By Jennie Korus
The planet’s current population (7.8 billion) is expected to grow more than 25 percent over the next 30 years to an estimated 9.8 billion people. So we need to start thinking today about how we’re going to feed ourselves in a sustainable manner.
Oceans will play a key role in this effort, especially through aquaculture, which now accounts for more than 50 percent of the seafood produced worldwide.
“We must plant the sea and herd its animals … using the sea as farmers instead of hunters,” famed underwater explorer Jacques Cousteau said in 1971. “That is what civilization is all about – farming replacing hunting.”
Nearly half a century later, his advice seems even more urgent. Today the percentage of overfished and fully fished stocks are increasing while the number of available, non-exploited stocks is going down. That makes aquaculture even more vital as the planet’s population surges toward 10 billion.
In order to meet the demand for sustainable protein sources for all those people, aquaculture production will need to increase. Efficient farming practices are going to be crucial – and smart, data-driven aquaculture is the way to make that happen.
During the 20th century, humans put an immense amount of effort into improving agricultural practices. Now it’s time to do the same with aquaculture and develop sustainable practices that relieve the intense pressure we place upon our oceans.
Needless to say, the habitat in which fish live is vastly different from the environment agricultural livestock experience. That environment is one familiar to us – it’s the one we experience every day. As a coworker once put it: “If we’re hot, the cows probably are too!” That intrinsic knowledge has made it much easier for us to care for farm animals.
When farming fish in an environment that is largely foreign to us, how can we ensure the welfare of the fish while still maximizing production rates to meet the increasing demand? The answer lies in data.
Out with the Old
Until recently, data collection methods for salmon farming were fairly primitive. In order to assess the welfare of the fish and determine appropriate feeding times, workers needed to measure dissolved oxygen levels on the farm. (Fish need dissolved oxygen to breathe, so it’s the key factor to ensuring fish welfare and survival.)
To measure dissolved oxygen on a fish farm, workers would typically use a single handheld instrument to take measurements from a single location multiple times per day. This led to reactive farming practices and offered no insight into conditions between measurements.
Looking at the variability of dissolved oxygen levels on a single farm, we know conditions can change drastically over the course of a day – not only across a farm, but within individual fish pens as well. Each cage experiences its own microclimate depending on biomass, speed and direction of currents, dissolved oxygen levels and other factors.
In order to provide the best care for farmed fish, it is critical to monitor all pens continuously – and then manage each cage individually to improve care and minimize food waste.
In with the New
With the advances in technology – such as the advanced aquaculture intelligence solutions being developed by Innovasea – it is now possible to outfit an entire farm with dissolved oxygen sensors that collect data 24/7 and give users data access from anywhere. This has revolutionized the way farms operate and enables farmers to make educated, data-driven decisions in real time. It also enables them to observe trends over time and understand what conditions might trigger low or high dissolved oxygen events.
As technology advances, machine learning and advanced algorithms will help software predict future conditions. If farmers can anticipate low oxygen conditions, they can take preventative steps to aerate or oxygenate the water accordingly.
Feeding windows will rely solely on the hunger levels of the fish and not on environmental constraints. If farmers can maximize these feeding windows, they can complete grow-out cycles in the shortest amount of time, which can have powerful cost benefits.
A shorter grow-out cycle means less feed used. And because feed is the single greatest cost variable, this can have significant impacts on productions costs. A shorter grow-out cycle will also limit exposure to sea lice and reduce the fallowing period between production cycles.
Monitoring Other Factors
Dissolved oxygen may be the most important parameter to measure for fish welfare and feeding, but there are others to consider, including:
- Currents, which can bring in fresh, oxygenated water throughout the farm.
- Winds, which help create waves that churn the water and act as a natural aeration system.
- Water temperature and salinity, which determine the amount of oxygen the water can hold.
- Chlorophyll and blue-green algae, which can indicate high phytoplankton concentrations in the water. Phytoplankton can deplete oxygen levels and even produce toxins, both of which can quickly kill fish across an entire farm.
The ocean is a complex environment that is surprisingly foreign to us despite our reliance on it. The only way we can begin to understand dynamic subsea conditions is with advanced technology and sensors that allow for continuous measurements.
As the world’s population grows and society develops practices to sustain this growth, we need to continue to invest in smarter farming practices. Not only will this help solve the major global issue of feeding an exponentially growing population, but it will also relieve the pressure on our oceans.
About the Author
Jennie Korus is an aquaculture scientist at Innovasea and part of the Aquaculture Intelligence team in Halifax, Nova Scotia. Jennie holds an honors degree in Marine Biology and Statistics from Dalhousie University and an advanced diploma in Ocean Technology from NSCC. She is currently working towards her master’s in Oceanography at Dalhousie with a focus on fish stress and environmental monitoring on aquaculture farms.