03-03-2026
NOVA FCT is one of the partner entities in two seahorse population conservation projects (CavalSado and Cavalos de Tróia). The results were recently disclosed, confirming the high ecological importance of the Sado estuary for seahorse conservation. Developed in 2025, these projects had as their main objective to survey populations of these species along the estuary, filling a historical knowledge gap in the region.
The initiatives were led by MARDIVE – Science and Education Association for Marine Biodiversity Conservation, MARE – Marine and Environmental Sciences Centre, NOVA School of Science and Technology – NOVA FCT, and ARNET – Aquatic Research Network. They also had the partnership of the Nature Conservation and Forests Institute (ICNF) and funding from TRÓIA-NATURA, the Circular Seas Program by Coca-Cola in Portugal (implemented by the League for Nature Protection – LPN), and Setúbal Municipal Council.
The study used scientific diving at 19 sampling points, mostly located in seagrass meadows, oyster fields, and port structures, allowing assessment of the distribution, abundance, and diversity of seahorses and pipefish in different estuary habitats. The results were very encouraging: seahorses and/or pipefish were recorded in 15 of the 19 points, with a total of 56 individuals observed, belonging to 2 seahorse species and 3 pipefish species.
The work also identified key conservation areas, highlighting Sol Tróia (classified as a seahorse hotspot), Tróia Marina (pipefish hotspot), and a third priority area, Marbella Marina, due to the high abundance and diversity of species recorded. Two priority conservation habitats in the estuary were identified for the first time, information that reinforces the need for protection and sustainable management of this ecosystem.
Despite the positive results regarding species presence and diversity, the projects highlight several threats that jeopardize the integrity of these habitats and seahorse and pipefish populations. Among the main pressure factors are habitat degradation, marine litter, lost fishing gear, underwater noise, dredging, and climate change effects. This scientific information forms a fundamental basis for future monitoring and to support management decisions, territorial planning, and definition of protection measures in the Sado estuary.
The CavalSado and Cavalos de Tróia projects also include a strong environmental education and awareness component, bringing the Sado's biodiversity closer to schools, local communities, and decision-makers, and reinforcing the role of science in promoting knowledge-based solutions for marine conservation.
The project reports are available for consultation: CavalSado and Cavalos de Tróia, where detailed information can be found on observed species, occupied habitats, identified threats, and conservation recommendations.
NOVA FCT, in collaboration with MARDIVE, MARE, ARNET, ICNF, and all involved partners, invites the academic community and society at large to learn about these results, disseminate the produced information, and actively contribute to the protection of seahorses, pipefish, and Sado estuary habitats.
