People and the sea: How do we break the cycle of abuse?

A project aims to disentangle humans’ often exploitative relationship with the sea

Understanding the ocean’s past is crucial to protecting its future. So says an international team of researchers embarking on 4-Oceans, a project to disentangle humans’ relationship with the sea.

The role of the sea in defining human history has been considerable. The waves have had their hand in sculpting Ireland’s fortunes for centuries; and our way of life has in turn steered a course for the sea.

The 7,000km of the island’s coastline have provided food and commerce, given passage to invading forces, inspired tradition, art and curiosity. The great and dark expanse of the ocean lends well to an impression of the unknown, leading to stories rife with misimpression, mystery and fear.

Such trepidation is evident in the Immrama, a group of old Irish tales of voyages to the otherland by sea. None provides a more shocking portrayal of the ocean unknown perhaps than that of Máel Dúin. Putting to sea on a voyage of revenge for the death of his father, Máel encounters islands inhabited by beasts, fortresses, demons and a river sky that rains salmon. The salmon features prominently in Irish folklore as the king of fish.


But despite its frightful limitlessness, the ocean is not invulnerable, and much of our relationship with it has been built on exploitation. Humankind has been crafting its livelihood from the sea since well before any official records began.

Bronze Age middens mark the sites of coastal foraging in Ireland for oysters, winkles and limpets.

By the mid-16th century, Irish ships were fishing in the North Atlantic, French boats landed mackerel in Bantry Bay, and there was an export market for salmon. Social classes could even be defined in the past by the seafood they ate, with shellfish often referred to as "bia bocht", a poor person's food.

It is no wonder, then, that Séamus Heaney posed the question, “did the sea define the land or the land the sea?” It is apparent that after generations of nourishing this land-dwelling species with both sustenance and legend, humankind is taking its toll on the waters from which much of its fortune has derived.

A study by the Ellen MacArthur Foundation estimates that by 2050 there will be more plastic in the oceans by weight than fish, a status achieved by decimating one while discarding the other.

It has also been declared by the United Nations that almost 30 per cent of global fish stocks are overexploited, while almost 60 per cent are at their maximum levels of exploitation. These threats transcend arbitrarily constructed borders and national limits, compounding the challenge of gathering accurate records.

While it may be indisputable to say that humans have had catastrophic effects on marine fish stocks, establishing a baseline from which to determine the extent of our impact is difficult.

Steep increases

Large-scale fishing industries existed in medieval Europe, with archaeological evidence showing steep increases in cod and herring catches in England around AD 1000. The discovery of the Grand Banks of the North Atlantic sent mariners in pursuit of novel wealth, extracting fish and whales between 1550 and 1650 to the equivalent value of the silver mines of Latin America at that time.

Now, two researchers from Trinity College Dublin are among a four-strong team of principal investigators spearheading the 4-Oceans project. Professors Poul Holm and Francis Ludlow work at the Trinity Centre for Environmental Humanities. Reaching beyond our own shores, they aim to forge a better understanding of global historical marine exploitation. The project will bring together leaders with expertise across the humanities, natural sciences and social sciences.

The acronym 4-Oceans is derived from the assertion that before the industrial age, the four oceans exploited by humans were the Pacific, Indian, Arctic and Atlantic. It is hoped the 10-year study will provide an insight into when and where marine resources became of major significance to humankind.

The forces that have driven and constrained marine exploitation are central to this question, including natural long- and short-term climatic changes. The El Niño, for example, is a cyclical phenomenon in the Pacific that has been known to Peruvian fishermen since long before modern science.

Another illustration is the 1815 volcanic eruption of Tambora in Indonesia, the ash from which veiled sunlight in what became known as the "year without a summer". While crops failed worldwide, lower temperatures led to a catch bonanza of mackerel off the coast of New England.

The team will also examine the forces that have influenced the cost and demand of marine resources. They note that humans are driven not by what we eat, but what we want to eat. For this reason, evolving cultural preferences, the development and exchange of ecological knowledge, demographic change, conflict and the growth and shift of global markets are all elements to be considered.

Exalted oysters

A prime specimen of shuffling markets is the amenable oyster. In Victorian times, oysters were a standard addition to steak and kidney pies, before being exalted to their present culinary status. In Paris, quarrymen used to shuck oysters as an easy lunch that could be carried in the pockets while tunnelling catacombs beneath the city.

Shark fins have been harvested as a Chinese delicacy since the Song dynasty, carrying unsubstantiated associations with virility. The practice of removing the fins from living sharks before tossing the animals back into the sea is one driven by human preference, but which raises concern both in terms of ecological damage and animal rights.

The outcomes of the project, which include a World Atlas of Historic Marine Exploitation, will influence how academics, citizens, and managers think about the value and consumption of marine life. In sweeping a vast geographical scale over a broad period of time, they will go further to highlight our shared ocean legacy.

Ludlow adds: “The 4-Oceans project will ultimately introduce much-needed chronological depth to how we view urgent societal and environmental issues across the globe, through our understanding of the past,” adding that the project will “advance our understanding of the role of ocean life in human history”.


The 4-Oceans project has been launched in association with the United Nations Decade of Ocean Science for Sustainable Development.

The decade challenges the global scientific community to build a foundation of research that strengthens the management of our oceans and coasts for the benefit of humanity. The importance of such efforts in the present context was highlighted during a session of the UN General Assembly in December.

Addressing the socio-economic recovery from the Covid-19 pandemic, the European Union stressed that efforts should incorporate keeping oceans healthy and productive. Ensuring the resilience of society and economies, it argued, could only be achieved by overcoming inter-related challenges of climate change, biodiversity loss, hunger and poverty.

The findings of studies such as 4-Oceans, which look into the past, will ultimately give footing to projects that build up a shared outlook for the oceans and humanity.

One such project is the SeaFood with Healthy Oceans Programme, a proposal under the UN decade. Based on the knowledge that natural reefs are self-supporting ecosystems, this initiative aims to build up sustainable aquaculture on human-built reefs. Their aims incorporate food security by innovative methods that avoid the problems associated with both traditional aquaculture and exhausting wild fish populations.

Other projects in the UN decade involve public awareness campaigns; empowering students through curriculum development; and showcasing traditional ecological knowledge.

By taking us on a deep ocean journey, these collective endeavours will illuminate a world that is generally beyond the grasp of common perception. Life in the ocean has long been seen as a limitless resource worthy only of consumption.

"Think of the word 'seafood' itself," writes Paul Greenberg, American author and fishing historian. "It's not an unusual characteristic to reduce the natural world down to very few elements," he notes – highlighting the common simplification of complex networks of life to something purely edible.

Greenberg’s book, Four Fish: The Future of the Last Wild Food, explores the history of the wild fish that dominate our menus – salmon, sea bass, cod and tuna – examining the forces that get them to our plates. “We tend to go with our appetites rather than our minds,” he writes, pointing out the necessity for humankind to shift its perspective of the oceans as a mere food factory.

Misinterpretation has been a theme of our historic legacy with the seas, whether in folklore or fisheries. A sustainable outlook requires a major adjustment from certain conventional ways of thinking. It is then, perhaps, only through better understanding of that past that we might nurture a balance in our shared ocean future.