Conference for the restoration of European estuaries Ideas, approaches and implementation

Transcription

1 Conference for the restoration of European estuaries Ideas, approaches and implementation Presentation Michiel Firet, Programma Rijke Waddenzee, Eems-Dollard Below you can find the written outline of the presentation Michiel Firet gave on February 22, in Leer, Germany. You can find the pictures of the Powerpoint Presentation on the website PS: If you have any questions you can contact Michiel at: Slide 1 Let me introduce to you. I am Michiel Firet, work for Staatsbosbeheer, the Dutch national organisation, commissioned by the government, for the management of a considerable share of all nature reserves in the Netherlands. Together with 7 other nature organisations we feel and take responsibility for a good nature-management of the Waddensea. Part-time I work for the program towards a rich Waddensea commissioned by the Dutch minister for nature in I am responsible for the ecological targets concerning the Ems-estuary in this program. Slide 2 Do we know the Ems-estuary? Is it the fluid mud in the Unterems, visible at Herbrum? Is it the pride of workers in the Papenburg-region, or the booming business in the harbours of Eemshaven, Delfzijl and Emden? Or is it the large amount of birds who visit the Dollard? Or is it the presence of rare fish-species, looking for a route to the inland waterways? Slide 3 In this presentation I will give a summary of the ecological mismatch in the estuary. Then I shall tell something about the Inspiration-map, leading to a call for help to achieve an ambitious but realistic set of measures. A set of measures to restore the ecological balance in the entire estuary, in combination and with respect for society demands of social-economical development and sustainable coastal protection. Slide 4 The Ems-estuary is important for fish species like the European Flounder Slide 5 The Ems-estuary is important for fish species like the European Smelt Slide 6 Estuaries are a clear example of ecosystems that are during a long time influenced by the use of man. In the UN a debate is starting about the question if we are shifting from the Holoceneera to a new Antrophocene era. I think that our view on healthy ecosystems of estuaries was, is and shall be influenced by the use of land by man, in and around the estuary. Program toward a Rich Waddensea has asked an impression artist to draw a 3-dimensial image of an estuary which has all ecological elements in a sound way. For understanding the Ems estuary the elements the following elements are important: Multichannel system Eb- and floor-channels Saltmarches Turbidity maximum zone Tributaries

2 Slide 7 The study area for Program towards a Rich Waddensea is the whole Ems-estuary, from Herbrum to the outer delta between Borkum and Rottumeroog. And it is good to know that the study-area is the downstream part of a larger catchments area, in Germany and the Netherlands (e.g. Bargerveen peat moor Westerwoldse Aa). Slide 8 What are the ecological key-factors of an estuary? Estuaries are a part of shallow coastal zones with a high import and production of organic matter, and a wide diversity of habitats with continuous changing conditions in salinity, velocity and elevation. Slide 9 What is de function of the Dollard for species like the flounder of the smelt? Do they find the right habitats? And what does the accumulation of mud means for them? Slide 10 A natural phenomenon is the turbidity maximum zone. Today we get enough information about the unbalance of this zone in the Unterems. The challenge is to get this zone again in natural proportions, vertical depth and horizontal length. Slide 11 As a result of ongoing channel deepening the Ems-estuary, especially the tidal river, suffers from an increase of the tidal wave. The Ems isn t the only tidal river and estuary with a tidal wave. With as a result a net increase of suspended matter upstream, leading to tidal pumping. In scale and ecological impact we can compare the Elbe and the Ems. But the spectacular tidal wave bore of the Severn is attractive for sportsmen and local tourism. Yet, a bore is a signal of an ecological unbalance on hydro-morphological level. Slide 12 The main characteristics of the hydro-morphological unbalance of the Ems-estuary as a whole are in the middle and outer estuary: an ongoing process of deepening of channels for shipping and removal of shallows turning the flood channels, with originally lower current velocity to the main entrance resulting in an increase of the incoming tidal current and with as a result changing the tide channels to the channels with a lower current velocity since ca s the multi channel system is transformed to a one gully system the tidal amplitude is increased and moved far upstream, original with the peak near Emden on a level of ca. 3 m. (Papenburg 1.7 m.), now with the peak at Papenburg and about 3,5 m. The picture in the left bottom corner shows the changing in depth of the middle and outer estuary, with net accretion ( red by the Osterems and the Bocht van Watum, and net deepening of the main shipping lane. Slide 13 How sound is the Ems-estuary? To get an answer we have to look at the quality of habitats, and the abundance and reproduction of species. Very in general we can say that the intertidal mud planes are in intermediate state. Important elements as sea grass and mussels bed have decreased. The habitat quality of the shallow channels and the possibility for fish to get along the turbidity maximum zone are of more concern. Slide 14 In the same way our study (about the ecological functioning of the Ems-estuary; knowledge document ) gives a summary of the trends of estuarine species. The species of the Ems water system are in danger, birds and mammals, which we easily perceive, are on a more or less sound level. Although decrease of primary producents and hyperbenthos will have effect on birds as well.

