Aquaculture - A sustainable food source

Shells on the shore of Clew Bay © Daria Blackwell

As cruisers, we are more attuned to food sources than most. We fish responsibly taking only what we need for our own sustenance at sea. But wild fish stocks are under pressure. Can aquaculture help?

Most cruisers generally spend more time connected to land than on the sea. When on land and when provisioning for ocean crossings, do we choose our food sources responsibly? Negative publicity about various protein sources is making it difficult to reach informed decisions about how to purchase food supplies when needed. What impact do the cattle, chickens or fish farms have on our environment? What happens to rainforests when agriculture expands to feed vegetarians? What impact does monoculture have on our environment overall? What is good for you and for the earth at the same time?

We can't tackle all of it, but given our connection to the oceans, we are going to make a case for aquaculture as one of the earth's most sustainable food sources and the role of aquaculture in restoring global fish stocks.

Environmental factors

As someone who had grown up along a stretch of Ireland's most pristine ocean, sailing and fishing were a natural for Alex. Many hours were spent learning to tie knots, experimenting with different gear, and finding the choice spots. He learned about the tides, the currents, the moon cycles, the water temperatures, the wind, and coastal contours.

This love for fishing taught him much more than how to catch and fillet a fish. Fishing had taught him about our environment. It was in every way a slow simmer of his curiosities around how marine and terrestrial environments were connected that caused him to pursue a career in marine science.

Alex returned to Ireland with a Masters in Marine Biology and started an oyster (Crassostrea gigas) hatchery. He drove the length and breadth of the land working with locals on how to farm oysters. To then create a local market for oysters, he started teaching chefs how to select and prepare oysters. He even wrote an oyster cookbook.

Then disaster struck. On the one hand, Alex's hatchery suffered a long streak of catastrophic mortalities, which very adversely affected his business. On the other hand, and totally unrelated, the native oyster (Ostrea edulis) fishery, with which he was very involved, suffered a parasitic disease outbreak, which would plague it for decades to come. That taught him about how the most intricate environmental changes could have the most significant impact upon entire marine ecosystems. It showed him how human actions intertwined on land and sea could impact the sustainability of a species.

In the 1990s, finfish aquaculture was established in Clew Bay. It specialized in Atlantic salmon and rainbow trout. Its establishment coincided with a catastrophic collapse of the wild Atlantic salmon populations, long declining as a result of overfishing, obstruction of spawning grounds, pollution, and agricultural runoff. But a connection was made between salmon farms and the decline of native salmon. The farming practices were blamed for the collapse of the wild fish.

Over the years, many questions have been raised about aquaculture practices around the world. Being a rather new way of raising food, it has taken a few years of experience and experimentation to refine the practices applied in fish farming. We are about to make a case for aquaculture as one of the most sustainable food sources available to mankind.

Sustainable aquaculture can help save the ocean's biodiversity while improving your health

Aquatic foods can be farmed or caught wild. They can be sourced from inland freshwaters (lakes, rivers, and wetlands), coastal areas (estuaries and mangroves), marine fisheries, or ocean waters. Recent studies have demonstrated that aquatic foods have more and better-quality nutrients than many terrestrial foods. In fact, Harvard Chan School of Public Health has created an online resource to help people value the nutritional quality of the aquatic foods they eat.

Those of us who have crossed oceans have inevitably come across the giant fishing trawlers and factory ships that are out there hoovering up the fish stocks. Certain pelagic species populations have collapsed, while others are in danger of depletion or even extinction.

The influence of both land- and marine-based human activities have distorted marine ecosystem dynamics and rendered countless species at risk of extinction. Increasingly, marine ecosystems are becoming unnaturally altered, perhaps beyond repair. It's not enough to think about how to save an endangered species. It is now critical to return the balance of entire ecosystems which are intricately interconnected.

Yet, one billion people globally are fed by small scale fisheries and aquaculture, which produce more than half of today's world's fish catch. The massive trawlers that are encroaching on the small-scale fisheries are putting the coastal communities at risk of food deprivation. The United Nations estimates that "Illegal, Unregulated, and Unreported" (IUU) fishing accounts for about 15-30% of global annual catches. Yet the UN has also set a goal of eliminating malnutrition and hunger.

It becomes increasingly difficult to reconcile the need to feed masses of people. This is compounded by the tragedy of fishermen having to dump bycatch overboard - a shameful waste. Aquaculture could provide a solution. Yet, many people have been swayed against aquaculture by misinformation that is being spread by people who are not knowledgeable in these matters. And sadly, what people see on TV and read in the papers becomes accepted without backup scientific evidence.

The Blackwells have looked into matters from a scientific point of view, Alex as a fisheries biologist with a Master's degree in Marine Biology and Daria as a former biochemist. They happen to live in a region where sustainable fish farming is a booming industry. Oysters, mussels, salmon, and other species have been farmed here responsibly for a long time. Alex serves on the Board of the Clew Bay Oyster Cooperative, was once an oyster farmer, and knows many of the farmers personally.

The Clare Island Sea Farm in Clew Bay is owned by Norwegian seafood company MOWI, the world's largest Atlantic salmon farmer and one of the world's leading seafood companies, ranked as number one on both market capitalisation and sustainability. They produce their own environmentally certified feed and have a verifiable value chain from roe to plate. MOWI holds both the 2018 and 2019 awards for the world's most sustainable protein producer.

There are oyster farms and mussel farms throughout Clew Bay. These cultivate the cupped oyster, Crassostrea gigas, which was originally brought in from Japan and has been bred in hatcheries around Europe starting in 1966. Gigas oysters are a fast-growing species that is also tolerant of a relatively wide range of salinity and temperature. They grow well in mesh bags on trestles and are favoured by farmers.

Overarching all these activities in Clew Bay is the Oyster Co-op, which has been promoting aquaculture as a sustainable source of employment since the late 1970s. All aquaculture operators are also members of the Co-op.

There are a few key points we have taken away that undoubtedly helped shape our opinions on aquaculture's place as a sustainable protein producer. It's our way of saying eat more aquatic foods farmed responsibly to help save the oceans and the planet.

Click here to learn more.

This article has been provided by the courtesy of Ocean Cruising Club.