Abstract:
This study investigated the catch trends, spatial distributions,
exploitation status, and reproductive potential of the sparids – Pagrus
caeruleostictus, Dentex canariensis and Dentex gibbosus, in the coastal waters
of Ghana. Samples of the species were obtained from commercial catches at
Tema, Elmina and Sekondi from February 2016 to July 2017. Also used were
secondary data from the Fisheries Scientific Survey Department and Fridtjof
Nansen cruise reports. P. caeruleostictus was the most abundant of the three
species, while D. gibbosus was the least abundant. The asymptotic length (TL∞)
and growth coefficient (K) values for P. caeruleostictus, D. canariensis and D.
gibbosus, respectively were 52.7 cm and 0.52 yr-1, 70.9 cm and 0.25 yr-1, and
60.7 cm and 0.16 yr-1. The fishing mortality (F) calculated for the three species
was greater than natural mortality (M), accounting for a greater percentage of
total mortality (Z), and leading to an exploitation ratio (E) higher than 0.5.
Except for D. gibbosus which appeared underexploited (Ecur<Emsy), the other
species were exploited above their maximum sustainable yield (Ecur>Emsy). The
respective male and female length-at-first sexual maturity was estimated as 36.2
cm and 28.0 cm for P. caeruleostictus, 51.7 cm and 31.6 cm for D. canariensis,
and 54.3 cm and 56.4 cm for D. gibbosus. P. caeruleostictus and D. gibbosus
had two spawning periods in a year, occurring in September and March, and in
January-February and July-October, respectively. D. canariensis, however, had
one extended spawning period taking place between May and September. The
oocyte diameter frequency distributions were unimodal and the fecundities
ranged from about 250,000 to 6,000,000 for all three species.
