Featured Research

from universities, journals, and other organizations

Dutch Wadden Sea may become bottleneck for wading bird

Date:
April 26, 2010
Source:
University of Groningen
Summary:
The Dutch Wadden Sea, due to a decline in food resources, may become a bottleneck in the annual cycle of a wading bird known as the knot, according to new research.

The Dutch Wadden Sea, due to a decline in food resources, may become a bottleneck in the annual cycle of a wading bird known as the knot.

This has been revealed by PhD research by Casper Kraan. He studied two subspecies of the knot, the Calidris canutus islandica and the Calidris canutus canutus.

"It appears that neither species is able to fatten up properly in the Wadden area any more," says Kraan. He conducted his research at the Royal Netherlands Institute for Sea Research (NIOZ) and will be awarded a PhD by the University of Groningen on 26 April 2010.

The islandica breeds on the Canadian and Greenland tundra and then flies to the Wadden area to overwinter. The canutus breeds in Siberia and uses the Wadden Sea to fatten up for the last stage to western Africa. Kraan: "Although the two subspecies have different strategies, they have the same problem -- declining food resources."

Kraan investigated what species there were in the tidal mudflats. "The Wadden Sea has changed enormously since the 1950s," according to Kraan. "The number of shellfish and crustaceans has declined while the number of worms has remained the same. Many of the animals that gave extra structure to the mudflats have significantly declined in numbers. That's true, for example, for mussels and cockles. This reduction in diversity of the tidal flat system has a negative effect on the knot population. Between 1996 and 2005, wintering knots lost 55% of their foraging area. The decline in the number of knots at 42% is pretty much parallel."

The Macoma balthica, a clam that is the most important food source for knots, was at the centre of Kraan's research. "This used to be a very common shellfish in the Wadden area, but now it's unusual to find these clams in a soil sample. One of the possible causes is the mechanical cockle fishing industry that was permitted up until 2005, which resulted in a decline in the quality of shellfish. But there are also other damaging influences, such as the recent mild winters," emphasizes Kraan.

Kraan developed a mathematical model to explain the relationship between animal species (in this case the clam) and environmental variables. "The existing mathematical approaches were not able to explain the so-called spatial auto-correlation. Auto-correlation is the idea that a group of clams in a certain place is not independent of another group of clams a little way away. Now there is a new method that can better predict the relationship between the species and its habitat, not only clams, but also, for example, seals or vegetation. We can now clearly show which environment suits a certain species and which does not."

A new mathematical model was not exactly Kraan's aim when he started his research. "I started with the idea of taking nice samples on the mudflats and doing fun things with them," says the PhD student. "At a certain moment I had a fantastic data set, but then I discovered that the existing statistical techniques were not able to cope. That's how I ended up in difficult mathematics territory. My maths teacher from secondary school thinks it's hilarious -- I was never particularly good at maths. But once you get the hang of it, maths is great fun. With hindsight I'm really pleased things worked out like this."


Story Source:

The above story is based on materials provided by University of Groningen. Note: Materials may be edited for content and length.


Cite This Page:

University of Groningen. "Dutch Wadden Sea may become bottleneck for wading bird." ScienceDaily. ScienceDaily, 26 April 2010. <www.sciencedaily.com/releases/2010/04/100426081250.htm>.
University of Groningen. (2010, April 26). Dutch Wadden Sea may become bottleneck for wading bird. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2010/04/100426081250.htm
University of Groningen. "Dutch Wadden Sea may become bottleneck for wading bird." ScienceDaily. www.sciencedaily.com/releases/2010/04/100426081250.htm (accessed September 30, 2014).

Share This



More Plants & Animals News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Dolphins Might Use Earth's Magnetic Field As A GPS

Dolphins Might Use Earth's Magnetic Field As A GPS

Newsy (Sep. 30, 2014) A study released Monday suggests dolphins might be able to sense the Earth's magnetic field and possibly use it as a means of navigation. Video provided by Newsy
Powered by NewsLook.com
How To Battle Stink Bug Season

How To Battle Stink Bug Season

Newsy (Sep. 30, 2014) Homeowners in 33 states grapple with stink bugs moving indoors at this time of year. Here are a few tips to avoid stink bug infestations. Video provided by Newsy
Powered by NewsLook.com
California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins