Happy World Wetlands Day! This day is to remind us how important wetlands are to human. Unfortunately wetlands are degrading which has led to diminishing populations of waterbirds at least in northern Europe. However, by counteracting eutrophication and overgrowth we can accomplish flourishing waterbirds communities in which also threatened waterbirds prosper.
Due to human activity more than half of the world’s wetlands have been lost during the past century. The degradation of the remaining ones have led to decrease of waterbirds even in Finland – the land of thousand lakes. Nationally the number of threatened waterbird species has sextupled during the last fifteen years. That’s really alarming. Especially increased leaching of nutrients into waterways has decreased the suitability of wetlands for waterbirds. Eutrofication leads to overgrowth and increases turbidity and populations of cyprinid fish which result in decreased amount of suitable habitat and food for waterbirds.
We studied birds’ responses to wetland management performed in fifteen wetlands in southern Finland during the years 2004-2012. Results were enchanting. Management increased significantly the numbers of both breeding and staging waterbirds. Especially valuable was to notice that together with common species the numbers of red-listed birds increased. To become red-listed a species has to decline rapidly or its population has to be small. Thus red-listed species are in strongest need of conservation. Another remarkable notice in addition to aiding threatened species is that the wetlands were among the most important wetlands in southern Finland already before management. Yet their importance to waterbirds multiplied due to management.
Wetland management aimed to counteract eutrofication driven overgrowth and to restore open areas. Cattle grazing proved to be most efficient management actions but also cutting and dredging increased the numbers of dabbling ducks, waders, rallids and bittern. Management also brought back black-headed gull colonies, which are important in providing shelter for breeding waterfowl. Cattle grazing increases diversity in the landscape which explains its excellence in wetland management. Grazing and dung diversifies plant and insect communities, which are both important food for birds.
Investing in management is profitable
The evaluation of cost-efficiency revealed that money spent in management is money well spent. On average an investment of 150 000 euros multiplied the number of breeding black-headed gulls by thousand and gave 30 times higher number of staging dabbling ducks compared to starting point.
As much as one third of the world’s value to human kind has been evaluated to derive from shallow waters. Among other things wetlands provide us water for agriculture and drinking, reduce disaster risk and are one of the mainstays of biodiversity. Waterbirds play an important role in cultures of both westernized and indigenous communities. You don’t have to be a passionate birdwatcher to get excited about waterbirds. The waterfowl in city parks delight huge numbers of citizens throughout the world and brighten the ordinary days of our lives. Also large and stable populations of waterfowl are essential in securing popular hobby of hunting.
It is important to evaluate the efficiency of management for finding the best and cost-efficient ways to enhance the conditions of wetlands. Transparent discussion of the use of common funds has a fundamental societal importance. Therefore it is valuable to obtain evidence-based knowledge also on the efficiency of nature conservation.
Climate change is increasing the significance of wetland management
Global warming is pronouncing the role of North-European wetlands for waterbirds and also the need of their management. Many waterbirds are arriving here earlier in spring and leaving later in autumn than previously and thus spending more time in these wetlands. If wetlands don’t meet the demands of waterbirds, this might have population level effects as already seen in declining trends of many species. The necessity of wetland management may also be pronounced in the future as climate change has been projected to increase precipitation and leaching of nutrients into waterways – and continuing the degradation of these valuable habitats.
The study in full detail is available through Scientific Reports webpages:
The work is funded by Maj & Tor Nessling Foundation. From their website you can also found a blog post of the achievements of wetland management in Finnish.