Bertarelli-Annual-Report-2023-R9-low (1) - Flipbook - Page 38
37
Conservation
Impacts
Bertarelli Foundation
Research on nutrient
pathways leads to
plans underway for
Indian Ocean
Researchers in the Marine Science programme have
pioneered understanding into how seabirds provide
important nutrients across tropical islands and coral
reefs. Most of these nutrients are in the form of guano
(excrement) which help drive nitrogen and phosphorous
cycles. The importance of these nutrients has been
demonstrated by measuring the differences between
coral reefs off islands with healthy seabird populations
and those with invasive rats. Reef fish biomass is 48%
higher off rat-free islands and rates of two critical
ecosystem functions, grazing and bioerosion, over three
times higher adjacent to rat-free islands. Parrotfish
around rat-free islands grow 35% faster and their overall
mean body size is 16% larger. While seabird nutrients
do not enhance resistance to coral bleaching, they may
promote reef recovery due to their positive influence on
calcareous algae and herbivorous fishes. This year, the
team’s latest paper (Benkwitt et al., 2022) shows that
seabird biomass is particularly important for providing
terrestrial and near-shore nutrients, while seabird
diversity is important for offshore nutrients.