Environmentally Friendly Aquaculture, Creating a Cleaner and Safer Planet

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By Dr Bill McGraw

25 g shrimp harvest 23 August 2020

One complaint I regularly hear about aquaculture is that it can negatively impact the environment by the direct destruction of valuable estuarine habit, like mangroves, to make an area for pond construction. In addition to this, aquaculture ponds can discharge nutrient-rich effluents in coastal environments which often causes oxygen depletion, resulting in killing local fauna, as well as causing intense algal blooms and settleable solids which can blanket the bottom of estuaries causing mortalities of sedentary organisms like oysters and clams. 

Another problem with corporate aquaculture is that viruses, antibiotic resistant bacteria and parasites are released into the environment during effluent discharge, which can infect local marine life. A classic example of this, which can be readily found on the internet, is sea lice which attach to the skin of salmon grown in aquaculture pens, which basically suck the life out of them. The sea lice then reproduce and infect wild fish that travel through adjacent waterways near the aquaculture cages.

Utilizing closed recirculation systems that are biosecure and don’t exchange water, all of the problems described above can be eliminated. I have spent 25 years working in the field of aquaculture creating algal based systems that don’t release any water and instead recycle and collect all waste so that it can be applied to plants grown in soil. I have determined over the course of 10 years of research that aquaculture waste contains all the essential elements that a plant needs, and includes incredible amounts of phosphorous and nitrogen, eliminating the need for synthetic fertilizers made from fossil fuels and mined from the earth. So these benefits are just awesome for the environment. 

organic tilapia

An added advantage of applying aquaculture waste to plants is that once nutrient deficiencies are eliminated, plants are less vulnerable to pests, cancelling the need for pesticide application. Moreover, the vigorous growth of plants quickly cover available area, reducing light, slowing the growth of weeds. Currently in Panama, the outrageous, long term use of glyphosate has resulted in the proliferation of super weeds that are not only resistant to herbicides, but also grow at a much faster rate and aggressively outcompete valuable plants for nutrients and space. I have experienced this for over a decade while working here in Panama. The weeds here are an absolute nuisance. 

Another environmental benefit of recirculating, zero water exchange systems is that they are small and can be located just about anywhere. I have developed an inexpensive greenhouse structure (3$/m2) that can withstand the 2.5 meters of rain we get here in Panama as well as the intense north and south winds that regularly destroy more common greenhouse structure designs. By locating aquaculture recirculating systems further inland away from sensitive habitat, estuary systems can remain intact and pristine. 

tilapia grown from algal waste

And lastly, another complaint purported by internet health enthusiasts is that a tilapia grown in aquaculture tanks or ponds is bad for you and you should not eat it. This of course is just not true. Fish grown on corn and soybeans are high in omega-6s and low in omega-3s which can create inflammatory conditions in the human body when consumed. It is important to note here that inflammation is the main culprit in the current worldwide viral pandemic which is negatively affecting nearly everyone on the planet. However, fish and shrimp grown in algal rich, zero water exchange systems are naturally high in omega-3s as algae is a healthy and natural superfood. After all, you are what you eat. 

We need to take the time to find food that is good for us or grow our own. My company, Panama Fresh Organic, that is thriving here in Panama, regularly delivers super fresh seafood directly to people within hours of harvest. This is unheard of in Panama as there are no seafood stores, and seafood bought from pick-up trucks that regularly travel around is often of poor quality, sometimes not even on ice. Unfortunately, the availability of fresh and tasty shrimp is non-existent, as all shrimp that are grown here are frozen with preservative added and shipped to Europe, while wild-caught offered for sale requires very close inspection to ensure adequate freshness for safe consumption. Aquaculture can have a positive impact on the environment and provide some great nutrition at the same time. As climate conditions worsen with floods destroying croplands, trade wars causing disruption in the accessibility of seafood and supply chains slowing certain types of food availability, smaller, more local, biosecure, totally contained and fully integrated systems will become more valuable. It is important that we understand the importance of these systems and give them our full support.

peppers grown from waste

This piece was prepared online by Panuruji Kenta, Publisher, SEVENSEAS Media