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Investigaciones marinas

On-line version ISSN 0717-7178

Abstract

TRUJILLO, Ernesto; MARTINEZ, Guillermo  and  LEON, Luis. Sizing and theoretical configuration of a longline for growing pearl oysters (Pinctada imbricata Mollusca: Bivalvia) in the Bay of Charagato, Cubagua Island, Venezuela. Investig. mar. [online]. 2007, vol.35, n.1, pp.39-54. ISSN 0717-7178.  http://dx.doi.org/10.4067/S0717-71782007000100004.

A farming longline was sized by theoretically analyzing the system’s hydrodynamic resistance and configured using analogue simulation with the help of scale models. The variables determined were mother line tension (TLM), the relationship of the anchoring aspect (RA), and movement (PR) of the mother line. These resulted in anchoring system tension (T2) and attack angle (α2), and the vertical tension for a section of the mother line (TF) and the attack angle of the catenary (α). The model of the anchor end and a section of the mother line were constructed using lineal scale factors of 40 and 18.86 and force scales of 9,776.3 and 1,233.13, respectively. The minimum tensions (T2) obtained for RA were 1/4 and 1/5 based on the theoretical tension (T1) 777.15 kgf, with attack angles of 84.9° and 90°. A longline section with six lanterns and loaded with adult organisms had central units 3 and 4 at an operational depth of 7.37 m, an average PR of 93.6%, and an attack angle of 55.86°. A tensiometer should be used for an in situ validation of the theoretical results in order to determine the structural equilibrium of the system with minimum investment and maximum performance

Keywords : sizing; anchoring system; farming longline; analogue simulation; aquaculture; pearl oyster.

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