FISHERIES BIOLOGY PARAMETERS OF THE YELLOW CHUB (KYPHOSUS INCISOR) FOR MANAGEMENT AND CONSERVATION IN THE OLD PROVIDENCE MCBEAN LAGOON NATIONAL PARK

Abstract

Some parameters of the fiheries biology of Kyphosus incisor (yellow chub) were estimated from fiheries monitoring and a hand line and hook size selectivity experiment carried out in the Old Providence McBean Lagoon National Park from 2006 to 2012. Both monitoring and fihing experiment were conducted to obtain scientifi information for management and conservation of K. incisor, including the active participation of islander fiherman, which favored outcomes of interest to the management of the Park. Size range for fihes was 26.5-58.0 cm total length (TL), showing allometric growth [W (g) = 0.02 LT (cm) 2.95]. There was no statistically signifiant deviation from the 1:1 sex ratio. The mean size at maturity (MSM) for females was estimated at 47.4 cm TL (95% CI, 47.1 - 47.6 cm), whereas the proportion of advanced stages of maturity increased during the second half of year, which suggests that spawning peaks occur between December and March. Size composition of catch time series suggested that this species is harvested in sizes close to the MSM; however, the indicator (mean catch size /MSM) trend was growing. The selectivity experiment aimed at comparing the fih size caught by three different J-style hook sizes, standardizing other sources of variation, in order to determine the hook size that maximizes the probability of catching fih above the MSM (9 hook). Management and conservation measures of K. incisor obtained from this study are as follow: I) in the hypothetical case of a ban, it must be established consistent with the reproductive peak of the species, i.e. between December and March; II) minimum capture legal size should be between 47 and 48 cm total length, III) restrict the use of small hooks (10 or lower); IV) increase in fihing effort with the entry of new fihermen should not be allowed; V) process of management measures by fihing agreements with resource users should continue.