
%0 Journal Article
%A Sims, NA 
%T Population dynamics and stock management of the black-lip pearl oyster, <I>Pinctada margaritifera</I> (L.), in the Cook Islands, South Pacific
%J Marine and Freshwater Research
%D 1992/12/01
%V 43
%N 6
%P 1423-1435
%K 
%R https://doi.org/10.1071/MF9921423
%U https://www.publish.csiro.au/paper/MF9921423 
%X Permanent transects were used to measure changes in abundance of Pinctada margaritifera in Manihiki lagoon, Cook Islands. Growth in situ, mortality and recruitment were also studied. A correction factor for searcher efficiency was also determined, allowing earlier estimates of standing stocks to be adjusted. Overall abundance in Manihiki decreased by 18% in one year. Most losses were attributable to fishing (F=0.19; M=0.11). Mortality (27%) and recruitment (9%) were presumably underestimated because of heavy fishing of juveniles. Total mortality, estimated by Wetherall plots, decreased from 0.48 to 0.35 over the year owing to a decline in fishing for larger oysters. The average shell diameter of recruits was 110 mm. This was also an approximation of Ic,. von Bertalanffy growth parameters of K=0.26 and L&#8734; = 183 mm were estimated from shell size increments. Yield-per-recruit calculations indicate that minimum size limits are not effective. Reserve areas, quotas, and other restrictions on effort should instead be used to protect broodstocks. 
