This study was conducted to assess the effects of excessive aquaculture structures and stocking density on water quality and aquaculture production given the policies in place in Bolinao, which is one of the major aquaculture producing municipalities in the Philippines. Results of the study showed that the average stocking density of the aquaculture operation fell within the optimal value, but there were operators whose stocking densities were more than double than that of the optimum. The aquaculture production analysis showed that stocking density affects production. Beyond a certain level, further increases in stocks result in decreasing productivity. Excessive number of fish pens and cages with overstocking may lead to fish kills due to deteriorating water quality and other associated damages that are detrimental to the aquaculture industry and to the greater community. The study suggests that several policy implications and better regulation of coastal aquaculture operation are needed.