DRAFTING…
1. Historical
Following are extracts related t0 successional processes in seagrass beds from a draft paper I wrote in the 1980s based on my observations at Barbados & Carriacou 1967-70.
 Fig. 1. Conceptual model of shallow water (<3-4m) successional processes in seagrass beds. Relationships were inferred from observations made at Barbados and Carriacou, 1968-1970Stabilizing organisms include bottom epifauna and flora such as rhizomatous seaweeds, several species of seagrasses, and sessile fauna such as sponges, gorgonians, and corals.
 Fig. 2. Further details of hypothesized successional sequences. There is a succession of different species associated with increasing degrees of bottom stabilization (see Fig. 2). Annual swells prevent sustained establishment of early successional stages (including seagrasses). Storm events cause formation of blowouts in seagrass beds, which subsequently migrate seaward accross the beds, keeping the beds in earlier stages of succession (the most common state). In earlier and mid to later successional stages, destruction of the protective seagrass canopy by sea urchin overgrazing (associated with massive populations) can lead to large scale destruction of the beds by wave action. Very stable systems may develop monolithic structures (bound together by sponges, coralline algae) that eventually exclude seagrasses. Earlier stages of the successional sequence, cited in Patriquin, 1975, have been documented by other researchers (e.g. Williams, 1990) but no comparable schemes appear to have been elaborated for later successional stages. However an apparently unpublished, or later published manuscript – “Succession and Composition of the Thalassia Community – by Ramon Margalef and Juan Rivero from the late 1950s or early 1960s outlines a similar concept, and similar associations of species in Puerto Rico – see References Patriquin, D.G. 1975. Migration” of blowouts in seagrass beds at Barbados and Carriacou, West Indies, and its ecological and geological implications Aquatic Botany Volume 1, Pages 163-189. View PDF Williams, S.L. 1990 Experimental Studies of Caribbean Seagrass Bed Development in Ecological Monographs PDF |