The Empty Sea: The Future of the Blue Economy

By Ilaria Perissi and Ugo Bardi

The “Blue Economy” is used to describe all of the economic activities related to the sea, with a special emphasis on sustainability. Traditional activities such as fisheries, but also undersea mining, tourism, and scientific research are included, as well as the phenomenal growth of aquaculture during the past decade. All of these activities, and the irresistible prospect of another new frontier, has led to enthusiastic and, most likely, overenthusiastic assessments of the possibilities to exploit the sea to feed the world, provide low-cost energy, become a new source of minerals, and other future miracles. This book makes sense of these trends and of the future of the blue economy by following our remote ancestors who gradually discovered the sea and its resources, describing the so-called fisherman’s curse – or why fishermen have always been poor, explaining why humans tend to destroy the resources on which we depend, and assessing the realistic expectations for extracting resources from the sea. Although the sea is not so badly overexploited as the land, our demands on ecosystem services are already above the oceans’ sustainability limits. Some new ideas, including “fishing down” for untapped resources such as plankton, could lead to the collapse of the entire marine ecosystem.

How Neanderthals crossed the sea in canoes, how it was possible for five men on a small boat to kill a giant whale, what kind of oil the virgins of the Gospel put into their lamps, how a professor of mathematics, Vito Volterra, discovered the “equations of fishing,” why it has become so easy to be stung by a jellyfish while swimming in the sea, and how to play “Moby Dick,” a simple board game that simulates the overexploitation of natural resources are just some of the questions that you will be able to answer after reading this engaging and insightful book about the rapidly expanding relationship between humanity and the sea. 

• Language: English
• Publisher: Springer
• Release date: Feb 12, 2021
• ISBN: 9783030518981

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© Springer Nature Switzerland AG 2021

I. Perissi, U. BardiThe Empty Sea https://doi.org/10.1007/978-3-030-51898-1_1

1. Introduction

Ilaria Perissi¹   and Ugo Bardi¹

(1)

Dipartimento di Chimica, Università di Firenze, Italy, Italy

If you ever were stung by a jellyfish while swimming in the sea, you know how painful it is. To be accurate, we should say that jellyfish do not sting, but instead their tentacles emit noxious or urticating substances on contact. Nevertheless, they are beautiful creatures, and if you ever saw a group of them swimming in their tank in an aquarium, you know that you could stay there for hours admiring their ethereal qualities and unique form of locomotion (Fig. 1.1).

But, no matter how beautiful and fascinating these creatures may be, a brief contact with one of them is more than enough to ruin your holiday. The abundance of jellyfish in the sea is one of those gradual changes that over time has become the new normal, a bit like the increasingly intense and frequent heat waves in summer. Young people swimming at the beach today organize anti-jellyfish squads that watch the waters so that their friends can swim in peace. But those of us who are a little older can remember how, long ago, the jellyfish problem just did not exist. Surely, there were plenty of poisonous jellyfish in the sea, but they were rare enough that no one was preoccupied with the risk of being stung.

Fig. 1.1

Jellyfish kept at the Berlin aquarium. In the foreground, one of the authors (UB)

Perhaps you have also had the opportunity to swim at some distance from the beach. In this case, you may have noticed something else. Where have the fish gone? Apart from a few small fish near the beach, there seem to be no swimming creatures in the sea except the human ones. Again, that looks normal to us, but if you think that once upon a time the coasts were inhabited everywhere not by tourists but by fishermen, then you must conclude that there is something strange going on. If the sea had always been the way you see it now, what could the fishermen catch with their small boats, certainly unable to go very far? Did they fish for jellyfish? Or how did they make a living? They are mostly gone now. Certainly, there are still fishing boats in the world, plenty of them, but no longer the romantic kind of boats of the past. Now fishing is an industrial activity done with fast boats equipped with all sorts of fancy tools, from radars to sonars. Sometimes, they look more like spaceships than fishing boats. What happened to the sea?

Obviously, the occasional observations we can make while swimming near the beach are no proof of anything. But many things have indeed changed in the sea in recent times and not just with fishing. For one thing, the data show that jellyfish and other invertebrates have become much more common today than they were just a few decades ago. Lobsters were once a fancy and expensive food that few people could afford, but, today, they have become common enough to begin to appear, frozen, in supermarkets and even not especially fancy restaurants have them on the menu. In certain regions of the world, in particular in China and Japan, even jellyfish are becoming a fairly common food. Not that they are very nutritious or particularly tasty: they are made mainly of water. But it is said that they are acceptable after being dried and sprinkled with some spicy sauce. In this case, they are crunchy, a little like cucumbers. In the West, jellyfish are not normally considered as food, but things change fast. How about a jellyfish pizza? Why not a jelly burger?

