Figure 2 . a . Shaded areas indicate the annual
percentage of days with southwesterly waves due to winter storms; colors
indicate wave height (see the scale). The bars indicate the mean density
± standard deviation (SD) of Diadema africanum before and after
the mass mortality events on La Palma and Tenerife. Averages were
calculated using the Abades, Boca Cangrejo and Teno site density data
for the studied years on Tenerife Island and the Pta. Fraile, Playa del
Pozo, Pta. Fuencaliente and La Bombilla sites on La Palma Island. Red
arrows indicate the mass mortality year. b . D. africanumindividuals showing first signs of the disease on the ambulacral plates
column, and a general view of the Las Galletas site on the southwest
coast of Tenerife (Photos: José Carlos Hernández and Antonio Espinosa).