The seven week research mission monitors the health of the largest tuna fishery in the world, which is vital to the economic well-being of the Pacific.
SPC principal fisheries scientist Simon Nicol said the expedition would gauge whether various tuna species were being fished sustainably.
Its findings will be added to data collected over 15 years of tagging surveys, Dr Nicol said.
"Our ability to sample randomly across states but also sample every year across that 15 year timeframe allows us to look at what the trends are and rebuild the power of the data set to ensure that it's representative of the entire population by the cumulative value of the 15 years of data, rather than just a single year of data," he said.
To avoid any potential for Covid-19 transmission to the remote communities of the Pacific, the 50 day tagging cruise will not make any port calls.
The vessel, which embarked from Honolulu, will only undertake tagging in the tropical waters of the high seas and the vast Kiribati Exclusive Economic Zone.
This will include the first opportunity to collect data on tuna sustainability in the Phoenix Islands Protected Area, since its establishment 12-years ago.