It is also true that overfishing has caused the disappearance of many fish species, especially those that were easy to catch near the coast. It is what Daniel Pauly called aquacalypse in a study that he published in 2009 [1], one of the first reports on the destruction of the marine environment by human activities. Not that all fish have disappeared, but the populations of the most prized fish, from tuna to salmon, have been shrinking in all the seas of the world. So, there are fewer fishermen and they catch less and less because there is always less fish. But for most of us, nothing seems to have changed in the availability of fish. At the supermarket, you can still buy as much fish as you want at reasonable prices. If overfishing is a problem, how come consumers have not noticed it?

Indeed, overfishing is not visible if you try to detect it from what you can see available on supermarket shelves. But the fish you buy today is not anymore the fish of a few decades ago. Most of it is farmed fish, bred and raised in an artificial environment, the product of a new industry called aquaculture that maintains the shelves of the retail stores well stocked with the most prized fish. The success of aquaculture has led to a complete reorganization of traditional fishing. Instead of producing fish for human consumption, fishing is now oriented mostly on the production of fish to be used as feed for aquaculture. It is a revolution that causes fishing boats to go fishing for species that once nobody could have imagined as being food for human beings. Have you ever been served sand eel or capelin at a restaurant? Unlikely, but these are species actively searched by the fishing industry as sources of feeds for more valuable species, such as salmon. But the race to the bottom goes on. It was unthinkable a few years ago that the fishing industry would engage in exploiting the tiny shrimp called krill, once just whale food, but today another source of protein for fish feeds. Curiously, though, krill is also considered as a food for humans, and you can order fried krill in Japan by asking for okyami. Some people seem to be seriously thinking of plankton as food for humans. Do you want to know what it tastes like? It is reported that it tastes fishy [2]. Are you surprised?

Now you begin to understand. Fish eat jellyfish and, if fish disappear, jellyfish thrive and you are more likely to be stung. It is all part of a gigantic change occurring everywhere in the seas of the world. It is not only about fish and fishing; the sea itself is changing. It is becoming more acidic because of the absorption of increasing quantities of carbon dioxide from the atmosphere. It is becoming polluted with all sorts of chemicals, from metals to pesticides, including the plastic waste that is forming the great plastic islands in the oceans. And the sea level is also rising because of two parallel effects, both related to global warming. First, the rising temperature of the water causes it to expand. Then the melting of the continental ice adds water to the oceans. So far, these effects have been small enough to be difficult to notice without appropriate instrumentation, but, in the future, pollution and sea level rise will cause tremendous damage to humankind.

Sometimes, we hear that there exist no problems, only opportunities, and some people seem to be applying this concept to the changes taking place in Earth’s oceans. This mind-set underlies the concept of the blue economy, and its close relatives blue growth and blue acceleration . These terms encompass all of the activities that justify our exploitation of marine resources. In addition to fishing, the sea is also exploited for its mineral resources: the drilling platforms that you see offshore to extract oil and gas are a good example. Think also of desalination plants, nowadays more and more widespread to fight the droughts caused by global warming and to supply water to thirsty humans. These plants produce huge amounts of drinking water, but there is always a cost as large quantities of energy are required to move the water away from the salt and against the osmotic pressure. And then there are many other activities based on the sea: transportation, tourism, military operations, scientific research, and many others. The sea is no longer the romantic lair of brave and noble fishermen. It is an arena for industrial development. It is an economic resource.

Of course today there is no more talk of the wild ideas that were fashionable in the science fiction novels of the 1950s, such as submarine cities. But we talk about many other things that were not even imaginable before our times, referring to the treasures that are believed to be contained in the sea. It is said that the blue economy will bring us a new era of prosperity, and not just that, it will be sustainable prosperity . This idea has become so popular that it is also used to define technologies unrelated to the sea as long as they are sustainable, as described in the book The Blue Economy by Gunter Pauli (2009). But the popularity of the blue economy is, more than anything else, the result of a specific factor: the spectacular development of aquaculture. Once, aquaculture was a small-scale activity, mostly done in China to produce shrimp and other seafood for supplementing the family diet. But, today, aquaculture produces almost as much as traditional fishing and generates a much larger turnover at hundreds of billions of dollars per year globally. It is one of the few industrial sectors that you can still expect to grow dependably every year and sometimes at double-digit rates. This growth has led to seeing the blue economy as a great success of human intelligence and resourcefulness. Our march toward the conquest of the sea is proceeding smoothly toward ever more amazing successes. We will get everything we need from the sea: food, energy, minerals, even cosmetics, and do not forget the expansion of tourism and trade routes. It’s the blue economy, baby! But can we really have our cake and eat it, too?

