Neusiedler See

The saline systems discussion group visited the National Park of Neusiedler See – Seewinkel, one hour to the east of Vienna and near the border with Hungary. The trip focused on the management and loss of saline waters, one of two threats facing saline systems into the near future. (The other threat is the unnatural salinization of freshwater systems, for which we visited Hallstatt – see previous post).

The park was the first national park in Austria, established in 1983. It is an agricultural region that has changed from pasturing cattle to cultivating vineyards; it has been designated a UNESCO World Heritage Cultural Site. It has also been designated a Bird Heritage Site because 340+ bird species migrate through the small region every year, attracted by one of largest reed belts in Europe.

Lake Neusiedler See on the horizon, fringed by the second largest reed belt in Europe.

Reeds are still traditionally harvested for roof thatching.

 We met Alois Lang, who has worked at the park since its inception. Using a large, high-resolution topographic model of the region, he explained the physical characteristics of the area that make it so unique. Neusiedler See is a very shallow (max depth 2.2 m, average depth 0.8 m). It is endorrheic, fed by precipitation and regulated by evaporation, though nowadays a weir ensures that the lake does not completely dry up or flood anymore, drastically changing its hydrology.

Alois Lang explains the morphology and hydrology of the Neusiedler See - Seewinkel region.

 The same strong winds push sand out of the lake onto the eastern bank, creating sandy soils that proved perfect for vineyards, changing the land use from cattle pasturing and haying to family-owned wine production 70 years ago. We saw hundreds of neat rows of grapevines on our way to the park, covered in nets, passed over by biplanes, and enveloped in a noisy ambiance of automated gunshots, all in an attempt to keep the migrating birds out of the vineyards during the concurrent grape harvest.

The sandy soil and climate of Neusiedler See are perfect for vineyards.

Next, we met with Prof. Alois Herzig, the former director of the park and biological station, and Harry, who is in charge of park education. They animatedly discussed the park’s management successes and challenges. Rather than owning land, the park annually rents the land and the right to manage it from the local landowners. In this way, the park is composed of 10,000 hectares of little islands of land surrounded by agriculture and linked together by plots of land that have gone fallow as part of a government-subsidized program, adding another 3-4,000 hectares.

Map of Neusiedler See; the green areas show the national park.

Fallow plot in between two vineyards.

The management of the land depends entirely upon the decisions of the 28 national park staff; they are not dictated numbers by government entities, such as bird population numbers or hectares conserved. If they notice something that works, they continue to do it. For example, they noticed that cattle-grazed land provided more bird habitat than mowed land or untouched land, so they paid to borrow traditional grey cattle from southern Austria and Hungary. In this way, they reintroduced a traditional land use practice in the region which also serves an ecological function.

The national park has enjoyed other successes in addition to recovering grasslands. The lake was once used as an eel fishery, introducing an exotic species that decimated the local fish population. In order to become a national park, the government required this industry be stopped, helping to recover the lake’s natural species assemblage. 

They also count successes within the community of Neusiedler See. The national park serves as a role model for sustainable land use and through the years there has been a change in the way locals value and use their land. So much of the land is now rented to the park or allowed to go fallow because it is of economic value to the whole community because of the ecotourism it brings, which supports stable jobs so young people can afford to stay in the community.

Birds and wine draw tourists to the region.

The town of Illmitz near a saline pond.

The national park faces challenges ahead. The first is money. The current budget is based on a contract between the regional and national governments, each paying 50% of a budget upon which the governments, without consulting the park, decide every year. The budget for 2014 is uncertain as both governments consider defunding both the national park and the fallow land subsidy. Should the park be unable to pay its rent to landowners – which already requires 60% of the budget – the landowners may choose to redevelop the land. The budget restrictions also leave only 3% for monitoring and 2.5% for education. The park does not receive revenue from tourism, so its land management, tourism advertising, and monitoring data rely solely on personal agreements it has made with local landowners, industries, and university researchers in Vienna.

IGERT saline systems group with Harry and Prof. Alois Herzig of the National Park.

