Freshwater environment on Rhodes and the endangered fish by Maria Corsini-Foka

The freshwater environment of Rhodes and the endemic endangered fish Ladigesocypris ghigii (Gianferrari, 1927)*

Maria Corsini-Foka

Biologist, Senior scientist

Hellenic Centre for Marine Research, Institute of Oceanography, Hydrobiological Station of Rhodes

Cos Street, GR 85100 Rhodes-Greece

mcorsini@ath.hcmr.gr

Return of life and material to the dried-up Platis stream (Detail from the work created by Insa Winkler and the children of Soroni elementary school, 2011)

Abstract

Along the last few decades, the uncontrolled exploitation of terrestrial and water resources, mainly aimed to satisfy the increasing requirements of the so-called “development”, has produced evident environmental problems in the island of Rhodes, problems that involve land, freshwater, sea, flora and fauna richness, lanscape. With the exception of the Natura sites, created before a decade and recently amplified, the development was not planned “at island measure”, being its natural limits and its beauties not considered. Many of these problems are strictly related to the freshwater environment and reflect not only on the life living there and around, including the endangered and protected endemic fish Ladigesocypris ghiii (Gizani), but on the whole life and richness of the island. The freshwater bodies and the main problems connected to the water resources of the island are briefly presented, while information on the endemic cyprinid Gizani and the actions already performed for its protection are given. The rhythm of degradation of environment and loss of natural resources is increasing and future urgent actions for their conservation are discussed.

Keywords: Rhodes, water resources, Ladigesocypris ghigii, endangered species, environmental conservation.

Introduction

Rhodes, the largest island of the Dodecanese Archipelago, is known not only for its history and the unique monuments. Although its limited extension, it is also known for the beauty of its coasts and richness of the underwater environment as well as of its inland area, geo-morphologically diverse and rich of forests and rare vegetation, due mainly to the presence of running waters and springs essential for life, and the favorable climatic conditions.

The uncontrolled exploitation of terrestrial and water resources, mainly based on human egoistic interests under the umbrella of the so-called “development”, does not take into account the landscape beauty and natural variety of the island and its well-defined limits as well as the culture and traditions of local people.

Alterations of the natural environment, terrestrial and aquatic, due mainly to human activities cause the extinction of various animal and plant species and seriously threaten the existence of many others all over the world (www.iucnredlist.org). In many small streams and some artificial lakes of Rhodes lives the endemic cyprinid Ladigsocypris ghigii (Gianferrari, 1927), a species endangered and protected by national and international laws. The survival of this small unique fish is strictly correlated to the general freshwater problems, mainly the perseverant draught conditions and the degradation of natural habitats.

A Life-Nature program and other actions have been recently performed and /or are going on with the aim to improve the survival conditions of the species and increase public awareness, but the freshwater problems of the island intensify in time and space due to the increasing rhythm of land and water exploitation and the general inaccuracy towards the natural environment conservation. An overview of the today situation of the threatened Gizani and its habitats is presented and diversified perspectives aimed to approach an amelioration of the hydrobiotopes conditions of the island are discussed.

Fig. 1. Main freshwater systems of Rhodes (Presence of Ladigesocypris ghigii population).

Freshwater bodies in Rhodes

The two sides of the island, mainly the eastern, are interspersed with various streams which sometimes flow in relatively wide channels, in a calm and silent environment. These streams are exceptionally vulnerable to external interventions, because of their limited dimensions in length (from few kilometers to some hundred meters), width and depth. They are supplied by the rainwater and by the many springs, and may be changed into dangerous torrents in winter, while during the summer they dry up along the greater part of their course (Corsini-Foka et al., 2002a).

