According to a study done by the Seabird Ecology Group of the Faculty of Biology and the Biodiversity Research Institute (IRBio) of the University of Barcelona, the impact of the rise in sea temperatures predicted by the Intergovernmental Panel on Climate Change (IPCC) could have an impact on the survival of the North Atlantic populations of Bulwer’s petrel in the Azores, Canary Islands, and Cape Verde. According to the study’s findings, which were published in the journal Science of the Total Environment, the seabird population of Cape Verde would be the most vulnerable to the new climatic conditions.
The Procellariidae family of pelagic seabirds includes the Bulwer’s petrel (Bulweria bulwerii), which eats fish, cephalopods, and crustaceans. The species nests in the Macaronesian archipelagos in the Atlantic Ocean, primarily on sea cliffs, small islets, and coastal rocks. Most birds from the Azores and Canary Islands spend the non-breeding season in the central Atlantic, while the rest of the birds from these islands and all of the birds from Cape Verde move to the South Atlantic.
The study examines how the seabird populations in temperate or tropical regions are affected by climate change. The majority of demographic studies on seabirds have prioritized sampling in Arctic or Antarctic regions because, according to Raül Ramos, lecturer at the Department of Evolutionary Biology, Ecology and Environmental Sciences of the UB and IRBio, “the effects of climate change have always been predicted to be severe in polar environments.” “Our study,” the researcher continues, “gives us the chance to test the hypothesis that the impact of climate change will undoubtedly not only affect species from polar latitudes but also other species confined to more tropical environments.”
Cape Verde’s populations are the most vulnerable ones.
The paper examines the potential effects on North Atlantic populations of a number of variables, including the increasing sea temperature, the North Atlantic Oscillation Index, the Southern Oscillation Index, and the wind. According to the study’s findings, the factor that has the biggest negative impact on the adult survival of the three different populations of Bulwer’s petrels is the rising sea surface temperature.
“Seabird populations in all three populations are expected to be indirectly impacted by sea temperature, with common elements. In other words, it is not that climate change may cause birds to experience more or less cold, but rather that these negative effects may have an impact throughout the trophic chain. So, changes in temperature could affect the amount of nutrients and plankton in the primary feeding grounds of Bulwer’s petrels, which could change the number of prey.The study’s first author, researcher Marta Cruz-Flores (UB-IRBio), makes this observation.
The tropical population of Cape Verde would be the most impacted by the increase in sea temperature, according to IPCC projections (2090–2100), which would be explained by the interaction of several factors. According to Professor Jacob González-Sols, head of the UB Seabird Ecology Group, “the first factor, possibly the most relevant one, is that tropical regions are the areas where IPCC models predict the sharpest temperature rise in any of the studied scenarios (2090–2100).”
Second, because petrels in this population experience the narrowest temperature range of any — they are accustomed to a more stable temperature range — any rise in temperature could agitate them even more. In addition, unlike other subtropical and temperate populations of the species, the tropical Cape Verde population is a permanent resident; as a result, individuals are affected by the same habitat and environmental factors all year long.
How will the Bulwer’s petrel adapt to climate change?
In the future, the ability of the Bulwer’s petrel to lessen the effects of climate change may depend on how well it can adapt to changing environments and hunting grounds.
Depending on the species, seabirds have a life expectancy of between 15 and 50 years. Adults typically prioritize their own survival over reproductive efforts—for example, when faced with any kind of relatively abrupt environmental change. “The individual plasticity of these species should therefore enable individuals to adapt to the changes in order to lessen the effects of climate impact on their populations, even though our study predicts a severe impact of climate change on the survival of the species,” Raül Ramos says.
The global threat to the preservation of species is not just climate change. The issues with species conservation are actually worse on the land where seabirds only breed. “The populations of petrels in the Atlantic, Pacific, and Indian oceans are in danger due to the introduction or predation of terrestrial predators like rats, cats, and other animals that feed on eggs, chicks, and even adults. On the few uninhabited islets and islands in the areas where the species is distributed, the availability of nesting habitat—burrows or holes where adults can lay eggs, incubate eggs, and feed chicks—is a serious issue. Take note of the professionals.
Seabirds are threatened globally
The indirect temperature effects discussed in this article may also have an impact on other seabird species that live in tropical and subtropical oceanic environments. Stormbirds, shearwaters, and other petrels that breed in the Caribbean or Macaronesian archipelagoes could serve as examples.
The article in this context emphasizes the value of metapopulation studies, which combine data and information from various populations of the same species in order to comprehend global demographic processes. When analyzing the trends and threats affecting a species in a specific location, when in reality it has a wide distribution, demographic studies focused on a specific population, while also of great scientific value, are frequently inconclusive.
Accordingly, metapopulation studies like the one we recently published, “despite being much more expensive on an economic, logistical, temporal, and personal level, are decisive for understanding how species interact with the environment and thus foreseeing their adaptation strategies in the face of the challenge of climate change,” writes lecturer Raül Ramos.
