THE WORK OF A LIFETIME. For over 40 years Giuseppe Notarbartolo di Sciara has been involved with the natural history, ecology, behaviour, taxonomy and conservation of marine megafauna. He has a passion for whales, dolphins, seals, sharks and manta rays.
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Professor Giuseppe Notarbartolo, why have you devoted your life to marine animals?
I grew up in Venice, in close contact with salt water, and as a child I had a passion for whales and dolphins. I was always very interested in nature and animals, and I believe that all children grow up like that, but as they age they get separated from this passion for the natural world that for some reason has instead remained in me throughout my lifetime. My interest was curiosity in the beginning, and it became imperative to use science for conservation in the second part of my life.
“Not much was known about the Mediterranean whale population when we started our observations.”
Giuseppe Notarbartolo, you studied ecology and animal behaviour at the University of Parma. Why did you then go to San Diego, California where between 1968 and 1985 you became deeply involved with marine megafauna?
In Italy at that time there was no way I could study these animals, so I moved to the United States after having the very good fortune of meeting Walter Munk in Venice. One of the greatest oceanographers of the 20th century, he invited me to come to the Scripps Institution of Oceanography at La Jolla where he was a professor. Eventually he became my mentor and I stayed with him and his family for nine years. After some time as an associate with a local small research institute I was accepted as a PhD student at Scripps. My thesis was about manta rays in the Sea of Cortez, in Mexico.
Please tell us something about your work with manta rays?
Manta rays are among the largest fishes. They are relatives of sharks, but are much wider than longer; they have big wings. An adult giant manta ray can reach seven metres across, but there are also many smaller species and they were largely unknown at the time. I went and stayed with fishermen of the Sea of Cortez and I discovered that one species of the manta rays they were catching was new to science. When describing it formally I gave it the name of Mobula munkiana in honour of my mentor.
Are manta rays, whales, dolphins, sharks and seals part of the same family?
They are not. They come from very different evolutionary histories, but they are all considered megafauna because they are large. Rays and sharks are cartilaginous fishes, while whales, dolphins and seals are mammals. The largest whale is the blue whale, which reaches 24 metres. It’s bigger than a bus. The fin whale, a common Mediterranean species, is just slightly smaller but still gigantic with its 20 metres.
You came back to Italy in 1985 and created the Tethys Research Institute specialising in the knowledge and research of the Mediterranean.
Not much was known about the Mediterranean whale population when we started our observations. With my team we demonstrated that of all the seas that surround Italy the Ligurian Sea was by far the most important in terms of whales and dolphins. But it was under the impact of intense human activities, including a very destructive type of fishing using large-scale pelagic drift nets that can be tens of kilometres long.
Surely they were not catching whales?
The nets are used to catch swordfish and tuna, but they catch anything that swims at the surface of the sea including whales and dolphins that drown in the nets when they get caught and are discarded by the fishermen. It was a massacre. I proposed that a large area of about 80,000 square kilometres between western Liguria, northern Sardinia and the French coast become a protected area with no drift net fishing. Prince Rainier of Monaco gave my proposal his support, as did Carlo Ripa di Meana, at the time the minister of the environment of Italy, who spoke with his colleague Marie-Ségolène Royal, the minister of environment in France. In 1999 the Pelagos Sanctuary for Mediterranean Marine Mammals was created by an agreement signed by Italy, France and Monaco, and is still in force today.
How many whales now live in the Mediterranean?
There are at least 3,200 fin whales and also several species of dolphins. One small offshore dolphin is called the striped dolphin (Stenella coeruleoalba) and in the area of the sanctuary there are probably 30 or 40,000.
Are there many more whales and dolphins around the south of France, Monaco and Liguria than elsewhere in the Mediterranean?
Yes, because of the way the Mediterranean water circulates that is a high-productivity area where the deep water which is rich in nutrients comes to the surface. When it reaches sunlight photosynthesis starts and the food chain is triggered: first microalgae, then zooplankton, then small fishes eating the zooplankton, and finally the big predators are attracted by all that. Conversely, in most of the Mediterranean, the offshore waters are normally rather poor.
“We are already seeing the effects of climate change on marine animals.”
Giuseppe Notarbartolo, are large marine creatures widely distributed in the world’s oceans?
It depends on the species. As a general rule, at higher latitudes there are more marine mammals than in the warm waters, because colder waters are generally more productive and contain more food to sustain their large bodies.
What is the state of health of the oceans and their populations, and should we worry about it?
