What environmental issue is commonly associated with the spread of aquaculture?

The spread of aquaculture is commonly associated with the environmental issue of the spread of invasive species. When fish or shellfish are introduced into non-native environments for farming purposes, there can be unintended consequences. These non-native species may compete with local species for resources, alter food webs, and disrupt the local ecosystem.

In aquaculture, species that are fast-growing and commercially desirable are often chosen for farming. When these species escape into natural habitats—whether through accidents, flooding, or intentional release—they may proliferate and outcompete native species for food and habitat. This can lead to genetic dilution of wild populations and a decrease in biodiversity, negatively affecting the ecological balance of the area.

The other options do not align as closely with the environmental impacts typically associated with aquaculture. Fish farming capabilities may not be reduced in general; rather, they can be enhanced. The reduction of local fisheries can be a consequence, but it is not as directly tied to the operational aspects of aquaculture itself as the spread of invasive species. Lastly, the increased fish variety refers more to aquaculture’s potential benefits and does not typically represent an environmental issue.