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| The amazing Corfu Killifish Valencia letourneuxi reaches 8 cm in length. Photographed in Corfu by B. Nagy. |
Corfu's inland waters
August 30th 2016
Last year in July and also this late August I visited Corfu with friends and colleagues to explore its inland waters. Here I share some snap-shots and some details of the island's aquatic wonders.
Corfu (aka Kerkyra - its name in modern Greek) is a well-known naturalist's retreat. Especially since it was showcased in a Gerald Durrelian context (books,films), the island is sometimes thought of as a temple for Mediterranean natural history. The Durrels where introduced to nature on Corfu by a wonder greek naturalist, Theodore Stephanides - he is the one who wrote one of the earliest limnological studies of the distaster caused by the alien Mosquitofish in inland waters....
Anyway....Corfu is the only island in Greece to sport two freshwater fishes that carry its name: The Corfu Killifish (Valencia letourneuxi) and the Corfu Dwarf Goby (Knipowitschia goerneri). The island also has populations of a the northern clade of Epirus Riffle Dace (Telestes pleurobipunctatus), Thesprotian Minnow (Pelasgus thesproticus), Mediterranean Killifish (Aphanius fasciatus), Freshwater Blenny (Salaria fluviatilis) and European Eel (Anguilla anguilla). Many marine transient and migratory fishes enter the island's many fresh waters, its four major lagoons and near-navigable river-mouth transitional waters. There is no other island in Greece with such great "inland water ichthyological interest" (neck-to-neck with Evia, Lesvos and Rhodes perhaps).
For scientific explorers, the island's inland waters are known as being "poorly explored".
This led to the idea that some of its fishes - such as the two fishes that bare its name (above) had gone extinct! Sure they have dramatically declinded, but when can you say "extinct"...This was really officially posted on the IUCN Red List site and published in official RED DATA book accounts here in Greece and reported by us also (see 2010 paper below). So during the last years some of us have scouted out to find these "poorly known" creatures. In 2011 various naturalists and scientists re-discovered the whereabouts of two populations of Corfu Killifish and in July 2014 a Czech-Greek team finally re-discovered the Corfu Dwarf Goby (see paper below). Fish are becoming interesting to visiting naturalists and photos can be found on the Internet of these species from various locations on the island (see below).
Unlike most Greek islands Corfu is remarkably rich in inland waters. One reason we do not know much about its fishes is the large number of waters on the island. Perhaps there are over 100 lentic and lotic aquatic sites on the island; lagoons, ponds, pools, marshes, rivers, streams, water meadows. Today, looking at a map of its rivers - I counted more than 20 major autonomous river basins - most which have some significant perennial flowing stretches (see my traced map below).
The island coastal lagoons are also important and near-unique for the Greek island context. And one of these is Lake Korission - a wonderful coastal lagoon in the south. A lovely expanse of placid warm water backed by the most spectacular dune system in Greece and a rolling Italianate landscape - so lush, yet wild and cultural all at once. Korission is truly beautiful and because of this it is threatened...
What I think is important is a holistic appreciation of the inland waters of Corfu. A full and thorough survey. It is ridiculous to keep wondering if or not a species is extinct (or extirpated). A baseline survey, cartography of all inland waters and habitats, and monitoring is needed to protect the aquatic nature of the island. Conservation-relevant scientific research will also reveal what can be done for conservation (restoration, re-introduction of the fishes, habitat enhancement, strict enforcement, alien species eradication, community participation etc.). Its about time to do this kind of inventory-conservation work, or soon we will really mourn the loss of a few remarkable tiny fishes from Corfu.
We know so little about this island's inland waters that finding and re-discovering these scarce species has become a contentious issue. It shouldn't be that difficult to chart the island's inland waters....
This is where our team supports the assessment that the Corfu Killifish is "apparently extinct" on Corfu, published in 2010....mea culpa. Read here:
Current_distribution_and_ecology_Valencia_letourneuxi_2010
This was quickly corrected with the "re-discovery" of the species by European hobbyists and the collection and documentaiton by our team in September 2009; reported at a conference in 2010 (see: Giakoumi, S., Zimmerman, B., Chatzinikolaou, Y., Economou,
A.N. & Kalogianni, E., 2010. New records of the critically
endangered Valencia letourneuxi (Sauvage 1880) and issues
of conservation. p. 295-298. In: 14th Panhellenic Ichthyological
Congress, Piraeus 6-9 May, Greece. (in Greek
with English summary).
This was later published in October 2012 in:
Recent_contributions_to_the_distribution_of_the_freshwater_ichthyofauna_in_Greece
Our recent Paper on the Corfu Dwarf Goby re-discovery by the Czech-Greek expedition in July 2014...please read this 2016 paper to learn more about this enigmatic fish - thought to be totally restricted to Lake Korission:
Rediscovery_of_Knipowitschia_goerneri
Photos from 2015 and 2016, most are mine ,but where noted Giannis Gasteratos has graciously let me borrow his - and I also thank the other two visitors to Corfu, P. Sutton and B. Nagy, who have photographed the rare fishes.