We should be very worried. Our planet is about one-quarter land and three-quarters ocean. We always thought that the oceans were too big to be affected by human impact, but this is no longer true. We should be careful about damaging the oceans because they have been saving us by absorbing much of the heat that has been building up in the atmosphere, accumulated through the greenhouse effect humans are causing. If it weren’t for the oceans, we would be baked by now. The oceans are also extremely important because of the oxygen that they produce through the photosynthesis of their microalgae, which is about 50% of the oxygen produced by the plants on the planet. We are already seeing the effects of climate change on marine animals.
What is happening?
As an example, in 2014 there was a strong phenomenon in the Northeast Pacific with a big lens of anomalously warm water caused by global warming that started moving towards Canada and Alaska. The temperature of the water quickly shot up to more than 3°C higher than the norm, and this caused mass mortalities in dolphins and marine birds and a major shift in the distribution of many marine animals, which moved toward the north. Similar examples are becoming more frequent and more intense.
Do you fear that changes in the water mass’s movements driven by temperature will have consequences on the lives of Mediterranean marine species?
Yes, and change is not only happening in the Mediterranean, nor is it only affecting marine mammals. We are heading towards a future in which coral reefs may disappear altogether, including in the famous Australian Great Barrier Reef. The warming of seawater is killing corals by disrupting the delicate symbiotic relationship of the coral polyps with microalgae that live in their soft tissues.
What about rising sea levels?
It is still in the order of a few millimetres per year, but if the water from the ice sheets on Antarctica and Greenland slides into the ocean, a fast sea level rise in the order of one metre or more is likely. This is not a fantasy, it’s a concrete possibility. The latest report of the Intergovernmental Panel on Climate Change (IPCC) of the United Nations (UN) said that this could happen before 2100. Such an event would cause floods in numerous coastal cities and have disastrous consequences for many human activities, such as shipping.
What about plastic pollution?
It would seem easier to stop throwing plastic garbage in the oceans than to stop using oil-based fuels. However, even if we were able to manage to stop releasing plastic into the environment, we will still have the legacy of up to 200 million tonnes of plastic that we have already put in the oceans. Although most of this garbage may eventually sink to the bottom, a large amount will remain floating in the water column, disaggregating with time into smaller and smaller bits – microplastics or even nanoplastics – capable of being absorbed by living organisms, humans included, with noxious effects.
Are we humans at the root of all these problems?
Scientists say that the current era should be called the Anthropocene because the planet has been so radically modified by humans that labelling a new geological era with the name of humans is justified by the observations. Three possible scenarios have been proposed of how the Anthropocene can develop. One scenario is that we will eventually rein in all these bad things that we are doing to the planet. Another is that we will detach ourselves completely from the natural world and live in a sort of cocoon where we are protected from what happens to the outside. The third is that we are not going to be able to do anything about it and humanity will be heading towards very hard times.
Giuseppe Notarbartolo: fishermen in the Sea of Cortez with a spinetail devil ray.
Photo by Fay Wolfson.
Giuseppe Notarbartolo: Munk’s devil ray. Notarbartolo needed to translate the knowledge of the Mexican fishermen into scientific knowledge. Eventually he discovered that one species of the manta rays the fishermen were catching was new to science, and when describing it formally he gave it the name of Mobula munkiana in honour of his mentor.
Photo by Ben Meissner.
Giuseppe Notarbartolo examines a newborn whale shark conserved in the fish collection of the Scripps Institution of Oceanography in La Jolla, California, in the early 1980s. Whale sharks are the largest existing sharks (and fishes for that matter), exceeding 18 m in length as adults.
Giuseppe Notarbartolo tagging fin whales. In 1986 he and his team started collecting very small biopsies from the skin of Mediterranean fin whales by hitting them with crossbow bolts having a special tip. The whales did not even seem to notice. Genetic analyses performed on the samples helped to determine that these whales are a Mediterranean population, isolated from their Atlantic conspecifics.
Photo by Margherita Zanardelli.
Mediterranean monk seal. In the 20th century, the monk seal was brought close to extinction by human activities, mostly by small-scale fishermen due to competition for dwindling fishing resources. The species is now showing hopeful signs of recovery.
Photo by Joan Gonzalvo.
Bottlenose dolphin. The common bottlenose dolphin subpopulation in the Mediterranean is listed as vulnerable by the International Union for Conservation of Nature.
Photo by Marina Costa.
“If humans were to try harder to coexist with the natural world, a smoother coexistence is not impossible.”
Giuseppe Notarbartolo, the hard times of the global COVID pandemic stopped the world for a few months.
