In depth read,  Versus

Wild Fishing vs Aquaculture

Which one is more sustainable?

More of us are starting to re-evaluate our diet in order to do our bit for the environment. Especially when it comes to our meat and protein sources.  

Meat used to be an expensive option and not attainable for many social demographics. As we got richer however, meat became accessible to more people.

Meat has become common place on our dinner plates

It eventually became commonplace on our plates. Instead of it being used in celebratory meals, it started to make an appearance in our everyday diet. Now we see people stepping away from processed meat in search for sustainable and environmentally friendly alternatives. 

Fish as an alternative meat to beef, pork and poultry, has come up a few times in conversations. They have a significantly smaller carbon footprint than typical farmed animals do and they need far fewer resources.  

An example of low impact beef would be sustainably farmed beef from a local farmer

Fishing is not a new concept…

…it is an ancient practice that humanity has performed for nearly 40,000 years1. Like farming, it is also a way of life for many people. Entwined in many cultures and rituals. It’s a dangerous job. It takes a lot of dedication, education and passion. A lot of respect is due to people who choose this vocation.

But there are also abusers of the system. Unregulated trawlers that overexploit fisheries, illegal fish i.e. fishing over the regulated catch quota.

If the amount of wild fish we catch exceeds the rate at which fish can reproduce and replenish then populations will decline over time2. Overexploiting would mean we exceed that rate and fish species can become endangered.

Fish are part of an important ecosystem…

 …with other animals such as seabirds and other fish relying on them for food. If one part of the system goes, then the whole system could collapse. Popular fish like Atlantic Salmon are on the endangered species list. This is due to extensive fishing and reaching below the minimum biomass levels. Consequently, this has led to the death of many species seabirds due to starvation including Atlantic Puffins3 .

Picture of a Puffin on the Atlantic coast.
Image by Kristal Hayes

A fishery…

…is an area where an associated fish is harvested for commercial use rather than a specific organisation e.g. Atlantic salmon off the west coast of Norway and Ireland would be major fisheries.

Wild fish are caught in a number of ways from, the rod and line that may be the typical picture associated with fishing

Angler on the north sea.
Image by S. Hermann & F. Richter

To trawlers with massive nets that have the capacity to scoop up tonnes of fish at a time. There a number of mechanisms used to commercially catch wild fish on trawlers and these methods would depend on the type of fish being fished.   

One of the most damaging of all commercial trawlers is a drift net. This practice uses kilometres in length of nets left to drift with the current to catch any fish available, although this method was banned in EU waters except for the Baltic sea. This method would mean a large number of unwanted marine lives would be caught in the nets as well as the wanted fish and is an unsustainable way of fishing, hence the ban. 

Fishing net associated with commercial fishing.
Image by Richard Revel


…could be an answer to help ease pressure off declining fisheries. Aquafarming is a process by which certain aquatic plants and animals are cultivated (or bred) in controlled conditions. It means that a certain species of fish can be grown without the need of physically fishing for them and could help with taking the pressure off wild fisheries and in the repopulation of depleted fisheries.  

Wild fisheries are under pressure form extensive farming.
Image by joakant

The farming of fish, seaweed and crustaceans or Aquaculture is the fastest growing food sector in the world 4 increasing 50-fold from the 1960’s to 20155. The difference between wild fishing and farmed fish is the same as hunting wild land animals and raising livestock. 

With global population on the rise it is expected to reach 9 billion people by the year 2050; if climate change hasn’t made a substantial impact on that figure. That means we will have a lot more mouths to feed with the same amount of resources, and we’re not doing such a good job at that already. 

So, aquaculture seems like a good bet to try and tackle this problem, right?   

Well, what is new, can be scary and fish farming has been met with levels of pessimism and resistance.

In its experimental stages, fish farming proved to be damaging to the environment with pollution from the effluent of farmed fish leaking into clean open waters, transfer of viruses and disease to wild fish population; this mostly happens in floating pens, and the use of chemicals.

With time, research and better practices, it has come and leaps and bounds, and is now producing more fish than wild fisheries.  

What’s the process in farming fish?

Typically, fish eggs are grown in hatcheries or wild juvenile fish are caught then moved to bigger pens where they are monitored and kept until harvest. The pens can be in floating open water pens or offshore in tanks.

Open water pen for fish farming.
Image by Paul A. Sounders/Getty Images

Feeding the fish…

…is the highest cost for aquafarmers. The fish are fed pellets of a particular fish meal characterised for the individual species’ needs.

Many of the fish that are grown in the tanks are Carnivorous fish. They require large amounts of fish feed for nutrition, mostly consisting of smaller fish.

Carnivorous fish eat smaller fish like sardines (pictured above).

Other food sources are added to the fish meal including soy and maize. These are all unsustainable feed ingredients and are unnatural to marine life as soy is indigestible to fish. There has been further research to reduce the anti-nutritional factors6 and make it more digestible for the fish. This still it seems to me an unnatural thing to feed the fish and would take up land use to grow the soy. 

With further research, new sustainable fish meal has been developed using natural ingredients such as microbes, micro algae, seaweed and insects. Another research paper has suggested to feed the fish with by-products from the seafood industry7. Unused meat from fish that have been filleted and discarded. {maybe picture of fish tails ? If not too yuck} 

Is aquafarming sustainable?

Just like everything, it needs to be managed well with proper legislation and regulations. The aim for aquaculture is to take the pressure off of fisheries and not just to develop a whole new bigger market. We can feed a lot of people very efficiently and sustainably with farmed fish. Some of these farms mimic nature and create a symbiosis with a variety of seaweed, crustaceans and fish to try and grow healthy fish with less pollutants and effluents.  This is called Integrated multi-tropic aquaculture system8 .

A salmon farm in Norway has topped the Farm Animal Investment Risk and Return for sustainability 2 years in a row. This shows the huge potential that is there and how sustainable it can be, if done right.  The most important person in all this is you, the consumer. If you start caring where your fish comes from, who supplies it, how it’s caught and reared, then producers and companies will be forced to react your wants. Supply and demand.  

If you are still unsure in what fish you should avoid and which is okay to eat, here’s an excellent link to a list of fish and a sustainable rating beside each one-> . Always talk to your fish monger about where they source their fish and how sustainable it is. Maybe even do some further research yourself to make sure. 

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