The staff of the P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences and the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS) analyzed long-term data on the catches of three species of predatory fish in the northwestern Pacific Ocean over the past 50 years. The analysis was based on the results of pelagic trawl surveys of the Pacific Branch of the All-Russian Research Institute of Fisheries and Oceanography (TINRO, Vladivostok), which included over 75 thousand stations from the sea surface to a depth of 3.5 km (Fig. 1). The aim of the study was to determine how the distribution boundaries and abundance of three species of predatory fish in this area changed over time.
In pelagic marine ecosystems, predatory fish play an important role. As predators of the highest trophic level, on the one hand, they represent a link in the food chain along which energy and organic matter are transferred from lower to higher trophic levels. On the other hand, they consume large quantities of commercial invertebrate and fish species. In the northwestern Pacific Ocean, three species are most common among predatory fish: the long-snouted lancetfish Alepisaurus ferox, the North Pacific daggertooth Anotopterus nikparini, and the Pacific pomfret Brama japonica (Fig. 2). The first two species actively consume Pacific salmon, saury, and other pelagic fish, while the latter is a promising commercial target.
“The maximum northward expansion of the daggertooth, lancetfish and pomfret was recorded in summer, spring and autumn, respectively. The maximum northward expansion of all three species was typical for the 2000s. The maximum absolute catches of lancetfish were recorded in winter, while those of the daggertooth and pomfret were recorded in spring and summer, respectively. The maximum absolute catches of the daggertooth and pomfret were recorded in the 1980s, while those of the lancetfish occurred in the 1990s,” said A.M. Orlov, Doctor of Biological Sciences and employee of the Laboratory of Lower Vertebrate Behavior at the Institute of Ecology and Evolution of the Russian Academy of Sciences.
The information obtained seems useful for preserving the biodiversity of the pelagic ecosystems of the North Pacific and the rational exploitation of the stocks of the studied species. In addition, the analysis allows us to link changes in their distribution with seasonal and longer-term climate dynamics. Seasonal changes in distribution fit well with the pattern of northward migrations as water temperatures increase and southward migrations as temperatures cool. Long-term shifts in distribution are likely due to global warming.
“Maximum distribution of the daggertooth to the north, The results are published in the work: Orlov A.M., Volvenko I.V. 2025. Distribution and abundance of large pelagic predatory bony fishes in the northwestern Pacific over a half-century // Water Biology and Security. Article 100373.