O4 - Aquatic ecosystems

The impact of aquatic ecosystems provisioning services on tourism

Lead Author: Constantin Cazacu and Mihai Adamescu (Bucharest University, UB)
Editor: Asja Bernd (UBT)


The Danube River catchment spreads across nineteen European countries before reaching the West coast of the Black Sea (Guttler et al 2013). Just before reaching the sea, the Danube River creates a delta covering about 5100 km2 forming a complex alluvial system dominated by wetland ecosystems that have a great socio-ecological and economic importance. Being at the end of the river catchment, deltas are strongly influenced by human activities (Tiron et al 2009), which usually occurs at catchment level further upstream.

In the past, wetlands were considered as "wastelands" with reduced or no "benefits" for local economies compared with other ecosystem types, such as agro-systems, forests etc. (Zedler et al. 1998). In some other cases wetlands were considered as "threats" to human health (Dale & Knight 2008), so their surface was reduced or some of their functions were altered (Davidson 2014). Amongst the most frequent causes of wetland loss are:
i) drainage (for agricultural and urban development) (Chen et al. 2012, Davis & Froend 1999),
ii) hydrologic alteration (including channelization, embankments, dikes etc) (Coleman et al. 2008),
iii) habitat fragmentation (Mooney et al. 2005),
iv) climate change (Giosan et al. 2016),
v) nutrient and sediment inputs (Brutland 2008),
vii) infrastructure development (Russi et al. 2012), and
viii) invasive species (Zedler & Kercher 2004).
Within the last 30 to 40 years, however, wetlands regained their place among valuable habitats. In this respect, an international convention regarding their conservation as important habitats for migratory birds was adopted in Ramsar, Iran, in 1971 and was ratified by 169 states (Mooney et al. 2005). This international cooperation played a significant role in changing the trend in wetland loss (Gardner et al. 2015). Globally, two hundred million hectares of wetlands were designated as "Ramsar sites" of international importance and are now benefiting from conservation management measures.

Figure 1: Pelikans are just one of many bird species in the Danube Delta. (Credit: Vasile Alexe)

Large and compact areas of wetlands create a high number of habitats that host a high biological diversity. Due to the fact that these areas are difficult to reach on the ground, people inhabiting them managed to preserve many of their traditions. In the particular case of the Danube Delta, the large number of ethnic communities (i.e. Russians, Greeks, Ukrainians, Turks, Italians and Romanians) gives this area rich cultural characteristics.

Figure 2: Fishing is an important tradition of the local communities, and a major provisioning service in the delta.

The many different bird and fish species, the uniqueness of land and seascapes, and the local communities with their traditions make this area a nature-based touristic attraction. Most tourists come to the Danube Delta to enjoy nature through boating, canoeing and row boating, sport or leisure fishing, birdwatching, or open water swimming (fresh water or in the Black Sea). In addition, the area is very attractive from a scientific point of view with many research activities focused on studying climate change impacts on delta ecosystems, water circulation, sediment transportation, biodiversity, economic set-up and more.

Figure 3: A channel in the delta.

This storyline explores the link between aquatic ecosystem provisioning and cultural services and touristic attraction of the area based on earth observation data. Remote sensing imagery from satellites such as Sentinel 1 and 2 is especially useful for the monitoring of wetlands, as they allow for assessing short-time changes. Wetlands are very dynamic ecosystems, that undergo changes both quickly, for example in water level (Díaz et al. 2018). Satellite imagery enables us to map these changes, and then link them to further data, e.g. touristic activity.

Our approach involved several steps and methods. To identify the relevant ecosystem services within the Delta, we classified remote sensing imagery, mostly from Sentinel-2, to map the distribution of ecosystems. We then applied a biophysical approach in combination with stakeholder knowledge to determine the ecosystem services (Cazacu et al 2018, Holzer et al 2018). For cultural services, we additionally assessed geo-located pictures shared on social media platforms, as flickr. Through analyzing the picture location as well as the content, we could identify what areas, seasons and attractions tourists preferred. Lastly, we related tourist presence with different variables, namely aquatic system productivity, accessibility, hydroperiod (the period during which the wetland holds water), the Normalized Difference Water Index, the distribution of strictly protected areas and the presence of beaches, in a multivariate statistical approach.

Figure 4: Distribution of cultural ecosystem services across the data. It can be noticed that lakes, river arms and channels, as well as forests, rank higher than other ecosystems. Credit: Constantin Cazacu

So far, our results indicate that accessibility and system productivity play an important role in the distribution of tourists, and that physical interactions with the landscape are the major attraction. We are looking for further ways to incorporate remote sensing-derives products to improve our understanding of wetland functioning.

Figure 5: Water lilies grow in many parts of the Danube delta.



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This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 641762
Document Last Updated: May 2019