2022 Itchenor Reach - Chichester Marina
During summer 2022 CHASM installed a sonde data logger on one of the wooden markers near Chichester Marina on Itchenor Reach. The aim was to complement the data being gathered by the sonde and telemetry unit on West Pole outside Chichester Harbour.
The unit wasn’t able to capture real time data because it wasn't linked to a telemetry unit, but instead it logged data for comparison with West Pole for three months over summer. The data gathered enabled us to monitor temperature, conductivity, turbidity, dissolved oxygen and chlorophyll every 15 minutes. The site inside Chichester Harbour is a great location for detecting run off from land following rain and comparing what happens in an enclosed harbour area with the open coast data from West Pole. Summer was chosen because it is drier, so the effects of rainfall will be more noticeable.
An extraordinary find was the hugely depleted O2 found during the extremely hot period
The end graph (Graph 6: Chichester Marina_Chichester_L) shown in the link below demonstrates the reduced oxygen concentrated seen between mid-July and early October 2022. Concentrations during this period never reach 100%, the expected concentration. Instead, readings average approximately 60%, at times dipping below 20%.
Full analysis of the data still needs to be done, but these findings came as a huge surprise and prompted the EA to install the sonde and telemetry now in place in the same location.
The situation was rectified once the weather broke in the autumn and measurements resumed their normal 100% concentration. It will be interesting to note observations in summer 2023.
Many thanks to the F Glenister Woodger Trust for funding the hire of the sonde data logger, to the Environment Agency National Data Monitoring Unit for keeping us on track, and to Chichester Harbour Conservancy for again doing the hard work of getting the unit installed!