Jordsand – A defunct Danish Hallig
Transcription
Jordsand – A defunct Danish Hallig
Jordsand – A defunct Danish Hallig By John Frederiksen1 Just before the turn of the millennium, the small Danish Wadden Sea island Jordsand ceased to exist. In the winter of 1999, the nature observation hut on Jordsand was set on fire; the ritual symbol of Jordsand no longer existing as an island in the Wadden Sea. This marsh island (hallig) had finally gone as a result of continued erosion by the sea for centuries. The remainder became part of the high sand bank between the Danish mainland and the German island of Sylt (Fig. 1). By 1974, Jordsand was still a small island surrounded by mud flats and high sand banks, as shown in the aerial photograph of Figure 2. Fig. 2 - Jordsand in 1974 with the observation hut. In the back-ground the mainland coast can be seen. Photo: Svend Tougaard, Ribe. Fig. 1 – Satellite photo of the island Sylt (left) and the sand banks (white) on the location of the former isle of Jordsand, 4-8-2006. (Source: Wikimedia Commons) Jordsand - seen by the eyes of the past Today, when looking at the Wadden Sea from the geest cliff on the mainland, it is hard to imagine that in the Middle Ages the present coastal zone of 6 - 7 km width was covered by an almost uninterrupted marsh surface and, according to contemporary sources, only separated from the mainland by a tidal gully. What we do know, however, is that Jordsand for a long time was a hallig similar to the present Halligen in the North Frisian Wadden Sea. These are remnants of a former large salt marsh area destroyed by the sea. And from several historic maps and nautical charts we also know that Jordsand must have had a significant size in 1600s and 1700s. 1 Fig. 3 - Section of Willem Blaeu’s chart from 1612 of the Wadden Sea around the islands of Rømø (“Rym”), Jordsand (“Jurtmans huys”) and Sylt. Former Danish member of the Wadden Sea Board of the Trilateral Wadden Sea Cooperation. 1 The first time Jordsand appears at a nautical chart is in 1585, when the Dutch cartographer Lucas Waghenaer’s (1534-1606) "Spieghel der Zeevaerdt" was published. In 1612, his successor Willem Blaeu (1571-1638) published a nautical chart of the Wadden Sea between the Elbe and Blåvandshuk as part of his work “Het Licht der Zeevaert“. This chart was mainly based upon information from Waghenaer’s chart (Fig. 3). At both charts, Jordsand (“Jurtmans huys”) has the same size as the island of Mandø. At Jordsand two houses are depicted. In mid-1600s, the map and chart collection of Schleswig-Holstein by the Danish cartographer Johannes Meier (1606-74) was published in the work "Newe Landes-beschreibung there zwey Hertzogthümer Schleswich und Holstein" (Fig. 4). The size of Jordsand was, roughly measured, 6 km2 (600 hectares). Meier’s charts and maps of his contemporaries are considered to be reasonably accurate, although it is difficult to determine which information results from actual measurements and which originates from oral narrations. Fig. 4 - Section of Johannes Meier's chart (1648) of the Wadden Sea between Sylt and the mainland, showing Jordsand, and also an indication of a sea battle in 1644 between the Danish fleet and a combined Swedish-Dutch fleet. On the chart sketch of 1689 by the Danish cartographer Niels Hegelund, Jordsand appears at about the same size as on Meier’s chart, although its shape is somewhat different. Because of Hegelund’s records of the area's appearance and specified water depths and anchorage (indicated by two anchors) in the Lister Deep, this information is supposed to be very accurate. Especially as this chart was intended to serve important political decisions (see below). 2 Fig. 4 - Hegelund´s chart sketch of Lister Dyb (Lister Deep) from 1689. In 1807, the first thorough cartographic measurement of the Danish Wadden Sea was carried out. A comparison with today's navigational charts indicates that Jordsand is accurately positioned. The island's size had by this time been reduced to approximately 40 ha. Jordsand’s degradation From 1807 onwards, the degradation of Jordsand went fast. In 1807 the island was 40 ha, 100% of which consisted of marsh land. In 1873 the surface area had decreased to 20 ha, of which 75% was marsh lands. In1936 there was not more than 8 ha left, and in 1973 only 2.3 ha, of which less than 10% was marsh land. Only 0.2 ha was left in 1994. Finally, in 1999, the island Jordsand did not exist anymore. Fig. 5 – Aerial photographs of Jordsand in 1973 (left) and 1996 (right). Photos by Svend Tougaard. 