Westerhall
Location: St. David, Grenada
Site Type: Basin mangrove wetland; reference site for long-term ecological monitoring
Overview
The Westerhall mangrove is one of Grenada’s key reference wetlands, selected for long-term monitoring because of its relative stability and representative structure. Located in St. David, it forms a basin-type mangrove where tidal exchange is restricted and water often remains pooled for long periods. This environment supports specialized plant and animal communities and provides a valuable comparison to more disturbed sites elsewhere on the island.
Ecological Monitoring
Vegetation surveys confirmed that Westerhall supports all three Caribbean mangrove species: red (Rhizophora mangle), black (Avicennia germinans), and white (Laguncularia racemosa). Dense red mangrove roots line the wetland edges, while taller black mangroves grow further inland. Stable isotope testing of mangrove leaves showed a strong mix of seawater and freshwater influence, reflecting the semi-enclosed character of the basin.
Between January and May 2020, survey teams recorded a wide variety of birds. They observed residents such as the Antillean Crested Hummingbird (Orthorhyncus cristatus), Gray Kingbird (Tyrannus dominicensis), Bananaquit (Coereba flaveola), and Grenada Flycatcher (Myiarchus nugator). Wetland specialists like the Green Heron (Butorides virescens), Snowy Egret (Egretta thula), and Yellow-crowned Night-Heron (Nyctanassa violacea) also used the site. Migrants including the Barn Swallow (Hirundo rustica), Spotted Sandpiper (Actitis macularius), and Semipalmated Sandpiper (Calidris pusilla) highlighted Westerhall’s role as a stopover for birds traveling across the Caribbean.
Fish surveys revealed an active aquatic community. Researchers identified Atlantic Trumpetfish (Aulostomus maculatus), French Grunt (Haemulon flavolineatum), Mangrove Snapper (Lutjanus griseus), and Yellowtail Snapper (Ocyurus chrysurus). Small benthic feeders like gobies (Gobiidae) and blennies (Labrisomidae) occupied the mangrove roots, while predators such as barracuda (Sphyraena barracuda) patrolled the open water. This mix of small and large species showed that Westerhall sustains a complete food web, with mangroves providing essential nursery habitat.
Archaeological Context
Archaeologists have not confirmed a settlement directly within the Westerhall mangrove. However, Dr. Jonathan Hanna’s predictive model of settlement patterns shows that this area was highly suitable for Amerindian occupation, most likely more than 1,100 years ago. The model uses environmental features - such as fertile soils, access to freshwater, and proximity to marine resources - to highlight where past communities were most likely to live. This means that, even though no artifacts have yet been documented inside the wetland, the surrounding coastal zone may once have supported early settlements.
For more archaeological background and site inventories, see: grenadaarchaeology.com.
Conservation Significance
As a relatively intact basin mangrove, Westerhall provides a crucial baseline for comparison with more impacted wetlands in Grenada. Its role as a reference site means data collected here can help interpret changes observed in other mangroves, from vegetation shifts to bird and fish populations. Protecting Westerhall is therefore important not just for its own biodiversity, but also for understanding and managing the health of Grenada’s coastal ecosystems more broadly.