The research, involving internationally renowned institutions in the US, Australia and Switzerland, shows that the convergence of marine species in temperate and polar regions is not only due, as previously thought, to the impact of environmental conditions such as climate, but also to competitive biotic mechanisms
This scientific finding is highly significant as it highlights the importance of incorporating biotic interactions into global species distribution models in response to climate change, something that has been largely ignored until now
An international research project led by Dr Néstor E. Bosch, a member of the Biodiversity and Conservation (BIOCON) group at the ECOAQUA University Institute, part of the University of Las Palmas de Gran Canaria (ULPGC), reveals for the first time in the marine environment that biological interactions play a fundamental role in the assembly and ecological similarity of reef fish communities at high latitudes, beyond what was initially thought.
Traditionally, it has been considered that the latitudinal gradient in diversity, in which the number of species decreases from the tropics to higher latitudes, is directly related to environmental factors such as temperature and climatic stability. However, this study, recently published in the prestigious Journal of Biogeography (JCR Impact Factor: 3.6; Ranking: 48/200 Ecology (Q1)), shows that biological interactions between organisms have a much greater influence in temperate and polar regions than science has established for these latitudes to date.
These biotic interactions have always been considered key in the tropics, where environmental conditions have been more stable throughout evolutionary history, allowing species to specialise in their ecological niche so that they can coexist without displacing each other.
On the other hand, explains Bosch, lead author of this study, ‘in temperate and polar regions, where climatic conditions have been more unstable,’ the environment (e.g., temperature) has traditionally been given ‘a more important role’ than the aforementioned interactions, ‘selecting those organisms with biological characteristics that allow them to survive, grow and reproduce in those environments.’
The study, entitled “Biotic Mechanisms Strengthen Functional and Phylogenetic Convergence of Reef Fish Assemblages at Higher Latitudes”, analyses for the first time in the marine environment to what extent this process of biological interaction explains the similarity in ecological traits of species inhabiting temperate latitudes, using a novel conceptual framework that allows the effect of the environment to be eliminated first.
BIOCON/ECOAQUA researcher Dr Néstor E. Bosch conducting a census of marine life in the kelp forests (Ecklonia radiata) of the Abrolhos Islands (Western Australia).
The analysis was based on empirical data from more than 3,325 reef fish communities across more than 100 degrees of latitude, using advanced statistical techniques to separate environmental effects from biotic effects.
The study shows that the convergence in the biological characteristics of species present at high latitudes responds not only to environmental demands, but also to biotic competitive processes, which encourages the prevalence of similar ecological traits in temperate and polar environments. This mechanism, previously observed in studies with terrestrial plants, is documented for the first time in marine fish on a global scale in this research.
‘Our results show that convergence in biological traits that determine fitness for living at high latitudes is not only due to an environmental effect, but also to a biotic process in which generalist species with a high degree of mobility exclude species that are competitively inferior in exploiting a range of limited resources,’ says Néstor E. Bosch.
Climate change and the Canary Islands
The results of this study highlight the dual role of the environment and biotic interactions in the assembly of current ecological communities. At a practical level, these results are ‘highly relevant as they highlight the importance of incorporating biotic interactions into species distribution models in response to climate change, something that has been largely ignored until now,’ notes the ECOAQUA researcher.
Coral reef communities sampled by BIOCON/ECOAQUA researcher Dr Néstor E. Bosch during campaigns in Western Australia organised by the Reef Life Survey foundation (https://reeflifesurvey.com/).
According to Dr Bosch, these results ‘indicate that it is not enough to consider climate and environment to explain the structure of marine communities. Competition and relationships between organisms also have a significant effect, especially under limiting conditions. That is why it is essential to preserve ecosystems and their complex interactions if we want to anticipate, for example, the effects of climate change or the arrival of invasive species.’
This scientific finding is essential for island regions such as the Canary Islands, where human pressure and environmental impacts test the resilience of marine ecosystems. Incorporating biotic interactions into prediction models will improve climate change management, marine protected area planning, and responses to the introduction of invasive species. The integrity of ecological relationships ensures greater community resilience to environmental disturbances.
In addition to ECOAQUA, the study involved six other internationally renowned researchers from prestigious institutions such as the Institute for Marine and Antarctic Studies (University of Tasmania, Australia), the Centre for Environmental Science (University of Maryland, USA), the Institute of Ecology and Evolution (University of Bern, Switzerland), the Department of Fish Ecology and Evolution (Swiss Federal Institute for Aquatic Science and Technology, Switzerland), and the Smithsonian Environmental Research Centre (USA).
This article has been produced as part of the Juan de La Cierva-Formación programme, which funds the postdoctoral contract of Dr Néstor E. Bosch, financed with funds from the Ministry of Science, Innovation and Universities, the State Research Agency and the European Union through the Next Generation EU programme. All analyses and data used are open access through the Reef Life Survey programme (https://reeflifesurvey.com/) and the Australia Ocean Data Network (AODN, https://portal.aodn.org.au/).
You can find the scientific article via this link: https://onlinelibrary.wiley. com/doi/full/10.1111/jbi.70011