Ecosystem management policy implications based on Tonga main tuna species catch data 2002–2018

From 2002 to 2018, the Tongan Long Line fishery collected and compiled
catch data (limited to presence records) for Albacore, Bigeye, Skipjack,
and Yellowfin. The Tonga Ministry of Fishery and the South Pacific
Community (SPC) Office in New Caledonia provided this data. To ensure
adherence to regulations, at least two fisheries offices cross-verified
the entire fish catch. The data consists of daily fishing positions
(latitude and longitude) and date (day, month, and year), organized in a
1^0 spatial grid. Our study utilized catch per unit effort (CPUE), a
standardized metric indicating fishing efficiency and effort, calculated
by dividing the weight of the catch in metric tons by the number of hooks
deployed per fishing record. To align with the temporal scales of the
predictor variables, we aggregated the CPUE data into monthly and annual
datasets using Microsoft Excel.