The mistreatment of the oceans continues without anyone stopping it.
With rising temperatures, water levels and acidity, and without effective measures being taken to curb overfishing and the arrival of plastic, the future is not very bright.
Not even in the II Conference of the Oceans, recently held in Lisbon, has the 142 participating countries reached binding and ambitious agreements.
— The Earth's temperature has risen 1.1 degrees in the last decade since pre-industrial times (1850-1900) due to human activity, and the oceans are not immune to this furnace effect.
In the role of sink that they have been assigned, water masses help mitigate climate change and have stored 90% of the excess heat generated by human activities.
But at a price.
In the last two decades, the warming of the upper layer of the water - up to 2,000 meters deep - has run amok and reached unprecedented levels last year, when much of the oceans "were affected by at least one wave of intense marine heat”, indicates the World Meteorological Organization (WMO).
High temperature spikes have doubled since 1982 and hit warm-water coral reefs, kelp forests and seagrass beds, which are at high risk, particularly ferocious.
Collapses also occur in fisheries, with species moving further north or deeper in flight.
— One of the most recognizable consequences of warming is the bleaching episodes suffered by coral reefs, such as the one that occurred this year in the Australian Great Barrier Reef, the fourth in the last seven years.
Closer to home, in the Mediterranean Sea, heat waves are causing coral populations to collapse, reveals a study by the CSIC and the University of Barcelona published this year.
In some cases, their biomass has been reduced by between 80% and 90%.
Heat spikes follow each other without giving time for recovery.
— In 2021 the escalation of sea level rise continued.
In the last decade it has risen 4.5 centimeters and the annual increase between 2013 and 2021 is more than double that between 1993 and 2002, indicates the WMO.
Behind it comes thermal expansion (when the water heats up, it expands and occupies more space) and the loss of ice, both from the melting of the poles and from the glaciers.
Coastal populations are more exposed to floods, vulnerability to tropical cyclones increases and the retreat of the coasts causes populations to be forced to migrate.
On average, the planet's glaciers have shrunk by 33.5 meters since 1950 and 76% of that loss has occurred since 1980.
— Last year was especially bad for glaciers in Canada and the northwestern United States due to summer heat waves and fires.
In Greenland, an exceptional episode of melting occurred in mid-August and it rained for the first time at Summit Station, the highest point of the ice sheet, located at 3,216 meters.
— The oceans contain 30% of the CO2 from human activity.
This gas dissolves on the surface of the water and is then distributed until it reaches the depths, where it accumulates.
And the oceans are becoming more acidic because this process lowers their pH.
The IPCC (United Nations group of experts on climate change) has warned that the pH of the open sea surface is at its lowest level for at least 26,000 years and that the rate of loss is unprecedented, at least since that time.
This process harms, for example, the development of species that build their shells or skeletons with calcium carbonate, such as corals or molluscs, and it can also affect phytoplankton.
It will be better for one of the typical Mediterranean jellyfish, the Cotylorhiza tuberculata,
— At the end of June, a four meter basking shark was sighted on the beaches of Oleiros (Galicia).
Shortly after, he appeared dead from a digestive obstruction caused by plastic objects.
It is one of the victims of the garbage dump that the oceans have become.
There are also animals that become entangled in pieces of plastic that cannot be freed, and microplastics (fragments smaller than five millimeters) have been found in the intestines of 58% of sardines and 60% of anchovies.
Nothing strange given that each year it is estimated that about 13 tons of this material end up in the sea.
If the trend is not reversed, scientists say, there will be more plastic than fish by 2050. Marine fauna also faces overfishing and especially harmful fishing gear such as trawl nets,
— It is essential to reduce greenhouse gases and commit to renewable energies.
Limiting warming to 1.5 degrees would require "rapid and large-scale mitigation" and an approach involving business, industry and all stakeholders, says the IPCC.
Organizations such as Oceana or Greenpeace denounce the lack of ambition of the Second UN Ocean Conference, held in Lisbon at the end of June, and call for a global treaty in which all nations commit to protecting at least 30% of international waters by 2030, where species would recover.
Spain aims to meet that figure and reach 25% in 2025. At the moment, only 12% of national waters are protected.
Conservationists warn that the measure must be effective.