References

1.

Aquacalypse PD. Now [Internet]. The New Republic. 2009 [cited 2016 Mar 14]. Available from: https://​newrepublic.​com/​article/​69712/​aquacalypse-now

2.

FDL staff. Plankton: what it is and how to cook with it [Internet]. Fine Dining Lovers. 2017 [cited 2020 Jan 1]. Available from: https://​www.​finedininglovers​.​com/​article/​plankton-what-it-and-how-cook-it

© Springer Nature Switzerland AG 2021

I. Perissi, U. BardiThe Empty Sea https://doi.org/10.1007/978-3-030-51898-1_2

2. The Discovery of the Sea

Ilaria Perissi¹   and Ugo Bardi¹

(1)

Dipartimento di Chimica, Università di Firenze, Italy, Italy

Keywords

Ocean lifeHistory of fishingFish as foodFishermenFish preservationCanningFreezing

2.1 The Aquatic Ape: Humankind and the Sea (Fig. 2.1)

Because there is nothing more beautiful than how the ocean doesn’t want to stop kissing the beach, no matter how many times it is thrown away.(Sarah Kay)

Fig. 2.1

Mediterranean landscape: The Chia Beach in Southern Sardinia. It is likely that the first continuous contact our remote ancestors had with the sea was along beaches like this one, probably in Africa. There is also evidence that they were already travelling by sea several tens (perhaps hundreds) of thousands of years ago

Have you ever heard of an aquatic ape? Surely, you never found anything like that in zoology books. It is rare even in terms of fantasy creatures in comics and cartoons: apes (and monkeys as well) just do not seem to get along well with water. Not that apes and monkeys do not know how to swim, they do, but they do not seem to do it often, nor they seem to like the idea. There are just a few exceptions; one is that of Japanese macaques. In winter, they love to soak in hot springs, while in summer, they appreciate the pools built by their primate cousins, the sapiens, better known as human beings .

A characteristic of the sapiens is that they are poor swimmers even in comparison with other primates. The problem is that the human being is structured for bipedal motion and that is not suitable for the kind of swimming that comes naturally to most land animals. Quadrupeds swim literally walking in the water, and their body structure makes it easy for them to keep their heads out for breathing. It is a question of the architecture of the skull: in humans, the occipital hole is central, and the head stands vertically on the spine. In other mammals, instead, the occipital hole is further back, and the head is held vertically by special muscles. So, a dog does not need to learn to swim; it swims without problems from the first time it jumps into the water. Even cats are good swimmers, despite the fame they have of not loving water. Humans, instead, must learn a movement that allows them to stay afloat while keeping their heads above the water for as long as it takes to breathe. Untrained humans falling into deep water have good chances of drowning.

The problem with swimming must have been the same for the various species of the genus Homo that preceded and accompanied us in our long evolutionary history, the creatures nowadays called hominins or hominini (not to be confused with the term hominid that also includes the great apes). We do not know how good our remote ancestors were at swimming, but, since they had acquired the same standing position as us, modern humans, they had to have the same problem we have with the need to keep our heads above the water. But, just as we can learn to swim, so probably they could. For example, the fossil record shows that some of our ancient cousins, the Neanderthals, suffered from an ear disease called exostosis, an abnormal growth of bone within the ear canal. Today, this disease affects those who practice water sports, and it would seem to indicate that those Neanderthals spent time at sea or in water. That is somewhat in contradiction with other data showing that the Neanderthals did not eat fish, not normally at least. It may be that the ear disease was the result of living in cold and damp environments: after all, some Neanderthals were cavemen. But maybe they just liked surfing in the sea, like today’s Hawaiians!

At this point, we should also mention the hypothesis that sees our remote ancestors not just as seashore dwellers but as truly aquatic animals living most of their time in the sea, more or less like seals or penguins. That is, they might have been the only aquatic ape ever having existed. The idea was first proposed in the 1960s by Alister Hardy who had noted that some characteristics of human beings are absent in other primates [3]. Two of these characteristics stand out as peculiar: humans are hairless and have subcutaneous fat. These are typical features of marine mammals : whales, dolphins, and others, while they are not present in land mammals. So, Hardy’s idea was that humans could have followed an evolutionary path similar to the one that led some land animals to become marine creatures, as happened to seals, whales, penguins, and others. Ancient marine humans would feed on mollusks, crustaceans, and fish and therefore spent most of their time swimming in shallow waters near the coast. That was what led them to develop the typical features of marine animals. But, unlike seals and penguins, humans somehow managed to readapt to land. The concept was popularized by the Welsh science writer Elaine Morgan, and it gained a certain popularity in the 1970s.

