The River Sateska is located in the south-west of North Macedonia. Currently a tributary of Lake Ohrid, it originally flowed directly into the River Black Drim but was re-routed in 1961/2. It now accounts for 39.36% of the Lake Ohrid watershed and is consequently one of its most important tributaries.[1]

Sateska
Sateska is located in North Macedonia
Sateska
Mouth location within North Macedonia
Location
CountryRepublic of North Macedonia
Physical characteristics
Mouth 
 • location
Lake Ohrid
 • coordinates
41°10′04″N 20°43′37″E / 41.1677°N 20.7269°E / 41.1677; 20.7269
Length38 km (24 mi)
Basin features
ProgressionBlack DrinDrinAdriatic Sea

Artificial Reroute edit

In 1961/2, the River Sateska was diverted from its natural path into the River Black Drim and instead routed into Lake Ohrid, which it enters on the northern shore between the cities of Ohrid and Struga. The Lake Ohrid catchment was expanded by 460 square kilometers in the process.[2] The diversion was motivated by three main considerations:

  • to reduce the sediment load upon Globočica Reservoir;
  • to secure the hydroelectric potential of dams on the River Black Drim; and
  • to drain Struga Marsh wetland areas.[3]

Environmental Impact edit

Since the 1960s, the River Sateska has been a major source of pollution and other negative anthropogenic impact upon Lake Ohrid,[4][5] which is one of the most biodiverse inland waters on the planet.[6] At peak times, the river can bring up to 129 tonnes of suspended material into the lake per day,[7] which interferes with reed belts and spawning grounds for fish,[1] a situation that has deteriorated after the abandonment of measures to reduce erosion.[3]

The River Sateska is also the largest source of phosphorus inputs to Lake Ohrid and the second highest contributor of nitrogen (29%),[7] both of which can instigate eutrophication processes. Indeed, the mouth of the Sateska holds some of the lowest quality water in all Lake Ohrid[8] and displays evidence of eutrophication.[9][3] Water oxygen levels have been influenced and a shift in species composition has been observed.[3]

Due to environmental concerns, the World Heritage Committee has requested the Republic of Macedonia to explore options to re-divert the Sateska back to the River Black Drim.[3]

See also edit

References edit

  1. ^ a b Jordanoski, M., Velkova-Jordanoska, L., Veljanoska-Sarafiloska, E. "Ecological Effects of River Sateska and its Tributaries on Ancient Lake Ohrid" (PDF). Natura Montenegrina. 7 (2): 541–547.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  2. ^ Apostolova, N., Scarry, D., and Verhoeven, Jos T. A. (2016). "Studenchishte Marsh as an Integral Part of Ancient Lake Ohrid: Current Status and Need for Protection". Wetland Science & Practice. 33 (2).{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. ^ a b c d e World Heritage Centre, ICOMOS and IUCN (2017) Reactive Monitoring Mission Report Natural and Cultural Heritage of the Ohrid Region (Former Yugoslav Republic of Macedonia), World Heritage Centre, Paris, France.
  4. ^ Deutsche Gesellschaft für Internationale Zusammenarbeit (2015). Initial Characterisation of Lakes Prespa, Ohrid and Shodra/Skadar. Implementing the EU Water Framework Directive in South-Eastern Europe.
  5. ^ Kostoski, G.; Albrecht, C.; Trajanovski, S.; Wilke, T. (2010-12-17). "A freshwater biodiversity hotspot under pressure – assessing threats and identifying conservation needs for ancient Lake Ohrid". Biogeosciences. 7 (12): 3999–4015. Bibcode:2010BGeo....7.3999K. doi:10.5194/bg-7-3999-2010. hdl:10535/6457. ISSN 1726-4189.
  6. ^ Albrecht, Christian; Wilke, Thomas (2008-12-01). "Ancient Lake Ohrid: biodiversity and evolution". Hydrobiologia. 615 (1): 103. doi:10.1007/s10750-008-9558-y. ISSN 0018-8158. S2CID 20082566.
  7. ^ a b National Commission of UNESCO for the Republic of Macedonia (2018) Progress Report on the Implementation of the Recommendations according to the World Heritage Committee Decision 41 COM 7B.34. (Available at World Heritage Committee website.)
  8. ^ Japan International Cooperation Agency (2012) Data Collection Survey for Ohrid Lake Environmental Improvement.
  9. ^ Trajanovska, Sonja; Talevska, Marina; Imeri, Alma; Schneider, Susanne (2014-06-01). "Assessment of littoral eutrophication in Lake Ohrid by submerged macrophytes". Biologia. 69 (6): 756–764. doi:10.2478/s11756-014-0365-9. ISSN 1336-9563.