 Ecologically, the main challenge is now water retention. Water management in the area focuses on maintaining stable lake levels and avoiding floods. Water is also free and unlimited, so sloppy water use among the farms is common. This inefficient consumption lowers the water table so much that the smaller Seewinkle saline ponds, which naturally tend to dry up in the summer, are drying up permanently because the groundwater that feeds them is now too deep. The park has lost 60 ponds in this way, and now focuses on educating the importance of saving the remaining forty ponds in its area.

Birds at a Seewinkel pond.

Seewinkel saline pond.

 Many of us were struck by how similar the region was to the Nebraska Sandhills in appearance and ecological function. This will lead to many interesting future discussions in the saline systems group about how saline systems are understood and managed.

Heading back to the city, marked by Vienna's "Home Mountain"

(Post written by Victoria)

(Photos by Victoria and Nathan)

Hallstatt

Some IGERT members have formed a small paper discussion group on the resilience and management of saline systems. These unique systems exist both in Nebraska and Austria, and we are curious about how the two compare. Two different threats related to salt and aquatic systems are predicted to become more serious in the coming decades: the loss of naturally saline lakes, and the anthropogenic salinization of freshwater lakes. We will visit examples of both of these situations in Austria. First, we visit a freshwater system influenced by salt.

Members of the saline systems discussion group travel to Hallstatt, in the western part of Austria near Salzburg. Hallstatt is part of the Salzkammergut, or “salt kingdom,” where salt has been mined for thousands of years, providing the region with economic stability and a vital natural resource. The region is also characterized by several freshwater lakes. Our mission is to learn more about how these two natural resources coexist and their socio-economic connection.

The town of Hallstatt seems tiny from the ferry, hugging the shores of the lake Hallstättersee and creeping up the surrounding mountains. The town has about 1,000 permanent inhabitants. Every morning, two fishermen cruise the lake with nets and return with the catch of the day for the locals and restaurants to prepare for dinner. Swans, introduced to the lake to please Empress Elisabeth when she would vacation here; today they cruise the lake looking for handouts from the peasant tourists.

We ascend a nearby mountain to visit the local salt mine. Hallstatt has been a mining center since about 7,000 years ago, and this is thought to be the oldest salt mine in the world. Neolithic people mined the salt to preserve meat; this area became one of the first known human settlements, and its archaeological importance is recognized by an era of time named after it (Hallstatt Era 800-400 BC).

Roman ruins underneath a sports shop in town.

We enter the salt mine through a tunnel dug in the 1700s, and descend to where the salt is located. The salt was deposited in layers from seawater periodically evaporating during the Mesozoic Era. The deposit is rich with iron from the seawater, giving the salt a red color. (Thanks to the guide for being so patient with all of our geology questions!)

Entrance to the salt mine.

Salt deposits in the mine.

The mine has continuously functioned through the millennia. The mining techniques adapted with technology, and today the salt is mined by being dissolved into water under pressure. The salt is then transported as brine through pipes 40 km to the town of Ebensee, where it is placed in evaporative pools to extract the salt.

The evolution of brine pipes.

An old brine pipe.

The system is so efficient that the mine only employs 28 workers total. Because of the loss of jobs in the mining industry, young people have left town for opportunities elsewhere; the population has shrunk by half, and many of the houses have become rental properties for tourists.

Hallstättersee receives wastewater discharges from the mine through one of its tributaries. On two occasions in the last few decades, the brine pipes burst leaks, releasing large amounts of brine into the lake. News reports suggested that the brine sank to the bottom immediately and therefore had no impact on the lake; we were interested in the effects of sudden intense additions salt on the benthic ecosystem. Our discussion papers found that the brine spills caused ectogenic meromixis (the lake stops mixing during “turnover” periods) and hypoxia (low or no oxygen) in the deeper regions of the lake which showed temporary die-off of benthic fauna. Even though one brine spill was much larger than the other, the lake took the same amount of time to recover from the shock by flushing the salt out of its basin (3 years, or 6 times its water residence time).

Hallstattersee

As far as we can tell, culturally and economically, though the lake is beautiful, here salt is king. The lake is lucky that it has the natural ability to respond quickly to the occasional “oops” of large brine spills, because the salt isn’t going anywhere soon.

(Posted by Victoria)
(Photos by Victoria)