This is the third of the five modules of the 'Fish and People' fisheries science learning tool. In this module the basics of fishery biology of a range of representative Indo-Pacific marine species is described. The module emphasises the relationship between biological traits such as growth rate, age at maturity, life-span, and fecundity, to resilience of populations to fishing pressure. Fast-growing, short-lived species tend to be more resilient to fishing than slow-growing, long-lived species. Pre-colonial Pacific Island societies by and large existed at human population densities that were far below the carrying capacity of their coastal fisheries and pressure from commercial fishing was non existent. As a consequence island communities did not ‘encounter the limits’ of their coastal subsistence fisheries. People went about their daily lives harvesting from the sea and blissfully unaware that fish and marine invertebrate populations could be overfished to the point collapse. Despite the existence of some traditional measures for increasing stock densities of valuable fisheries (taboos), usually in the context of feasting rituals, most Pacific Islanders traditionally have the fatalistic belief that fish stocks will always recover, no matter how severely they are depleted. Now that human populations are growing almost exponentially and export markets for some fisheries are intensifying, there is an urgent need for the effective communication of a scientific understanding of the limits to fisheries and the life cycles of marine organisms overall. The fatalistic attitude of many people is primarily due to a widespread lack of awareness of how important the connection between the number of adult fish in a population is to the rate of production of the next generation. The more a population is reduced in size by fishing, the fewer fertilized eggs it produces and the fewer juveniles end up being added to (recruiting to) that population. The fact that part of the life-cycle of fish and most marine animals is a tiny larva, generally invisible to the naked eye, that disperses on ocean currents for days, weeks or months till it is ready to settle and transform into a juvenile, is also part of the reason most people don’t make the connection between over-fishing and declining fishery ‘production’.