From Climate Scepticism

BY MARK HODGSON

Fishing for an answer

I posted a comment on Open Mic yesterday, based on an article in the Guardian with the heading “Brown bear cubs in Japan die of starvation amid salmon shortage” and sub-heading “Experts blame rising sea temperatures caused by climate crisis for cub deaths at Unesco heritage site”. The Guardian is not alone in reporting on the story in this way. Sky News has a very similar article with a very similar title: “Brown bear cubs starving to death in Japan due to salmon shortage” and a very similar sub-title: “As many as eight in ten brown bears cubs born this year in Japan’s Shiretoko area have died, with experts blaming rising sea temperatures for dwindling salmon numbers.”

The suspiciously similar titles, sub-titles (and narratives) might suggest that once more news pieces are being generated by press releases, and regurgitated by journalists who are all too happy to play this game, especially if they support the “climate crisis” narrative. Nevertheless, to the credulous, it might look like “case closed”, with climate change obviously being the culprit. For instance, the Guardian tells us:

Pink salmon that hatch in rivers in Hokkaido spend the winter in the sea, before returning to streams in Shiretoko between August and October to lay eggs. Brown bears typically lie in wait for the salmon as they make their way upstream, but have been forced to swim in the sea because of the shortage of river fish….

…Experts said sea surface temperatures off Hokkaido remained above 20C from mid-July to early August 2021, 5C higher than average for that time of the year…

…Fishers caught 482,775 pink salmon in rivers in Hokkaido, Japan’s northernmost main island, between 25 July and 5 September in 2020, but only 23,298 last year, according to the Hokkaido Salmon Propagation Association. Given statistical evidence showing that good catches occur every other year, the 2022 haul was surprisingly small.

Bang to rights then – a devastatingly small salmon harvest in 2022 compared to previous years. Except that it’s possible the reason so few salmon made it into Hokkaido’s rivers in 2022 is because so many were caught at sea before they could get there.

According to the Tradex Foods website reporting on 21^st November 2022 on the 2022 salmon harvest:

Japan is set to see the largest harvest of Hokkaido Chum Salmon since 2016 – however the country is still in need of more Salmon.

Preliminary catch totals as of November show 166 million pounds harvested – already surpassing 2016’s total.

This year’s harvest equates to about 57 million pounds more Chum Salmon than the past 5-year average.

And although Hokkaido Chum Salmon is mostly consumed domestically, our sources have advised Japan is still trying to source more Salmon.

Japan typically buys a lot of their Salmon requirements from Russia, however due to war imposed sanctions and Russia’s container shortages – imports of Russian Salmon into Japan have been strained this year.

Imports of Russian Sockeye into Japan for 2020 and 2021 were upwards of 40 million pounds annually, however preliminary data shows Russian Sockeye imports into Japan this year are hovering around only 15 million pounds.

Japan’s sanctions against Russia mean that Japan’s previously substantial salmon purchases from Russia had declined by over 60%, and so Japan is fishing more salmon (at sea) than for many a long year. Politicians and “green” campaigners are quick to blame the Russian invasion of Ukraine for many domestic woes, including high energy prices, but I’ve never heard anyone blame it for the problems encountered by Russia’s starving bears. And yet it just might be part of the explanation. Who knows?

Other articles are available. Teller Report informs us that not only Hokkaido autumn salmon but also sea urchins were dying in large numbers in 2021. This was blamed on the “largest ever” “red tide” in Hokkaido. This is a large plankton swarm that is not normally found in the area. Some speculation is to the effect that this is due to warming ocean temperatures as Karenia Mikimotoi plankton moved north (so climate change again), but that claim sits more than a little uneasily with another suggestion that the red tide also consists of Karenia Brevis plankton, which has moved south from colder seas to the north (in which case, presumably, not climate change).

Conclusion

Whatever the cause of declining river salmon in Hokkaido, the explanations seem to be complex and multi-faceted, and the simple blaming of climate change is perhaps just too convenient. By the way, the bears are hungry, not just because of a shortage of salmon, but also because a shortage of acorns, another of their staple foods. Acorn shortages seem to be a regular problem, unfortunately, but not because of warm weather – quite the contrary. An online article which appears to date back to 2010, when another acorn shortage led (as now) to hungry bears wandering into areas of human habitation with unfortunate bear/human consequences tells us that in that case oak trees didn’t grow enough buds due to unusually low temperatures in spring, though admittedly a hot summer also exacerbated the situation. None of the articles I have looked at in connection with Hokkaido’s currently hungry bears bother to discuss why there is an acorn shortage. I don’t know the answer, but perhaps last year was a mast year? As the Tree Council website tells us:

A mast year occurs roughly once every 5-10 years, and is where a tree species such as oak drastically increase the number of acorns they produce. The oak trees put so much energy into this bumper crop of acorns that they leave themselves little energy to continue producing the following years. So, since last year was a mast year, this year our beloved oaks are recovering resulting in far fewer acorns for wildlife and nature-lovers to enjoy.

Why do oak trees do this?

We do not know for sure why oak trees do this. But one theory is that there is an evolutionary advantage to producing an unreliable number of acorns each year. If it were too reliable, the theory goes, surrounding wildlife populations like that of squirrels, deer and birds would adjust and learn to eat the entire yearly crop. Mast years stop this from happening. In these years, oak trees flood the ecosystem and produce too many acorns for local wildlife to consume, meaning more will have the chance to grow into saplings come spring. And in the several years that follow a mast year where we see far fewer acorns, like this one, the cut to the food supply helps to control these wildlife populations so that there are fewer animals to gobble up acorns when the mast year comes back around.

If that is the explanation in Hokkaido, then again it’s nothing to do with climate change, but it’s unfortunate for the bears that a dearth year following an acorn mast year might have occurred at the same time as Japanese humans have eaten many of the salmon that would otherwise have been destined for Hokkaido’s rivers and for its bears, due to a war in Europe. Or maybe a butterfly beat its wings somewhere….

Footnote

Three years ago the Guardian reported on another Japanese acorn shortage leading to bears attacking humans. Again there seemed to be a lack of curiosity as to the reason for the shortage, but then we were told:

“There is less to eat in the mountains and that is why they are coming down into villages…”

Rural depopulation and the resulting abandonment of farmland is also a factor, as it has blurred the once-distinct borders between forests and villages.

Conservationists have warned that encounters between bears and humans – a traumatic experience for both parties – will continue unless more is done to ensure an adequate supply of acorns and other foods to sustain them in the summer and early autumn.

The rise in the number of attacks in recent years has left officials struggling to strike a balance between protecting Japan’s dwindling bear population and keeping the public safe. Possible solutions include establishing safe feeding spaces to prevent bears from venturing into populated areas or leaving supplies of acorns on higher ground.

Whatever the reason for the problem, nobody was then blaming climate change. Nor were they doing so in 1915 when there were serious problems with marauding bears during a series of incidents so dramatic that they even have their own Wikipedia page.