Two synchronised lakewide surveys across Kenya, Uganda and Tanzania on the real acoustic cruise track, replicating and extending Michael Graham’s 1927 baseline. Each survey runs acoustics for biomass and bathymetry, CTD physicochemistry, and bottom and pelagic trawling. Experimental fishing follows the 2017 lakewide survey sites every quarter, with a single sediment coring campaign. Fishing landing sites around the shore carry the monthly Catch Assessment Survey and a one off Frame survey, with socio-economic surveys at the same sites each quarter. Current cage aquaculture sites are mapped for the water quality and biosecurity work.
Survey layers
Depth strata follow the LVFO scheme: inshore under 20 m, coastal 20 to 40 m, deep over 40 m. Lake shading indicates relative depth, deeper central basin darker. Environmental DNA is collected at every CTD station and at all river inflows on both surveys.
Campaign sequence
The same lakewide network is occupied twice to bracket the mixing and stratification cycle. Experimental fishing repeats quarterly at the 2017 survey sites. Sediment coring is a single one off campaign for the century long reconstruction. Landing sites are monitored continuously through the year: a Catch Assessment Survey every month, a one off Frame survey, and socio-economic surveys each quarter.
The network at a glance
How this builds on Graham
Graham occupied about 235 stations from the SS Kavirondo along radial transects. The modern radial acoustic track echoes that design while adding calibrated echosounding, depth stratified CTD, pelagic trawling, environmental DNA and sediment coring at the inflows, urban discharge zones and cage aquaculture sites he never reached. Toggle the 1927 overlay to see the two designs together.
Acoustic track, waypoints and docking points from the LVFO survey files. CTD and net haul stations placed on real waypoints, counts per the 2022 survey (52 CTD, 29 net hauls). Experimental fishing shows the 2017 lakewide trawl and gillnet sites, digitised from the survey map. Graham 1927 stations digitised from the historical chart. Fishing landing sites from the geocoded Frame survey dataset, shown at the nearest shoreline point, as recorded coordinates are village level geocodes. All digitised layers indicative. Lake outline from Natural Earth. Lake Victoria 100 • info@lakevictoria100.com