Revolution in the Seas: Ending Overfishing and Building Pesco-Ecology, Sustainable Agro-Ecology of Fishing

By Didier Gascuel

Revolution in the Seas: Ending Overfishing and Building Pesco-ecology, Sustainable Agro-Ecology of Fishing provides an in-depth analysis of the dynamics between humans and disrupting marine ecosystems by extracting its wild animals. It highlights practical changes that can be implemented to prevent overfishing and create a new way of fishing, the pesco-ecology that benefits marine life, coastal communities, and human consumers alike.

Written by a leader in fisheries science and conservation, this book begins by diagnosing the issue of overexploitation, showing the dynamics and consequences on living marine resources and ecosystems. It then goes on to demonstrate how recent scientific discoveries, including tropic network functionality, are changing humans’ approach to fishing sustainably. The final sections are devoted to ecological, economic, and social solutions.

Revolution in the Seas: Ending Overfishing and Building Pesco-ecology and Sustainable Agro-Ecology of Fishing is a vital resource for fisheries scientists, managers, academics and students in marine biology or fisheries studies. All stakeholders and citizens involved in building a sustainable relationship between humans and the sea will also benefit from this book’s revolutionary content.

• Translated to English for global accessibility
• Analyzes systems and protocols that have led to overexploitation
• Examines innovations and key rules for implementing a new way of fishing and rethinking sustainability

• Language: English
• Publisher: Academic Press
• Release date: Oct 27, 2023
• ISBN: 9780443159114

Didier Gascuel

Didier Gascuel is an ecology professor at the Institut Agro in Rennes, France, where he is head of the Fisheries and Aquatic Sciences Center and leads a master’s programme in Fisheries and Aquaculture Sciences. For nearly 30 years, he has been involved in the assessment of marine resources, fisheries, and ecosystems health, especially in European waters and in Western African countries. His current research focuses on the sustainable exploitation of marine resources and the modelling of the impacts of fishing and climate change on ecosystems. He is a member of the Scientific Committee of the French Institute for Ocean Science, Ifremer, and has been a member of the Scientific, Technical and Economic Committee for Fisheries (STECF, 2008–22) of the European Union. From 2009 to 2017, he was the chairman of the French Association of Fisheries Scientists, which actively contributes to the public debate on sustainability of human maritime activities. He has published more than 200 scientific articles and presented over the past 5 years nearly 100 conferences for the public across France, on various topics related to sustainable fishing, marine biodiversity, and the impacts of climate change.

Book preview

Introduction: Fishing, mining, and agricultures

From one crisis to another, without us even realizing, a world has disappeared. It once occupied our coasts with its harbours, its tight rows of boats along the quays, its sailors, its boatbuilders, and its women who worked ashore. Thousands of people who, at the cost of hard and often hazardous work, made their living from harvesting the sea’s resources. It was a world of solidarity with its own rules, professions, and know-how. A world that still shapes our imagination with its stories, its beliefs, and its maritime dramas. Yet only a few fragments of that world remain today. A few dozen boats in a handful of ports, a few thousand professional fishers. A lot of older people and few young faces. And barely anyone to sing the sea shanties but tourists from the city.

Over the past century, in all developed countries, other worlds vanished in a similar fashion, taking their skills and culture with them. This is particularly true of a certain kind of peasant farming, but also for the mining, coal, and metallurgy sectors. However, the dynamics are different. There is something specific about the decline of marine fisheries, a special cause that concerns us all and provides the reason for this book.

In the case of coal mining or metallurgy, humankind exploits a resource that they know to be finite and nonrenewable. Miners first extract the nearest, most easily accessible deposits or those with the highest ore content. Then gradually, as the resource is depleted, they need to go further and deeper and to exploit veins with a lower mineral content. Operating costs rise and financial profitability falls. This happened in the countries of old Europe, notably in Great Britain and France. Meanwhile, markets have become global and here, as in other sectors, it has become more profitable to source from abroad. Despite innovation, recovery plans, and heroic labour struggles, the old pits closed one after the other and the workers were laid off. Within a few years, at the turn of the 1980s, the closure of coal mines and steel companies in Europe put tens of thousands of workers out of work. Entire communities were abandoned and regional economies remained devastated for decades, leaving the social and cultural fabric to be rebuilt. Mining was dead, the victim of the depletion of local resources and of international competition.

