**Part 3**

**Tidal and Wave Dynamics: Estuaries and Bays** 

152 Hydrodynamics – Natural Water Bodies

Stumpf R.P., Gefelbaum G. and Pennock J.R. (1993). Wind and tidal forcing of a buoyant

Yankovsky E. and Chapman D.C. (1997). A simple theory for the fate of buoyant coastal discharges. *Journal of Physical Oceanography* 27 (1997), 1386–1401 ISSN: 1520-0485. Warrick J. A. and Stevens A. W. (2011). A buoyant plume adjacent to a headland—

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plume, Mobile Bay, Alabama. *Continental Shelf Research* 13, 1281-1301. ISSN: 0278-

observations of the Elwha River plume. *Continental Shelf Research*, 31,85-97. ISSN:

**8** 

*Jamaica* 

**The Hydrodynamic Modelling of** 

**at the Center of Bay Circulation** 

Ava Maxam and Dale Webber

*University of the West Indies* 

**Reefal Bays – Placing Coral Reefs** 

Reefal bays are a common type of bay system found along most Caribbean coasts including the Jamaican coastline. These bay systems are associated with and delimited by arching headland with sub-tending reef arms broken by a prominent channel. Traditionally, these bays are termed "semi-enclosed" as their limits are defined by the sand bar or reef partially cutting off waters behind them from open sea (Nybakken, 1997). Yet, it has been shown that circulatory patterns emanating from the lee of reef structures can persist beyond the forereef (Prager, 1991; Gunaratna et al., 1997). This raises the possibility of re-characterizing these systems where the reef is defined as the centre of a dynamic bay, inducing a continuous re-circulation of the inside waters beyond the traditional limit (Figure 1). In this study, hydrodynamic modelling, particle tracking and a novel gyre analysis method were used to assess the reefal bay's signature spatial and temporal patterns in circulation, with the goal of characterizing the reefal bay as unique in its function. This was carried out on the

Hellshire southeast coast of Jamaica where four of seven bays are typical reefal bays.

Fig. 1. A number of hypothetical bays are presented where A represents the open bay, B the traditional definition of the reefal bay, and C the reef proposed as circulatory centre of the

Reef systems often function to reduce the shoreline wave action and influence sediment dynamics. They therefore provide the ecological link between land and sea, as nurseries offering protection for marine life, as recreational sites, and as receiving sites for industrial

**1. Introduction** 

reefal bay system.
