Seahorses are among the most sensitive bioindicators of coastal marine health, yet the habitats they depend on, seagrass meadows and structurally complex, sheltered substrates, have been steadily lost to coastal development, leaving few refuges for the species in urbanised and industrial waterfronts.
HIPPO-REF, a joint initiative of the Institute of Marine Research (IIM-CSIC) and the Port Authority of Vigo, set out to test the opposite assumption: that an active commercial port can also function as a site of ecological restoration. The project builds on Hippo-DEC, the MITECO-funded research that first confirmed recurring seahorse presence within the port of Vigo, and adapts the Seahorse Hotel concept pioneered by the University of New South Wales in Sydney to the Atlantic port context.
Four artificial reef-type refuge structures, built from corrugated iron mesh, were deployed at the A Laxe underwater viewpoint (Nautilus underwater observatory) following a site-selection process based on current, water quality, substrate and proximity to marine vegetation. After a one-month maturation period, monthly scientific diving surveys and non-invasive ROV monitoring have so far confirmed ten sightings of Hippocampus guttulatus, including a juvenile, direct evidence of local reproduction, alongside pipefish, cuttlefish with egg clutches, spider crabs, lobsters and a growing benthic community of algae, sponges, bryozoans, molluscs and echinoderms.
A new phase now extends the network with two additional refuges at Peiraos do Solpor, reinforcing HIPPO-REF’s place within the Port of Vigo’s wider restoration strategy and its potential as a low-cost, modular, replicable model for other European ports.