Settlement of Mussel Perna perna Seed on Artificial Collectors Deployed on Sea Surface

Abstract

The low settlement of mussel Perna perna seeds on artificial collectors deployed on sea subsurface has been a major obstacle to the mussel farming improvement in Brazil. This study aimed to compare the seed settlement on artificial collectors deployed on the sea surface with the aid of buoys and at the subsurface (20 cm depth) in Cocanha Beach, Caraguatatuba City, Sao Paulo State, Brazil. Mann–Whitney test showed significant differences (P < 0.05) between treatments for each class of length, with the best settlement occurring on the sea surface collectors for all classes (P < 0.05). It is concluded that deploying artificial collectors with buoys on the sea surface increases the number and the biomass of settled mussel seeds when compared to the non‐buoys deployed collectors on the sea subsurface.

Settlement of juveniles of pearl oyster (Pinctada imbricata) on artificial collectors in Caraguatatuba, Sao Paulo, Brazil

“…The area of Cocanha Beach was classified as oligotrophic by Castro Filho and Miranda (), due to the low concentration of chlorophyll‐a, these data confirmed by Bordon et al . (). Thus, the drift of organic matter can partially compensate the low concentration of phytoplankton in the water, ensuring supply of food for filter‐feeding organisms as P. imbricata .…”

“…Bordon et al . () reported the settlement of brown mussel Perna perna juveniles on horizontal collectors maintained on the sea surface with the aid of buoys, relating this fact to the behaviour of larvae of this species that in natural environment settle on the intertidal zone of rocky shores. It appears that the larvae of P. imbricata have a similar preference but further studies are needed in order to confirm this hypothesis.…”

“…Two replicate artificial collectors manufactured from discarded braid fishing nets and ~1 m long were monthly deployed within the study area between January 2009 and June 2010. The collectors were similar to those used for seed collection of the brown mussel Perna perna (Bordon, Marques, Alves & Medeiros ) and were maintained neutrally buoyant on the sea surface with the aid of polystyrene buoys (5 cm in diameter) which were spaced 20 cm from each another. Two auxiliary parallel cables, spaced 1 m apart and equipped with floats, were used to support the collectors, the ends of which were attached perpendicularly to two commercial long lines (Fig.…”