Wild fish are losing race to the bottom

Review: Damien Enright

Paul Greenberg’s book poses the question: Given mankind’s depletion of wild fish stocks to dangerous levels, how are we to develop fish farming systems that will make up for the reduced wild fish harvest without further damaging ocean eco systems — and, in fact, allow them to recover so that they survive as an exploitable source for artisan fishermen and as part of our global heritage?

It suggests solutions and holds out hope, mixing palatable science with ‘national geographic’ narrative. It is neither over-specialised nor depressing.

If we have ever asked “which fish can I eat without worrying?” this book will help answer our question. If we digest even half of it, we will be a great deal better educated about the viability of the fish on our local fishmonger’s slab.

As New York Times columnist Greenberg says, terrestrial food production is now reaching its limits and exploiting the oceans is “the final option, the only remaining way for humans to convert the world’s biomass and sun energy into more humans” — an evolutionary course upon which we seem to be inexorably set.

He asks: Can wild fisheries survive at all? Will all the fish we eat in the future be farmed? Is fish farming sustainable? What is its effect on ocean eco-systems as a whole?

In seeking answers, he follows the journey of the four globally most popular and valuable fish — salmon, sea bass, cod and tuna — from the ocean to our plates. His story of each species grips the imagination.

He relates the early Norwegian experiments to create a farming-friendly, fast-breeding, fast-fattening salmon variant and the establishment of salmon farms in Chilean fjords. Worldwide, the vast majority of salmon we see on the fishmonger’s slab is farmed.

One of the very few wild salmon fisheries left is in Alaska — wild salmon are still netted in Irish estuaries — where the US Fish and Game authority allows local people, Eskimos, to net fish only after a counted quota of spawning fish has passed up the rivers. Greenberg visits this remote fishery.

Sea bass, he explains, are inherently unsuitable for cultivation and wasteful of resources, although some farming success has been achieved. Easy-to-handle, vegetarian barramundi are similar in quality and appearance. Labelled as “Asian sea bass they have become a top-end product on supermarkets shelves. ”

Cod were once super-abundant but greedy human harvesting led to the irreversible collapse of that fishery. Cod-farming is hugely problematical.

Mark Kurlansky, author of the definitive book Cod, notes that the farmed codfish do not have the sought-after flakey texture of wild cod because, confined in cages, they have not led “cod lives”.

As a result of the sushi craze, tuna is now the most valuable global species. Greenberg tells us that the netting of young tuna for fattening in cages removes more tuna from the wild than does commercial hunting, while the tuna feed-conversion ratio is 20 kilos of wild fish feed to one kilo of tuna produced. This is a criminal wastage of lesser fish, vital to the food chain. While posh diners in upmarket restaurants eat raw tuna sushi, wild fish species starve.

There is a strong argument for not farming carnivorous fish at all. While industrial-scale supertrawlers are responsible for seriously depleting wild stocks, so also are industrial-scale fish farmers farming the wrong fish.

Clearly, fish farming can make a vital contribution to supporting earth’s burgeoning population. However, such farming must be non-destructive to marine eco-systems. We cannot afford to farm fish that require more feed to produce a pound of edible flesh than do our domestic animals. Caged salmon can require up to six pounds of wild fish to produce one pound of edible flesh, although normally “only” three pounds of wild fish are required, and seaweeds and soy may increasingly form the basis for salmon diets. Also, there is convincing evidence that escaped farmed variants “negatively affect wild strains, displacing self-sustaining wild fish with a domesticated race that is not capable of surviving without human support.” Farmed striped bass, however, are sterile hybrids and cannot breed with wild bass.

Why, Greenberg asks, do we attempt to tame “posh” species that take such a toll on the oceans’ eco-systems when there are fish like the excellent Asian panga and African tilapia that succeed in industrial processes, eat primarily vegetarian feed and have no interaction with, and pose no danger to, ocean fish?

Yes, growing food for vegetarian fish can lead to forest clearance but the return per acre from fish is far higher than from domestic animals, so fewer trees are felled.

Instead of attempting to tame new fish species, we should choose a handful that we know are eco-friendly and can stand up to industrial-sized husbandry.

If we want variety in our fish diet — mackerel, monk or megrim — we will get it from small-scale, sustainable wild fisheries.

Greenberg notes that “with wild fish we have chosen, time after time, to ignore the fundamental laws nature places on ecosystems and have consistently removed more fish than can be replaced by natural processes.” The human race is collectively turning a blind eye to this inevitable fact.

Greenberg points out that “when wild stocks become over-exploited, we turn to domestication”. But “there is no ‘ocean policy’, at least none that looks at wild and domesticated fish as two components of a common future... ”. He quotes Sir Francis Galton, the Victorian eugenicist: “As civilisation extends they [wild creatures], are doomed to be gradually destroyed off the face of the earth as useless consumers of cultivated produce”

This progression is ever plainer to see. Terrestrial wild creatures decline because their resources are plundered for human production — jungles shorn, savannahs farmed, marshland drained — while wild fish decline because rivers are dammed or polluted, seas overfished or the food chain fish vacuumed up to provide feedstuff for farmed fish, poultry or animals.

In conclusion, Greenberg argues that a profound reduction in fishing is required. The world fishing fleet is estimated by the UN to be twice as large as the oceans can support. Significant areas of ocean eco-systems must be converted to no-catch zones.

For humans, fish hunting has always been a source of nutrition; however, it must now be controlled.

While Greenberg condemns the policies that have allowed superboats to hoover up tens of thousands of tons of fish, pushing species after species to the brink and leaving a sterile ocean, he champions traditional and artisan fishermen — like those who land fish at my local west Cork pier — who have no impact upon sustainability because the amount they take does not endanger stocks. Indeed, he says they should be paid more for their catch, receive more subsidies and their way of life should, at all costs, be sustained.