Recruitment of the mussel Mytella strigata in artificial collectors on the Amazon Macrotidal Mangrove Coast

This study assessed the efficacy of artificial collectors in recruiting Mytella strigata along the Amazon Macrotidal Mangrove Coast. The experiment involved three treatments (PVC plate, PET, and polyethylene screen), each repeated thrice. The study was conducted over 315 days, during which settlement density, bivalve biometry within the collectors, and environmental variables, such as temperature (°C), salinity (g.kg-1), chlorophyll-a (mg.m-3), particulate organic matter (POM), particulate inorganic matter (PIM) (mg.L-1), water transparency (determined using a Secchi disc), and rainfall data (mm), were assessed at 45-day intervals. The recruitment of M. strigata was observed predominantly during the rainy season. Both mussel shell size and average settlement density significantly varied (p < 0.05) based on the type of collector, collection period, and their interaction. Polyethylene mesh collectors demonstrated a higher settlement density compared to PET and PVC substrates (p < 0.05), but mussel shell size was lower in this treatment compared to the shell size of juveniles in PVC and PET collectors. Among the collectors, PVC ones proved more effective for collecting M. strigata, considering the quantity of fixed juveniles and the size of the individuals. Regarding the region’s environmental conditions, recommendations are that producers place collectors in the water from January, with juvenile recruitment occurring February‒June.