In the case of agriculture, the demise of the old world took longer. Over time, from one generation to the next, sons stopped taking over their fathers’ farms and the countryside emptied, almost unnoticed. It was a slow process and one that we all let happen, with no widespread media coverage and with no real public debate. Admittedly, the decline of the old world went hand in hand with the emergence of a new one. The Green Revolution that began after the Second World War, with its mechanization and massive use of fertilizers and pesticides, considerably increased agricultural output and productivity per worker. In both Europe and the United States, the number of farmers was divided by eight or ten between 1950 and 2020, but at the same time, total production increased three or four times. A new form of agriculture was born, with all its excesses and its environmental impacts, but one which, it must be acknowledged, achieved a certain level of productive efficiency. That world has quite literally been transformed. The satellite-guided combine harvester has replaced the draught horse.

The marine fishing industry shares both similarities and differences with these two sectors. As in farming, the technological advances have been numerous and the increase in productivity per fisher has been staggering. From boats and fishing gear to navigation and communication devices, everything has changed. However, this astonishing rise in fishing power has not resulted in a more efficient production system: quite the contrary. Given the technological progress, it was somewhat inevitable that the total number of seafarers would decrease, just as the number of farmhands has decreased. Fewer workers and fewer boats, but all much more efficient! Yet the analogy ends here because the sum of gains in individual productivity has led to a decline in overall output. In Europe, total landings from marine fisheries have fallen from 7 million tonnes in the 1970s to less than 4 million tonnes in recent years. In the North Sea, Europe’s major fishing ground, these figures dropped from 4 million tonnes to 2 million. And in the North-East Atlantic, on the American coast, catches decreased threefold between 1970 and 2020. For all the major industrial countries, the transformation has been a failure.

Like the miners, the fishers had to go out further and deeper to seek untapped resources that were once considered of little interest, to exploit new sources with an ever-decreasing ‘fish content’. However, unlike with the mines, this process was not inevitable. Fisheries resources are renewable living resources, resources that have been renewed while feeding people for millennia before us and resources whose renewal could and should have continued as they were harvested. If this has not been happened, or not sufficiently, it is because fishing has been too intensive, because fish populations have not had time to recover as quickly as they were exploited, because a tipping point was reached during the 20th century.

Fishers are now under threat. They have to deal with an increasingly aggressive global market, rising energy costs, the now fierce competition from a growing worldwide aquaculture industry, and the aftermath of the health crisis and of the war in Ukraine. But, as we shall see, the root cause of their difficulties lies elsewhere. It is due to the degradation of the natural resource they exploit. Economic returns are often low because fish have become scarce; because big boats, powerful gear, and copious amounts of diesel are now needed to exploit largely depopulated sea beds; and because the ecosystems themselves have become unstable, providing fishers with irregular incomes. We have partly destroyed the ecological capital we used to live on. In the case of marine fisheries, there was no slow death or transformation, but a certain form of collective suicide, that is, ecological suicide.

At sea, undoubtedly earlier and more powerfully than elsewhere, humankind has come up against the limits of the biosphere. This is a story that concerns us all, and one that implies our responsibility. Of course, the fishers were the driving force. But they only worked to fulfil society’s expectations, in an ideological context that we helped shape. The measures taken by fishers representatives or political leaders, implicitly responding to the demands of their clients or constituents, have been insufficient or ineffective, if not downright counterproductive. The awakening of the scientists—and of society as a whole—was a long time coming. Consumers demanded ever more fish and, of course, at the best price. Citizens applauded the amazing resourcefulness of the fisheries minister who came back from the intergovernmental negotiations every year, boasting of having obtained higher fishing quotas. Quite a stab in the back for the future of sustainable fisheries. Almost all of us, through our consumer habits or our voting slips, have contributed to this or, at the very least, allowed it to happen. And we sometimes encouraged it.

