|Recruitment of Tapes philippinarum in the Venice Lagoon (Italy) during 2002–2007|
|Pellizzato, M.; Galvan, T.; Lazzarini, R.; Penzo, P. (2011). Recruitment of Tapes philippinarum in the Venice Lagoon (Italy) during 2002–2007. Aquacult. Int. 19(3): 541-554|
|In: Aquaculture International. Springer: London. ISSN 0967-6120, more|
Clam culture; Nursery grounds; Recruitment; Tapes (Ruditapes) philippinarum (Adams & Reeve, 1850) [WoRMS]; MED, Italy, Veneto, Venice Lagoon [gazetteer]; Marine
Currently, Tapes philippinarum, the Manila clam, is the primary fishery resource for about 1,000 fishermen and aquaculturists in the Venice Lagoon. The recruitment of this clam is a key component supporting shellfish culture industry that is almost completely dependent on the gathering of wild clam seed in nursery areas where the juveniles accrue at high densities as a consequence of favourable environmental conditions. The objective of the present study was to identify the areas optimal for the recruitment of T. philippinarum, herein referred to as nursery areas, and to evaluate the recruitment success each year for the period 2002–2007. Sampling was conducted with a hydraulic dredge at 25 stations, in at least three separate periods from April to September each year for 2002, 2003 and 2004, and at 15 stations for 2005, 2006 and 2007. The zero-year cohorts of this species were usually first detected in bottom samples in late spring (May and June). Some setting appears to occur throughout the summer. The peak of seed density, expressed as number of individuals retained on a 1-mm mesh screen per square metre of sampled substrate, was recorded in September. Measurable fluctuations in annual recruitment have been observed, with peak densities of juveniles in 2002 and 2003 (about 2,000/m2) and minimum densities in 2006 (about 44/m2). In the summer 2007, densities over 30,000/m2 were found at the mouth of the River Brenta, immediately adjacent to the southern end of the Venice Lagoon. These intensive, multiyear surveys of this species furnish critical information on seasonal reproduction patterns and recruitment success, which is essential for the rational development of a local fishing master plan and for the formulation of a management strategy for sustainable utilisation of this shellfish resource in the Venice Lagoon.