IUCN Red List Category: VU A2cd+4cd (Draft)
Animalia | Chordata | Vertebrata | Actinopterygii | Syngnathiformes | Syngnathidae | Hippocampus | Hippocampus algiricus |
Taxonomic notes: Genetic research suggests that this species is part of the Hippocampus kuda complex and is very closely related to both H. kuda and H. reidi. Further research is needed.
This species occurs in the Eastern Central Atlantic ocean off the coast of West Africa, from Senegal to Angola (Alfonso et al. 1999, Lourie et al. 2004, Mamonekene et al. 2006). The type specimen was located off the coast of Algeria in the 1850s (Kaup 1856), but subsequent research and a lack of any additional specimens from this well-monitored area indicates this sourcing is likely an error. Pending further evidence, the range is considered to exclude North Africa or the Mediterranean.
The habitat and life history of Hippocampus algiricus are mostly unknown (Lourie et al. 2004), but this species has been found clinging to large sponges (Wirtz et al. 2007). Like all seahorses, the females transfer eggs to the male’s brood pouch (Breder and Rosen 1966). All seahorse species also have vital parental care, and many species studied to date have high site fidelity (e.g., Perante et al. 2002), highly structured social behaviour (e.g., Vincent and Sadler 1995), and relatively sparse distributions (Lourie et al. 1999).
This species is usually found in the shallow photic zone up tto a depth of 25 m (Wirtz et al. 2007). Size at maturity is roughly 9 cm with a maximum size recorded for the species of 19 cm (Lourie et al. 2004, Foster and Vincent 2005).
This species is known primarily from museum specimens (e.g., Wirtz et al. 2007) and information from population monitoring is unavailable. However, population declines are suspected as a result of habitat degradation and coastal development (Portmann 1989), mortality from intense trawling bycatch (Baum et al. 2003, McPherson and Vincent 2004, Giles et al. 2006, Perry et al. 2010), which occurs throughout this species’ range (Kristjonsson 1968, Portmann, 1989, FAO 2001), and large volumes of documented international trade (Evanson et al. 2011, UNEP-WCMC 2011).
Population declines due to the pressures from international trade have been acting on this species in West Africa for well over 15 years and are expected to continue into the future. Hippocampus algiricus has also been selected by the CITES Animals Committee for the Review of Significant Trade following COP15 (CITES 2012).
Trade of Hippocampus algiricus specifically was undocumented in the 1990s (Lourie et al. 2004), however, as early as 1996 there has been recorded trade of hundreds of kilograms of seahorses annually from West African countries such as Guinea, Gambia, Senegal and Togo (Vincent et al. 2011b) and since this species is the only seahorse recorded in some of these areas, it is fair to assume that much of this trade was in H. algiricus. Recent surveys in West Africa have also confirmed that trade in H. algiricus for traditional medicine has been occurring since at least 2000, if not before (K. West pers. comm. 2012).
Between 2004 and 2008, an average of 700,000 individual wild seahorses were traded internationally every year from West Africa (Evanson et al. 2011, UNEP-WCMC 2012). These seahorses were exported predominantly to Asian countries (UNEP–WCMC 2012), presumably for traditional medicines (Vincent et al. 2011a, b). Due to the apparent increase in trade of H. algiricus over the last decade, the advancing economies of Asian countries importing this species, and the increasing trawling pressure on West African fisheries that occurs in the same habitat as H. algiricus (FAO 2001), it is suspected that exploitation levels will increase, with a corresponding increasing in pressure on H. algiricus populations. Recent surveys have begun to uncover this trade and show that pressure on this species has been increasing over the past 10 to 15 years (K. West pers. comm. 2012).
The international trade of dried, wild seahorses is large (Evanson et al. 2011, UNEP–WCMC 2012) and potentially increasing, and is a likely threat to H. algiricus populations (Vincent 1996, Vincent et al. 2011a). This threat has been recorded from as early as 1996 (Vincent et al. 2011b) all the way up until 2010 (UNEP–WCMC 2012) and it likely to continue into the future.
Habitat degradation along the coast is also a concern for this shallow-intertidal species. There is a history of marine contamination from heavy metals, pesticides, oil, and human wastes, as well as coastal development and intensive fishing (Portmann 1989), which may affect populations of H. algiricus.
Shrimp trawling, with high levels of by-catch and ever-increasing demand, occurs extensively along the coast of West Africa in the same habitats as H. algiricus (Kristjonsson 1968, Blaber et al. 2000, FAO 2001). It is known that trawling catches large numbers of seahorses as bycatch when populations of seahorses are present in trawling areas (Baum et al. 2003, McPherson and Vincent 2004, Giles et al. 2006, Perry et al. 2010). It is expected that bycatch of H. algiricus occurs in West Africa, to the detriment of these populations. Fishing pressure from artisanal fishers has also increased dramatically in recent years and this, coupled with little enforcement of minimum mesh sizes for shrimp trawling in countries such as Guinea, is putting heavy pressures on local seahorse populations (K.West pers. comm. 2012).
The trade in this species is regulated through CITES Appendix II.
Hippocampus algiricus may occur in the Bijagos Archipelago Biosphere Reserve in Guinea-Bissau (within the species’ suspected range, Agardy 1999).
Research into the phylogeny of this species is extensive (Casey et al. 2004, Teske et al. 2004, Teske et al. 2007, Floeter et al. 2008, Sanders et al. 2008, Woodall et al. 2009).
This species is listed as Vulnerable (A2cd+4cd) because of suspected population declines of at least 30% in the past and continuing into the future. There are no population monitoring data, but evidence suggests that continued habitat degradation and levels of exploitation have lead to declines in the past and that these declines will continue into the future. Heavy trade has been recorded since as early as 1996 (Vincent et al. 2011b) giving evidence that declines in this species have been occurring for at least 15 years. Harvest and trade appears to have accelerated in recent years (Evanson et al. 2011) and it is believed that trade will continue into the future.
There is a history of coastal marine pollution and development throughout this species’ entire range along the West African coast from the early 1980's onwards (Portmann, 1989), which previous studies have indicated can adversely affect seahorse populations (see Vincent et al. 2011a for a review). In addition, trawling occurs throughout the range of H. algiricus, along the coast of West Africa (Kristjonsson 1968, Blaber et al. 2000, FAO 2001); and it is known that trawling causes substantial seahorse by-catch and mortality (Baum et al. 2003, McPherson and Vincent 2004, Giles et al. 2006, Perry et al. 2010). Fishing pressure from artisanal fishers has also increased dramatically in recent years, which is putting heavy pressures on local seahorse populations (K. West pers. comm. 2012).
Furthermore, the international trade in this species is substantial. Heavy trade has been recorded since as early as 1996 (Vincent et al. 2011b) and since the listing of the species on CITES Appendix II, there has been documented trade of approximately 700,000 individuals, on average, per year between 2004 and 2008 (Evanson et al. 2011). This documented trade has continued through to the latest trade records on the CITES Trade Database (UNEP-WCMC 2012). It is suspected that trade of this volume has likely resulted in past population declines and will lead to further reductions of H. algiricus populations as trading pressure increases.
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