An international team of specialists reconstructed the evolutionary history of ophiuroids, a group of marine echinoderms related to starfish, present in all oceans and ocean depths worldwide.
This study, published in the journal Nature, used genetic analyses of hundreds of species to understand how biodiversity is distributed in the oceans and how ecosystems are connected on a global scale.
Researcher Martín Brogger from the Institute of Marine Organism Biology (IBIOMAR-CONICET), based in CENPAT in Puerto Madryn, participated in the study, contributing relevant data from the deep South Atlantic through records from oceanographic campaigns in the Argentine Sea and Antarctica.
The results show that the current genetic diversity represents only a fraction of the evolutionary legacy that existed in the past: over 60% of ophiuroid species have gone extinct, leaving isolated assemblages adapted to specific conditions in unique marine biomes.
Abyssal connectivity versus coastal diversity: key findings for conservation
According to the study, in abyssal regions – extremely deep, cold, and high-pressure environments – shared genetic lineages between very distant areas (such as between the North Atlantic and southern Australia) demonstrate global evolutionary connectivity.
However, in intermediate and coastal zones, geographical and thermal barriers restrict genetic flow, leading to regional assemblages that maintain differentiated biological identities for millions of years.
“The study shows that each deep-sea environment has a unique and irreplaceable set of species. Therefore, protecting each region individually becomes essential in conservation strategies,” says Brogger.
Although there is genetic interconnection in abyssal zones, it is not enough to homogenize biodiversity. Each marine territory maintains its own biological signature, with high genetic diversification and strong regional differentiation.
Argentina and the South Atlantic: unexplored biomes to understand evolutionary history
Argentina’s participation was crucial in incorporating one of the least studied but most extensive regions on the planet into the study.
Thanks to the biological collections of IBIOMAR-CONICET and the Argentine Museum of Natural Sciences (MACN), fundamental samples from the deep South Atlantic were included, reinforcing the strategic role of our country in international scientific networks.
“Without these collections, which are a critical scientific infrastructure, this global study would not have been possible. They allow for the inclusion of valuable data from areas with limited representation in ocean science,” emphasizes Brogger.
The research emphasizes that deep ocean biodiversity is neither replicable nor uniform, and understanding these distribution patterns is essential for formulating effective marine conservation policies, both regionally and globally.
In this regard, Brogger highlights that “Argentina, due to its bathymetric and latitudinal breadth, harbors a true oceanic puzzle, with a great variety of unique biomes of enormous value to the world’s biological heritage.”