But this story is also about our common future because the maritime fisheries are a test of our capacity to shift towards greater sustainability and resilience. Fishing is a small economic sector, a victim of the ecological crisis. A few thousand jobs and an economic activity that is barely worth more than the tomato farming sector. It should be easy for large, industrialized countries to rescue the sector and maintain a thriving fishing industry for the benefit of the coastal economy. Yet this recovery is proving to be complex, as it raises new questions. Can a natural resource be exploited in a truly sustainable way? Are we humans able to limit our own capacity for self-destruction? Why haven’t we done so until now? Can the assets provided by nature be used for the benefit of as many people as possible? And what needs to change radically to finally break out of this process of decline and secure a sustainable future for the exploitation of the sea’s living resources? If we fail to put an end to this ‘small ecological crisis’, will we be able to solve the big one… and sustainably feed the 9 or 10 billion people expected to live on our planet by 2050?

There is little choice for fishing. If it wants to halt its long decline, to survive in a world of increasingly tough international competition, and to build a sustainable development approach, it simply must change. Its production and regulation systems need to be overhauled. A new kind of fishing industry has to be invented. Let us be honest: we are not starting from scratch. Awareness is already growing, both among the general public and among those most concerned. There are already some pioneering fishers, some remarkable experiments, some promising changes, and some encouraging results. We will talk about them in this book. However, these positive developments do not scale: they are too slow, too partial, too local, and too fragile. Resistance is all the stronger because the challenges to be met are so profound. And because they clash with short-term economic interests.

Change is a battle, and the ambition of this book is to contribute to the fight. It is the view of a scientist putting forward analyses, new approaches, and some strong proposals to fuel the current of transformation that is gathering momentum at the heart of the crisis. We need to understand what has happened, why it has happened, and what needs to really change if we are to get back on the right path. The first part of the book aims to provide a more detailed diagnosis, to show the depth of the crisis, its origins, and its implications. It takes stock of the ecological situation and analyses the effects of overfishing on the functioning and health of ecosystems. The second part focuses on a crucial issue: What useful lessons have we learned over the past few decades? What do we know about the conditions for sustainability today? We need to question the seemingly unstoppable dynamic that is steering an entire economic sector towards mass suicide. We need to understand why attempts at management have failed repeatedly and spectacularly for so long. Finally, the third part presents the three radical changes to be hoped for, and that mark the three dimensions of a real revolution in the seas. The goal is not to provide a recipe for management. Solutions will have to be developed jointly, on a case-by-case basis, with everyone involved. Nonetheless, a number of guiding principles for action can be outlined. They define some radical shifts and show us how we can all move towards resilience. For the fishing industry, and well beyond.

Part I

The dynamics of overfishing the marine ecosystems

Part I Introduction

The phenomenon of overfishing of the oceans is now well-known among the general public. But everyone has a rather vague idea of what it is, with certain approximations and at times mistaken certainties. We should therefore first spell out the diagnosis. Where did we start when it comes to fishing and living marine resources? When and how did overfishing arise? Which resources does it most affect? What do we know about the impacts of gear on the seabed? How does the exploitation of one species have a knock-on effect on all its prey, predators, or competitors? What are the consequences for the overall functioning of marine ecosystems and for biodiversity? How do the effects of fishing interfere with other human-made impacts? And with climate change?

We need to understand what has happened, to take apart the machinery driving the dynamics of overfishing, and to differentiate between anecdotes, symbolic cases, and generalizations. To try and establish a comprehensive assessment. In this section, we will briefly discuss the history of fisheries, to find out where we started from. We will analyse the recent changes that give meaning to what we can observe today. Then we will dwell at greater length on the impacts that overfishing has on the ecosystem, as these impacts are what really concern us for the future.

