Sustainable Rearing of Marine Bait Worms (polychaetes) as Alternative Protein Feeds For Mariculture Hatcheries and Baits For Artisanal Fisheries In Coastal Kenya

Kenya's coastal communities depend heavily on wild-harvested polychaetes (marine bait worms) for artisanal fishing bait. These polychaetes have been tested as a source of protein in fish feeds and mariculture hatcheries as live protein feeds. However, polychaete harvesting activities, including digging beneath mangrove roots, cause root damage, mangrove collapse, and disruption of marine fauna and fisheries breeding ecosystems. These activities accelerate the depletion of mangrove species listed as endangered by the International Union for Conservation of Nature (IUCN): Avicennia marina and Rhizophora mucronata.

This study aims to develop sustainable culture methods for marine polychaetes using recycled organic substrates as a cost-effective alternative to wild harvesting in the Shimoni-Vanga coastal region of Kenya. Pilot-scale polychaete rearing units are being established to evaluate growth performance and survival under varying stocking densities, substrate types, and feeding regimes. Cultured bait worms are being tested as live feed in rabbitfish and prawn hatcheries to assess their viability as an alternative to commercial protein sources.

Community engagement activities, including sensitization campaigns, are being implemented to reduce mangrove destruction by promoting the transition from wild bait harvesting to worm culture as a sustainable livelihood. Mangrove ecosystem health is being monitored through baseline and quarterly field surveys to track reductions in harvesting-related disturbance. Preliminary findings indicate strong community interest in small-scale polychaete culture as a pathway to mangrove conservation.

Expected outcomes include a replicable worm culture protocol, reduced pressure on mangrove ecosystems, expanded alternative livelihood opportunities, and a scalable model for integrating aquaculture innovation with coastal conservation in Kenya.