CCMAR’s research extends far beyond the Algarve coast. From the temperate Atlantic to the Southern Ocean, our researchers are seeking answers to fundamental questions about how marine ecosystems function and change.
In March of this year, two CCMAR researchers returned from Antarctica after participating in distinct yet complementary scientific expeditions. They returned with new samples, data and perspectives on some of the most extreme and sensitive environments on the planet.
Working in Antarctica is an exercise in international collaboration in itself. Without a permanent national base, Portugal operates within the infrastructure of other countries, making these campaigns valuable opportunities to strengthen scientific partnerships. Pedro Guerreiro carried out his work from Chile’s Escudero Base and Caio Ribeiro's team operated from the Chinese Great Wall Station on King George Island.
When adaptation can become vulnerability
As part of the COOLFISH project, Pedro Guerreiro and José Teixeira — a Master's student of Marine Biology who joined the team — focused on Antarctic fish and their remarkable adaptations to extreme cold. Some species have developed antifreeze proteins to prevent ice formation in their tissues, while others have lost haemoglobin entirely, resulting in transparent blood. These are both rare evolutionary solutions that enable survival in waters ranging from -2°C to 4°C.
But could traits that have been advantageous for millions of years become liabilities? In collaboration with CIIMAR and international partners, the project aims to determine whether these adaptations are reversible, or if they limit the ability of these species to respond to a rapidly changing, warming ocean. One of the questions under investigation is the function of aglomerular kidneys, which lack a filtration system and help to prevent the loss of antifreeze proteins.
By collecting larvae and juveniles, conducting genomic analyses and carrying out experiments under varying environmental conditions, the team is working to understand the limits of adaptation in these Antarctic fish. This knowledge is essential not only for understanding their biology and evolution and anticipating the impacts of climate change on the ocean, but also for its significant biotechnological potential. Some of these traits mirror human conditions such as anaemia and low bone density, making these species promising models for biomedical research.
Where the ocean reveals its first signs of change
In parallel, the expedition joined by Caio Ribeiro, as part of the POLAR-BIOMAP project, focused on how polar ecosystems respond to climate change. In the King George Island region, the team conducted both coastal and offshore sampling campaigns, analysing everything from phytoplankton communities to the physical and chemical properties of seawater.
The aim is to understand how factors such as rising temperatures and ocean acidification affect primary productivity, biogeochemical cycles, and the stability of food webs. In total, ten sampling stations were carried out, combining water and plankton collection with in situ measurements, supported by laboratory analyses and environmental modelling.
This integrated approach brings together chemical oceanography, microbial ecology, and ecotoxicology, enabling the identification of potential tipping points in highly sensitive ecosystems, with implications that extend far beyond polar regions.
What Antarctica tells us about our future
Despite the geographical distance, the knowledge generated through these expeditions has direct relevance for other regions, including Portugal. The poles act as sentinels of climate change, where environmental shifts occur more rapidly and intensely.
By studying the limits of life under extreme conditions, CCMAR researchers contribute to a more comprehensive understanding of the ocean and help anticipate future scenarios that may also affect Atlantic coastal ecosystems.
