Pike against Swedish algae problem


This 3 December 2018 video is called Pike React to Fish in a Bottle.

From the University of Groningen in the Netherlands:

How sticklebacks dominate perch

Analysis reveals waves of stickleback domination along the Baltic coast

August 27, 2020

A research project on algal blooms along the Swedish coast, caused by eutrophication, revealed that large predators such as perch and pike are also necessary to restrict these blooms. Ecologist Britas Klemens Eriksson from the University of Groningen and his colleagues from Stockholm University and the Swedish University of Agricultural Sciences, Sweden have now shown that stickleback domination moves like a wave through the island archipelagos, changing the ecosystem from predator-dominated to algae-dominated. Their study was published on 27 August in the journal Communications Biology.

Eriksson experimented with the effects of nutrients on algal blooms while working as a postdoctoral researcher in Sweden. When he added nutrients to exclusion cages in the brackish coastal waters, algae began to dominate. This was no surprise. However, when he excluded large predators, he saw similar algal domination. ‘Adding nutrients and excluding large predators had a huge effect,’ he recalls, 10 years later.

Food web

The big question that arose from these results using small exclusion cages was whether the results would be the same for the real Swedish coastal ecosystem. This coast consists of countless archipelagos that stretch up to 20 kilometres into the sea, creating a brackish environment. Here, perch and pike are the top predators, feeding on sticklebacks, which themselves eat the small crustaceans that live off algae.

To investigate how this food web developed over the past 40 years, Eriksson (who had moved to the University of Groningen in the Netherlands) connected with his colleagues at Stockholm University and the Swedish University of Agricultural Sciences to gather data on fish abundances and to carry out a series of field studies. They were inspired by recent suggestions that regime shifts can occur in closed systems such as lakes and wondered whether algal blooms in the Baltic sea could also be a consequence of such a regime change.

Grazers

Eriksson and his colleagues sampled 32 locations along a 400-kilometre stretch of coastline. ‘We visited these sites in the spring and autumn of 2014 and sampled all levels of the food web, from algae to top predators.’ These data were subsequently entered into a food web model, which helped them to find connections between species. The models showed that the small sticklebacks were important for the reproduction of the larger predators. And a local increase in sticklebacks means that a lot of the grazers in the ecosystem are eaten, which drives algal domination.

‘If you just look at the abundances of fish, you find a mixed system in which different species dominate,’ Eriksson explains. But looking at the changes in these fishery data over time showed an increase in sticklebacks that started in the late 1990s, initially in the outer parts of the archipelagos. ‘This is presumably caused by a reduction in the number of large predators. The reduction is the combined result of habitat destruction, fishing and increased predation by cormorants and seals.’ Sticklebacks migrate from the outer archipelagos inwards to reproduce, linking coastal and offshore processes.

Predation

Reduced predation increases the survival of sticklebacks, while both eutrophication and warming help to increase their numbers even further. As the sticklebacks reduced the number of grazers, algae began to replace seagrass and other vegetation. Furthermore, the sticklebacks also fed on the larvae of perch and pike, thereby further reducing their numbers. ‘This is a case of predator-prey reversal,’ explains Eriksson. Instead of top predators eating sticklebacks, the smaller fish strongly reduced the number of perch and pike larvae.

Over time, the stickleback domination moved inwards like a wave: regional change propagated throughout the entire ecosystem. This has important consequences for ecosystem restoration. ‘To counter algal blooms, you should not only reduce the eutrophication of the water but also increase the numbers of top predators.’ It means that those organizations that manage fisheries must start working together with those that manage water quality. ‘We should not look at isolated species but at the entire food web,’ says Eriksson. ‘This is something that the recent EU fishery strategy is slowly starting to implement.’

Furthermore, the propagation of local changes throughout a system has wider implications in ecology, especially in natural ecosystems that have complex interaction and information pathways. ‘And we know this from politics and human behaviour studies. A good example is the Arab Spring, which started locally and then propagated across the Middle East.’

