Singapore Intensifies Efforts to Conserve Native Horseshoe Crabs and Critically Endangered Seahorses

Scientific institutions in Singapore are escalating focused conservation initiatives targeting two native marine species: the horseshoe crab and the seahorse. This concentrated drive is deemed vital given the substantial regional threats imperiling both groups of animals within the Republic's waters.

Republic Polytechnic (RP) has initiated Singapore’s inaugural captive-breeding program for the coastal horseshoe crab, which commenced in 2024. A specific pair of these crabs is currently under intensive observation, having yielded approximately 1,700 eggs distributed across three separate tanks to mitigate risks from single-system failure. Dr. Laura Yap, programme chair for RP's Diploma in Environmental and Marine Science, is applying methodologies refined since 2015 from successful captive breeding of the mangrove horseshoe crab. Both the coastal horseshoe crab (*Tachypleus gigas*) and the mangrove horseshoe crab (*Carcinos অভিনdicauda*) are classified as locally vulnerable, with current wild populations estimated at under 1,000 mature individuals for each species.

The coastal variant faces particular vulnerability due to habitat degradation stemming from land reclamation, which fragments necessary migratory pathways. The current project, slated to conclude in September, seeks the necessary permits to reintroduce the laboratory-reared juveniles into their natural environment. Concurrently, significant attention is directed toward studying Singapore’s native seahorses, all of which are categorized as critically endangered. Save Our Seahorses (SOS) Malaysia, a non-profit established in 2005, intends to partner with Singaporean entities by June 2026 to conduct a comprehensive mapping of these syngnathid fishes within the Republic's waters.

Dr. Adam Lim, director of SOS Malaysia, has emphasized that effective conservation mandates unified participation across all societal sectors. Singapore currently lacks a dedicated specialist for seahorse research, a gap the collaboration seeks to address. These creatures fulfill indispensable ecological functions: horseshoe crabs act as bioturbators, sustaining migratory bird populations, while seahorses regulate complex marine food webs by preying on bottom-dwelling organisms. The coastal horseshoe crab, which can reach up to 25cm in diameter, is considered a keystone species maintaining ecosystem stability through nutrient release during foraging.

The Estuarine seahorse (*Hippocampus kuda*), which relies heavily on camouflage in shallow seagrass beds, is listed as 'Vulnerable' on the Singapore Red Data Book. Conservation science is informed by broader regional contexts; RP’s prior work since 2015 included field surveys and outreach alongside captive rearing, aiming to establish successful breeding protocols for the mangrove species before extending to the coastal variety. Globally, seahorses face threats from habitat loss, pollution, and over-collection, with some species experiencing global declines of 30-50%. The partnership between Malaysian and Singaporean groups, building on SOS Malaysia's 21 years of surveying, positions the effort to advance understanding and foster a dedicated research champion for seahorses within Singapore.