A marine heat wave can bring an overpopulation of jellyfish

Asexual reproduction of the polyps of the jellyfish 'Aurelia aurita'. / N.Huot

The ULPGC researcher Vanesa Romero demonstrates in her thesis that heating increases the frequency of reproduction

CANARY ISLANDS7 The Gran Canarian palms

Jellyfish are organisms
with a great capacity to adapt to the environment. These animals, among the oldest on the planet, show great stability in the face of adverse external factors such as starvation, hypoxic conditions, and ocean acidification, which seems to have contributed to their survival for around 600 million. of years.

The doctoral thesis of the Canarian researcher Vanesa Romero Kutzner provides further evidence of her ability to adapt to the environment, by studying the metabolic response of 'Aurelia aurita' (also called the common jellyfish),
having been artificially subjected to marine heat waves linked to climate change. And the result is that it can increase its reproduction.

The important consequences of marine heat waves on the loss of biodiversity have been proven. However, the results of the Canarian researcher, from the Eomar Group of the University Institute for Research in Sustainable Aquaculture and Marine Ecosystems (IU-Ecoaqua) of the ULPGC, indicate that the polyps of the 'Aurelia aurita' are capable not only of surviving,
but to increase the frequency of its reproduction.

In addition, these polyps are capable of recovering their metabolic rates when they return to their usual temperature, after being exposed to the anomalous high temperatures simulated for the study, says Ecoaqua in a statement.

This ULPGC research, entitled 'The respiratory metabolism of marine plankton: analysis of time series in bacteria and jellyfish', used both a traditional method of measuring oxygen consumption and an enzyme-based method of analyzing the electron transport system ,
that allowed a more detailed study of respiratory metabolism.

As a result of the results achieved in the respiratory rate, it is also possible to calculate the carbon demand and, therefore, of prey that are necessary to satisfy this respiration.

The results on carbon demand, in four different species belonging to the phylum cnidaria, have been recently published in the scientific journal 'Frontiers in Marine Science'.

Other research results showed that, under starvation conditions,
more respiratory CO2 is produced, compared to the oxygen consumed. This finding has been fundamental in the conclusions, since it is commonly estimated that the relationship between the concentration of CO2 and respiratory O2 is direct. In this way, the variability in this relationship must be taken into account to calculate, for example, the carbon fluxes in the ocean.

Its about
first study of its kind carried out during the metamorphosis of jellyfish and its impact is relevant to the extent that its results can have a direct effect on the economy of coastal areas when there is an increase in colonies.

Overpopulation has a direct impact on tourism, for the deterrent of bathers due to their bites. They also warn about the consequences in aquaculture and industrial facilities, damaging fish and other marine species, or affecting seawater intakes in desalination plants.

More than 2,000 species of an organism that is 95% water

More than 2,000 species of jellyfish are known. It is a simple organism, which practically lacks organs (more than 95% is water). Thanks to its ability to adapt and its strategic life cycle, which covers different ecological niches, it is expected that this species can proliferate in future anthropogenic conditions, even recovering its role as a monopolistic predator, says the statement from the Ecoaqua institute.

Vanesa Romero's thesis has been directed by two professors from the ULPGC, Professor May G├│mez and Dr. Ted Packard. Both the author of the thesis (who obtained a cum laude grade) and the directors belong to the Ecophysiology of Marine Organisms (EOMAR) research group at IU-ECoaqua. The development of this thesis has been possible thanks to the scholarship of pre-doctoral contracts of the ACIISI, and the European Social Fund.

During his academic career, Romero has received recognition from La Caixa for his remarkable record in the Marine Sciences degree. He has also been a speaker at numerous international conferences, such as the Ocean Science Meeting or the Jellyfish Bloom International Symposium (Cape Town) .

Source link