3 Fig. 6 - Jordsand’s degradation from 1807 to 1994. The delineation shows the area’s with vegetation coverage. After Jespersen and Rasmussen(1996), modified by Svend Tougaard. Apparent from the sketch in Fig. 6, the degradation of marsh land mainly took place on the northern and western sides of Jordsand. The last remnants of the marshes disappeared in 1983 but simultaneously with the erosion of the marshes, sand ridges were built up on the eastern side. In 1999 the last vegetation-covered sand ridges were also engulfed by the sea. In the period 1976-78, attempts to stop the erosion were carried out by means of the construction of brushwood groynes (see Fig. 7). These coastal protection measures failed though, and the maintenance of the groynes was abandoned in 1987. Fig. 7 – Construction of brushwood groynes by volunteers in 1977 (left; photo: John Frederiksen) and aerial view of brushwood groynes in 1991 (right; photo by Svend Tougaard) 4 The main reason for the degradation of Jordsand was that the island, like the current Halligen in the North Frisian Wadden Sea, was never surrounded by a proper dyke to protect the island against the destructive forces of the sea. Moreover, in the last 50 years Jordsand was located within the only tidal basin in the entire Wadden Sea where the hydrological conditions had undergone drastic changes due to the construction of dams between the islands of Sylt and Rømø and the mainland in 1927 and 1948, respectively. Since then, tides and storm surges flow in and out through only one tidal inlet (Lister Deep) between two barrier islands; no water transport across tidal watersheds was possible any more. Whether these changed conditions have contributed to the downfall of Jordsand has not been documented. However, measurements of the tidal range in the Sylt/Rømø tidal basin in1968 and 1994 respectively, demonstrated an erosion of 1.3 million m3 of sediment for the entire intertidal area in these 25 years, which is equivalent to an average surface erosion on 1mm/year. Jordsand - an inhabited hallig Since the early 1900s Jordsand and surroundings has been subject to regular surveys and monitoring to document its natural values and its importance. Less, however, is known of Jordsand’s cultural (historical) conditions through time. Only few findings and artifacts have been able to provide pieces to the puzzle of how human habitation has unfolded in this isolated and exposed edge of Denmark. Details at the nautical charts from (1585),1612, 1648 and 1689 indicate that there has been human settlement (two farms) on Jordsand in that period. Earlier settlement has been reliably reported already in 1200s; at that time the hallig was much larger. In the Danish king's records from 1231, Jordsand is referred to as "Hjortsands House". This has been interpreted as the king's residence during his hunting trips on the island, e.g. on deer. The name Jordsand is thought to be derived from the Danish word “hjort” for "deer". At what time in its history the hallig was inhabited all year around, and when this was replaced by seasonal habitation could not be determined with certainty. From local archives it can be proven that in 1543 there was one settlement on the island; in 1607 the archives referred to two settlements. From records in the late 1600s it can be seen that permanent habitation of Jordsand probably ceased around 1695, partly due to a violent storm surge that year. Since then, the island is considered to have been used only for cattle grazing and hay making during the summer season. From 1700 onwards, archives deal almost exclusively with correspondence between land owners and authorities about requests for tax reductions, probably in conjunction with the damage and loss of land on the island due to the continuous attack by the sea. In 1897, the owners requested the Prussian State to pay for the reconstruction of the shepherd’s brick hut and the dwelling mound where it was built on. These had been destroyed by a storm surge 1½ years earlier. The application, however, was refused and the dwelling mound was never reconstructed. In August 1923, a storm surge, where sheep and horses were drowned, made the “full stop” of Jordsand as an island with agricultural use. 5 Traces of past habitation In 1969, the first archaeological evidence of Jordsand’s habitation history was discovered, when the owner unearthed a fresh water well made of bricks. In 1975, an other brick-made well was found and in 1978 the last remnants of a clay-made well appeared. The most recent find showed up in 1982, when a profile of cut clayblocks was exposed. All four records are within a distance of approx. 