The largest stream is the Gadouras, on the eastern side of the island, the springs of which are situated on the declivities of the Attaviros Mount (1.213 m height) and on the southern side of the Profitis Elias Mount (800 m height) (Fig. 1). It retains water throughout the year, mostly near its springs and upper branches, but also in its lower places. A project for the building of a dam along the course of the Gadoura stream, in the Laerma region, has been carried out, for the creation of an artificial lake, with the aim to satisfy most of domestic supply and irrigation needs of the island. Works for the building of this large dam started in 2001. In 2005 the dam was almost concluded and the lake has begun to fill up (maximum total capacity 67.5 million m³). The panorama and the aspect of the hydrobiotope downstream the “Gadouras Dam” has rapidly changed (Fig. 2). Water supply downstream during the period of construction and also later, both during winter and during the draught summer seasons, has declined dramatically; large quantities of sedimentary material systematically flushed downstream from the construction site deteriorated the natural substrate composition, resulting in the alteration of the hydrological and morphological characteristics of the stream (Stoumboudi et al., 2007). In a very recent past, a few meters above its mouth to the sea, the Gadouras formed deep pools among the rocks that were filled with crystal-clear water, giving a striking spectacle similar to the mountain regions (Fig. 3). For long years, this spectacle existed only in the memory of the lucky people which had the chance to admire it. During winter 2011, after a prolonged period of rainfall, the dam lake of Gadouras filled completely and the outflow helped the downstream to begin to partially re-acquire a live aspect.


Fig. 2. Views of Gadouras downstream on July (left) and Sptember 2007 (right).

Fig. 3. Aspects of Gadouras downstream on May 2001. (Photos: M. Stoumboudi)

Fig. 4. The Loutanis stream on June 2009.


Fig. 5. The drying up of the artificial lake of Apolakkia: April 1999 (left), December 2000 (centre), June 2009 (right).

The other principal streams in the east side of the island are the Loutanis (Fig. 4), reached at the end of its course by the Seven Springs waters, the Kontaris in the Asklipio area, the Lardos stream, the Chas-Makaris system in the Archangelos area, the Pelemonis system in the region of Psinthos-Afandou (Fig. 1). On the west side there are the Argyros stream, in the Kalavarda region, the Platis that, except at its springs, has dried up almost completely in the recent past (because of over-abstraction) (Mamuris et al., 2005), the Agia Eloussa stream tributary of Platis, the Butterfly Valley, the Paradisiotis and the Kremastenos streams. In the southwestern part of the island there is also the small Nani Lake, that was the unique existing in Rhodes in the 20’s, originated at the beginning of the previous century by a landslide which created a dam and retained the water from a stream (Ghigi, 1929). This lake sometimes doesn’t retain water, probably because of water abstraction for irrigation purposes. In the south of the island small streams, mainly one, supply the artificial lake of Apolakkia. The water level of this lake, created for irrigation needs at the end of 80’s, presented a constant decrease since summer 1999 (reduced rainfall, illegal water abstraction in the adjacent streams, accumulation of detritus, lack of maintenance works), resulting in the exceptional reduction of its volume and in a general degradation of the biotope and landscape up to 2009 (Fig. 5.). Other two small dams for the creation of freshwater reservoirs are under construction in the south of the island, the Kritinia and Skolonitis dams.

At the end of the 20s, during the Italian occupation of Rhodes, an extended systems of freshwater canalizations and small dams was built for agricultural purposes in various regions of the island, like in the areas of Psinthos-Afandou, Eleoussa, Loutanis-Seven Springs, Archangelos, and others. These nets of canals and dams, in part are still used today for irrigation, other are damaged, others have been transformed in recreational touristic sites (like Seven Springs).

The Natura 2000 sites

The importance and rarity of the natural richness and the landscape beauty of the island is demonstrated through the characterization of large regions as protected, in the frame of the European net NATURA 2000. One site, in the west side of the island, comprehends a part of the Apolakkia beach and marine zone, the small island of Karavola, the gulf of Glyfada, the Akramitis, the Armenisti, the Attaviros mounts (SCI-Site of community importance GR4210005) and the Apolakkia artificial lake, the small islands of Georgiou, Strongili, Chtenies, Karavola, the Attaviros and Akramitis mounts (SPA-special protected areas GR4210030), another in the east side including the Profitis Elias mountain, the Seven Springs, the Butterfly Valley (SCI GR4210006) and the Loutanis estuary, the downstream Gadouras, the Lindos peninsula, the small islands of Pentanisa and Tetrapolis, the Profitis Ilias mount, the Seven Springs (SPA GR4210029). Finally, also the south tip of the island with Prasonisi and the wetland of Livadi Kattavias is included in the net NATURA (SPA GR4210031).

