Final answer:
The vast majority of harvests from the oceans, known as marine fisheries, provide essential animal protein to many worldwide. Overexploitation and unsustainable practices have led to significant declines in fish populations, with socio-economic impacts on communities dependent on fishing.
Step-by-step explanation:
The vast majority of the harvest from oceans consists of fishes, which in fisheries terminology are referred to as marine fisheries. These fisheries include a variety of fishing practices, ranging from industrial-scale to artisanal methods, and play a critical role in providing a main source of animal protein for billions of people worldwide.
However, many marine fisheries are facing a crisis due to overexploitation. Current harvest rates have led to a situation where the most economically important marine fisheries worldwide have either collapsed or are at the risk of collapsing. The Food and Agriculture Organization (FAO) has monitored this decline and found that a significant percentage of marine stocks are fully exploited or overexploited, signaling a dire need for sustainable management of these resources.
Bycatches from non-selective fishing methods such as gillnetting and trawl netting pose additional challenges, catching unwanted species which can account for a substantial portion of total catch. Moreover, pollution, loss of habitats, and various forms of environmental degradation are exacerbating the decline in fish populations. The outcome of this overharvesting is not just ecological but has dramatic socio-economic impacts on local communities reliant on fishing for livelihood and sustenance.