Russian scientist: High-abundance period for Pacific population of Japanese sardine nearing its end, prospects favorable for Tsushima population!

The Japanese sardine resource is undergoing a structural turning point. Aleksey Baitalyuk, Deputy Director of the Russian Federal Research Institute of Fisheries and Oceanography (VNIRO) and Director of its Pacific Branch, recently stated that the high-abundance period for the Pacific population of Japanese sardine is coming to an end, while the situation for the Tsushima population is exactly the opposite—resource conditions are optimistic. This assessment comes from VNIRO's continuous monitoring of the two sardine populations in the Sea of Japan, and signals that the fishing grounds at the center of Russia's Far East sardine fishery will shift.

Sardine-iwashi (Japanese sardine, Sardinops sagax) is a traditional large-volume species among the pelagic fish of the Russian Far East. After the resource collapse of the 1970s–80s and a low period lasting decades, the resource recovered strongly from the mid-2010s, becoming one of the main pelagic species for the Russian Far East fleet's fishing operations and exports to Asia. Baitalyuk's reference to "the high-abundance period for the Pacific population nearing its end" means that this resource peak, which has lasted about a decade, is entering a downward phase; meanwhile, the Tsushima population in the Tsushima Warm Current waters is taking over as the new engine of resource growth.

Dynamics on the fishing side corroborate the scientific assessment. As of late September, the Russian fleet had not yet begun fishing for sardine-iwashi and mackerel in the South Kuril waters, but the sardine catch in the Primorsky Krai waters had exceeded 550 tonnes. The fleet has concentrated its operations in the coastal fishing grounds off Primorye, consistent with the assessment that the Tsushima population resource is aggregating toward the southwest.

The favorable situation for the Tsushima population is not an isolated case but part of the ecological structural changes in the Sea of Japan. The Tsushima Warm Current flows northward along the western side of the Sea of Japan; in years when the warm current is strong, the suitable habitat for warm-water pelagic fish such as sardine and mackerel expands northwestward, benefiting both the Russian coastal waters off Primorye and the east coast of the Korean Peninsula. The population on the Pacific side, by contrast, is affected by the Oyashio Current and the Pacific Decadal Oscillation, and its resource cycle is not synchronized with that within the Sea of Japan. Baitalyuk's assessment is based precisely on this regional differentiation: the resource prospects of the Sea of Japan as a whole cannot be summarized by the performance of a single fishing ground.

The generational turnover of the sardine resource affects two strands of the industry chain. The first is exports to Asia: sardine-iwashi is one of the Far East pelagic fish categories with the largest circulation in the Chinese, South Korean and Japanese markets, widely used for salted-dried processing, canning and as raw material for aquaculture feed. If a downward resource cycle is established, the export supply base of Far East sardine will gradually contract. The second is bait and fishmeal: sardine is an important source of fishmeal raw material in addition to the processing by-products of Far East crab and bottom fish, and changes in supply will affect regional fishmeal prices.

The rise and fall of pelagic fish resources in the Sea of Japan is also a common issue for fisheries management among Northeast Asian countries. Sardine populations have long, large-amplitude natural fluctuation cycles, and historically have shown boom-and-bust cycles on a scale of decades. Baitalyuk's public warning of the end of the high-abundance period provides fishing enterprises and traders with a forward-looking signal: the fishing capacity and trade flows formed during the resource peak need to be prepared for a downward cycle.

Three answers will emerge in turn: VNIRO's next round of resource assessment conclusions for the two populations, when the Russian Far East fleet will start fishing for sardine-iwashi in the South Kuril waters, and how the weight of the Tsushima population will change in the formulation of the 2027 quota. The supply stability and price trends of Far East sardine need to be assessed by Chinese importers within a medium-term resource cycle, rather than extrapolated from the supply inertia of the high-abundance years of recent times.