No, and the figures are incontestable. According to the FAO (SOFIA, 2008), 52% of stocks (of the 200 most consumed species) are fully exploited, leaving no room for further expansion, 19% are overexploited and 8% are depleted. This means that the proportion of stocks for which the maximum wild capture potential has been reached or exceeded stands at 79%. Only 20% of stocks are considered as ' moderately exploited ', although unfortunately this percentage is falling constantly ; it stood at 40% in 1974 and at 23% in 2005. Lastly, 1% of stocks are recovering from depletion.

Believing the sea's resources to be unlimited, we have allowed the unlimited expansion of fishing. But contrary to commonly used terminology, fishing is not a form of production, it is the « extraction» of a natural resource from a given geographical area. Sadly, it is because we have been unaware of this simple reality that the state of fisheries resources around the globe is now such a cause for concern. We have fished excessively and badly and we have done so for too long. Moreover, over the last 50 years fishing technologies have vastly improved. Fishing vessels are bigger and more effecient and location techniques are increasingly effective. Modern fishing technologies mean that, for a fish, there is now nowhere to hide.

To summarise, fishery resources are like an investment, which, every year, yields interest. The challenge is to protect this investment and to rebuild it when necessary, so that we can fish sustainably, i.e. spending, over the long term, only the interest.

The extinction of a species of fish such as cod or blue fin tuna is possible but highly unlikely. There will always remain several thousand individuals, which should ensure the survival of the species. Caution is nonetheless required because one thing is clear, even massive fish stocks can suddenly collapse under the pressure of overfishing. The fish we know as the Mediterranean Bluefin Tuna (Thunnus thynnus) faces such a risk today. And rapid stock depletion has occurred in the past. It happened to Cod, which were once fished off the Grand Banks off Newfoundland. In this region, where fishing had begun almost century earlier with the « terre neuvas » (Newfoundland fishermen), up to 800,000 tonnes of Cod was fished during the 1970s. Stocks collapsed, and on an unprecedented scale, leading to a total fishing moratorium being put in place in 1992 and until fish stocks recovered significantly. Tens of thousands lost their livelihoods. Today, 17 years later, there has still been no recovery.

Worse still, other species of fish, of virtually no economic value, appear to have moved into the ecological niche left vacant by the Cod. This infamous case ought to serve as an example for fisheries management around the world. Admittedly, however, despite this calamitous lesson, we still cannot rule out the collapse of a number of other major fisheries stocks.

Instances of « overfishing » have been chronicled for centuries. For most of this time they remained localised around areas where human populations had settled. But with the emergence of fishing fleets and preservation techniques, fishing began to expand, to become the globalised industry it is today. The pace of its expansion has been driven by increasing demand, which is driven by rising population levels. From 1950 to the 1980s world fish production doubled from some 40 million, to around 80 million tonnes. Since then, fish « production » has peaked, and has even been showing signs of falling. Yet over the same period, from 1950 to today, the world's population has gone from some 2.5 billion individuals to nearly 7 billion. There will be some 9 billion in 2050, yet nature can only provide what it produces naturally, not more.

Scientists working in the field of fisheries and marine sciences conduct research to carefully monitor the state of health of commercially exploited fish populations, which are known as “stocks”. A reduction in the average size of fish from such a population is one indicator of overfishing. And resource depletion, in other words, a reduction in the quantities fished for the same fishing effort, is another. Of course these are indicators, not definitive proof. Scientists are constantly monitoring and checking such indicators so it is on the basis of taking regular measurements, which are checked and rechecked, that it is possible to conclude that a stock is being overfished.

Marine sciences face, however, a number of difficulties. There is much we don’t understand about marine ecology and research teams are not given the resources they need to carry out their research in what is a challenging environment.

Another problem is that some of the species that are fished, are not strictly speaking, “stocks”. This is the case in the Mediterranean, where fish species are more « mixed » and fisheries management is, consequently, more difficult.

The problem is that we have been exploiting fish stocks for a long time and more often than not measures are only taken after it has become clear that the health of a stock has become a cause for concern.