Chapter 1 When humankind comes up against the limits of the biosphere

Abstract

This first chapter establishes the diagnosis, showing the dynamics and consequences of the overexploitation of living marine resources. It presents a long-term retrospective that highlights the fabulous richness of the ocean before humans started to covet them and identifies the first impacts of fishing. It is a fascinating story that gives us a better understanding of where we came from, what has happened and of the world we now live in. The chapter then focusses on the more recent period, following the Industrial Revolution. With the beginning of the systematic exploitation of the world’s largest fish stocks, the dynamics of overfishing enter a new phase. For the first time in its history, mankind is really coming up against the limits of the biosphere on a global scale. The accumulation of more and more efficient means to catch fish is progressively leading to the depletion of resources and finally to a decrease in the total catch. The demonstration is implacable and cruel: we live in a world with finite resources and we must quickly learn to deal with it.

Keywords

Wilderness; Early fishing impacts; Fishing history; Fishing gear; Global catch trend; Stock collapse

Since the earliest days of human history, people have eaten seafood. Neanderthals gathered shells from the foreshore, caught fish in pools and, using spears and axes, hunted the large colonies of seals and walruses that were found everywhere along the European coast. However, the history of fishing really began with modern Homo sapiens, when the first harpoons were invented in Africa some 90,000 years ago [1]. Since then, from one innovation to another, fishing pressure has increased constantly. We have testimonies from these ancient times that tell the same story of exuberant nature and growing impacts, of fleets that had to go out further and further to find fish, exploiting new resources, with ever more efficient fishing gear. It is a fascinating story and we need to tell it, at least briefly, because it gives us a better understanding of where we came from and of the world we now live in. The more recent period, following the Industrial Revolution, deserves to be discussed in more detail, because it signals a new phase in which man really came up against the limits of the biosphere on a global scale. It helps us analyse and understand the dynamics that drive the overexploitation of the sea’s living resources.

In times of plenty

From all the accounts to have reached us from ancient times, one powerful conclusion emerges: the abundance of the past is not a mere fable. There was a time when the sea was full of big fish. A world that is hard to imagine today. Huge colonies of seals populated the shores of Europe and North America. Herds of whales came to our shores in great numbers to breed, while schools of hundreds and sometimes thousands of dolphins were extremely common in almost all the world’s seas. Turtles and manatees were counted in tens of thousands in the tropics, seabirds in millions in all latitudes. Fish that we find huge (and rare) nowadays—like tuna, marlin, turbot, halibut, large cod, and sturgeon—were abundant everywhere. Further south, there were swordfish, groupers, and numerous others. Sharks abounded in all oceans.

The best evidence of this past abundance is the fishing gear that was used for centuries. As early as the Neolithic period, large fixed fisheries were built on the Atlantic coast. These wooden or stone installations, which were submerged at high tide, trapped fish as the sea receded. For thousands of years and until the end of the Middle Ages, they accounted for a significant share of the catch in old Europe [2]. Then, from the 16th to the 18th century, no doubt because coastal resources were already becoming scarce, these fixed fisheries entered into conflicts of use with fishing on foot, practised on the foreshore. They gradually disappeared in the 19th and 20th centuries, when the advent and development of mechanized fishing emptied the sea of some of its fish and rendered the fixed fisheries permanently unproductive.

Another well-documented example from ancient times comes from the Greeks and Romans. Throughout Antiquity, they exploited the Mediterranean’s coastal resources using equipment that would seem derisory to us today [3]. There is no tide there, so no fixed fisheries; instead, they had to venture out to sea. There are plenty of mosaics showing these tiny boats, sailing within sight of the coast with one or two men on board, with no engine, no depth sounder, no GPS. You will see a man, standing at the front of the boat, brandishing a harpoon or a trident. On another boat, a few metres of netting is being deployed, and a tiny plaice is thrown into it. These crafts sustained a maritime economy for centuries.

