Aquaculture, Pisciculture, and the Future of Farmed Fish

The world has a massive appetite for all types of aquatic fish species ranging from tuna and tilapia to mollusks and seaweed and everything in between. In 2009 total world production of fish and fish products was 140 million tons. And this volume of fish products we consume is growing at a rapid pace.

Latest numbers show that 3 billion people rely on fish as a vital and fundamental protein source in their diet, and the demand is not going to subside anytime soon. Most of this demand is now being addressed by an aquaculture industry that in 2009 was growing at 7% a year.

Aquaculture came along as a relatively new way to farm all sorts of aquatic species we eat on a daily basis while keeping up with the massive demand. It’s nothing new as it was used in ancient China and Central America to feed growing empires, but never on the massive scale we see today. Our traditional fisheries  sustained us for eons, but the human population grew to outpace the amount we could take in from the wild.

Currently 50% of the seafood we consume comes from aquaculture operations. The UN Food and Agriculture Organization ( FAO) stated that we need to increase our yearly output from aquaculture by 40 million tons by 2030 just to meet current consumption rates.

This increase will come mainly from China which produces a whopping 67% of farmed fish in the world compared with a very paltry 4.5% for all of the Americas.

China, Vietnam, and Thailand have been leaders in the aquaculture industry for years now because of a traditional diet heavy in fish and a population that grew exponentially in the past 50 years.

The US Aquaculture industry brought in $1.2 Billion in revenue in 2010 and this number has only increased since then. But the Chinese industry is expected to hit $100 billion in the next 4 years.

But all this production comes at a hefty environmental cost. The biggest issue with farmed fish, let’s take salmon as an example, is that wild fish have to be caught and feed to the salmon. These wild caught fish include fisheries that are already stressed by over fishing like sardines and anchovies. This in turn is upsetting the balance in the ecosystem for the wild fish populations that we are already striving to save through conservation and regulations.

The next biggest issue concerning aquaculture is that of the waste that collects from these growing areas. Large pens and nets are kept in either deeper waters or coastal waters, this is popular in both Norway and Chile, and these pens are filled with fish to the bursting point. The reason these farms are usually off the coast is for easy access to shipping, feed, and maintenance.

But this practice leads to problems with the natural flow of the water being diverted and in turn not being able to naturally handle the waste by product of the operation. Eventually the entire surrounding area can become inundated with fish waste, overwhelming it’s natural capacity to dispel it.

This has led to to the use of chemicals in the water to inhibit growth of certain bacteria, and antibiotics being feed to the fish to prevent diseases which are rampant in these cramped dirty spaces. Eventually “dead zones” can form where the influx of waste leads to a bacteria and algae  overgrowth which can create these zones that can no longer support a healthy living ecosystem.

Furthermore if the fish are being farmed inland the water is being taken from somewhere, and when the water is so choked with waste that it cannot be used anymore, it is simply dumped back into its original source causing a bevy of environmental issues. Farms inland also accumulate massive amounts of waste which can seep into groundwater and pollute local ecosystems like rivers and streams.

The US is absolutely guilty of using these methods, but there is also a large stringent process before the fish reach market that make it safe for consumption. Some Asian countries, China in particular, are increasing aquaculture production to keep up with soaring demand but at soaring environmental costs. The regulations in China are also different and many times not nearly as strict as they need to be, leading to recent trends of a distrust in the western world of Chinese farmed fish.

Despite all this the future for Aquaculture is bright and there are many researchers, private companies, governmental organizations, and intergovernmental organizations working on the biggest issues facing this industry. Producing more sustainable food, utilizing waste streams, and overall advancing and updating the methods being used.

Researcher Yoni Zohar at the Institute of Marine and Environmental Technology in Baltimore is currently working on many of these issues. In Yoni’s lab the entire process of raising fish in coastal areas is transferred into a completely indoor environment. Factors including water quality, temperature, water flow, and waste disposal are tightly controlled. The water isn’t taken from the Ocean at all and through advanced methods the water used is an exact mimic of the ideal water conditions that the fish would have in the wild.

This controlled environment allows waste to be properly filtered and removed, eliminates the use of antibiotics, and fish that are very picky about water conditions ( the gilt-head seabream for example) spawn and grow as they would naturally.

These technologies are being successfully used but only in controlled lab settings, it has yet to be scaled to a commercially viable level and therefore will only remain in the lab for the near future.

In a more practical application of these new technologies, a company called Cooke Aquaculture in New Brunswick, Canada is using experimental methods to reduce waste in their coastal pens. Guided by a local marine biologist, the fish waste from pens filled with Salmon and Sablefish, is reused further down the food chain, mimicking natural processes of the local food webs.

First off creatures like mollusks, who are experts at filtering water, take up the small organic particles and waste floating away from the pens. The mollusks are utilized like a natural filtration ring surrounding the pens. Further away from this center are other mollusks like abalone that feed and filter finer waste and particles. And even further away are species of seaweed that use the effluent waste leftover to grow.

Utilizing natural food webs is not an entirely new idea, but something that has the potential to add multiple streams of revenue for a business and decrease waste streams from their product.

One simple method that is also gaining traction around the world for raising fish is Aquaponics. Simply put aquaponics introduces plants grown in a closed-loop system to an aquaculture system that allows bacteria and fish waste to be utilized by the plants roots. The plants, in tandem with beneficial bacteria, filter the water, utilize the waste from the fish, and add another sustainable revenue stream to the system.

Aquaponics has a huge part to play in the advancement of clean fish farming. It addresses the biggest problems of fish farming; unmoved waste, heavily contaminated water, and use of antibiotics. These issues can be ameliorated or entirely absent from a fish farmed aquaponically making it a system of farming with huge future potential.

These aquaponics operations currently are just using fresh water, we’ll see what the future holds for saltwater culture, and the most popular fish for these systems is Tilapia. Tilapia is a star of aquaculture for a few reasons. The most important being that it can be feed an entirely vegetarian diet consisting of already commonly farmed crops, it grows rapidly, and it doesn’t mind living in very dense populations.

The demand for Tilapia is outpacing production and the industry is expecting growth to continually rise in coming years. Outside of Tilapia there are a myriad of species that can be used in Aquaponics and the potential and usefulness of this system in aquaculture is yet to be fully realized on a large commercial scale.

The aquaculture industry is quickly becoming essential to feeding the world’s growing population and understanding the role that it plays in our worldwide food system has become a necessity for our collective future.

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