There is a need for more capable and affordable means to measure optical properties and biological constituents of the Gulf of America and its estuaries, as well as other marine and freshwater environments. These measures are crucial for monitoring and estimating the abundance of organisms such as those producing harmful algal blooms (HABs). Effective methods to extend the measurement distance and dynamic ranges, increase sampling volumes and improve sensitivity compared to traditional optical instruments will enable scientists and resource managers to improve HAB prediction and decision making.

This presentation discusses the design, characterization, and field testing of a new type of in situ optical water parameter measuring instrument based on Time-of-Flight (TOF) lidar optical detectors. The work is a progression of the laboratory results presented at GOMCON 2024. The instrument’s capability to optically sense chlorophyll fluorescence up to several meters away from the sensor are presented. Field sampling results from the Tampa Bay estuary are compared to several commercially available optical water parameter instruments and to laboratory-analyzed water samples. Operation using internal battery power and data logging, and tethered operation using a cell-phone and cloud-connected data distribution system are also presented.