The processing of fish for human consumption gives rise to byproduct in the form of heads, viscera, frames, skins and others such as tails, fins, scales, mince, blood, etc. The material generated after processing is valuable as a raw material from which fishmeal and fish oil often is produced. It is estimated that roughly a third of fishmeal produced is made from seafood by-product from fish for human consumption. The trend in general is for that proportion to increase as more whole fish are used for direct human consumption, and society becomes more successful at collecting the byproduct material. A large section of by-products that is used to produce fishmeal and fish oil comes from wild capture fish processing for human consumption but an increasing amount comes from the by-products of aquaculture processing. The data from Jackson and Newton (2016) on the use of fisheries byproduct to produce fishmeal indicates that roughly 66% of fishmeal made from by-products originates from wild capture fish and 34% from aquaculture. That report also indicated that as aquaculture grows, there will potentially be even more raw material available for fishmeal and fish oil production.
According to the FAO, world capture fisheries have reached a plateau with some fluctuations after 1988. The levelling off of world capture fisheries is in a big part due to the increasing awareness of the need for sustainable fishing of wild capture fisheries since its production is crucial to the livelihoods, food security and nutrition of billions of people. National governments, international organisations, nongovernmental organisations, agencies and retailers are trying to ensure the sustainability of fishery resources while at the same time working together to create a global awareness of the importance of protecting our fishery resources.
As discussed in more detail in the sustainability section for forage fish, fisheries management generally applies the concept of maximum sustainable yield (MSY) where the objectives are to maintain fishing mortality at or below levels associated with MSY, thereby ensuring continuity of sufficient stock biomass for reproduction and future recruitment of fish into the fishery. The concept is integral to the FAO Code of Conduct for Responsible Fisheries (CCRF) whose principles are used as a reference point in many certification schemes.
Illegal, unreported and unregulated fishing (IUU) damages the whole of the seafood sector and needs to be addressed. The European Commission (EC) has proposed measures that would restrict access to the European Union (EU) market for countries whose fishery products may be identified as IUU. In addition, sanctions are to be applied in the event of any infringements being committed. The use of by-product from raw material that originates from IUU is wholly unacceptable.
Decisions on the status of fishing stocks are often based on advice by national government agencies, as well as marine research organisations such as the International Council for the Exploration of the Sea (ICES) which coordinates and promotes marine research on oceanography, the marine environment and ecosystems, and living marine resources in the North Atlantic Ocean and adjacent seas. ICES functions through committees, expert groups and workshops, and is a network of more than 5,000 scientists, from 690 research institutions in 20 countries. ICES provides information and advice to member countries and international bodies so that they can make informed decisions on the sustainable use of the marine environment and its resources. Generally, total allowable catches (TACs) and quotas for fisheries are decided internationally and nationally by the respective governments based on scientific advice from organisations such as ICES and other independent advisory marine research bodies relevant to each area or country. These mechanisms for fishery management are well recognised and understood, but they are dependent on national government resource for data capture, stock modelling and assessment of quota, implementation of regulations, and enforcement.
In a similar manner as for forage fish, the IFFO Responsible Supply scheme (IFFO RS) allows producers of fishmeal and fish oil from byproduct to demonstrate that the raw materials are responsibly sourced and produced where fisheries that may be the origin of that material are independently approved under the IFFO RS standard. The Marine Stewardship Council (MSC) Fisheries Standard and the FAO CCRF plays an integral part in recognition of compliance to the IFFO RS in the fisheries assessments.
Aquaculture is growing globally and has been listed by the FAO as the fastest growing protein sector for a period of at least the past two decades. Although that rate of growth is declining, it still retains that position, with the most recent estimate by the FAO for the period 2005-2014 at 5.8% per annum (down from the preceding decade at 7.2%). With that continued growth comes the prospect of an increasing supply of byproduct material, and an associated opportunity for some increase in fishmeal and fish oil production from that source. Aquaculture processing tends to be located geographically close to production, and will aim to maximise the value of the product by ensuring it is handled in a way that does not compromise quality. Those are also important criteria for fishmeal and fish oil production, and assuming that the byproduct is equally well-handled, then aquaculture byproduct can also theoretically produce some good quality fishmeal and fish oil.
Aquaculture is an important source of byproduct raw material and it is encouraging that a number of standards are available to ensure responsible aquaculture production. The standards address key areas such as environmental impacts of farming, sourcing of feed ingredients and feed raw material, with many also addressing sustainability issues and creating a framework for differentiating sources of aquatic products in this respect. The FAO provides an overview of current aquaculture standards and certification schemes.
The increasing awareness of the importance of sustainable use of fishery resources has led to significant improvements in fishing stocks. Current systems and programs that are in place along with sustainability certification schemes and increased consumer awareness are already resulting in more fishing stocks being managed within sustainable limits.
The use of byproduct from both capture fisheries and aquaculture aligns with broader policies such as the European Union’s policies on a "Circular Economy", "Blue Bioeconomy" and "Blue Growth", the FAO’s guidance on protein sources for animal feed[11} and several of the UN’s Sustainable Development Goals (SDGs). It therefore is widely recognised as being an important contributor to many goals, and fishmeal producers are effectively providing an important service to humanity with this operation.
 Jackson and Newton, 2016. Project to model the use of fisheries by-products in the production of marine ingredients, with special reference to the omega 3 fatty acids EPA and DHA. Institute of Aquaculture, University of Stirling, UK and IFFO, The Marine Ingredients Organisation.
 FAO 2016, The State of World Fisheries and Aquaculture. Contributing to food security and nutrition for all. Rome. 200 pp.