Assessing trophic interactions among three tuna species in the Solomon Islands based on stomach contents and stable isotopes

Trophic research is essential to the conservation and management of fishery resources. This study analyzed feeding habits nutritional interactions among three tuna species in waters Solomon Islands (5°12′S–15°20′S, 157°31′E–172°19′E). A total 103 bigeye ( Thunnus obesus ), 296 yellowfin albacores 264 albacore alalunga ) samples were collected from September December 2019. Samples for stomach content stable isotope analysis randomly selected. The results showed that contents rich prey, 48 prey identified, including fish, cephalopods, crustaceans, with high between-phenotype component (BPC). Yellowfin consumed largest variety food smallest. intensity higher than tuna. had highest empty rate (35.69%) lowest average fullness index (0.064). degree was mainly 1, difference them significant P <0.001). Food overlap (0.3–0.6) Levins (<0.6) low, indicating a specialized tendency. Bigeye feed on Ommastrephes bartrami Myctophidae, Hyperiidea Aluterus monoceros , Gempylus serpens Loligo chinensis . δ 13 C 15 N values standard ellipse area corrected small sample sizes (SEAc) niche (TA) tuna, range (NR) (CR) highest. this will help improve our understanding ecology these their important roles ecosystem web structure.