As we continue to empty our oceans of fish, many people believe aquaculture is the solution. It has the potential to continue providing the world with seafood, without depleting our oceans any further. It’s a great idea, but it’s not that simple. Aside from disease and antibiotic issues that arise in often overcrowded fish farms, there’s also the issue of feeding farm-raised fish.
For many species, the fishmeal used to feed them is made from wild-caught fish. So, we’re not actually lessening our impact on the ocean, we’re just switching from depleting one species to another. But, a new study led by Stanford University offers a sustainable alternative: make fishmeal from the waste products of seafood processing plants.
Contributing to one-third of the global supply, China is the world’s leading producer, consumer, and processor of fish. Production in the country has tripled in just the last 20 years and three-quarters of that seafood comes from fish farms. The impact these farms have on wild species is huge. The waste from Chinese seafood processing plants can be 30 to 70 percent of the incoming volume of fish. Normally, it’s just discarded, but by using it to feed farmed fish instead, Chinese fish farmers could replace between half and two-thirds of the volume of fishmeal they currently use.
There are two issues with this solution that need to be dealt with: quality and food safety. The waste produced by processing plants is lower in protein than wild-caught fish, but this could be easily solved by adding plant-based protein (like algae) to the fishmeal. As for safety, there is concern that waste could transmit diseases. The researchers note that this could be address with the help of strict regulations and additional research on safety risks.
“This is a critical juncture for China,” lead author Ling Cao, a postdoctoral scholar at the Center on Food Security and the Environment, said in a news release. “If the country makes proactive reforms to its aquaculture sector, like using fish-processing wastes instead of wild fish, and generally reducing the amount of fishmeal in aquafeeds, it can greatly improve the sustainability of the industry. If not, the consequences for the entire global seafood supply chain are going to be really serious.”
To learn more:
- Read the news release from Stanford University: Stanford-led study says China’s aquaculture sector can tip the balance in world fish supplies.
- Read the news release from Leiden University: A sustainable approach for the world’s fish supply.
- Read the abstract in Science: China’s aquaculture and the world’s wild fisheries.
Copyright © 2015 by Marine Science Today, a publication of Marine Science Today LLC.