Swedish crime novel author Maj Sjöwall, RIP


This 2010 video says about itself:

Nordic Noir – Maj Sjöwall and Per Wahloo

BBC documentary about Scandinavian crime novels.

From The Local site in Sweden:

Maj Sjöwall, one of the ‘creators of Nordic Noir’, dies aged 84

Maj Sjöwall, one half of a Swedish crime-writing couple credited with inventing “Nordic Noir”, has died aged 84, her publisher said on Wednesday.

Sjöwall, a pioneer of gritty realism and an inspiration to modern crime writers, “passed away today after an extended period of illness,” Ann-Marie Skarp, head of publisher Piratforlaget, told AFP.

With her partner Per Wahloo, who died in 1975, Sjöwall penned a ten-book series centred on the dour, middle-aged and decidedly unheroic Martin Beck and his team of detectives in Stockholm’s National Homicide Bureau.

Books like “Roseanna”, “The Laughing Policeman” and “The Abominable Man”, featured tightly structured plots packed with realistic details, charting the unglamourous slog and grind of police work.

“Her and Per Wahloo’s ten novels about Martin Beck… will become classics and have inspired, I dare say, all now living authors of crime novels,” Skarp said.

The duo also penned the series decades before the likes of Henning Mankell and Stieg Larsson made the genre of “Nordic Noir” into a worldwide hit.

“They broke with the previous trends in crime fiction,” Henning Mankell wrote in an introduction to the 2006 English edition of “Roseanna”. His own Inspector Kurt Wallander series would owe much to Beck three decades later.

Sjöwall was “the giant on whose shoulders the titans of modern Scandi crime fiction stand,” Britain’s Daily Telegraph wrote in 2015, in a story headlined “The couple who invented Nordic Noir”.

Both committed Marxists, they went beyond crime fiction, breaking new ground by carrying out a forensic examination of the failings of Swedish society. The modern themes they tackled included paedophilia, serial killers, the sex industry and suicide.

“Through the eyes of Martin Beck and his colleagues, they held a mirror up to Swedish society at a time when the ideals of the welfare state were beginning to buckle under the realities of everyday life,” Scottish crime writer Val McDermid wrote in the introduction to the 2006 edition of “The Man Who Went Up In Smoke”.

Born September 25th, 1935 in Stockholm, Sjöwall studied journalism and graphics. She worked as a translator, and art director, and as journalist for Swedish magazines and newspapers. It was through her work that she met Wahloo, a successful political journalist, in 1961. The two quickly became a couple and had two sons.

Then they decided to launch the Martin Beck series.

After dinner and having put their sons to bed, they would sit opposite each other and write through the night, a chapter each.

“We worked a lot with the style,” she explained to The Guardian newspaper in 2009. “We wanted to find a style which was not personally his, or not personally mine, but a style that was good for the books.”

Before actually writing, the couple carefully planned their plots, travelling, taking hundreds of photographs, meeting people and drawing maps, Sjöwall explained in a Q&A in the first book “Roseanna”.

After Wahloo’s death from cancer aged 48 in 1975 — weeks after the last book in the series, “The Terrorists”, was published — she continued working as a translator.

She also collaborated on “The Woman Who Resembled Greta Garbo” with Dutch crime writer Tomas Ross in 1990.

The Martin Beck books have been translated into 40 languages and served as the source material for dozens of movies.

Great spotted woodpecker and jays


This 2012 video shows a Siberian jay and a Eurasian jay in Gästrikland province in Sweden.

Today, again to the Bosdrift cemetery.

Before I arrived, a magpie near the old harbour.

Near the entrance, a blackcap singing.

A wood pigeon calling.

Great tit and robin sounds.

A carrion crow. A nuthatch sings.

A buzzard and a chiffchaff call.

Two Eurasian jays looking for food on the forest floor. One of the birds has more white on its head than the other one.

A male great spotted woodpecker climbing up a tree.

Close to the exit, a dunnock sings.