Marine organisms such as corals and molluscs are under threat from the acidification of the seas.

The sea increases its acidity as it absorbs 30% of the carbon dioxide (CO2) produced by human beings. This phenomenon limits the availability and quality of food from the seas and reduces the services they provide.


With advanced techniques, the scientists of the network investigate the acidification of the seas to study and forecast its effects to support public policies aimed at mitigating and adapting to climate change.

PROBLEM.

The acidification of the oceans is occurring rapidly as a result of the increase in the emission of carbon dioxide, CO2, into the atmosphere, from the use of fossil fuels. This affects some marine organisms, such as corals and molluscs, which are particularly vulnerable to changes in seawater chemistry. The energy that organisms expend to overcome conditions of higher acidity reduces the energy available for physiological processes such as reproduction and growth.

Acidity levels are not the same throughout the planet and there is very little information available for Latin America and the Caribbean as it is a recent research topic for the region that demands the creation of new human and technological capacities.

Acidification negatively impacts marine ecosystems and the services that the sea provides to society. National economies dependent on tourism and fishing will be directly affected. In the region, the economic impact of ocean acidification will be different in each country. Countries such as Chile, Mexico and Peru have a high economic dependence on fishing resources, especially mollusc farming; while Colombia, Costa Rica and Cuba have a greater dependence on tourism associated with coral reefs.

Without the necessary information, it is not possible to identify the evolution of ocean acidification, which implies a serious risk to the great diversity of species and coral reefs that protect the coasts.

INFORMATION FOR ACTION.

The network aims to provide information to establish the current levels of ocean acidification and analyze long-term trends and thus promote policies aimed at reducing CO2 emissions. These policies are necessary to prevent the loss of marine species of commercial interest and the disappearance of coral reefs.

In the North Pacific, this information on the impact of acidification on organisms has made it possible to modify production processes on a large scale.

With this information, the authorities have the scientific basis to develop policies to reduce CO2 emissions, which must include the transition to low-carbon economies and raise society's awareness of environmentally responsible behavior, such as promoting sustainable transport. It aims to protect, restore and extend ecosystems that capture CO2 in the long term, such as mangroves, salt marshes and seagrass beds, known as “blue carbon” ecosystems.

To do this, new technologies, capacities and methodologies must be developed to fill the current information gaps in the region. One of the ways is by monitoring acidification and studying its effects on some marine organisms.

The network allows to help meet the United Nations Sustainable Development Goal 14, Life Below Water, to minimize and address the effects of ocean acidification and foster scientific cooperation, increase knowledge and transfer marine technology.

THE SCIENCE.

Nuclear and isotopic techniques are effective tools to study ocean acidification and have greatly contributed to understanding the effects of this problem, for example in the study of biological processes such as calcification.

When the level of acidity increases and the concentration of carbonates decreases, environmental conditions become corrosive to organisms that use calcium carbonate to produce their shells and skeletons. Scientists use nuclear techniques, with radioactive isotopes such as calcium-45 and carbon-14, to study and understand the present and future effects of acidification.

Corals make it possible to reconstruct the environmental conditions of the past. Its annual growth bands are revealed by X-ray techniques. Network scientists use mass spectrometry techniques to measure the isotope boron-11, which makes it possible to determine the acidity of water in the past, and uranium/thorium to determine the age of fossil corals.

The network has scientists trained in these techniques to accurately measure ocean acidification.