More recently, we have the case of the cod fishery that began on the Grand Banks of Newfoundland in the 16th century [4]. The first boats there were small and carried about a dozen men. Each fisher stood facing the wind, wedged into a barrel for protection, and clad in a large leather apron. They wielded a hand line with a single hook at the end, which they moved up and down continuously, most often fishing from sunrise to sunset. These fisheries were highly prolific and yielded around 100,000 t each year. Three centuries later, at the height of the great Newfoundland fishery, the number of hooks per sailor on board was in the thousands and the lines were miles long. Then mechanized fishing developed there too, before the stock collapsed seemingly forever. To anyone who doubts the abundance of the past, I suggest you try it: go to sea to fish with a harpoon or a trident, in the manner of the Greeks or Romans; go to the banks of Newfoundland to catch cod with a handline; try to renovate or build a fixed fishery on a tidal coast. You will inevitably return empty-handed, but with a clearer picture of the world we come from and which we have partially destroyed.

The final evidence of this lost abundance dates from the discovery of the New World. While working on her thesis in 2005, Andrea Sáenz-Arroyo, now a researcher at the National Autonomous University of Mexico, compiled and analysed all the accounts written by the early discoverers of the Gulf of California in the 16th and 17th centuries [5]. The descriptions of the naturalists who embarked with the Spanish conquistadors, the accounts of the British pirates, and the manuals written by the first missionaries all converge to describe colonies of hundreds of thousands of sea lions, herds of whales of up to 500 heads, the extraordinary densities of green turtles and hawksbill turtles (a species that has become very rare). They report abundant catches of huge fish, now identified as the Atlantic goliath grouper (Epinephelus itajara, a beast that can measure up to 2.5 m and weigh 450 kg) and the manta ray (Manta birostris, with a wingspan of up to 9 m). They also describe huge pearl oyster beds, which were exploited for centuries before they were lost altogether. These accounts undoubtedly contain a certain degree of lyricism and exaggeration, but the narrators’ enthusiasm or indeed amazement is clear: this world was vastly different from ours. The state of nature on Earth was radically different.

This world of the past, with its lavish resources, will not return. It existed simply because humans were absent, or largely absent there. There were just a few thousand individuals, scattered over huge continents, whose lives were far from idyllic. There are now 8 billion, soon 9 billion of us on Earth. It would obviously make no sense to harbour nostalgia for a bygone era. Especially since several centuries of inventions have engendered immense progress, for example in health, human rights, and culture. The aim is therefore not to revert to a supposedly pristine natural state; it is to build the future on our understanding of the past. It is to invent a new form of development, reconciling man, and ecosystems.

Early impacts and early blindness

The history of fishing also shows that humans have had an impact on marine resources for centuries, almost unwittingly, or at least with no real awareness of the sometimes irreversible damage they were causing [6]. The first impacts go back to ancient times: seals and sea cows in prehistoric times; coastal shellfish beds, certain freshwater fish stocks, marine mammals near the coast, and sharks whose fecundity was also very low, probably as early as Antiquity or the early Middle Ages. The case of the sturgeon is emblematic. This migratory fish, which can measure over 2 m and weigh several hundred kilograms, used to swim up all the major European rivers, from Italy to the Baltic Sea, to reproduce. In the early Middle Ages, it was a common species and an important part of the catch in freshwater or estuaries, as well as an apparently common food. Analysis of archaeological sites in the southern Baltic Sea shows that it accounted for up to 70% of the fish consumed between the 7th and the 9th centuries [7]. Gradually, the species declined everywhere, becoming a luxury food in the 12th century, a ‘royal fish’, before almost disappearing. It is thus one of the first proven victims of overfishing and habitat degradation.

Until around the year 1000, sea fishing mainly concerned coastal species. Large offshore species were only impacted when they approached the coast. Inland, throughout northern and western Europe, fish consumption largely consisted of freshwater species such as salmon, eel, or trout, as well as carp and pike. By the end of the 10th century, there was a radical change in consumption practises in many areas, and sea fish such as cod and herring supplanted all other species [8]. It would appear that the production of freshwater species then decreased, probably due to the overfishing of certain stocks and the damage already done to the environment. It was at this period that tanneries and other extremely polluting craft industries developed. The number of mills and dams on the rivers increased and formed obstacles to the migration of eels and salmon. In other words, freshwater resources were experiencing their first major ecological impacts, and people were looking elsewhere to satisfy the growing demand. This can be seen as the start of a process that would continue for centuries and up to the present day: ‘Once I’ve overfished this area, I’ll go and fish somewhere else’.

