1. Before and after a disease outbreak: tracking a keystone species recovery from a mass mortality event
- Author
-
Nuno Castro, Susanne Schäfer, Ricardo José, João Canning-Clode, Sónia Costa, Francesca Gizzi, João Monteiro, Jesús Jiménez, and Sílvia Lourenço
- Subjects
0106 biological sciences ,Population ,Aquatic Science ,Biology ,Citizen science ,Oceanography ,010603 evolutionary biology ,01 natural sciences ,Population density ,Disease Outbreaks ,Madeira ,Abundance (ecology) ,Animals ,Marine ecosystem ,Disease ,14. Life underwater ,Keystone species ,education ,Pathogen assessment ,Ecosystem ,Population Density ,geography ,education.field_of_study ,geography.geographical_feature_category ,Bacteria ,Portugal ,Ecology ,010604 marine biology & hydrobiology ,Outbreak ,General Medicine ,Pollution ,Long-spined sea urchin ,Habitat ,Sea Urchins ,Archipelago ,Widespread die-off ,Environmental Monitoring - Abstract
Mass mortality events involving marine taxa are increasing worldwide. The long-spined sea urchin Diadema africanum is considered a keystone herbivore species in the northeastern Atlantic due to its control over the abundance and distribution of algae. After a first registered mass mortality in 2009, another event off the coasts of Madeira archipelago affected this ecologically important species in summer 2018. This study documented the 2018 D. africanum mass mortality event, and the progress of its populations on the southern coast of Madeira island. A citizen science survey was designed targeting marine stakeholders to understand the extent and intensity of the event around the archipelago. Underwater surveys on population density prior, during and after the mass mortality, permitted an evaluation of the severity and magnitude of the event as well as urchin population recovery. A preliminary assessment of causative agents of the mortality was performed. The event was reported in the principal islands of the archipelago reducing the populations up to 90%. However, a fast recovery was registered during the following months, suggesting that the reproductive success was not compromised. Microbiological analyses in symptomatic and asymptomatic individuals, during and after the event, was not conclusive. Nevertheless, the bacteria Aeromonas salmonicida, or the gram-negative bacteria, or the interaction of different types of bacteria may be responsible for the disease outbreak. Further studies are needed to assess the role of pathogens in sea urchin mass mortalities and the compound effects that sea urchins have in local habitats and ecological functioning of coastal marine ecosystems. info:eu-repo/semantics/publishedVersion more...
- Published
- 2020