Aquaculture accounts for about a third of the total weight of fish and related products, and is expected to rise, whereas traditional fishing weights may fall, he said in the January issue of BioScience. Diana acknowledges the well-publicized problems with fish farming: The escape of farmed species that then become invasive or infect wild species with diseases. The pollution of local waters by fish-farm effluent. Changes in land use, especially associated with shrimp farms.