From the year 1000 onwards, boats became larger and moved further away from the coast. New resources were harvested… and the same process was repeated at sea. Cod is a textbook case in this respect. Based on an analysis of the isotopes contained in the vertebral remains of 300 cod, a team from the University of York has shown that the diet of the populations of England and Belgium was based on local catches from the North Sea in the eleventh and 12th centuries [9]. From the 13th century onwards, however, the origin of the catches became more diverse. It would appear that local resources were no longer sufficient, suggesting maximum exploitation of Channel and North Sea cod, or at least that yields had become low enough to make fishing further afield worthwhile. New fisheries therefore developed, first in the north of Scotland and on the Arctic coasts of Norway, then on the coasts of Iceland from the 14th century, on the banks of Newfoundland from the 16th century, and finally off the coast of New England from the 17th century.

As soon as a stock is exploited, the oldest individuals tend to disappear. It would appear that this process played a role in the expansion of the cod fisheries from the 13th century onwards, first to the north and then to Iceland, Canada, and the American coast. What is particularly striking is the frequent references made, in the early days of the Newfoundland fishery, not only to the extraordinary abundance of this new resource but also to the presence of very large cod, with man-sized specimens sometimes being landed. There is no reason to believe that the catches in the early days of the North Sea fishery were very different. However, the 16th-century fishermen would not remember this. The same process was repeated a hundred years later, when the first cod caught in New England were described as enormous… as if the fish initially caught around Newfoundland had been forgotten.

In short, technical progress and the geographic expansion of the fisheries eclipsed a process of depletion that had already begun. This explains how an idea that would last for several centuries came about, as summarized by Hugo Grotius—undoubtedly the first European jurist specializing in maritime law—in his 1609 work Mare liberum: ‘The capture of fish in rivers cannot be free for it would soon exhaust the river of fish, but fishing in the sea is free, for it is impossible to exhaust its wealth’. However, there is little doubt that significant declines in abundance and depletion of older individuals were already occurring in many marine fish stocks. Not to mention the whales, some populations of which had been in serious decline since the late Middle Ages [10]. All along the European coasts, the impacts on offshore resources were already noticeable several centuries ago. Some coastal stocks collapsed when intensive fishing and environmental impacts combined. Fishers and coastal communities certainly suffered. But from the viewpoint of the system as a whole, this did not matter. It was always possible to go further out, in a sea that appeared to be inexhaustible.

The inexhaustible sea?

In 1883, the Fisheries Exhibition was held in London, which was, in a way, the first World Fisheries Congress. Scientists from all over the world attended and Thomas Henry Huxley, a professor at Imperial College, a friend of Charles Darwin’s, and one of the best biologists of his time, was asked to give the opening lecture. The theme of the event was: ‘Are fisheries inexhaustible?’ And Huxley’s answer was unambiguous. Based on calculations of fish densities and predation mortality rates, he concluded: ‘I believe, then, that the cod fishery, the herring fishery, the pilchard fishery, the mackerel fishery, and probably all the great sea fisheries, are inexhaustible; that is to say, that nothing we do seriously affects the number of the fish. And any attempt to regulate these fisheries seems consequently, from the nature of the case, to be useless’. The statement was controversial, and Edwin Ray Lankester, Professor of Comparative Anatomy at the University of Edinburgh, retorted: ‘It is a mistake to suppose that the place of fish removed on a particular fishing ground is immediately taken by some grand total of fish […]. If man removes a large proportion of these fish from the areas which they inhabit, the natural balance is upset’. Ironically, Lankester’s answer seems the most reasonable to us today, even though it is based on the old hypothesis of nature in equilibrium. Huxley’s scientific reasoning was more innovative. It was a first attempt to quantify at the scale of the stock… but the parameters of his equation were