For certain stocks, especially in the North-East Atlantic, the North and Baltic Seas, and also for certain species, a total allowable catch (TAC) has been set. The total allowable catch is the maximum catch that a particular stock can support. This limit then determines the quotas or quantities of fish that can be fished by country, by fishery or potentially by individual vessels. In regions such as the Mediterranean or the Black Sea, fishing is managed by limiting the fishing effort.

Other measures include the minimum landing size, which is usually based on the size of a fish at sexual maturity. The aim here is to enable any particular fish to reproduce at least once. Unfortunately, in the same way as for quotas, there are both “biological” minimum sizes, which take into account the reproductive criterion mentioned above, and “political” ones, which take little account of scientific opinion in order to meet short term economic goals.

This said, it is worth noting that more and more fishermen are independently adopting more and more stringent practices (landing sizes greater than those set by regulations for example) in order to preserve marine resources and at the same time protect their own livelihoods over the short, medium and long-terms. Better product marketing may also help with fishery resource management: less is fished but nothing is wasted. Product care is also important. Produce could be better preserved on-board, keeping it fresh and increasing its value to the customer.

Yes, probably. The question is knowing which ones, how many, and of what size. If overfishing continues individual fish will no longer live long enough to reproduce. This may explain the collapse of certain fish stocks occurring today, but the real danger is probably that overfishing alters ecosystem equilibria. The disappearance of 'large' predator fish for example opens up an ecological niche for other species to enter. The once hunted thus become the new hunters: even hunting the original predators no longer able to grow to full size. Moreover, the original predator's population base can be decimated by the new predator, which is often much smaller, and sometimes of no commercial value.

If large fish continue to be caught at the same rate as today, the ocean of tomorrow will be inhabited by small fish, crabs and jellyfish. Marine ecosystems will be profoundly disrupted and exploitable fisheries stocks will be wiped out, or almost. And such a nightmare scenario would have repercussions for other marine ecosystems, including the disappearance of coral reefs, for example. There would be a sort of domino effect the contours and limits of which we cannot predict because the consequences of overfishing on the food chain are so poorly understood, and rarely taken into consideration.

The nutritional value of Krill is highly debatable but this is not the main problem. If we were to fish krill we would be fishing the lowest link in the entire ocean food chain, on which all marine ecosystems depend, not only whales, but also small fish (which are eaten by larger ones or by birds, sea-lions, dolphins and of course by humans). We would be endangering the entire chain. So plans to fish krill pose a serious threat to the ocean's main ecosystems, as well as, ultimately, to our own food supply.

To answer this question, we have to be clear about what we mean by aquaculture.

As an example, the farming or breeding of oysters or mussels, in other words, shellfish farming, is a form of aquaculture. Shellfish farming makes highly intelligent use of natural microscopic algae to feed and fatten shellfish. Similarly, the farming of species such as Carp using algae or other plants as feed is also sustainable, provided that the environmental and health aspects of production are properly controlled. It is worth noting that, internationally, fish farms are in fact mostly rearing this type of fish.

What is problematic about modern aquaculture is the farming of species of carnivorous fish or shellfish. Such species are very popular in western European cuisine. They include bass, bream, turbot, salmon, trout and bluefin tuna. This creates a number of very unusual and acute problems, which are described below.

On an efficient farm, the rearing of 1 kg of carnivorous fish requires around 2.5 kg of wild fish, although 4 kg is more often needed and sometimes up to 14kg is needed to fatten a Bluefin tuna. This is a major obstacle because the quantity of wild fish available is severely limited. As a result, this type of aquaculture will not resolve the problem of overfishing, it will exacerbate it.

Any significant expansion of the amount of carnivorous fish reared in farms will therefore require an intelligent use of the available animal protein. In other words we need to : produce fish-meal with fish from managed fish stocks and on a quota basis, use all the waste from fish processed for human consumption and use bycatch in fish-meal products for aquaculture. Aquaculture offers an ideal customer for fish protein from unwanted catch or other waste. Another possibility is vegetable protein, which offers a complementary solution.

The question is a valid one but it overlooks the nature of modern aquaculture.

Yes, a fish in the wild consumes at least as much as a fish reared on a farm, and probably even more because it uses energy to hunt and catch its prey.

