This workshop and the resulting proceedings came into being as a result of cumulative concerns by aid agencies, nongovernmental organizations and by government authorities and researchers on the mass installation of artificial reefs in the Philippines. Artificial reefs are usually constructed from materials such as scrap tires, metals, concrete blocks, bamboo and nondegradable synthesis such as polypropylene rope. What are their environmental impacts? Do they increase fish harvest in a sustainable way by providing additional nursery habitat for reef fishes, additional productive surface area or additional substrata to filter-feeding benthic communities or an additional site at which planktivorous fishes can aggregate? Or do they simply aggregate surviving adult fishes, generate increased fishing mortality rates, and thus, deliver a transient increase in catches in fish communities many of which are already overexploited. The answer to some of these questions are found in this book.