitat as well as being targeted by some small-scale fishers (Perry et al. 2010).  

In addition to the substantial demand for this species, its in-shore seagrass habitats are also threatened throughout its range. Major threats faced by seagrasses include; eutrophication, sedimentation, coastal construction, dredging and invasive species and these threats result in decline in and fragmentation of seagrass habitats (see Short et al. 2011 for an overview of threats facing seagrasses).

Seahorses' life history and ecological traits may increase their susceptibility to these threats (see Habitats and Ecology).

• 5.4.2 Intentional use: (large scale) [harvest]
• 5.4.1 Intentional use: (subsistence/small scale) [harvest]
• 5.4.3 Unintentional effects: (subsistence/small scale) [harvest]
• 5.4.4 Unintentional effects: (large scale) [harvest]

All Hippocampus species are listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). This means that countries who are signatories to CITES are subject to regulations on the export of seahorses. Countries are required to provide permits for all exports of seahorses and are meant to provide evidence that these exports are not detrimental to wild populations. However a lack of basic information on distribution, habitat and abundance means many CITES Authorities cannot assess sustainability of their seahorse exploitation and meet their obligations to the Convention.  The challenge is particularly large in that most seahorses entering trade are caught incidentally as bycatch and thus imposing export quotas would achieve next to nothing for wild populations. 

CITES has recommended a minimum size limit of 10 cm height for all seahorse specimens in trade (CITES Decision 12.54). This limit represents a compromise between the best biological information available at the time of listing and perceived socioeconomic feasibility.  But we urgently need information on wild populations to assess their conservation status and take conservation action, as well as refine management recommendations.  For example, evidence on variation in the spatial and temporal abundance of seahorses would enable areas of high seahorse density to be identified, as the basis for considering area restrictions on non-selective fishing gear that obtains Hippocampus species as bycatch.  An understanding of the technical and logistical feasibility of returning to the sea live seahorses taken as bycatch in various types of fishing gear would provide the basis for considering the feasibility of minimum size limits and/or other output controls. Establishing monitoring program of landings of seahorses at representative sites, taking into account different gear types and means of extraction and recording catch and effort metrics would allow us to assess population conservation status and develop management recommendations for various fishery types.

• 5.2 Policies and regulations
• 3.1.2 Trade management
• 2.3 Habitat & natural process restoration
• 3.1.1 Harvest management
• 1.2 Resource & habitat protection
• 4.3 Awareness & communications
• 2.1 Site/area management
• 4.2 Training
• 1.1 Site/area protection

Details of declines in Hippocampus barbouri populations are sparse, but the existing indirect evidence suggests cause for concern, especially as H. barbouri is among the more commonly traded species internationally (Evanson et al, 2011, UNEP–WCMC 2012a). Due to this extensive and continuing trade, coupled with mortality from ever-present bycatch and destruction of its seagrass habitats, a continuing decline of at least 30% is suspected in the past and into the future. Using the precautionary approach, this species is assessed as Vulnerable under criterion A. 

In 2002 this species was assessed as VU A4cd. This species was also assessed in 1996 under the name Hippocampus histrix but this identification was an error.

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