Costa, Eliardo G.
Paulino, Carlos Daniel
Singer, Julio M.
Total Authors: 3
 Univ Fed Rio Grande do Norte, Dept Estat, Natal, RN - Brazil
 Univ Lisbon, Dept Matemat, IST, Lisbon - Portugal
 Univ Lisbon, CEAUL, FCUL, Lisbon - Portugal
 Univ Sao Paulo, Dept Estat, Sao Paulo - Brazil
Total Affiliations: 4
SORT-Statistics and Operations Research Transactions;
Web of Science Citations:
We construct credible intervals to estimate the mean organism (zooplankton and phytoplankton) concentration in ballast water via a decision-theoretic approach. To obtain the required optimal sample size, we use a total cost minimization criterion defined as the sum of the sampling cost and the Bayes risk either under a Poisson or a negative binomial model for organism counts, both with a gamma prior distribution. Such credible intervals may be employed to verify whether the ballast water discharged from a ship is in compliance with international standards. We also conduct a simulation study to evaluate the credible interval lengths associated with the proposed optimal sample sizes. (AU)