Interview with Pierre Mollo, member of Iodysseus’ scientific team.
How plankton can influence the direct weather by creating rain. How it impacts our daily life. How the decreasing population of diatoms (a type of micro-algae) or the increasing populations of dinoflagellates or cyanobacteria may threaten our health in the near future. Why the worst impacts of plastic pollution in the oceans are not the ones we see in the media. Lastly, why the Iodysseus program is working on issues concerning the planet’s global ecosystem. Answers from Pierre Mollo, lecturer/researcher and marine biologist.
Every human being has saltwater in his or her veins: plasma, a reminder of our marine origins. Some, however, have more than others—Pierre Mollo, for example. Raised in Port-Louis (Morbihan department, region of Brittany), he grew up eating godaille, the leftover fish given to fishermen. His grandfather and other elderly folks called it “the bread of the sea”. Nothing would keep young Pierrot from dedicating his life to it. In 1969, at the age of 21, he quit his factory job. His goal: travel to Japan. He remembers: “The Japanese were 20 years ahead of us in terms of marine biology, micro-algae cultures, phyto- and zooplankton.” The knowledge he gathered was useful to the fishermen in Houat, as well as marine-related fields. As teaching material was scarce, he supplemented his studies with Anita Conti’s book L’Océan, les bêtes et l’homme (Ocean, Animals and Man). He also met “the lady of the sea” personally. His commitment to plankton has led him to work to inform and alert the public to the cause. Through conferences, films, and books, Pierre Mollo sheds light on the “ecology of the invisible”—the universe of microorganisms that are necessary to our planet’s biology. He earned a Ph.D in ethnology, then turning to research and becoming an ambassador to the “little people of the sea”. Ever humble, he continues to introduce himself as a marine biologist, still devoted to his beloved island of Houat (Morbihan, Brittany). Pierre Mollo founded the Plankton Observatory in his hometown of Port-Louis; the observatory is dedicated to the prevention of health risks caused by decreasing plankton biodiversity—which has already begun. Pierre is also a music lover; he was recently the inspiration for and co-writer of a symphony called La Voix des océans (The Voice of the Oceans), an ode to marine life. He was also the source of inspiration for the Iodysseus project, along with skipper Eric Defert. Pierre Mollo joined our scientific team. He is our Voice of the Oceans.
Iodysseus - Among all services provided to the planet and its inhabitants, the ocean and plankton ecosystems absorb 25 to 30% of emitted CO2 and produce 50% of our oxygen in exchange, according to current estimates. You claim that these numbers are even higher. Why?
Pierre Mollo – Phytoplankton—micro-algae—form a sort of “transparent prairie”, an area immeasurably bigger than the Earth’s total land mass. Like forests, they require three elements: light, mineral salts, and CO2, which they transform into oxygen. CO2 is heavier than our atmosphere, so why wouldn’t it fall into the ocean two thirds of the time, seeing as the ocean covers 70% of the planet’s surface? Are winds—whose importance I won’t deny—diverting CO2 over the continents, en masse? I contend that the oceans and phytoplankton absorb 70% of carbon dioxide, based on their surface area. The oceans may only trap a part of this percentage, over the long term, but that’s another story. If we imagine that the Earth has two lungs, the oceanic lung is the most predominant. In short, plankton are the ones who decide whether we have sunny or rainy weather, as stated by Guy Jacques, and this has been the case for the past 3.5 billion years. We are living on planet Plankton.
Iodysseus - Sunny or rainy weather? Are you referring to the role of plankton in regulating the atmosphere and climate?
Clouds are not made up of water vapor alone. They are seeded by particles like bacteria and other microorganisms that end up in the rain that falls on us. This means that every time that we act in a way that impacts the ocean, it will sooner or later come back to us, since everything happens in cycles. For me, to study plankton is to predict the future. Nowadays I work with students on an Erasmus+ program for the Likès middle and high schools in Quimper. These students will be 50 years old in the year 2050. And 50 years ago, I was in their shoes, just coming back from Japan where I had been introduced to aquaculture. The question I asked then, and am still asking now, is: how will phytoplankton and zooplankton provide us with proteins in the 2000s? When the world’s population reaches nine or ten billion people, plant resources will be insufficent due to a lack of space. Our goal is to find marine proteins to feed humanity—provided that we can harvest them in a sustainable way. Additionally, we aim to put an end to such nonsense as using 5 to 10 kg of fish flour to produce a single kilogram of tasteless, factory-farmed fish. Aquaculture can—and must—serve the resource, and not the other way around. It was this belief that pushed us to launch repopulation campaigns and establish the Houat fishery in the 1970s. At the time, I was employed by the fishermen’s cooperative to study the links and interactions between plankton and other marine organisms.
Iodysseus - Can you briefly explain these links?
It’s quite simple. The first condition is biodiversity at the water’s surface; everything begins with the richness and diversity of phytoplankton. If this diversity decreases, zooplankton diversity decreases as well, as does the diversity of larvae, fry, and so on—all the way up the food chain. Basically, resources are being depleted. In the plankton ecosystem, everything is linked: biodiversity, resources, and the complex equilibrium of the global system and the climate. Today, marine biologists are observing a decrease in plankton diversity. Looking back through sediment records, we observe a decrease in plankton populations, and major extinctions are the signs of critical phases in Earth’s history. For example, during a previous period of intense warming 56 million years ago, the Arctic Ocean was totally free of ice. Like tomorrow, once more, the answer is plankton biodiversity.
Iodysseus - This situation is the usual sort of competition in nature. Are there other reasons for us to worry?
Pierre Mollo – I’m getting to the point. Noctiluca scintillans acts as a beacon which signals a favorable environment for the arrival of other dinoflagellates, which are toxic: Dynophisis, Alexandrium, and Gonyaulax, for example. These species have significant effects on human beings: respectively acceleration of intestinal transit, paralysis, coma, and even death. Generally, two weeks after Noctiluca appears, Dynophisis will contaminate oysters and other marine filtering organisms, rendering them inedible. Furthermore, at other latitudes, the situation is worse—much worse. Karenia brevis. Some say that this species was the cause of the first plague of Egypt described in the Bible: waters from the Nile turned into blood, fouling the river and killing all the fish. The story is still relevant, more than ever before. No later than last year, one hundred tonnes of dead fish and marine mammals washed up on the western coast of Florida after a red tide—victims of Karenia. This species of dinoflagellate releases deadly neurotoxins directly into the water. Not only does it kill marine life, it can also harm humans via ingestion, or simply breathing it in. This has repercussions on tourism and the economy. In the US, losses due to harmful algal blooms (HAB) have reached nearly $1 billion for the fishing industry alone, and the number is constantly rising.
Iodysseus - Could this temporary, regional decline be linked to certain cycles, such as the Atlantic Multidecadal Oscillation (AMO), which occurs every 70 years? Aren’t we in a distinct warmer phase today?
Pierre Mollo – It is certainly an aggravating factor: diatoms are, in fact, extremely sensitive to water temperature. As I have verified myself, they prefer colder water in polar zones and can’t withstand temperatures above 18-20°C. However, their sensitivity to pollution is critical as well—they are even used as official bioindicators for water quality. Pesticides, fungicides, Round Up, chemically-synthesized fertilizer, everything that we humans spread in the Earth’s soil inevitably ends up in the sea through runoff into estuaries. In 2016, ecotoxicologists Geneviève Arzul and Françoise Quiniou revealed the impact of pesticides on coastal water. Their conclusion is clear: diatoms are the primary victims, and tiny amounts of pesticides such as Round Up are sufficient to cause irreparable damage. This assessment confirms other similar studies performed in the early 1980’s, nearly 40 years ago. On the other hand, overenrichment in nutrients (called eutrophisation), whether they originate from natural sources through the upwelling of deep water, or from manmade sources through agricultural fertilizers (phosphate and nitrogen), leads to the proliferation of dinoflagellates and cyanobacteria. These classes of phytoplankton lead to asphyxia and ecosystem death. This is happening as we speak—ponds, lakes, seas, and entire oceanic zones are undergoing desertification to an ever-increasing extent.
Iodysseus - How do these toxins enter our bodies and threaten our health?
Pierre Mollo – As I’ve already mentioned, simply through our lungs when we breathe. Inhaling dinoflagelates and/or cyanobacteria toxins present in aerosols is a recognized risk exposure. It directly impacts people living on coastlines and islands. It’s a very serious matter, knowing that around 50% of Europeans, and almost 80% of all humans, live along the coasts.
We always have been told, and I repeat it often: “come to the seaside, breathe the crisp, fresh air”. It’s invigorating, yes, and healthy—but this depends on which type of plankton are present when you breathe in.
Iodysseus - In your opinion, how will Iodysseus contribute to the cause of plankton?
Pierre Mollo – By sailing across the oceans, by carrying a message, by collecting more accurate data on the composition of marine aerosols and their interactions with the atmosphere. Plankton are most often dispersed into the air during storms—it’s too dangerous to analyze them in such conditions. The Iodysseus trimaran can attain speeds which recreate storm conditions by mixing surface water layers with its bow on the leeward float. This is highly interesting because, until now, we have only simulated these conditions in the laboratory—which inevitably skewed results. We’ll never do better than performing the experiments in situ, at sea. At the same time, we hope that Iodysseus will lead to improvements in aerosol capture equipment, which are still quite rudimentary. The aim is to convince industries to develop and automate these tools in order to set up a functioning network and marine aerosol quality monitoring models. The stakes are high—hundreds of millions of people are concerned.
Lastly, Iodysseus is important if we wish to continue enjoying the healthy sea air and everything that comes with it—from fishing to tourism. In addition, Iodysseus contributes to the development of marine biotechnologies, developing sustainable economic models which are sustainable in the long term. The sea holds the answers we need—an ocean of them!