Diurnal variation of net community production (NEP) and net community calcification (NEC) were measured in coral reef and seagrass biomes during October 2012 in the lower Florida Keys using a mesocosm enclosure and the oxygen gradient flux technique. Seagrass and coral reef sites showed diurnal variations of NEP and NEC, with positive values at near-seafloor light levels >100-300 µEinstein m −2 s −1 . During daylight hours, we detected an average NEP of 12.3 and 8.6 mmol O 2 m −2 h −1 at the seagrass and coral reef site, respectively. At night, NEP at the seagrass site was relatively constant, while on the coral reef, net respiration was highest immediately after dusk and decreased during the rest of the night. At the seagrass site, NEC values ranged from 0.20 g CaCO 3 m −2 h −1 during daylight to −0.15 g CaCO 3 m −2 h −1 at night, and from 0.17 to −0.10 g CaCO 3 m −2 h −1 at the coral reef site. There were no significant differences in pH and aragonite saturation states (Ω ar ) between the seagrass and coral reef sites. Decrease in light levels during thunderstorms significantly decreased NEP, transforming the system from net autotrophic to net heterotrophic.

In tropical small islands the application of hydrological modelling is challenged by the scarcity of input data. Using in-situ and statistically estimated data, a hydrological model was calibrated and validated for the Upper Navet watershed in Trinidad, a small Caribbean island. The model was built using the soil water assessment tool (SWAT). The sensitivity analysis, calibration and validation were performed in SWAT calibration and uncertainty program (SWAT-CUP) using sequential uncertainty fitting (SUFI-2). The results revealed that for the estimated volume of water flowing into the reservoir (Flow_In) there were six sensitive parameters. To estimate the reservoir volume (Res_Vol), a modification of only the effective hydraulic conductivity was required. The model’s performance for the Flow_In validation showed acceptable values (R2 = 0.91 and NSE = 0.81). The uncertainty analysis indicated lower than recommended values for both the R-factor (0.46) and P-factor (0.31). For Res_Vol, the model’s validation performance indicated acceptable values (R2 = 0.72 and NSE = 0.70) and the P- and R-factors were 0.80 and 0.64, respectively. Based on the statistical metrics, the uncertainty for the Res_Vol was regarded as reasonable. However, care must be taken with the model’s use in the dry season, as the simulated Flow_In was generally over-predicted. A second validation of the model was performed for the reservoir under different negative (removal) and positive (addition) water amounts which confirmed the model’s ability to estimate the Res_Vol. The hydrological model established can therefore serve as a useful tool for water managers for the estimation of the Res_Vol at the Navet reservoir.

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Human risk has further increased within the global maritime industry because of the coronavirus disease (COVID-19) pandemic. It also impacted the economic activity within the Caribbean islands, including its ship–shore delivery sector. Traditionally, this service includes human interface presenting safety and health hazards, and vessels employed operate on fossil fuels, releasing emissions that contribute to harmful GHG and air pollution. Opportunities have arisen for local maritime companies to introduce innovative strategies within the industry to rectify these challenges. Implementing unmanned aerial system (UAS) technology can reduce operational costs, human risk, environmental impact, and delivery time. This study assessed the feasibility of a UAS ship–shore delivery service to optimize near-harbor deliveries within six major ports of Trinidad. Data was gathered through field observations, a literature survey, questionnaires, and interviews with relevant stakeholders. Based on the above approach, the needs of the local ship–shore delivery sector were identified and categorized. An appropriate UAS which addressed these needs while maintaining the economic, environmental, and human safety requirements was then identified. Recommendations for overcoming the local implementation and operational challenges that were encountered are presented. This study may serve as a reference for conceptualizing a UAS ship–shore delivery service and offers resolutions for similar implementation challenges.