Macrofauna in the running waters

Apart the rich flora surrounding them (cf Theodoridis and Fantidis, 2006), characteristic native animals which may be observed with the naked eye in the shallow freshwaters of many systems of the island, are the endemic fish Gizani, Ladigesocypris ghigii (Gianferrari, 1927) (see below), the gastropod Melanopsis praemorsa (Linnaeus, 1758) (Gambetta, 1929), the crab Potamon potamios (Olivier, 1804) and the shrimp Palaemonetes antennarius (H. Milne Edwards, 1837), both listed in Lewinsohn (1976), the European eel Anguilla anguilla (Linnaeus, 1758), the still under study frog Pelophylax sp. (cf Speybroeck et al., 2010), the European green toad Bufo viridis (Laurenti, 1768) (Wilson and Grillitsch, 2009) and the Caspian terrapin Mauremys caspica (Gmelin, 1774) (Dimaki, 2002). During recent surveys, it has been ascertained that the crab P. potamios and the eel A. anguilla are frequently catched and used as food by local people also today: the crabs are caught with fishing pots, the eels unfortunately with chlorine. The native Caspian terrapin M. caspica has been photographed in the Paradisiotis stream together with an alien semi-aquatic turtle, a specimen of the Red-eared Slider Trachemys scripta elegans, released by privates. The Red-eared Slider thrives in warmer climates and it is native of the southern United States, mainly to the area around the Mississippi River down to the Gulf of Mexico. It has become common in various areas of the world due to the pet trade (http://en.wikipedia.org/wiki/Red-eared_slider). The import of this non-native species in the European Union countries is prohibited, because, when they reach too large size, they are uncarefully released in freshwater habitats, where they easily adapt, competing and seriously threatening native terrapin species. A consistent population of the Red-eared Slider is today preent in the pools of the public park of Rodini. Nani Lake is actually inhabited by the mosquitofish Gambusia holbrooki Girard, 1859, an alien fish species, probably imported to Rhodes by the Italians for the battle against malaria (Ghigi, 1929; Tortonese, 1947), and the common carp Cyprinus carpio Linnaeus, 1758, while, during the 80’s, the endemic L. ghigii inhabited this small lake (Corsini, 1994). The mosquitofish G. holbrookii is also present in private reservoirs, in small streams as the Kremastenos and in the ponds of Rodini public garden, in Rhodes town. In 1995 two Asiatic herbivorous carp species Hypophthalmichthys molitrix (Valenciennes, 1844) and Ctenopharyngodon idella (Valenciennes, 1844), together with the common carp C. carpio and the Prussian carp Carassius gibelio (Bloch, 1782) were introduced and survive in the artificial lake of Apolakkia (Corsini-Foka et al., 2002a; Stoumboudi et al., 2002c). Various ornamental allied of the common carp and the goldfish Carassius auratus (Linnaeus, 1758) are present in Eleoussa reservoir, together with Gizani. Sometimes, especially at the stream outfall, also the mullets Mugil cephalus Linnaeus, 1758 and Liza saliens (Risso, 1810) may be observed (Tortonese, 1947).