But farming has one very big difference with nature, it enables billions of fish to survive, when, in their natural environment, they would not. This means billions of extra mouths to feed over and above what nature would normally produce. It is worth remembering that fish lay tens of thousands, often hundreds of thousands and sometimes millions of eggs over their reproductive cycle. The vast majority of these eggs are never fertilised and of those that are, only a small number, 4, 5, 6 or 10 reach adulthood. Today, science enables almost 100% of eggs to be fertilised and a very high percentage of young fish to reach adulthood, yet they all need to be fed, which is the reason why acquaculture is problematic.

Yes, and it's likely that aqualculture will continue to rear carnivorous species, but aquaculture cannot feed the world. There is another problem too. the wild fish that are used as fish feed by fish farms, (also known as « forage » fish ), are at the base of the ocean's food pyramid. They include anchovies, sardines or capelins, which are eaten by larger fish (mackerel for example) and which are themselves eaten by Tuna but also by birds, sea-lions, seals, sharks, dolphins, whales and local human populations. Should these stocks of feed or «forage» fish disappear, it would mean the certain collapse of the base of the entire food pyramid and of marine ecosystems, of which man is a constituent part. Moreover, farm bred fish, whose diet would be extremely varied in their natural habitat, are systematically fed with the same species, which adds considerable stress to the stocks of those species. At the very least, this puts an obligation of those who fish these stocks to closely monitor their health, or risk seeing them collapse, and with them, their own sea-going livelihoods. By managing stocks of forage fish the same way as we would manage a forest, their sustainability, and availability at the base of the food pyramid, can be ensured. Yet it is also true that our planet's resources are finite and human expansion must respect limits.

Finally, the Food and Agriculture Organization of the United Nations (FAO) has also underlined the ethical issues that the use of forage fish raise, when, instead of being used as fish feed, they could be used to feed human communities which lack access to animal proteins and which certainly lack the means to buy reared (carnivorous) fish.

Yes and no. This is already the case for farms specialised in carnivorous species, whose diet (which is supplied in pellet form) has a 50% vegetal content at least (soybean meal and other vegetable proteins, wheat gluten, worse still, oilseed crops, corn gluten,…). Current research is even stretching this percentage to 80 or even 85% in some cases. This can be done but is it acceptable that species which are exclusively carnivorous in the wild become partly or wholly vegetarian ? In part this is a question for government. This said, it is clearly still essential that a farm bred fish should have nutritional qualities equivalent to a fish caught in the wild. It is therefore vitally important to provide the former with « polyunsaturated » fatty acids known as « Omega 3 », which are found principally...in wild fish! Omega 3 are also present in seaweed but the cost of extracting it is exorbitant. The most important thing to remember is that, ultimately, we are limited by the quantities that nature, in this case the ocean's fauna, is able to provide.

Yes, and this is why it would not only be an error, but also dangerous to assume that if fisheries were to collapse, there would always be aquaculture to replace them. Even if marine resources remained at their current levels, we would be no further forward. We are currently fishing in the region of 1103 million tonnes annually. Of this, 20 million is discarded into the sea and 90 is brought ashore. Of this 90 we consume a little over 50 million directly. We also indirectly consume around 30 million as feed for poultry, for pigs or via fish farming. If, tomorrow, we wanted to produce 20 million tonnes of carnivorous fish through aquaculture, we would have to fish the equivalent of the entire global annual catch, that is, 50 million tonnes (and up to 80 million if farms are inefficient), to do so. This would be an enormous loss, but also an absurdity even to try with the farming methods we use today.

Nevertheless, a number of options are being explored today : the European Commission has set a zero waste target for fishing, implying further improvement to fishing gear selectivity, as well as an obligation on vessels to bring ashore any bycatch currently discarded at sea. Given current performance ratios, these figures mean we can envisage a total global annual aquaculture production of between 10 and 20 million tonnes of carnivorous fish. This will however require international governance and a more responsible approach from States and governments and from the fishing industry : their economic survival depends on it.

All this underscores how we must, as of today, face up to the challenge of reconciling the three pillars of sustainable development: the environment, the economy and society.