100 meters (Fig. 8). The brick-made well found in 1969 was about 2 meters deep and 1 meter in diameter. It was built by rhombic, hand-shaped bricks, piled without binder in a spiral form with decreasing diameter from bottom to top (Fig. 9). Fig. 8 - Aerial photo of 27 September 1979 with locations of archaeological finds at Jordsand: 1 = brick-made well (1969); 2 = brick-made well (l975); 3 = clay-made well (1978) and 4 = clay block profile (1982). Photo: Svend Tougaard, Ribe. The profile of the cut clay-blocks (30x30 cm) at location 4 is shown in Fig. 10. Fig. 10 – Profile of cut clay blocks. Photo: John Frederiksen. Fig. 9 - The brick-made well found in 1969. Photo: Thorkild Funder, Ribe. Several sources have claimed that the two brick-made wells were cisterns and remains of the settlements in the 1500s and 1600s. Cisterns to collect fresh water from the roofs for the residents are characteristic features of the freshwater supply in many parts of the Wadden Sea area in the past (Fig. 11). It was, however, with great surprise that the excavation of the brick-made well of 1969 revealed that this well, unlike the characteristic cisterns on the Hal-ligen, rested on an “open” pine wooden frame, similar to wells on the geest (Fig. 12). 6 Fig. 11 - Excavated cistern from Hallig Hooge in the North Frisian Wadden Sea (1962), with closed brick bottom. Photo: Thorkild Funder, Ribe Fig. 12 - Part of the wooden foundation in 1979 of the well found from 1969. During these 10 years almost the entire well was washed away. Photo: John Frederiksen. The pine wooden ground frame and its nail holes could indicate that this well originated from the late 1800s and … perhaps had been in use until 1923, when the agricultural utilization on the island ceased? This hypothesis is supported by the shape and size of the bricks, and by their probable origin. In the 1800s, in the village Koldby on the mainland opposite Jordsand, two bricks ovens where operated where bricks of the same shape and size were produced as found in the well on Jordsand. Regardless the age of the wells one must pose the question of: how can “open-bottom” wells serve as storage of freshwater in this saline environment of the Wadden Sea? Were there any special conditions on and around Jordsand, which nevertheless made it possible to form and maintain a body of freshwater? A sufficient body of dunes would allow the presence of a fresh water lens in the underground, similar to conditions on the barrier islands of the Wadden Sea. An alternative explanation may be the presence of an aquifer in the subsoil. A hint in the latter direction is the information from a member of the family that landed the "last load of hay" from Jordsand in 1923. From his boyhood he remembered the existence of three freshwater springs in the Wadden Sea between the mainland and Jordsand. Two of these sources were close to the geest at Koldby and one was on ....... Jordsand. In 2002, a biological study was carried out at several permanent freshwater seepage areas along the Wadden Sea shore of the island of Sylt. This suggests that a specific structure in the underground may have given rise to the freshwater spring reported from Jordsand. There have, however, never been studies on the geological stratification in this part of the Wadden Sea that could shed light on this phenomenon. The question therefore remains: have investigations of this kind taken place, or is information available from anywhere else in the Wadden Sea to complete this interesting puzzle piece of the history of Jordsand? Jordsand´s wartime history From a historical perspective, Jordsand was a remote location. Nevertheless, a few events are noteworthy to be mentioned when writing the island's history. 