The main freshwater problems

In recent decades the freshwater resources of the island have been subjected to a general impoverishment which leads to a degradation of the hydrobiotopes. Many factors of natural and human origin have contributed to the expansion of this phenomenon and to a gradual change in the natural landscape. Global climatic changes and the well-known tropicalization of the Mediterranean region, Greece included (EMEKA, 2011) have resulted in decreased rainfall and in other meteorological phenomena like prolonged extremely warm periods, decrease of northwestern winds (the so-called meltemia) (Chronis et al., 2011) also in the area of Rhodes, accentuating drought conditions in the last years. The geological morphology of the island doesn't allow the existence of large basins. On the other hand, the water generates high velocity while descending the steep slopes of the mountains with a consequent limited seepage to the ground and poor underground water enrichment. Extended fires in 1987, 1992, 2008 and others destroyed the greater parts of the forests in the south-central island, diminishing the natural capacity of the ground to retain water.

The considerable rhythm of tourism development (new large hotels resulting in a continuous increase of bed number, grass gardens, swimming pools, showers, cleaning of thousands cars to rent and many buses as well, more and more larger cruise ships) continuously expands the demand for water, in particular during the four summer months, the draught period. It is to be underlined furthermore that the island of Rhodes supplies with freshwater also all the around waterless islands, namely Halki, Symi, Nisyros, Patmos, Kastellorizon, Lipsoi and small islands as Farmakonisi, Agathonisi. Also the water demand from these islands is exponentially increasing, according to the development of the touristic industry. Arbitrary pumping for irrigation of agricultural cultivation is a common practice on the island. To meet these needs, the over-abstraction of surface and underground water, especially in summer, has consequently resulted and the surface water becomes, furthermore, more salty. Drills, made everywhere, pump consequently water more and more at deeper depths. Education to a correct use of water for domestic purposes is furthermore not widespread. The frequent discharge of cement to the bed of the streams, the sand-gravel extraction from them for technical purposes, like in Platis at large scale and Loutanis at lower scale, and the use of stream banks for indiscriminate “concreting” contribute to the changes in the natural water course of streams, frequently impeding their free running, forcing their flow into restricted unnatural space, limiting furthermore the deposition along the coast of the material transported by the flow and degrading, sometimes cancelling, the small wetlands at the end of their courses. A common practice is also the periodical summer conversion of the small stream estuaries in abnormal sandy beaches obtained moving extraneous materials from other areas of the same island or other parts of Greece: this contributes to a further changing of the coastal panorama, already subjected to uninterrupted unplanned and indiscriminate building everywhere. The forced impediment of deposition of materials by the natural flow, the depletion of sand, stones, gravel from the river beds for technical works, the transport of materials from one part of the island to another, the casual and irrational moles construction for the protection of private proprieties along beaches or for small fishing boats refuges, combined with natural events, render more vulnerable the coasts to erosion phenomena. In addition, the environmental quality is often reduced by the deposition of plastic and metallic objects (litter) along the edges of the streams, while sometimes untreated waste waters are directly discharged along the streams.

Gizani, Ladigesocypris ghigii (Gianferrari, 1927)*

According to Economou et al. (2007), freshwater/brackish water ichthyofauna of Greece includes 161 species, of which 138 are typical freshwater species and 47 are considered endemic, many of these last critically endangered. Following Zenetos et al. (2009), introduced freshwater/estuarine water fish species in Greece account to 28.

Fig. 6. Gizani Ladigesocypris ghigii. (Photo: B. Zava)

One of the above mentioned endemic freshwater fish of Greece, is Ladigesocypris ghigii (Gianferrari, 1927) (Pisces, Cyprinidae) (Fig. 6), which lives exclusively in the island of Rhodes (Fig. 1).