This is true, but in the case of Bluefin Tuna the consequences of this type of farming are at least as problematic as for other carnivorous species. Tuna fish are fattened in a cage to produce the ' hyper-fat ' fish so desired by the japonese consumer. To fatten it, the fish is fed copiously. It is, in a manner of speaking, ' force-fed ' : with up to 15 kg of wild fish for every 1 kg of weight gained, .... that is 15 kg for just 1 kg on one Tuna reared in a cage ! This raises a variety of problems but the main one is that the market prices for species such as scad, sardine, anchovy or mackerel, which are consumed by poorer countries in particular, have soared. By fattening the Bluefin Tuna for a luxury market, a large number of people are deprived of an essential or even vital source of protein in their diet. In a world which will be home to 9 billion people in 2050 can this continue? and is it compatible with the United Nation's concept of responsible fishing ?

Another problem is that fish farms discharge a significant quantity of organic matter into the marine environment. This because the more that fish consume, the more waste is produced. The problem is a serious one, in particular for tuna farms. A number projects have not seen the light of day because of concerns about excessive marine pollution.

In answer to the first question there have been several initiatives, each more apparently appealing than the last. Their impact is impossible to gauge, not least because it is highly likely that fish larvae or young fish rereleased into the wild suffer the same fate as those born naturally, that is 99% are either eaten or will otherwise disappear. The only truly promising initiative, known as « sea ranching », involves releasing young salmon into the sea. After a long sea journey these salmon return to the rivers where they spawned. But the young salmon in question are not freshly hatched juveniles, but true young fish (smolts) which are expensive to rear to this stage of development. Also, the numbers returning have so far proved insufficient to ensure the profitability (or competitiveness) of this type of farming compared with others in which the fish are reared from eggs to maturity in a more intensive and more controlled way.

As for rearing fish as fish feed, the issue is a complicated one, but what is clear is that, in terms of resource use, as we discussed above, it is senseless waste. The farming of carnivorous fish species can't escape this fundamental handicap. Our ancestors were careful not to rear wolves, tigers or lions because if they had done they would have needed to rear or capture birds, rabbits, antilopes etc as feed stock. They very wisely reared herbivores (sheep, goats, cows, rabbits and so on) to supply their dietary protein needs. Yet in aquaculture, we are farming wolves, tigers and lions ! It is not only plainly absurd but also a historic error of judgement given that we know how difficult it is to feed the world today, and how much more difficult it will be in the future.

Ideally, it is better to choose a sustainably fished wild fish, but should the choice be between a farmed fish and a farmed shrimp, then the best strategy is to look for approved product labels indicating that the product, whichever it is, has been produced to the right standards : "Agriculture Biologique (AB)" in France, for example.

There are several '‘ecolabels' in use today.
Only a small number meet the standards for responsible fishing laid down by the FAO.

These are :
- MSC : Marine Stewardship Council,
- BIM-SSS â Board Iaseaigh Mhara ■Seafood Stewardship Standard (Ireland),
- MEL Japan – Marine Ecolabel Japan,
- ECOCREST ■Fondazione Acquario di Genova Onlus.

These are still rare in the shops but can be found on frozen sea-food, semi-preserve or tinned products. In the absence of any other recommendations these ecolabels are an effective aid to making the right choice.

Apart from harpoon gun fishing, no form of fishing can be 100% selective. The challenge is to understand the nature and scale of the impact of different fishing methods and, possibly, what is being done to improve them and reduce the collateral damage they cause on marine animals and habitats.

Man has developped a range of fishing gear enabling him to extract fish from the sea, both from the sea-bed, or near it, and from the open sea. Fishing gear can be divided into two principal categories: «active» and "passive".

Fishing trawls :

• Bottom trawls (nets in the form of a «sock») are dragged along the ocean bed, or close to it, and capture species inhabiting these areas, such as cod, whiting, some flatfish, shrimps or prawns and Norway lobsters...
• Pelagic or midwater trawls capture species inhabiting the water column, which include mackerel, tuna, herring, anchovies, sardines or bass....

