Remote sensing of zooplankton and other large marine particles

The optical properties of the ocean are traditionally described as being determined by water, phytoplankton, sediments and coloured dissolved organic material. Recently it has been shown that dense swarms of zooplankton (Calanus finmarchicus) forming off the northwest coast of Norway, are sufficiently abundant and coloured that their presence can be identified in ocean colour imagery (Basedow et al., Scientific Reports, 2019). The aim of this project is to better understand the optical properties of zooplankton and other large, coloured particles found in the ocean, to understand their impact on ocean colour signals and to identify the occurrence of swarms and other high concentration events where large particles make a significant contribution to the colour of the water. This work will contribute to the development of a range of potential new applications, including new tools for monitoring the abundance of surface swarms of Calanus and krill, both of which are subject to commercial harvesting operations. The work will involve a mixture of practical optical measurements using state of the art equipment including a Point Source Integrating Cavity Absorption Meter (PSICAM) to measure absorption properties of large particles, and processing and analysis of ocean colour remote sensing data to identify and potentially quantify high concentration events.