生まれ故郷を目指すサケの、「はらこ飯」という運命への覚悟と郷愁　　　　　気ままなリライト118

サケ不漁、郷土料理ピンチ　東北で激減「はらこ飯」高騰　温暖化で海に変化影響か - 日本経済新聞

A stark decline in wild salmon returning to spawn in Japan's northern regions, Hokkaido and Tohoku, this autumn has raised an ecological red flag. The alarm is prompting a profound reflection on the salmon's role beyond being a mere food source. Those majestic fish are symbolizing a cultural heritage, spiritual significance, and historical ties. The current shortfall in the harvest is a wake-up call, urging those regions to reconsider how human interventions, aimed at controlling nature for consumption, ecological balance, economic benefit, and culinary richness, have been impacting the wild salmon population. It's a critical moment to reassess our approach to managing those vital creatures and the ecosystem they support.

The once-celebratory homecoming of wild-seasoned salmon to Japan’s northern shores has turned bleak. Hokkaido, as the Japan’s largest hometown, reported a 30% year-on-year plunge in salmon harvests, with the count reaching just 19,19 million fish as of November 20. This decline paled in comparison to the staggering 80 to 90% drop in the Tohoku regions as of November 10. Aomori Prefecture’s catch dwindled to only 19,000 fish, and Iwate Prefecture to a mere 12,000. The situation in Miyagi Prefecture was even more dire, with a record low of 3,200 fish caught in its shores. "Gone are the days when we chased after swarms of wild salmon," laments Yoshiaki Takahashi, leader of a fisherman group in Minami-Sanriku Town, Miyagi Prefecture, part of the coastal area stretching across Iwate, Miyagi, and Aomori prefectures. From the start of the fishing season in late September to November 22, the catch was startling low, only 900 wild salmon, totaling a mere two tons, a drastic fall of nearly 90% from the previous season. Reflecting on better times, Takahashi adds, “There was a time when a boat could return with two tons of wild salmon from a single trip, a stark contrast to our recent meager hauls.”

What has led to the dwindling numbers of wild salmon returning to their ancestral spawning grounds? Is their legendary homing instinct being compromised? Could unseen obstacles be disrupting their journey back to their place of origin? Is the degradation of ecological integrity a factor in the depletion of the wild salmon population? Human activities, such as overfishing, might be reducing their genetic diversity and impacting the availability of their natural prey. Or, have those majestic creatures sought alternative spawning sites, driven away from their ancestral streams that have become inhospitable? Is there a chance that the salmon are eschewing a fate tied to culinary traditions, rebelling against becoming ingredients in a celebrated dish of northern Japan, called Harako Meshi? Are they steering clear of regions famed for their gastronomic delights, where their roe is more likely to end up in the bottom of epicurean stomach rather than growing in the safety of riverbeds and eventually journeying to the bosom of the seas?

Harako Meshi, treasured as a seasonal delicacy, has ironically played a crucial role in conserving the wild salmon population in its regions of origin. This exquisite dish, marrying the subtle flavors of salmon-tinged rice with the explosive taste of salmon roe, owes its unique taste to wild-born salmon. Farm-raised salmon from nations like Norway or Chile are not used as substitutes, primarily due to the discerning palates of seafood enthusiasts who find less appealing the taste of salmon raised in a completely controlled environment during their entire life cycle. The preference for the authentic taste of salmon reflects deeper cultural and ecological connections. Through this culinary choice, consumers and communities with ties to wild-born salmon have developed a heightened appreciation of their ecological significance. Local communities understand the salmon's challenging journey and its natural spawning process, where the nutrients from the decaying bodies of the fish not only nurture their offspring but also enrich the aquatic ecosystem and surrounding forests. The wild salmon’s deep-rooted affection for their hometowns has resonated with local communities, instilling a sense of pride and honor in being part of the salmon’s life journey. The sense has awakened a deep commitment to preserving those vital creatures, intertwining the traditional cuisine and ecological mindfulness.

The strategy for maintaining the wild-caught salmon population has been evolving. Initially focused on protecting wild-born salmon, there's now a growing reliance on hatchery-raised salmon that are released into the wild to be caught later. Local fisheries have been depending on hatchery programs as a means of reducing the fishing pressure on wild stocks, aiming to supplement the conservation of wild-born salmon. Those programs also are culturally and culinarily acceptable, largely because of the negligible taste difference in Harako Meshi, whether it's cooked from wild-born or hatchery-raised salmon.

This shift towards hatchery-raised salmon has begun without fully considering the impact on genetic diversity. The interbreeding of hatchery-raised salmon with wild ones could potentially weaken the overall survival strength of the wild salmon. This is due to the limited genetic variation in hatchery fish, which is likely to dilute the unique genetic adaptations that wild-born salmon have developed to thrive in their natural environment. Such potential genetic dilution could reduce the wild salmon's adaptability to environmental changes and lower their resistance to diseases, especially during their migratory journeys laden with trials.

The differing infant life experiences of wild-born and hatchery-raised salmon prompt a series of intriguing questions. How does the attachment to their birthplace, shaped by unique sensory and chemical cues, change in a hatchery environment where those cues are absent or altered? Will those hatchery-raised salmon have only a dim memory of their original habitat, missing the rich details, such as the poignant act of consuming nutrients from their mother’s decaying body? Can they only guess at the location of their man-made spawning grounds, somewhere near Japan’s northern coastlines? Consider a scenario where a wild-born mother salmon is caught off Hokkaido, with her offspring raised in a hatchery in Miyagi Prefecture. When those offspring reach maturity, where are they instinctively drawn to spawn? Do they follow the innate instincts tied to their mother’s original spawning site, or do the influences of their upbringing in the hatchery take precedence? Additionally, there's an underlying uncertainty. Assuming they manage to conjure up the images of their release points, will those salmon possess a strong enough bond with the unfamiliar natural surroundings to brave the upstream swim, as their wild-born peers do instinctively? Or, will they end up as stray salmon, caught off the coast and destined either to become part of increasingly expensive gourmet dishes like Harako Meshi or to contribute to the breeding of the next hatchery-raised generation?