The diffusion of the aquatic ape hypothesis led to the idea that the various mermaid legends existing in the world’s lore are a reminiscence of those very ancient times. In 2012, Discovery Channel had the bad idea to broadcast a documentary titled Mermaids: The Body Found, where they seemed to propose that these ancient marine humans were still existing or that their fossil traces had been found. It was science fiction, but many people believed that it was reporting real data and facts. In any case, the documentary had a certain success, part of the modern fascination with mermaids in cartoons and comic books. Maybe it is because they tend to wear a sexy bra (and sometimes not even that) (Fig. 2.2).

Fig. 2.2

The Copenhagen mermaid. A bronze statue erected in 1913 based on the story The Little Mermaid by Hans Christian Andersen

In the real world, the closest thing to Hollywood-style mermaids are the Japanese Ama, (literally sea women) specialized in deep diving to collect pearls and shellfish. It is a very ancient tradition in southern Japan, although, today, only a few of these sturdy ladies remain, mostly a tourist attraction. The photo is by Fosco Maraini (1912–2004), a great expert of Japanese traditions and culture. It was taken in 1954 when the Ama were still earning their living by fishing. Like the Copenhagen mermaid, at that time, the Ama did not wear a bra. But they didn’t have a fish tail (Fig. 2.3).

Fig. 2.3

One of the Japanese pearl fishing ladies, the Ama-san, during a dive, photographed by Fosco Maraini in the early 1950s

The theory of the aquatic ape occasionally reappears in the scientific discussion on the origins of humans, and, usually, it goes back home pelted with metaphorical rotten tomatoes. Most anthropologists believe this theory to be nonsense for several good reasons. The main one is that there is no evidence that humans have ever been aquatic animals. Then, the lack of hair and subcutaneous fat are characteristics that can be better explained in ways that don’t imply an aquatic life. In any case, if being naked gave advantages when our ancestors were semi-aquatic creatures, today we are no longer aquatic, so why did not we regain our hair?

Currently, there exists a certain consensus among anthropologists that our hominin ancestors lived mainly in savannahs, an environment to which they had adapted after abandoning their original forests. That’s not by any means universally agreed, but it makes sense, given the great ecosystem changes that were taking place at the time when hominins arose. It was a new evolutionary trick that Mother Gaia had developed: for hundreds of millions of years, plants had used a kind of photosynthesis called the C3 mechanism. Then, a new kind of photosynthetic mechanism appeared: the C4. It worked more efficiently in dry environments, and it expanded significantly in the ecosystem starting from about ten million years ago, during the period called Miocene. The C4 plants were grasses, not trees, and they seemed to survive better the periodic onslaughts of forests caused by fire occurring during this period. More or less at the same time, ruminants started roaming the savannahs in great numbers.

As a consequence of these events, some tree-dwelling primates changed their way of living and became denizens of the savannah. That was a much more dangerous environment for them: they had to become bigger to be a more difficult prey for the many powerful carnivores hunting in the savannahs. They also adopted a bipedal stance that may have enabled them to have a wide view of their surroundings. Most likely, they were creative omnivores adapted to switch to whatever resources were available: berries, fruit, tubers, and the like. Probably, they would also hunt to get meat, even though the concept of man, the hunter should not be exaggerated: meat may have been no more than an occasional dietary supplement for our remote ancestors. It may well be that their most useful tool was not the spear but the bag, as Ursula Le Guin argued in her 1986 essay The Carrier Bag Theory of Fiction. But it is also true that even modern apes go hunting, so, it is a tradition among hominids to kill for food, and, possibly, the sapiens is the most specialized hunter among hominids.

That our ancestors were savannah dwellers does not mean that they did not like water. On the contrary, there is evidence that they used the sea as a source of food from very ancient times. Archaeological data show that they moved along the beaches, taking advantage of the low tides to collect all the sea had left behind when it withdrew: algae, mollusks, crustaceans, and some fish that remained trapped in pools. That did not make them aquatic apes, but having a bipedal stance may have helped them to wade a little further than quadrupeds into the water while keeping their heads out of it. We do not know how important the beach resources were for the diet of our ancestors: for one thing, this type of nourishment does not have great caloric content. But, at that time, supermarkets did not exist and, to get a good steak, you had to catch it while it was still running on four legs. That must have had a considerable energy cost, to say nothing about the risks involved. Instead, it takes very little effort to collect a mollusk or a crustacean from the beach or a rock, so that may have been a better feeding strategy.

