Shifting to Novel Feed Ingredients in Aquaculture Can Deliver Key Sustainability Benefits: Prof. Ling Cao

A recent study in Nature Food highlighted the need for alternative ingredients to meet the growing demand for aquafeed. CFI asked the study's lead author, Prof. Ling Cao, Nanqiang Distinguished Professor, Xiamen University, about the study’s findings, its implications, and the challenges and opportunities she anticipates for using novel feed ingredients in aquaculture. 

Prof. Ling Cao is currently a full professor in the College of Ocean and Earth Sciences at Xiamen University. She earned her PhD in Aquatic Science from the University of Michigan, Ann Arbor, and later advanced her research endeavours as a research scientist at Stanford University. With her roots in a family-owned fish farm in China and training as both an agronomist and environmental scientist, Ling has strategically positioned her research at the crossroads of sustainable aquaculture management and marine conservation. 

How would you describe your current research focus, and what led you to this point in your career?

I focus on the sustainability assessment of blue-food systems, especially aquaculture, looking at how production can grow while supporting ecosystems and communities. 

I grew up on a family fish farm, which gave me a practical grounding. I later spent many years at Stanford working on ways to align aquaculture, fisheries, and marine conservation. I also serve as a volunteer judge for the global F3 (Future Feed for Fish) challenge, which keeps me closely engaged with innovations in sustainable feeds.

You recently led a publication in Nature Food on the instability of forage fishery supplies under various climate and management scenarios. What do these findings mean for the future availability and sustainability of aquafeed ingredients?

Our study indicates that, under plausible climate and management conditions, a ~20% shortfall in fishmeal and fish oil could occur. In such a case, fed aquaculture, especially high-value species, could face sizeable output losses (in the order of 30–70%), translating into a 15–35% reduction in retail seafood availability given aquaculture’s share of supply. 

The implication is straightforward risk management; treat marine ingredients as strategic, finite inputs and proactively diversify with credible alternatives to stabilise supply, costs, and long-term sustainability.

What has been the most interesting or exciting finding so far in your work on novel feeds for aquaculture species?

The most exciting finding is that well-designed diets using a combination of alternative ingredients can match, and in some cases outperform, fishmeal/fish oil diets. For several species and life stages, these formulations meet core nutritional targets with little to no performance penalty, and sometimes yield better growth, health, or fillet quality.

What sustainability benefits do you anticipate from shifting to novel feed ingredients in aquaculture?

Shifting to novel feed ingredients in aquaculture can deliver several important sustainability benefits. Most notably, it can reduce pressure on wild forage fisheries, helping to protect marine ecosystems while improving the sector’s resilience to climate and market shocks. Novel ingredients also enable more circular production systems by valorising by-products, and, when designed well, can significantly lower land use, water consumption, and greenhouse gas emissions. In addition, these ingredients support greater traceability and more reliable supply planning, as many can be produced on a contract basis year-round.

What are the biggest barriers to integrating novel feed ingredients in aquaculture?

At early stages of commercialisation, high costs and price volatility can limit uptake. There are also challenges around supply certainty, including reliable volumes, logistics, and consistent quality. From a technical and market perspective, ingredients must be nutritionally tailored to specific species and life stages, while farmer familiarity and retailer acceptance take time to build. In addition, a lack of regulatory clarity and harmonised approval processes across markets can slow adoption.

What trade-offs or unintended consequences are you concerned about in the switch to novel feed ingredients for aquaculture?

The important trade-offs and unintended consequences include potential challenges related to nutrient bioavailability, such as achieving the optimal amino acid balance, confirming adequate EPA and DHA levels, and ensuring palatability for target species. There is also a risk of environmental burden shifting across the life cycle, for example, through increased energy use in fermentation processes or land use associated with crop-based inputs. Finally, an over-reliance on any single new ingredient could create a different supply bottleneck, undermining the resilience gains these innovations aim to deliver.

What do you think are currently the most pressing, unanswered questions related to novel feed ingredients? 

Some of the most pressing unanswered questions about novel feed ingredients concern how they can be optimally combined and deployed at scale. In particular, there is a need to identify the right blends and precision nutrition strategies that minimise costs while still meeting EPA and DHA requirements. At the same time, the sector lacks robust, comparable life-cycle assessments and clear standards to substantiate and align claims for ‘sustainable feed,’ making this a critical area for further work.

In what ways can industry, academia, and policy better coordinate to accelerate the development and deployment of novel feed solutions?

Key stakeholders should form a coordinated alliance, e.g., an F3 (Future Fish Feed) Innovation Alliance, to co-host/co-sponsor F3 Challenges that spur innovation, convene recurring F3 meetings to share data and best practices, and jointly develop open formulations and species-specific quality specifications. 

They should establish joint industry–academia pilot pipelines from lab to commercial scale with shared protocols and metrics. Finally, regulators and industry should create time-bounded, science-based approval pathways and clear labelling standards for novel ingredients.

What research project are you currently most excited about? 

Currently, I’m most excited about the F3 Fish Farm Challenge, which incentivises fish farms to adopt alternative, innovative feeds at scale and succeed both commercially and technically.