Sprinkling: a new method of distributing live algae food in marine coastal ponds used for Manila clam Tapes philippinarum (Adams & Reeve) intensive culture.
Sprinkling, an agricultural irrigation technique, was tested in the intensive culture of Manila clams up to marketable size (35-50 mm). The sprinkling culture system was composed of 2 earthen ponds, 200 m2 each (10 × 20 × 0.75 m deep) separated by a mound on which the sprinkler (183 rain gun Komet model) was mounted. The radius of the circle covered by the stream of seawater sprinkled was 9-10 m. Daily water renewal was 100% of the pond volume with water and live algae, Skeletonema costatum, supply spread evenly over the surface of both ponds. Data obtained were compared with growth data obtained from a raceway system. Growth increments in the sprinkling culture system, in terms of size and liveweight were spatially uniform after 8 months of rearing with no difference in size distributions between locations within each pond. Sprinkling is a simple, low cost and efficient method of food distribution which resolves the major problem of decreasing bivalve growth associated with single-point water entry in small-scale raceways. Uniform growth obtained with sprinkling is principally due to an even scattering of feed over the whole surface area of large-scale ponds.