Dredges :
Dredges operate on the same principle as bottom trawls. They are literally dropped onto and towed along the sea bed, which they scour to extract their catch, especially molluscs, such as scallops, oysters or clams. Trawls and dredges have two different types of impact on the environment :

• 1. In the case of bottom trawls and dredges, and depending on the nature of the bed concerned, their impacts vary and can lead to a degradation of the area trawled, the destruction of certain habitats and the capture of economically valueless marine animals such as alevins (post larval fish), corals or seaweed.
• 2. In respect of their target species, trawls are not always used in a particularly selective way. They may capture «non target» animals including under-sized or non target species.

Considerable effort is going into reducing the impact of certain types of trawls, by, as far as is possible, limiting the impact on the sea bed caused by their ground ropes (systems of rubber or metal rollers which travel over the sea bed) and by being more «selective» (mesh size, selective netting, boards). Such efforts make it possible to significantly reduce the number of non-target animals captured, (in terms of species and sizes). Modified trawls are used, for example, in the French Norway lobster fishery, in the Gulf of Gascogne.

Nevertheless, deep sea bottom trawling does take place over fragile ecosystems (e.g. deep water corals) and impacts species with slow reproductive cycles and late sexual maturity (such as the grenadier, the sabre and the emporer). Its impact on ecosystems (except for muddy-sandy seabed areas) and marine resources are so worrying that the United Nations requested all countries using this fishing method to cease doing so by the end of 2008 if they were unable to demonstrate it's sustainability. The French government has launched an inquiry into the sustainability of deep sea fishing. It is due to report its findings in early 2010.

Lastly, although unintended captures seem to be rare in the case of large pelagic (midwater) trawls, accidental captures have been reported. In addition, trawling for too long leads to the fish being crushed in the bottom of the trawl net. At best, the result of this is a significant reduction in the commercial value of the catch.

Seine fishing : the principle of this method is to first surround a shoal of fish with a net before drawing the two wings of the net towards the vessel (seine fishing) and by closing the bottom of the net at the same time (purse seine fishing - Bolinche or Lamparo).

Seine fishing sometimes leads to the unnecessary capture of small-sized fish from the target species, as well as small cetaceans. However, this method is being improved all the time and non-target animals captured this way are increasingly returned to the sea alive.

Passive fishing gear includes nets, lines, traps and pots.

Nets : nets come in different shapes and structures depending on their use.

Whether fixed, or drifting, both gillnets and trammel nets form a barrier, which traps the fish as they pass. Mesh sizes can be regulated to ensure that only the largest fish are captured, and that the smaller ones are able to escape.

Net selectivity depends both on the behaviour of the target species and on the fishermen's knowledge of the area being fished. A well positioned net, in the right place and at the right time, can be highly selective. Conversely, if it'’s use is not optimised, a net can be an unneccesary trap, capturing crustaceans, fish, turtles or cetaceans indiscriminately.

Lines : Includes 'Palangre' lines or rod fishing. These techniques, which are used to catch tuna, salmon and bass, have an impact essentially when very large palangre lines are used, as these can also trap non-target species, including marine birds. This is occurring in Antarctic, in the case of Patagonian toothfish, for example.

Pots and traps come in many shapes and sizes depending on the target species. They are dropped onto the sea bed by pot vessels and generally have little impact. They even allow selection ; when the pots or traps are brought onboard the most commercially valuable individuals can be picked out and the remainder can be released unharmed, which is never or hardly ever the case for the fishing techniques described above.

In the case of passive gear, the loss or abandonment of nets, lines or pots and traps at sea poses a medium and long term threat because these devices will 'continue to fish'.

Finally, it is worth noting that depending on the fishing technique used, the amount of energy used by the fishing vessel can vary significantly. This is an important factor, especially in the context of rising oil prices and the introduction of carbon taxes. Indeed, and putting to one side the question of their impact on fragile habitats, trawlers will soon face, as heavy consumers of diesel, an economic dilemma. It is going to become more difficult to reconcile the market value of their catch, and current catch volumes, with the rising price of diesel and the carbon tax. In addition, reaching the break-even point while respecting the requirements of sustainable development, also presents a challenge.