Yes, and a retreated humanity had a visible effect on nature. Pollution decreased. Noise in the ocean decreased, with fewer ships and boats going around. Disturbance to wildlife by humans decreased. Despite the direness of the situation for so many human beings, the ability by nature of recovering was a very encouraging signal, meaning that in a short time species and habitats can recover if we only give them a chance. The potential for recovery is there, and all we have to do is behave more correctly towards nature, not only when we are suffering but also when we are well.
Is the extinction of other species due to the vast increase in human population?
All species become naturally extinct eventually and give rise to other species, but it is the rate of extinction caused by humans that is unprecedented, and scary. Overall, we have been losing wildlife populations by an average of 69% since the 1970s, and this is solely caused by the various activities of us humans. This is more obvious on land than it is in the oceans because it takes longer for humans to affect the oceans than it takes them to affect land, but we are seeing extinction happening everywhere. Currently, one-third of all shark species and one-quarter of all marine mammals are threatened with extinction. If we continue to build up heat in the atmosphere through the greenhouse effect we cannot count forever on the ability of the ocean to subtract that heat, and it’s not just heat. Part of the carbon that we put in the atmosphere dissolves into the sea water, and more acidic seawater creates problems for marine organisms that have a shell: corals, molluscs, crustaceans, etc., many of which are key parts of the ecosystem. Ecosystems are pyramid-shaped, where the predators – tunas, swordfish and sharks – are on top. Unfortunately these species are the most valuable on the fish market, and these are what fishermen are after, because they can yield huge profits to the industry. Eventually, the depletion of predators creates an imbalance in the marine ecosystems and negatively affects their health. If we keep doing things to the ocean as we are doing now we will soon have a very different ocean, greatly impoverished not only in terms of its ecological status but also of its inspirational values.
That’s a very intriguing story. Marine mammals are not known to attack humans, not even orcas which are the largest dolphins (an adult male orca can reach ten tonnes and nine metres in length). Orcas are very intelligent, live in family groups, are often very playful, and basically are so powerful that they can do what they want in the ocean. Normally orcas leave humans alone because they likely know that it’s better not to come into conflict with our species. However, there is this particular very small population – a group of only 39 individuals – living between the Gulf of Cadiz and Galicia. These animals patrol the coasts of Portugal and Spain and have been studied by my colleagues in Spain for many years. They’re known to the single individual and have “critically endangered” status. Normally at the start of summer, they station across from the Strait of Gibraltar to intercept the migration of the bluefin tuna which they prey upon. A few years ago one of these orcas started a fashion to approach a boat and play with her rudder, eventually breaking it off. By now we had more than 500 instances of interaction of this type, with several individuals in the population engaging in this sport. They probably find it very funny to break a rudder, and luckily most of the interactions stop there. These orcas are highly protected by the Spanish government, so there is a little bit of a conundrum because you cannot legally do much about this phenomenon which is obviously a nuisance to boaters.
Is there any good news?
We must not give up hope. I used to think that the Mediterranean monk seal as a species would have become extinct before my life will come to an end, but it is doing much better recently and I am not so convinced any more. Another success story here in the Mediterranean concerns marine turtles, today much more abundant than they used to be even a few decades ago. If humans were to try harder to coexist with the natural world, a smoother coexistence is not impossible.
Is a big economic and political change necessary?
I am convinced that progressive change will, by increments, be able to turn the tables. Science is fundamental for the solution of this and many other huge problems humanity is facing, as we’ve recently seen with the extraordinary results obtained through the COVID vaccines that have saved our day. However, even the mRNA vaccine example of being rejected by some holds a dire warning: science in itself is not sufficient. Humanity will also need to gain a greater trust in science and a broader understanding of its power and its limits, as well as how to deal intelligently with uncertainty.
Is there still a greater need for the acceptance of the reality of climate change by the broader public and by politicians?
There is now absolutely no doubt that climate change is happening – and the very recent episodes of heat waves that have caused suffering in so many of us speak very clearly. The same warning is coming from extreme events that happened very recently in so many parts of the world, such as flooding and wildfire. There is also no longer doubt that this level and rate of change is caused by humans. However, too many still do not realise this fact, or refuse to admit it – and solutions risk slipping away instead of coming within our grasp. Ultimately, we should do a better job of teaching science at school. This will have positive repercussions everywhere, including in the ocean.
Thank you very much Professor.
Portrait of Giuseppe Notarbartolo di Sciara by M. St. Clair Baker
All images courtesy of Giuseppe Notarbartolo di Sciara.
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