Discrete water samples for biogeochemical parameters collected in line with autonomous surface vehicle C-worker 4 sensor data in Belize's coastal zone - October 2019.

The aim of this campaign was to understand and identify controls on biogeochemistry of Belize's coastal zone and the influence of the Belize river. Data were collected in October 2019 over five days - during daylight hours, with the aim of capturing wet season influence of the river, however Belize experienced a drought. Data were collected to enhance and calibrate data collected by the Autonomous Surface Vehicle C-worker 4 as part Commonwealth Marine Economies Programme Belize (CMEP Belize). Discrete water samples were collected for dissolved O2, chlorophyll, nutrients, DOC, absorbance, and fluorescent dissolved organic matter (FDOM), Total Alkalinity (TA), Dissolved Inorganic Carbon (DIC), δ13CDIC and Particulate Organic Carbon (POC). All samples were collected using a 5L Niskin at ~0.5 m depth - the depth of C-worker 4 sensors. Dissolved O2, absorbance and chlorophyll samples were run in country by Sarah and Millie by Winkler Method, Spectrophotometry Absorbance and Fluorescence respectively. Samples for nutrients, DOC, FDOM, TA, DIC, δ13CDIC, POC were transported back to the UK for analysis. Both frozen (nutrients) and refrigerated samples (DOC and FDOM) were transported back to the UK in cool bags with frozen samples defrosting enroute back to the UK in preparation for immediate analysis. DOM, TA, DIC, δ13CDIC and POC are still waiting for analysis. Absorbance was run a second time back in the UK at the same time as FDOM (both absorbance runs are included).