Fish are certainly a food far superior to mollusks and crustaceans in terms of density of calories, even though not as dense as a steak. The problem is that fish move much faster than crustaceans (to say nothing about clams), and finding one left on the beach at low tide had to be only an occasional event. But these rare chances certainly showed our ancestors that fish was high-quality food, but how to get it? For humans, as for all land animals without fins, it is unthinkable to chase fish by swimming, the way penguins and seals do. To catch a fish while staying out of the water, you need special techniques that only a few non-marine animals have developed. Of course, many birds catch fish by rapid swoops into the water, and even some bats do the same. Fishing is a more complex story for non-flying animals , but necessity is the mother of invention, as usual. Polar bears lurk close to the holes in the ice where they know that seals come up to breathe. Grizzly bears, instead, catch salmon by ambushing them at the points where the fish are jumping out of the water to overcome the rapids. There even exists a wild cat specialized in fishing, called fishing cat (Prionailurus viverrinus) , that lives mainly in Bangladesh, in North-Eastern India. It fishes in rivers using rapid strokes of a paw. Unfortunately, there are very few of these cats left, and the species is on the verge of extinction. As for the domestic cat (Felis catus) , it is well-known that they appreciate fish very much, but, in most cases, they have to limit themselves to fish-flavored pellets or to the theft of the contents of the frying pan. But there are documented cases of domestic cats using their paws to catch fish from the sea or from rivers. Sometimes they even try that with the home goldfish, a characteristic theme of many cartoons and comic strips.

Humans can use techniques similar to those of their plantigrade cousins (the bears) to catch fish. They lack fangs or claws comparable to those of bears, but they can use harpoons and other tools with similar results. But, already from very remote times, our ancestors had developed more creative methods to fish. One example is the use of vegetable toxins to poison an entire pond or large tidepool and kill all the fish that can then be easily collected. It is a very ancient technology, still widespread during the Middle Ages in Europe. Even today, there are cultures of hunters and gatherers who use it. In ancient times, just as today, poison fishing is a tremendously polluting and destructive method that, unfortunately, has not completely disappeared. Fishing using insecticides is widespread along African coastlines, while in Southeast Asia, cyanide is used. And, of course, dynamite can be used to kill all the fish in a pond with results equivalent to those of poisons.

Maybe poison-based fishing was a tradition in antiquity, but that could be done only on a small scale. Surely, our ancestors could not poison the sea! For that, we had to wait for our times, but, apart from that, the ancients certainly had no difficulty understanding that the sea contained an abundance of resources incomparably greater than what they could find in rivers or lakes. Not to mention marine mammals: seals and whales were a fabulous source of protein, fat, and fur. But how could a non-aquatic ape capture them?

As we said, the sapiens are a creative and adaptable species, and, already in ancient times, our ancestors adapted to fishing the hunting technologies they had developed on land. The spear they used against land animals became the harpoon they used against marine mammals. It was a deadly weapon against seals and walruses that had to leave the sea to reproduce. Slow and heavy on the ground, they were certainly an easy target. Our ancestors also developed the variant called fishhook, which can be used for medium-sized fish. But the really brilliant invention, the one that paved the way for the exploitation of marine resources, was the fishing net. We find traces of this tool already at the dawn of the Holocene, the era that began about 12,000 years ago. Near the city of Antrea (now Kamennogorsk), in Karelia, fragments of fishing nets made with twisted willow twigs have been found that date back to about 8300 BC [4]. Already at that time, someone went fishing in one of the many local lakes or in the nearby sea. Even more ancient are weights found in Korea, probably used to bring nets to the bottom.

The fishing net is a very special technology, typical of the sapiens. No vertebrate has ever developed anything like this, although we must acknowledge that spiders have preceded us, developing their nets probably 250 million years ago. Incidentally, some species of spiders live by catching small fish. But they do not use their webs for this purpose; they simply jump on the fish. Thus, the webs of the sapiens are unique in the ecosystem as fishing tools.

Fishing nets can be used in a very simple way, with the fisherman wading into the water up to his waist to catch the fish that swim near the beach. Or the net can be used from the shore, attached to a stick, or even to block the escape of fish from a river or a pond. It is a simple tool that produced, and still produces, a remarkably high yield wherever fish is abundant. The fishing net can become even more