7 In May 1644, during the European 30-years War (1618-48), a big sea battle was fought between a Swedish-Dutch fleet of 30-40 light vessels, led by the Dutch admiral Maarten Thijssens, and 9 Danish battle ships, led by the Danish King Christian IV. This battle took place not far from Jordsand, and is depicted in Meier’s chart (Fig. 4). The Danish fleet with their heavy artillery shot the Swedish-Dutch vessels into pieces, and several hundred of the dead sailors are supposed to be buried on Jordsand. Almost 50 years later - in 1689 – again the small island was involved in the European power struggle. The Danish King Christian V decided to support the Dutch stadtholder William III, who also became King of England and Ireland earlier that year, in his strife there. The embarkation of several thousand Danish soldiers took place in November at the anchored transport fleet in the Lister Deep, via Jordsand. See Hegelunds chart for anchorage location (Fig. 5). 175 years later, another war, now between Denmark and Prussia (Preussen), resulted in a change of position of the border between the two countries approx. 50 km more to the North. This lasted from 1864 to 1920. During this period Jordsand was part of Preussen. Jordsand - a forepost of nature protection On both sides of the former border increased interest in nature protection had spread around the turn of the 19th and 20th century, and the Wadden Sea was already well known for its rich bird life. A summer visit of German birdwatchers on the island in 1907 was the very beginning of the German bird protection association "Verein Jordand" (Fig. 13). Unlike the island, the organization remained alive and is still very active indeed in the preservation of coastal birdlife, both in the Wadden Sea and along the Baltic coastline. This, more than 100 year old German initiative will probably be the only remain that will continue to highlight the name of the now defunct island in the Wadden Sea. Fig. 13 – Logo of the “Verein Jordsand”. After Jordsand again became part of Denmark in 1920, the "Danish Ornithological Society" continued the protection work on Jordsand. In 1922, the same year as the island's bird life was preserved, the Danish association contributed to the continuation of the German pioneering work by co-financing a warden in the summer months to study the rich bird life. The results of this voluntary work at "Denmark's first bird station" became the basis for the creation in 1939 of the first Danish Wadden Sea Nature Reserve “Jordsand and surroundings”. Since 1960, the birdlife on and around Jordsand has been subject to extensive scientific studies; it became one of the most important places in Denmark. In these studies an important role was played by the observation hut, that was set on fire in 1999 (Fig. 14). 8 Fig. 14 – The observation hut on Jordsand on fire. Photo: Svend Tougaard. Epilogue “Nothing in this area can survive unchanged. Erosion and sedimentation processes bring about continual change which, at the same time, both aids and hinders documentation efforts. In general, experience gathered in recent decades has shown that destruction of cultural signs or traces in the Wadden Sea Area continues to advance and that there is indeed reason to make immediate use of these cultural signs for research into the history of the land and its settlement before they disappear forever”...(Lancewad Report, 2001). Sources Palle Uhd Jepsen, 1976. Jordsand – Fuglenes ø i Vadehavet. Bygd 1976. N.H. Jacobsen, 1941. Jordsand. Haderslev-Samfundets Aarsskrift 1941. Margot Jespersen & Erik Rasmussen, 1976: Jordsand - Erosion und akkumulation einer hallig. Geografisk Tidsskrift: 13-23. Margot Jespersen & Erik Rasmussen, 1985. Jordsand – Danmarks eneste Hallig. Højer Mølle- og Marskmuseum. Margot Jespersen & Erik Rasmussen, 1991: The morphological development of the Wadden Sea Island of Jordsand since the storm surges in 1976. Geografisk Tidsskrift 91: 11–18. Margot Jespersen & Erik Rasmussen, 1996. En beskrivelse af de nationale geologiske interesseområder nr. 104 og 105 (delvis), published by "Skov- og Naturstyrelsen, Kopenhagen.. Anonymous, 1999. Lister Dybs Tidevandsområde og Vadehavsfronten; Kystinspektoratet, Lemvig. M. Vollmer, M. Guldberg, M. Maluck, D.Marrewijk & G. Schlicksbier, 2001. Landscape and Cultural Heritage in the Wadden Sea Region – Project Report. Wadden Sea Ecosystem No. 12. Common Wadden Sea Secretariat. Wilhelmshaven, Germany. Andreas M. Zipperle & Karsten Reise, 2005. Freshwater springs on intertidal sand flats cause a switch in dominance among polychaete worms. Journal of Sea Research 54(2): 143-150. Acknowledgements Special thanks to Svend Tougaard, Ribe, for the use of his photos and other valuable contributions to the article. Further, Hans Peter Krogh, Koldby, provided oral information about the brick-made wells. 9