This research investigates the livelihoods of artisanal fishing families at Lake Malawi. The key research question that it addresses is how artisanal fishers adapt their behaviour to cope with fluctuations in fish availability that occur naturally, i. e. that do not occur primarily as the outcome of human fishing behaviour. In Lake Malawi two such fish species, usipa and utaka, exhibit considerable spatial, seasonal, and interannual variability. These species are also by far the most important for the artisanal fishery. Fluctuating fisheries pose special challenges for livelihoods and fisheries management. For livelihoods they imply big seasonal variations in the ability of families to rely on fishing as a primary livelihood component, and they make fishing-based livelihoods insecure and risky. For fisheries management, they pose the problem that the true status of the resource is almost impossible to measure, with apparent risks in both directions: that overly restrictive management will result in an unexploited resource that could have made a greater contribution to the livelihoods of poor people and to the nutritional status of the population of Malawi more generally; or that overly lax management will result in a depletion of the resource beyond its sustainable yield. The research shows that fishers adapt to the fluctuating fish stocks in two main ways. One way is to specialise mainly in fishing but to emphasise mobility, so that short and medium term movements around the lake are made in pursuit of the resource. The other way is to maintain diverse livelihoods, combining fishing with farming and other non-farm income generating activities. There are, of course, also intermediate cases between these two opposing poles. The research demonstrates that migration for fishing purposes brings benefits both to migrants and resident communities. While for the migrants it is important to be allowed to settle for varying periods at different lakeshore beaches and villages; for residents the presence of the mobile fishers brings an increase of cash into circulation, the arrival of fish traders, the ability to open shops and bars to service this increased activity, and more buoyant markets for locally produced commodities. There are thus important income and employment benefits for resident communities that result from the behaviour of fishing migrants. At Lake Malawi, migrant fishermen tend to be from the Tonga ethnic group from the north of the country, and they generally differ in ethnicity from the resident communities where they take up temporary settlement. Fisheries policy in Malawi has been moving away from a top-down regulation by the Fisheries Department towards the idea of community management of fisheries. The argument is that if fishing communities are given their own powers to enforce regulations, within a participatory framework, then community self-interest will ensure that regulations are properly policed. This idea involves establishing territoriality over areas of the lake, so that "beach village committees" (BVCs) have regulatory powers over the lake areasa djacentt o villages. The researchd emonstratesth at there are many flaws in this concept in the case of Lake Malawi: BVCs are dominated by part-time fishing or non-fishing residents, migrants are excluded, territoriality is nonsensical for a mobile resource, and previously successful reciprocal relationships and other complex adaptive strategies are weakened and disrupted. The artisanal fishery in Malawi is opportunistic; it adapts to fluctuations either by ceasing to fish or by moving to other fishing grounds. It is argued that this sort of fishing requires minimal management, in which mobility and diversity are recognised and encouraged. If indeed there is a threat to the resource, it is rather the large scale commercial sector comprising a few trawlers of immense capacity relative to the yield potential of the Lake that pose that threat. There is an unequivocal need to monitor and regulate the catch volumes of this sector. For the artisanal fishery, however, a low key, flexible and resilient management approach is suggested; one that builds on the strengths of existing patterns of behaviour rather than seeking to change and undermine them.