Final answer:
If world capture fisheries continue to decline, ecosystems will undergo radical changes, larger species may become ecologically insignificant, and human societies, especially those relying on fishing, will suffer economic hardship and loss of food sources. Declining fish stocks might lead to unsustainable fishing operations and increased carbon emissions. A shift towards small-scale, sustainable fisheries could be part of the solution.
Step-by-step explanation:
If world capture fisheries continue to decline, we can expect significant consequences for marine ecosystems as well as human societies. Firstly, there is often a radical restructuring of the marine ecosystem resulting in previously dominant species becoming ecologically insignificant. Such alterations can have unpredictable impacts on other species within the ecosystem. Additionally, local human populations that rely on fishing for employment and income could face dramatic and long-lasting effects. Loss of an inexpensive protein source would increase the cost of living, affecting especially those populations that cannot afford alternative protein sources. The fish taken from fisheries have shifted to smaller species because larger species are being overfished, leading potentially to the loss of aquatic systems as viable food sources.
Moreover, overcapitalized fishing fleets, often supported by government subsidies, are wasting economic resources and have a significant impact on the environment, including a contribution to carbon dioxide emissions. Global declines in fish stocks lead to decreases in the efficiency of these fleets. In some regions, overexploitation threatens food security and endangers marine biodiversity. As larger, more valuable species are depleted, fisheries might collapse, which would have widespread economic repercussions.
Efforts towards sustainability might also include a shift in focus toward small-scale fisheries, which have a closer proximity to the resources they exploit and use more fuel-efficient gears. Such a shift may offer a better chance for sustainable exploitation of marine biodiversity.