3 Slide 15 So, the major challenge of restoring the Ems-estuary lies in the hydro-morphology. How can we help the fish species which depend on healthy habitats for their life stages? Slide 16 After this quick summary of the ecological mismatch of the Ems-estuary I will continue with some explanation of the work the Program towards a Rich Waddensea has done on the Emsestuary so far, and how we want to move forward. Slide 17 Programme Towards a rich Waddensea started with the work on the Ems in In 2012 the first results came available. These results are: A summary of the ecological state of the Ems estuary, already accepted as the common state of knowledge and implemented in regional policy documents The Inspirationmap and a brochure (in Dutch, German translation available) which identifies options for restoration. This map is intended for dialogue and co-creation Support of the Ems Naturlich Initiative Support of the Marconi-initiative Delfzijl Morfo-ecological quickscan of the Menkemadam-initiative Dialogue with the waterboards to identify possibilities for swimway-restoration Slide 18 The knowledge document ends with a table of possible options for restoration of the Emsestuary. The shown options (4, 7, 8, 11, 13 and 14) are situated in the middle and outer reaches. Also measures for the Unterems are proposed. Every measure is scored along the criteria ecological effectivity and towards the ecological reference. Slide 19 As a follow up of the scientific analyses in the knowledge document, we have tried to develop a long term reference image of a ecological sound Ems-estuary and a set of suggestions for restoration. It worked out that in combination with demands of socio-economical development and coastal zone safety it is not possible and not necessary yet the define a strict ecological long term target. So, the brochure gives a direction, a development, moving towards a sound estuary with natural dimensions. The next step for the Program towards a Rich Waddensea is to develop a set of measures, more in detail, and in connection with the socio-economical en coastal defence demands. Again, a set of worked out measures to inspire policymakers and businesses, to adapt in the upcoming policy-documents and in the search for concrete projects of co-creation. Slide 20 So, lets make the shift from inspiration to co-creation. What kind of measures are possible and how can they help to restore a hydromorfologic sound estuary-ecosystem? Measures are of more value when they act upon the real causes. When they help to reduce the tidal pumping, improve the supra-regional swimway from sea to inland, restore estuarine gradients and helps to move in the direction of the natural reference. And of course, support for the measures is very important. Slide 21 When we are looking for possible measures it is necessary to know where on the scales of time and space the measure will have effect. For the middle and outer reaches we have to deal with a timeframe of about 100 years and a spatial frame of about 40 km s. Slide 22 With the following slides I will present the first thoughts about a set of measures for the middle and outer Ems-estuary. This of course in addition to the measures for the Unterems, presented by the Lebendige Unterems project.

4 Slide 23 In the brochure Compass for natural dimension, the search of the golden ratio for the Emsestuary and the added Map of inspiration addresses the challenge of restoring the natural width, depth and length of the Ems-estuary. Working on the length of the tidal river is proposed by Victor de Jonge et al. A second line of thinking is restoring the natural depth of the estuary. Adapting this line of thinking will result in issues like a regime shift in shipping policy, and/or innovation in shallow water transport. I will be very clear, this kind of solutions are far-reaching and they go beyond the assignment of the Programme towards a Rich Waddensea. So we will pay no further attention to this kind of measures. Slide 24 A second set of measures can by summarized as adapting the natural width of the outer and middle Ems-estuary. It is common known that there is no big support for moving main dikes landward. But it is worth to investigate integral development projects with an added value for the hydromorfologic situation of the estuary. And with a added value for the social-economical development of the region and for the long term coastal defence strategy. What can we learn from projects like the Overdiepse polder (Waalwijk, Netherlands) project Waterdunen etc. And will eco-dredging in the middle- and outer Ems-estuary help us to get an increase of the intertidal area? Ideas we have to investigate more in detail. Slide 25 The biggest challenge for this year is to identify and work out measures which will reduce the incoming tide current velocity and power. Program towards a Rich Waddensea has done a quickscan on the Menkema-initiative, the idea to build a dam between Eemshaven and Knock. Although this idea has some ecological benefits, it is an artificial approach that acts on symptoms. Open estuaries are rare in the Waddensea-region. So, solutions to reduce the incoming tide energy in an open estuary situation are far more beneficial then an eco-dam. Ideas we have to investigate more in detail are presented on this slide. Some ideas are far beyond our today s way of acting with the estuary. Some ideas will show up as not realistic when worked out in detail. And there will be land-use conflicts. But when we wants to take restoration of a hydromorfological sound Ems-estuary serious, I think we should give ourselves the mental space to search for innovative solutions which will be realistic, for example because they can be combined with a sustainable economical course. Slide 26 On the sublocal and local scale there are opportunities to improve the quality of habitats. Maybe in a nice combination with for instance work on coastal safety. Maybe it is possible to artificial reactivate a 5-gully system in the Dollard, and use the clay for the Green Dollard dike concept. With the German Dollartdike as an example the Dutch waterboard Hunze & Aa s starts a pilotproject with this dike-concept. Slide 27 In order to achieve the right set of measures for an ecological sound Ems-estuary all parties involved should be willing to start the dialogue, about possibilities, about innovation, but also about the amount of changes that can be achieved in say 5 to 10 years. Restoring a ecological sound Ems-estuary isn t simple at all. It needs an paradigm shift in the way we are looking at, and using the estuary. Will it have impact on shipping? Or can we find smart solutions and achieve a real balance between ecological and socio-economical development? The challenge of the Ems-estuary isn t unique, so when we can find the answer for this estuary, maybe it will help solving similar questions in other Northwest European estuaries.

5 Slide 28 This year the Program towards a Rich Waddensea will work on a set of measures for the improvement of the ecological state of the Ems-estuary. The focus shall be on: - supralocal - midterm - ecosystem driven - technical possible - financial possible - acceptable We will filter the long list of ideas to a short list of possible measures. Then, we shall calculate on these measures. And filter more, to a ambitious but realistic set of measures. This set will be presented to governmental processes like the Integral Management Plan (IMP/IBP). Decision making will take place in these processes. But also private partnerships can adapt a measure in their development. So the simple question is, who can help in this next step towards an ecological healthy Emsestuary? For further information: