Some 1,500 representatives of science, governments, NGOs and the private sector will participate in Barcelona between April 10 and 12 (this week) in the 2024 Ocean Decade Conference promoted by UNESCO. It is the first major in-person meeting of the United Nations Decade of Ocean Sciences for Sustainable Development (2021-2030). And it can be the great showcase in which the world of science can show “its transformative drive” to confront the degradation of the oceans, in the words of Josep Lluís Pelegrí, researcher at the CSIC and former director of the Institute of Marine Sciences. (ICM-CSIC). There will be no binding political agreements but the voice of science will be shaped in the face of the great challenges posed by the protection of the seas.
A pressing problem in the oceans is the expansion of dead zones, with little oxygen in the water, the result of excessive growth of aquatic plants due to excess nutrients (nitrogen and phosphorus) used as fertilizers. A close example is the anoxia episodes in the Mar Menor. The loss of habitat and biodiversity are some of its feared effects. And now there is alarm over plastic spills, the subject of a complex global negotiation underway.
Remis Parmentier, veteran environmentalist, recalls the challenge of eliminating all discharges of dangerous, toxic, bioaccumulative and persistent substances to stop poisoning the sea. We pay a lot of attention to plastic because it is visible, he says, but there are other chemicals about which there is a great lack of awareness despite the fact that they are concentrated in food and our bodies. No less serious is the acidification of the oceans (the result of the high amounts of CO2 absorbed by the sea), which threatens living organisms, reduces biodiversity, degrades habitats and endangers fishing and aquaculture, says UNESCO.
Population growth and awareness that excess consumption of land-based meat has harmful effects have increased demand for food from the ocean, according to documentation prepared. But all this has brought about “immense pressure” on the marine ecosystem that forces us to consume seafood in a rational way and with long-lasting criteria.
“The oceans are changing, but our perception of them is also changing rapidly,” says Parmentier. The oceans are “the engine room of the global climate system”, the first link in many climate disorders. It is a new awareness that did not exist “even just nine years ago”, when the Paris agreement against warming was approved.
“The oceans are the regulator of the climate, the thermostat of the Earth. Therefore, the priority to protect them is to reduce greenhouse gas emissions, confront the impacts of climate change and mitigate warming,” says Loreley Picourt, executive director of the Ocean-Climate platform. 91% of the excess energy that the planet has accumulated due to climate change has gone to the oceans (which are warming more in their surface layers: 0.9ºC since pre-industrial times, Pelegrí recalls). These have been absorbing heat for thousands of years, "but their ability to sequester CO2 and attenuate heat is beginning to reach its limit," says Picourt.
“Unesco remembers that the world economy depends on the oceans through fisheries, energy, tourism and transport. Therefore, it is a source of employment, food, renewable energy and a great supplier of key substances for medical advances.
“The oceans can be our best ally and not a threat,” adds Picourt. Certain coastal ecosystems are a solution to warming. Mangroves, marshes and seagrasses are a great mitigator of climate change. In addition to storing large quantities, blue carbon ecosystems provide help with coastal protection against storms, and provide benefits in water quality, biodiversity, fishing, food security or tourism.
Another challenge is to better prepare local populations for ocean hazards, such as rising sea levels, storms, tsunamis or harmful algae. “Given that some impacts are irreversible, we must adapt the coastal infrastructure and coastal areas that will be on the front line in the face of these impacts,” says Loreley Picourt. "And how? She advocates for a mix of solutions that include the use of gray infrastructure (barriers, protections...) and green solutions (vegetation, wetlands) based on Nature.
The summit will come out with a recommendation to intensify the use of ocean observation platforms (including the convenience of having a digital representation of them, sensors, drones...) to have updated information on the changing climate, health of the oceans and alerts against their dangers.
The protection of the oceans requires “a cultural change” and assuming that the threats they pose “are the result of human behavior,” says challenge number 10 of the conference. It is necessary to disseminate the vital role of the oceans in human well-being and for “people to believe this change is possible, to have an experience of participation, and to foster a sense of belonging to Nature, so that they make it their own, so that estimate. so that your protection is much more than the mind dictates; that the resonance of the sea and water permeates a life fully integrated into Nature,” says Josep Lluís Pelegrí.
