Special COP21: the lost herring

Today I go out of my comfort zone to talk biology. Herring, more precisely. Well, fish in general, and mosquitoes also a bit. And foxes. I want to talk about another phenomenon that is happening right now because of climate change: changes in species habitat.

Catch_of_Atlantic_herring

It all got personal for me just over a year ago because of this catch of herrings. Or rather, its absence, for the very first time in 2014 since records began in the city where I come from. Each year, herrings migrate from the Norwegian or North seas to the Channel in autumn to spend their winter in our less cold waters. For over a decade, it has been noted that herrings were coming less south, and for the first in 2014 time they did not even come to the Channel. For the annual herring fest, my hometown had to import herrings!

Now, I’m not saying herrings aren’t fascinating, but you might be thinking that it is no big deal. Well true, especially as one year without herrings does not make a trend. However, some other species are on the move.

There are basically two moves happening whenever the climate changes:
– the retreat of species towards the last place where they can find their favourite climate
– the expansion of those who benefit from this climate change.
In our case of global warming, tropical species expand to mid-latitudes, and “cold” species retreat to the poles. During an ice age in contrast, polar species can expand to mid-latitudes, while “warm” species retreat to the tropics.

In the ocean, that is a problem as most of our food comes from cold water fish. If they move out of our territorial waters, we need to pay a lot more to obtain them.
The ones who stay and suffer in silence (like cods and lobsters seem to do in the US) are apparently more vulnerable to parasites and diseases, and have no real desire to reproduce (understandable during strong heat waves). Good quality fish becomes rare, so again we need to pay a lot.

Species habitat shift results in conflicts. I don’t know if that is studied in the ocean, but there was a team with us during Petermann2015 investigating these conflicts in the high Arctic, in particular between the invasive red fox and the retreating Arctic fox. They are the Arctic Islands project, and you should talk to them directly.

And even if you don’t eat fish and don’t feel particularly worried about arctic foxes, you should fear climate change induced species migration. At least, the one of that species:

Aedes albopictus, a.k.a. tiger mosquito, busy feeding on someone (Credit James Gathany/CDC)

Aedes albopictus, a.k.a. tiger mosquito, busy feeding on someone (Credit James Gathany/CDC)

The tiger mosquito, and its viral passengers Yellow fever, Dengue and Chikungunya. Not only is it annoyingly buzzing around your ears at night, but unlike your average mosquito it also carries deadly tropical diseases and parasites. In Europe, it’s in Spain and Italy, it’s in France, it is suspected to have arrived in Germany and the UK…  In the US, it’s been found in California and Washington state, and it happily lives and breed in nearly the whole east half of the country as far north as Pennsylvania.
All of that thanks to a warmer world, and an increased global connectivity!

The ad moment: to learn more on changes in fish habitat causes by humans, in particular by the opening of the Suez Canal, you should read this post by Umberto Binetti on Scisnack.

 

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