RT info:eu-repo/semantics/masterThesis
T1 Efectos de la larga exposición a condiciones de bajo pH en las estructuras calcáreas del erizo de mar Arbacia lixula (Linnaeus, 1758)
A1 Sosa Navarro, Naira
A2 Máster Universitario en Biología Marina: Biodiversidad y Conservación
AB The CO2 emissions due to human activities have caused the oceans to absorb a larger amounts of carbon dioxide. This situation has generated chemical reactions, leading to a decrease in pH and in the concentration of carbonate ions (CO32-) in seawater. This process is known as Ocean Acidification (OA) and has major repercussions on the physiological, ecological and behavioural functions of marine animals, especially in calcifying species, and it is considered a major threat to marine life. This study aims to determine the effects of OA on the sea urchin Arbacia lixula using a long-term natural experiment, the CO2 seeps system off Fuencaliente coast in La Palma Island (Canary Islands). In this area, there are spots were the pH drops to 7.56 units during low tide and a clear pH gradient can be found on the surrounding of those emission points. We have studied the external morphometry of the skeleton and Aristotle's lantern, as well as the fracture force, the sea urchin growth, and the mineralogy across the pH gradient.Regarding the growth of A. lixula, we have explored different growth rings reading techniques applied on the genital plates. The most useful techniques have been Moore, 1935 and Schuhbauer, 2010; with three other combinations of techniques, that also worked fine for reading rings. It was observed that in low pH zone, sea urchins decreased in body size and spine length but showed stronger test (more resistant to fracture). There was also a slight increase in the percentage of Mg in the calcite of the test and the lantern. These unexpected results have shown how these natural experiments are essential to understand the real consequences of OA on calcareous organisms.
YR 2022
FD 2022
LK http://riull.ull.es/xmlui/handle/915/28165
UL http://riull.ull.es/xmlui/handle/915/28165
LA es
DS Repositorio institucional de la Universidad de La Laguna
RD 10-may-2024