We all know we need to eat healthy- even if we don’t always do it- but fewer people are aware that they need to eat food that also has a healthy diet. If our food is sick, we can get sick too; we eat what they eat. Luckily, there are people who look out for that. Aquaculturists are concerned with healthy foods for their fish and shellfish. Fish bodies also need essential nutrients and their food source is something every seafood lover should be concerned about. We already know that with wild-caught fish we need to be informed about mercury levels and any other possible contaminants. Farm fish have slightly different concerns when it comes to their food. Not only can it be unhealthy, but the amount that farm fish need to eat can have massive and unsustainable reactions down the food chain.
When fish are farmed, they are often fed fishmeal and fish oil. Fishmeal is a mixed product created from forage fish, the small fish we know as herring, anchovies, sardines and many others. Larger carnivorous fish such as tuna or salmon need to eat several times their body weight in fishmeal to produce a profitable amount of meat. This can often lead to immense consumption rates of fishmeal, which is very expensive for the aquaculture farm and puts a high fishing pressure on wild-caught forage fish. There has been a recent push in aquaculture to find cheaper and ‘greener’ alternatives to fishmeal that provide each fish with the essential nutrients they need while still producing healthy seafood for human consumption. Whether or not they find one will have a massive impact on the entire seafood industry.
The demands of aquaculture
Aquaculture is one of the fastest growing food industries; it already supplies half of the world’s consumption of seafood. We’ve mentioned before that aquaculture could be the savior for seafood lovers by taking fishing pressure off of wild populations. It allows us to enjoy those species whose commercial wild fisheries have collapsed – like the abalone – while the wild population rebuilds itself. But in reality some fish farms only shift the pressure from larger fish to smaller fish. Forage fish destined for fishmeal are wild-caught in countries such as Peru and Chile in “reduction” fisheries.
The amount of fishmeal and fish oil we dedicate to aquaculture has expanded exponentially over the last decade to meet the growing demand and will only increase more unless alternatives are found. Researchers and the aquaculture industry have fervently been searching for fishmeal substitutes that are both healthy for the fish and affordable. We are seeing great promise with some of these substitutes, but there is still much work to be done.
There is a land-based example we can use. Fishmeal and fish oil have also been used as feed for swine and poultry farms for decades. These industries have already developed alternative feeds that are now more commonly used and based on grains, corn, and soybean. Terrestrial animals are naturally evolved herbivores and thus well suited for a vegetarian diet. Aquaculture is a different story. Fish do not adapt as well to an entirely vegetarian diet, especially with terrestrial crops, and tend to suffer from disease and low growth rates.
Forage fish do have an advantage. They reproduce quickly and are very resilient to fishing pressures. Many of the reduction fisheries are managed well and successfully regulated. With quota and catch limit systems in place, the use of forage fish as fishmeal could be sustainable. But the aquaculture industry continues to grow every year and it has become a very hungry mouth to feed. With the aquaculture boom over the last 20 years, there are many concerns that the reduction fisheries are depleting an essential food source for countless animals. It has the potential to collapse innumerable ocean ecosystems if not managed properly.
Aquaculture farms and environmentalists are motivated to find fishmeal alternatives. Fishmeal prices have risen dramatically in the last two decades from $750/ton 20 years ago to more than $2,100/ton last year. 60-65% of the operating costs of a fish farm is feed. With these costs, farming fish starts to become a very expensive venture.
But research is in favor of the aquaculture industry – where diets were once formulated to contain 40% or more of fishmeal, they are expected to drop to as little as 10% worldwide by 2020 with the addition of healthy alternatives. This means that fish farms will need to buy less pure fishmeal and more cost-effective substitutes.
Research is not just limited to looking for fishmeal substitutes. Scientists are examining how farmed fish make use of feed, different formulas, timing dietary needs with developmental stages and other strategies. They are attempting to analyze feed use efficiency as a whole in order to calculate the perfect diet for different species.
Farmed fish – just like the human body – need a specific mix of proteins, nutrients, vitamins and minerals to thrive. Fishmeal is already a natural and well-balanced source of high-quality protein, containing the perfect ingredients for optimal growth and health for both types of fish. It’s the same reason that seafood is so good for humans!
Interestingly, fish tend to be picky eaters just like humans. Imagine being stuck in a tank with food you won’t touch. Even if the food is chock full of all the essential nutrients you could ever need, it isn’t worth much if you won’t eat it. The biggest challenges to developing alternatives are finding feed that fish will eat, supplying the nutrients that fish need to grow, and making alternative ingredients that are commercially plausible.
Research is now providing us with solutions to achieving the same balance without sourcing forage fish. Alternatives that are currently being explored:
- Leftover trimmings – This solution is simple, effective, and reduces waste. Trimmings consists of the leftover bits that are not used in fillets or steaks in the fish processing industry. These have all the nutritional benefits of fishmeal and would normally go to waste. They are now contributing significantly as raw materials for fishmeal production.
- Insects and worms – The black soldier fly has proven to be a “greener” and cheaper alternative to fishmeal. With a high level of protein (60-65%) and a great digestibility for salmon in studies (82.1%) this little fly has become an area of strong interest for several large feed firms. The flies are raised on waste food or discarded scraps before being processed into a protein meal, so there is little to no environmental damage.
- A plant-based diet – Soybeans, barley, rice, wheat gluten and many others are already in use. But these often don’t have all the essential nutrients and must be mixed with other feeds. Soybean has been known to cause enteritis in fish. An interesting side effect of a plant-based diet is a change in the color of the fish meat. If consumers are used to buying red trout fillets, they might find it a problem to now buy a yellow fillet, even if there is no difference in taste.
- Seaweed – Algae has immense potential to become a viable alternative. Fast-growing and packed with nutrients, algae is quickly becoming a strong area of interest for the aquaculture industry. One of the main concerns over fishmeal alternatives is finding those that contain omega-3s. Fish do not produce omega-3s themselves, they accumulate it in the food they eat. In fact, omega-3s originate with the many types of algae that are at the bottom of the food chain. This is where algae could be amazing – they have the potential to replace fish oils as well as fishmeal in aquaculture use. Studies on trout and white seabass have been extremely promising, but no algae alternatives have been commercially developed just yet.
It is interesting to note that some aquaculture farms do not need to search for fishmeal alternatives. Shellfish such as oysters, abalone and clams are filter feedings and consume plankton. That means all farmers have to ensure is that their farms have a steady flow of water from the ocean and their shellfish will feed themselves!
Support sustainable seafood farming
As one of the fastest-growing food industries in the world, aquaculture is rising quickly to meet the demand of the world’s population of seafood consumers. The industry must learn and adapt quickly if it is to provide safe, healthy, profitable seafood that has little impact on the environment. Support sustainable aquaculture by ordering your farmed fish from Pucci Foods, a distributor that is committed to working with partners who practice sustainable seafood farming.