Are shifts in sea urchin diet on P. oceanica meadows within CO2 vents, directly linked to effects of ocean acidification?

During the past 200 years, one-third of the CO2 from human activities is being taken up by the oceans, causing a rise in CO2 levels and a pH decrease ('ocean acidification; hereafter OA). An additional pH decrease is expected by 2100. These changes are expected to alter the nutritional value of primary producers and, consequently, the flow of matter and energy to herbivores. In this study, we compare the diet of Paracentrotus lividus in control and naturally CO2-enriched sites within Posidonia oceanica meadows, in Ischia Island (Italy), using areas with naturally high CO2 from volcanic vents to investigate long-term effects of future OA. Given the particular relevance of the epibiont community that lives in seagrass leaves on P. lividus diet, OA effects on this community were also assessed. We found no significant change in the composition of urchin´s diet, however shifts were detected in the relative abundances of the species present in the gut content between the control and the low pH sites. Similarly, significant differences were found in the abundance and also in the composition of the epibiont community between the control and the low pH sites, which on average accounted for approximately 16 % and 9 % of P. lividus´ diet, respectively.

Promotor(s) & Supervisor: Begoña Martinez-Crego

ISCED Categories

The highlighted icons, represent the fields of education (in compliance with ISCED Classification) engaged during this course/programme.

0511 - Biology", "0521 - Ecology