Rhodolith beds can contribute large amounts of CaCO3 to coastal environments, playing an important role in Carbon sequestration. The spatial distribution of rhodoliths is a consequence of their sensitivity to light intensity, currents, wave action, sedimentation rates, and salinity, whereas mesophotic, low sedimentation quiescent conditions are optimal. Although there is evidence of a clear relationship between hydrodynamics and rhodolith morphology and mobility, there are few studies relating wave action and rhodolith mobility. We aim to assess the mobility potential by waves, of the rhodoliths of the Abrolhos Shelf (Brazil), that contains the largest rhodolith field in the world. Based on the local wave climate and its propagation through the shelf, the rhodolith mobility potential was evaluated. Rhodolith mobility potential distribution is directly related to shelf morphology and incoming waves characteristics. Despite being restricted to deeper areas of the shelf (>20 m), rhodoliths in the area are mobilized by wave action, especially from the more energetic waves associated with storms. Waves can mobilize rhodoliths in the area, with mobility potential distribution being controlled by shelf morphology and seasonal wave climate. Largest areas of mobilization are observed during energetic waves conditions associated to the passage of cold fronts.

Depth range
20- 110 m

Mesophotic “mentions”
2 x (total of 4870 words)

Classification
* Presents original data
* Focused on 'mesophotic' depth range

Fields
Oceanography

Focusgroups
Algae (Macro, Turf and Crustose Coralline)

Locations
Brazil - Eastern Brazil