The enough complicated scientific denomination of this small fish needs some historical explanations. The species name “ghigii” has been assigned in honor to the Italian scientist Alessandro Ghigi, professor at the University of Bologna and director of its Institute of Zoology during the thirties, who directed the “Italian mission for the study of the fauna of the Dodecanese”, in 1926. During the exploration of the island he first discovered this fish and collected samples from the “Mills river” (today this stream, near Koskinou village, is vanished) and from the “Argyrò river”, understanding their rarity and importance (Ghigi, 1929). The samples were examined by his assistant Luisa Gianferrari (1927, 1929), who concluded that they belonged to two new species of the genus Leucaspius: Leucaspius ghigii and Leucaspius prosperoi. These first samples are conserved in the collection of the Museum of Natural History of Milano (Conci and Michelangeli, 1974). Later, this cyprinid was also collected by the Italian naturalist E. Tortonese (1947), during his permanence in Rhodes from December 1942 to September 1943. He suggested assigning the two above Leucaspius species to the genus Pararhodeus. The fish attracted the attention furthermore of the Austrian scientists Paget and Kritcher (Kahsbauer, 1965), so, there are samples of this rare fish also at the Museum of Natural History of Vienna. Later, the cyprinid was examined by the Yugoslavian ichthyologist S. Karaman (1972), who created a new genus, Ladigesocypris, into which the two species, previously recognized by Gianferrari, were finally joined. The first part of the genus name “Ladigesocypris” was given by Karaman to honor W. Ladiges, while the second part of the genus name “cypris” derives from the family Cyprinidae, to which the species belongs.

The actual common name “gizani” (gr.: γκιζάνι, gkizàni) has an uncertain origin. In the past it was named “minià”, from the Italian word “miniatura” (miniature), due to its very small size. During the II world war it was sometimes used as a source of food for inhabitants of far villages.

During the 80s, Prof. P.S. Economidis performed the first surveys of Gizani populations in Rhodes Island. He repeatedly underlined the serious problems faced by this unique species for its survival (Economidis, 1988). The species was recognized as endemic to Rhodes and one of the most threatened freshwater fish in Europe (Economidis, 1991, 1992, 1995; Kottelat, 1997; Stoumboudi et al., 1999, 2002c; Smith et al., 2006). L. ghigii is officially listed as endangered species of top priority for protection in ANNEX II of the Habitats Directive of the European Union (92/43/EEC) concerning the protection of natural habitats and wild fauna and flora. It is also listed as endangered in the IUCN Red List of threatened species (www.iucnredlist.org/apps/redlist/details/11133/0). At national level, the species is protected by the Greek Presidential Decree N^o 67/1981.

Gizani is a Lilliputian champion of survival, using the successful nickname created for it by my colleagues M. Stoumboudi and R. Barbieri. Really, it manages to live in the streams of Rhodes, which, as mentioned above, present periodical fluctuations of the water quantity, since they flow during winter, but they dry up along the major part of their course during summer. Although this fish is adapted to face extreme and unstable conditions, the survival depends mainly from the few quantity of water remaining in summer, the season during which a massive reduction of its populations occurs. In recent years numerous existing populations exhibit tendency of persisting decline, while other are already disappeared. This decline is principally due to two factors: the human impact, contributing largely to the degradation of the main habitats of the species (deforestation, waste disposal, alteration of water course, non-native species introduction) and to the increasing draught (indiscriminate water abstraction/over-pumping and climate changes), and the decrease of genetic diversity.

The European Union, understanding the serious threats for the survival of this endemic fish, financed, through the Dodecanese Regional Government, a first program aimed prevalently to a preliminary study of the biology and ecology of the species, which was carried out by the Hydrobiological Station of Rhodes of the Hellenic Centre for Marine Research on 1991-93 (Corsini and Karantoni, 1993; Corsini 1994).

Later, the same EU financed an extended Life-Nature Program (http://www.life-gizani.gr) (Corsini et al., 2000; Corsini-Foka et al., 2002b; Stoumboudi et al., 2002b). The program was carried out between 1998 and 2003 by the Hellenic Centre for Marine Research (Institute of Inland Waters, Hydrobiological Station of Rhodes and Institute of Oceanography), the Development Company of Dodecanese, in co-operation with the District Authorities of South Aegean and the local Municipalities of Archangelos, Kameiros and Kallitheas and scientific experts from Universities of Greece and other countries. The program was co-financed by the Hellenic Centre for Marine Research and the Greek Ministry of Environment, Landing and Public Works and it was coordinated by M. Th. Stoumboudi.

