Aquatic ecosystems of rivers, lakes, and streams continue to be the most overlooked in global conservation strategies. Despite their ecological, social, and economic importance, freshwater biodiversity remains underrepresented compared to the prominence of marine environments and charismatic species.
This invisibility is also reflected in the United Nations Sustainable Development Goals (SDGs): SDG 14 focuses on oceans and SDG 15 on terrestrial ecosystems, leaving out much of the freshwater aquatic diversity.
The study that reveals the gap
A study published in the journal Water Biology and Security analyzed this gap. It was conducted by researchers from Brazilian and international institutions, such as the Federal University of Western Pará, the Federal University of Pará, the University for International Integration of the Afro-Brazilian Lusophony, and the Marine Science Center of the University of Algarve.
The team thoroughly reviewed scientific literature to identify:
- Which species are used as indicators in priority conservation areas.
- Which aquatic environments receive more attention.
- What methods and criteria guide the choice of species.
Predominance of charismatic species
The analysis showed a strong concentration in the phylum Chordata, which represents more than 70% of the studied species. Among them are:
- Bony fish.
- Aquatic mammals.
- Reptiles and birds.
Frequent examples are the loggerhead turtle (Caretta caretta), the bottlenose dolphin (Tursiops truncatus), the green turtle (Chelonia mydas), and the European otter (Lutra lutra). These species are often classified as “Vulnerable” or “Endangered,” reinforcing their role as symbols of alert.
However, the study also identified species at lower risk, such as the Posidonia oceanica, which appear due to their ecological or cultural relevance. The presence of aquatic plants and invertebrates, although minor, indicates the potential to expand taxonomic diversity in conservation strategies.
Selection criteria: limited and biased
The main criteria used to choose flagship species are:
- Conservation status (threatened in national and international lists).
- Visual appeal and charisma (dolphins, turtles, large fish).
- Ecological importance (trophic position, functional role).
- Geographic distribution and endemism (species restricted to vulnerable regions).
- Cultural and economic value, still little considered.
The predominance of visual attributes demonstrates a limited view that restricts the scope of conservation policies.
Geographical inequality in research
Most studies come from the global north (North America, Europe, and Asia), which accentuates the bias and leaves tropical freshwater ecosystems invisible. In megadiverse regions like the Amazon, this lack of scientific and political prominence perpetuates the vulnerability of its species.
The study proposes to decentralize research and strengthen the science produced in the global south, integrating local knowledge and demands from traditional communities.
The research shows that global conservation strategies remain focused on charismatic marine species, while freshwater ecosystems remain invisible.
To achieve fairer and more effective policies, it is urgent to expand selection criteria, integrate ecological and sociocultural dimensions, and give prominence to researchers and communities from the global south. Only then can aquatic biodiversity be protected and sustainable development ensured in territories like the Amazon.
