Oroklini Lake, Cyprus
Fish are supposed to be good indicators. Indicators of what?
At a small coastal marsh in southeastern Cyprus the fishes have guided us towards a different path of understanding the inner workings of unique limnosystem: its past, present and management for future rehabilitation. Our work at Oroklini Lake is the first to investigate fish and explore aspects of a holistic management.
Fish are important in understanding the integrity of ecosystems - and they help us unravel what a place needs to resotore any semblance of its past natural state.
The Oroklini Lake area or Oroklini Lake Wetland area has four regularly occurring species of fish:
- Striped Grey Mullet (Mugil cephalus)
- Thin-Lipped Grey Mullet (Liza ramada)
- Eastern Mosquitofish
- European Eel
But fish are very very scarce in the system!!! I mean you go down, watch for fish and usually see none! (But there are always plenty of birds)....So what does this indicate?
Our understanding so far gives the following research results.
Firstly we discovered that Oroklini Lake is a special heavily modified watland area that has been poorly researched in terms of its hydrobiology.
1) What was "Oroklini lake" before it was artificially "heavily" modified by humans? And this is a critical question because it may lead us to understand how the limnosystem worked, and how native fishes adapted and developed communities and strategies for survival when this was a natural wetland.
Answer: At least one 19th century map does show a lake at the spot - actually being fed by a stream so the "lake" was a natural area and since flow was from a stream - an estuary or river-mouth was present. We are nearly certain the site formed a coastal lagoon system. A seasonally-arid coastal lagoon system that may have gained waters either from the small stream and/or from south-wind marine water surges.
2) Is Oroklini a lake or a coastal lagoon?
Answer: Coastal Lagoon but with a grain of salt (!!!). Most visitors who see the "Lake" today would argue against this since the system is atypical...and in a very peculiar "degraded" situation today. In fact the "lake-like basin" is separated by a wide sandy coastal bar that is about 400 m wide and the connections to the sea are only two artificial drainage canals (the "West Canal" is actually no longer directly connected to the lake basin...). However I am calling it a heavily modified coastal lagoon for the following reasons: a) The historic map I have shows a natural lacustrine body by the shore with an inflowing stream, and the low depression near the shoreline creates conditions for flooding and water flow toward the sea. Coastal process - head-on south winds would build a sandbar. Also, the salina-like pan is salty - brackish usually today. I am sure it was originally a coastal lagoon habitat.
3) What would you expect to be the 'reference conditions' of the wetland?
Answer: Weird and varied coastal lagoon stuff (...). The system was MUCH bigger 100 years ago. So there was a connection with the sea (perhaps more run-off, perhaps marine wave flooding...). However it is a very small catchment and drought does effect and extirpate fishes. So I expect only Mugilids, Eel, Mediterranean Killifish - that's all. To construct references (i.e. refrence conditions to guid restoration) we need to look deeply into the ecological history of the site (and that's another project altogether).
4) What would you do now?
Answer: Just like you can restore and enhance habitat for birds, you can do the same for fish, and here some suggestions:
a) Protect the inflow and ensure outflows to the sea (one outflow, the East Canal exists - see report).
b) Ensure unobstructed passage of eels and mugilids from the sea. Provide "turf" for the elvers to scale the Spillway Sluice at the "Lake"-proper and provide passage from both Canals.
c) Ensure refugia for eels and mugilids during normal years.
d) Conditions are not optimal for introducing Killifish (Aphanius fasciatus) but perhaps an experimental attempt can be carried out. The big problem here is that most waters dry out on very dry years and in "normal years" there is an abundance of mosquitofish (a direct competitor and aggressive alien invasive). The question of re-introducing Mediterranean Killifish is important - it needs some bold experimenting.
Have a look at my report:
Please see acknowledgments in the report for all the people who banded together and helped us in this. And in 2018, the local Water Development Department also attempted their first eel pass- could work!
|Yours truly, looking for fish in the salty mud. Good help from Athina Papatheodoulou and friends.|
|Upper part of the "Lake" above the weir - floods in winter and is full of birds.|
|Restoration actions by BirdLife Cyprus.|
|Birds are good indicators too!|