Monday 5 December 2011

Extracts from the past: On Pasture Bay Beach


Whilst looking at old paperwork from the history of the project I found this very interesting paragraph.

‘The beach at Pasture Bay is historical and natural, although it has been greatly modified in the last century by man. Pasture Bay forms a cul-de-sac facing into the easterly prevailing winds, with extensive shallow reefs of coral and marine algae occurring immediately offshore. Wave chains entering the bay from the east are deflected to the southwest by Homer Point so as to apply maximum energy levels to the central portions of the Bay. Beach sand is calcareous, derived primarily from fragments of calcareous algae and, to a lesser extent, from coral. Historically, Pasture Bay beach vegetation was a mixed maritime forest community of trees and shrubs growing densely to the high water line. Sand, moved by the wind and waves onto the beach, was trapped within a few meters of the water’s edge by the dense vegetation. Wind rows of algae and marine grasses were deposited on the high tide line, providing a source of nutrient rich organics to be mixed into the sand. A sloping dune of 1 to 3 meters in height, stabilized by the shrubs and the trees, rose gradually from the water’s edge to provide the nesting habitat most preferred by Caribbean hawksbills. Because of the protection … the shoreline probably did not fluctuate by more than a meter in any year. An extensive deposit of sand was held by the beach forest to provide continuously available nesting habitat, regardless of the erosional or depositional cycle of the shoreline.’
‘At some point in the previous decades, the maritime forest was cleared from Pasture bay for grazing sheep … recreational access to a sandy beach with scattered clumps of seagrapes … . As a result foreshore (0 -10m) beach sand was blown back and away from the high water line, forming a vegetated rear dune too distant from the water for the hawksbill to use. The problem has been exacerbated  … by intense cleaning of the beach and berm … such that no blade of grass or fragment of leaf was left to slow the wind with its drifting sand. Without dynamic offshore sand bars to replenish the loss, existing supplies of sand were robbed from the lateral ends of the Pasture Bay, and the overall shoreline has receded, perhaps as much as 10m from historic dimensions.  By 1986, conditions had deteriorated until significant portions of the beach were rendered unsuitable for nesting because of exposed limestone rock, cobble beach, eroded root mats, and permanent pasture.

Pasture Beach, Middle section c.2000. The planting of the veg beds. ©JBHP.

Pasture Bay Beach, North end c.1990. ©JBHP

 The text is an extract from :
Hoyle, M. and Richardson, J.I. (1993). Survivorship, Mortality, Recruitment and Reproductive biology and Behavior of Adult Female Hawksbill Sea Turtles (Eretmochelys imbricata) Nesting at Pasture Bay, Long Island, Antigua, W.I. 1987 – 1992. Technical Report prepared by The Georgia Sea Turtle Cooperative, Institute of Ecology, University of Georgia, Athens, Georgia. 25 July 1993.