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| With Prof. Panayotis Dimopoulos looking for the Cladium mariscus fens at Lake Korission. July 2015. |
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| A make-shift traditional canoe in Lake Korission. July 2015. |
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| Lake Korission. July 2015. |
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| The canal connecting Lake Korission to the sea. July 2015. |
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| Spotted Sea Bass - Dicentrarchus punctatus - inside Lake Korission. July 2015. |
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| A dune buggy is one way to explore the dunes - helps to flatten them out a bit. And creates little roads so you don' t get lost if you walk. Also the ORV and other dune smashers make wonderful noises that keep you sane out here. July 2015. |
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| Looking south from the high dunes of Issos, south of Korission. July 2015. |
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| The parking lot at Issos beach. July 2015. |
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| The Corfu Killifish photographed in Corfu by a collector presumably from Hungary. This species was "re-discovered" in 2009 (documented by HCMR) and 2011 (by B. Nagy) to still exist on Corfu. To our knowledge P. Sutton also found the fish during the beginning of this decade. |
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| The Corfu Dwarf Goby - a tiny fish known to exist only in the Korission Lake area. This species was re-discovered by Czech-Greek operation in July 2014 after it had been lost since 1983 (when the original specimens for its taxonomic description were collected). It was presumed extinct. The photo belongs to Dr. Peter Sutton who captured the fish on the island and may also be credited for rediscovering it, as claimed in the newspaper cutting (below). |
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| Article in the Bradfordshire on Sunday reporting the "re-discoveries" by Dr. P. Sutton of the two rare fish that bare the island's name. Presumably this article is published in 2015 before our paper on the Corfu Dwarf Goby rediscovery was published or widely available (see: http://www.redbornecommunitycollege.com/page/?title=News+from+Autumn+2015&pid=601). Whoever was the first to "re-discover" the fishes in this poorly studied island doesn't really matter. The interest in the fishes is what is really important. I am very glad to see some famous people interested. |
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| As on many islands, invasive species are a problem. These prints belong to South American Coypus!! I first mistook them for otter.... Seen at Lake Korission, end of August 2016. |
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| The cleared canal of the cold-water Kounoufadi spring near Antinioti Lagoon, late Aug. 2015. On the Right the canal has been infilled with large rocks and straightened. The reclamation project has probably done much harm to the freshwater animals that survived here. |
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| Antinioti Lagoon in the North of Corfu. This place has severe pollution problems. On a very hot day in late August 2016. |
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| The bird-richest of the four major lagoons of Corfu is Alyki Lefkimmis Lagoon. It is a former saltworks on a natural salina lagoon in the southe of the island. July 2015. |
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| Niki Kardakari and myself (in pink cap) exploring the amazing re-growth of Populus alba riparian woods on the north shore of Korission lagoon (Photo: Giannis Gasteratos). |
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| The Greyish Oak Quercus pedunculiflora is one of the most robust and lesser known oaks in Greece, often in mesic - rather humid areas - near or in the riparian woodland. In Corfu it is quite common in some parts of the island and it does from riparian woodland communities. (Photo: Giannis Gasteratos). |
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| Goats at Issos Dunes, Korission. 50 years ago there were a thousand, now less than a hundred we were told. The woods need them. We need to study there relationship with the dune juniper woodlands.(Photo: Giannis Gasteratos). |
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| Curlew sandpipers at the northern edge of Korission. The lagoon's water levels had dropoed on the day we visited helping these important waders find a place for staging - before crossing the Ionian and Mediterranean towards Libya. (Photo: Giannis Gasteratos). |
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| Giannis and I took dip to explore the Natura 2000 site between the city and Messogi - here at Kaiser's Bridge. Posidonia meadows dominate.(Photo: Giannis Gasteratos). |
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| The mullet Mullus surmellatus is of course common here - I counted about 18 species in a 30 min snorkel.(Photo: Giannis Gasteratos). |
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| Gambusia holbrooki. American. Invasive. Destructive. (Photo: Giannis Gasteratos). |
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| Giannis captuered these fantastic Epirus Riffle Daces at on of the islnad's nothern streams. (Photo: Giannis Gasteratos). |
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| A rough picture of the inland waters of Corfu - more than 20 major river basins - many with perennial reaches. And the four major coastal lagoon areas - shown with arrows. (Modified from an article by B. Nagy 2011). |
Acknowledgements: I want to thank the following people for assistance: Giannis Gasteratos for his help in the 2016 work; Stamatis Ghinis, Panayotis Dimopoulos and Niki Kardakari for giving us a reason to visit the island. Also my thanks to the photographers of the two rare fishes "that bare the island's name" for not being to mad at me for borrowing their photos.
