Abstract

Seagrasses are an important coastal habitat providing an array of ecosystem services (e.g. carbon sequestration, nutrient/toxin filtration, nursery habitat, and oxygen production). However, research and sustainable management of these critical areas are lacking, especially in the tropics. We set out to identify when flowering occurs for the seagrass species in Trinidad and Tobago and what may facilitate their pollination other than water movements. Some seagrass species flower at night and potential pollinators are also more active in the dark (Van Tussenbroek et al. 2016). Therefore, we scheduled our weekly surveys in Williams Bay, Trinidad and Bon Accord Lagoon, Tobago for the evenings. Our data since June 2022 show turtle grass (Thalassia testudinum) flowering may be triggered by the start of rainy season (flowers from end of April to mid-June in Tobago and extending into July in Trinidad). Shoal grass (Halodule wrightii) flowers were seen only in Trinidad and from March-May. Paddle grass (Halophila decipiens) flowers were seen from late February to early May and in July in Tobago, and similarly March to mid-May in Trinidad. Clover grass (Halophila baillonii) flowers occurred in early March and early June in Tobago. No flowers of manatee grass (Syringodium filiforme) were documented. Clover grass and manatee grass are not present in Williams Bay. Potential pollinators, e.g. snails, amphipods, shrimp, polychaete worms and small fishes, were seen on turtle grass and shoal grass flowers. Seagrass genetic diversity may be reliant on pollinators and thus we must consider them when managing and restoring these habitats.