2023-10-27 09:58:34
Ten dead seabirds lie with their bellies up next to each other in a plastic container. These are a few of the many razorbills and guillemots that have been found on the Texel beach recently. Seabird researcher Kees Camphuysen (64) puts on a white lab coat. “We will first determine what life stage the birds are in.”
There is a heavy salt smell in his clinical white lab (with sea blue floor) at the Royal Netherlands Institute for Sea Research (Nioz). Camphuysen systematically goes through the birds and lists their characteristics. His assistant Threes Anna (64) writes along with the observations. First the feather pattern, then the wings and thickness.
The researchers work quickly, while occasionally correcting each other. Do they investigate birds together more often? “We’re even married,” Anna laughs as she prepares a razor-sharp knife.
Strandings
Every day, dozens of reports of dead birds along the coastline are made on Texel. It is mainly razorbills and guillemots that wash up. And while the razorbills shouldn’t be here at all at this time. Camphuysen investigates the washed up birds and tries to find an answer to this mysterious death.
Major strandings, as it is called when masses of dead birds wash up, are not a new phenomenon. Previously, these were usually caused by fuel oil leaking at sea. But according to Ecomare, those oil slicks in the North Sea hardly occur anymore.
It is very special that razorbills are found around this time of year. They shouldn’t be here until January and February. What is completely strange is that they are starved adult birds. According to Nioz, more than six hundred dead birds have already been found. Camphuysen thinks it has something to do with the sea water, which was abnormally warm this summer.
In general, razorbills stay far out to sea. The birds that winter in the North Sea mainly come from breeding colonies along the rocky coasts of the United Kingdom. They prefer to eat oily fish, such as sprat and herring, for which they dive dozens of meters deep.
Buttery fat
While Anna cuts the first bird open across the sternum, Camphuysen takes out a folder with images. “Look, this is what a healthy, fat bird should look like. There is a buttery fat under the skin and around the organs,” he says. “And this one is too skinny. There is no fat under the skin and the inside looks a bit ‘sharper’.” Anna carefully spreads the cut bird’s breast open further and looks at the images. This one is starving, she concludes.
The warming sea may play a role in this mass death. Fish cannot tolerate temperature changes very well, causing nutrient-poor water in some places, Camphuysen explains. “But apparently there are a lot of fish in certain places, because we sometimes also come across a fat bird.”
This impression was confirmed during a cruise: the researchers came across a lot of razorbills that were fat enough. “We don’t understand why half of them behave as if they are lazy and the other half is starving.”
Useful data
Finally, the stomachs are cut from the birds and placed on a petri dish. With the dishes on a cart, Camphuysen drives to another lab. He passes large windows overlooking the beach. There, on the Texel high tide line, there are around ten to twelve carcasses washed up per kilometer, and Camphuysen expects that number will only increase.
In a lab where it smells less salty, two other researchers bend over a microscope. Here the contents of the stomachs are examined. Camphuysen opens a large cupboard with dozens of drawers. “Here we have all kinds of bones and fish remains that we can find in the stomachs. If we don’t know what we have, here is the reference material.” He brings up some examples. “It is a macabre undertaking, but it does provide useful data,” he laughs.
Warming sea
He enters the data into the computer in his office. Camphuysen has been keeping track of bird strandings since 1974. His screen shows a graph of the number of stranded razorbills per year. There is hardly anything to see, except last year, where the outlier is appropriately drawn red. It seems obvious to the seabird researcher that razorbill mortality is a human-caused problem. “The sea has a fever. You could swim in the sea until mid-October, because the water was 18 degrees. That is not good.”
But the Texel does not want to jump to conclusions. “It is a very big puzzle and with every bit of research you get a small piece of the picture.” Camphuysen cannot yet say when the investigation will be completed. “We will continue until it is finished.” Camphuysen asks anyone who finds a washed-up bird to report it to him report. “But don’t clean up the birds, because then data will be lost.”
Also read:
Warmer seawater can disrupt the climate balance within a few years. ‘If the Gulf Stream stops, it will have major consequences’
The high temperatures in some seas and oceans these months are raising alarm bells among experts. The climate system is at risk to lose balance. Moreover, the biodiversity in the water is disturbed by the heat.
The climate makes the Arctic bird breeding season unpredictable
Due to the changing climate, the schedules of insects and breeding birds are increasingly out of sync. At least, that’s what biologists assumed. It turns out to be slightly different than they thought.
1698527255
#Masses #starving #razorbills #guillemots #Texel #coast #sea #fever