Tuesday, November 19, 2019

Western Aegean Freshwater Fish explorations: HCMR Yellow Fish project (Xerias Istiaia and the Beotian Kifissos)


The Xerias River on Euboea Island. Part of it is naturally intermittent - but there were spring in the Delta. An important N2K protected area. 

13-18 November - Eastern Central Greece

We are doing some late season fish sampling to gather assemblage data in rivers and wetlands and little-known areas that still have serious gaps in our databases. This for a new HCMR project "Yellow Fish", an awareness generating and outreach project to protect rivers and other waters from human negligence and neglect. Some sites we visted are protected areas, some are near N2K boundaries but just outside and not targetted at all for preservation, conservation or restoration.

See the initiating report for this project (in Greek) here:
Kitrino_Psari_HCMR-IMBRIW_EKPAA

I provide snap-shots from the recent reconnaissance electrofishig trip in the Western Aegean Ecoregion waters: two sites are shown here: one in the far north of Euboea Island and one in the mysterious Beotian Kifissos river. Both sites yielded fish discoveries.


 The Xerias Delta of Istiaia Wetlands of Northern Euboea Island

Mikro and Meglalo Livari (Lesser and Greater Lagoons) in the Xerias Delta.

Xerias a few hundred meters before its river mouth.
Yours truly at Xerias, note the dip-net I bought in Albania this summer: Had real big probs with my wrist and thumb this September - now I'm functioning 100% (I know you may not care about these intricate details...). 
Xerias bridge and the "water fall": BIG big problem for fish:total migration barrier.

Fish cannot climb this: FISH cannot CLIMB this. (Wake up!!!). This is within a Natura 2000 protected area and we need to act for some pretty rare and threatened species - this is is a priority.

The grey mullets - the Mugilids - they are important for otters as food (but they cannot swim up beyond the bridge barrier....).

This is another vulnerable - but nearly totally freshwater - and running-water- freshwater fish: the River Blenny (Salaria fluviatilis). We only found a single specimen and only below the bridge. THEY CANNOT climb up the bridge...(The population is obviously seriously threatened - we have not found them anywhere else in the Xerias river - we have checked last year). 
New species for Northern Euboea: an obscure dwarf goby, probably in the genus Knipowitschia. No idea it was here - also below the bridge (but it usually tolerates brackish conditions and would probably survive a severe drought (probably). 





And...yes we found Barbus euboicus within the Natura 2000 site of Mikro and Megalo Livari for the first time. In a recent publication my European colleagues determined that this species is NOT Barbus sperchiensis as formally alleged but the rare island endemic - the Evia Barbel. Important fish also threatened by barriers. 
We looked at the lagoons - there were Gambusia holbrooki (Eastern Mosquitofish), and lots of birds.
Wild Mute Swans - everyone loves birds, what about fish?

This is not totally irrelevant: an Egyptian Desert Cockroach (Polyphaga aegyptiaca - female): the first I see in Greece was even more exciting for me than any swan - any day...We found at a restaurant veranda in the quaint seaside town of Limni about 45 km. south of Istiaia. Best meal-discussion ever! 



The Beotian Kifissos River 

Dodwell's lithograph from 1805 featuring the spring-fed Melanos Potamos in the Kifissos valley. I should say we met up with our good HCMR colleague Dr. Christos Anagnostou at Livadeia and worked with him in this amazing and little-studied area. I post the piece of art to remind us all that these landscapes may have changed a lot - but the natural spring-fed waters and open cultural landscape nuances are still here. Conservationists be aware!
Mavroneri springs, near the village of Mavroneri. This place is not the site depicted in Dodwell's painting but it is very similar and in a rather natural state as a spring-fed wetland. 


Mavroneri Spring.

Walking with Christos Anagnostou along the Melanos Potamos. Beautiful cultural landscape. (Several sheepfold in the area with semi-fierce dogs; wolves and wild boar present occasionally). Note this area is about 100 Km north of Athens...

Mavroneri Spring and the church dedicated of course to the water deity...John the Baptist (Ai Giannis). 


The Beotian Kifissos at the Davlia Train Station. Waters were crystal clear and at low-flow (but not the artificial base flow of late summer, I guess). Fish were scarce -low density, very few large fish. I reckon its because of very low water levels in summer - we had some drought conditions in late summer this year (other years are worse). So...the potential dominant problem here may be water abstraction for agriculture.  This probably affects the fish populations.
Note the clarity of the waters... This is a distinctive river type as a fish assemblage type a four species community in cold waters in winter, warmish in summer (and rapid lowering of flow in summer and all through autumn) but with an extremely strong freshet  flood from spring snow melt from the Parnassus range. The river is embanked and straightened to a degree - to protect from flooding. But generally conditions seem fairly semi-natural. 
Sampling here with a three man team is not at all easy; the back-pack electrofisher does not work well in waters deeper than 1.3 m. The idea is to "surprise" the fish at natural barriers or when they take cover in cover -at falls, under-cut banks, tree roots (...they can see us well!).

Of the Kifissos fishes....Telestes beoticus (Beotian Riffle Dace): THE most emblematic endemic of the area.

Pelasgus marathonicus (Marathon Minnow): The "swamp-minnow" that also lives and thrives in slow-flowing river conditions; often in springs but can tallerate warm waters as well; a survivor! 

THE NEW FIND (!!): when I saw this fingerling I nearly panicked!! Its a chub (Squalius sp.). We have never found a chub -any chub- in the Kifissos. However, the late Alexander Stephanides had mentioned some kind of chub-like creature in the nearby Beotian Assopos - which had never been seen thereafter (read Economou et al. 2007). What could this chub be?
Better looks at the newly discovered Chub specimens in the Kifissos (they could easily be introduced translocated fishes - we don't know). So we are researching this. 
The second most EMBLEMATIC endemic of the region: Luciobarbus graecus (Greek Barbel). This was the commonest species along with the "easy-to-catch" Marathon minnow.


Luciobarbus graecus (Greek Barbel)
Luciobarbus graecus (Greek Barbel)
Luciobarbus graecus (Greek Barbel)
Potamon fluviatile (River Crab) - IUCN "Near Threatened" species. 
Spraints left by otters - Lutra lutra.

The upper part of the Kifissos - with a wonderful Platanus orientalis woodline (and many other tree species as well). This place not in the area's Natura 2000 delineation.
Mavroneri springs: This place not in the area's Natura 2000 delineation.