It was a multi-task project, with principal objectives to conserve the L. ghigii populations within the two NATURA 2000 sites existing at that time in Rhodes Island, to construct a fish refuge in Loutanis stream, to preserve the species genetic diversity and to enhance public awareness.

Fig. 7. Gizani in its natural habitat. (Photo: M. Stoumboudi)

The comprehensive study of the biological characteristics of this fish (development, nutrition, reproduction, genetic, behaviour) and the geographical distribution and status of its populations (Barbieri et al., 2000, 2003; Stoumboudi et al., 2002a, 2003; Mamuris et al., 2005; Poncin et al., 2005) gave the required elements in order to formulate management and conservation actions (see Stoumboudi and Cowx, 2003). The species lives on the average about three years, reaches usually a total length of 5cm, it is omnivorous and tolerates a large range of temperatures (from 10^oC in winter to 30-33^oC in summer). It prefers slow running waters and usually hides near the banks, under rocks or roots of plants, or amongst algae (Fig. 7). It has an opportunistic feeding behaviour, based on a great variety of food items, mostly plant, less, animal material. Possible predators are birds, crabs, eels, maybe also terrapins. The short time of its life and its small size confirm that this fish has no great chances to grow, strictly depending from the presence or not of water during summer. It is a serial spawner, it matures at age 1 (during the second year of life) and reproduces during spring until the beginning of summer Stoumboudi et al., 2002c; Poncin et al., 2005). As assessed in Stoumboudi et al. (2002a), L. ghigii presents an opportunistic reproductive behavior, probably as an adaptation to the instability of its natural habitats that is attributed mostly to the water quantity fluctuations. Following Stoumboudi et al. (2002c) and Mamuris et al. (2005), genetic intra-population variation is extremely low, thus increasing the risk of population collapse, while inter-population genetic variation is high.

In the frame of the Life-program, a pilot refuge was built for the first time in Greece. It was obtained in a natural pond along the Loutanis stream in order to help the survival during the draught period. Monitoring of this refuge showed that it enhances successfully the conditions for the Loutanis Gizani population during the summer period. Furthermore, samples of various populations are maintained by scientific structures to preserve genetic diversity (Corsini-Foka et al., 2002b).

Public awareness actions are aimed at expanding knowledge about the uniqueness, biology, ecology and necessity for conservation of Gizani, as well as increasing concern about sustainable water use. Actions, still going on at the Hydrobiological Station of Rhodes, include educational activities for teachers, students, tourist guides and operators, municipal authorities and production of informative material. Two distinct small recreation sites in areas of significant tourist interest, Aghia Eleousa and Psinthos, have been created and serve as information centres and locations hosting Gizani stocks (Stoumboudi et al., 2002b)

Since 2001, the Hellenic Centre for Marine Research (Institute of Inland Waters and Hydrobiological Station of Rhodes, in collaboration with scientific experts from Universities of Greece and other countries) carried out furthermore the program “Assessment and monitoring of the population state of the fish Gizani, during the building of the Gadoura dam in Rhodes”. The program, financed by the Ministry of Environment, Landing and Public Works, and coordinated by M. Th. Stoumboudi, aimed to monitor and evaluate the impact of dam building works on the abundance and status of Gizani population in the Gadoura stream and to substantiate measures for the conservation and/or reinforcement of its population after human interventions on its natural hydrobiotope.

The Gadoura stream supports the most important population of L. ghigii (Corsini-Foka, 1994). The population of Gizani in this stream was subject to a deleterious action, during the building of the Gadoura dam. From the beginning of its construction in 2001, and particularly since 2005, the availability of surface water downstream of the dam, that maintains the important, natural refuge-pools for Gizani during the dry periods of the year, has dramatically declined, threatening the extant population in this stream section with extinction (Fig. 2). This was a direct result of the lack of a compensation flow during construction and later. The Gizani’s habitats in the same region have also deteriorated through large quantities of sedimentary material that is being systematically flushed downstream from the construction site during high flow events (Stoumboudi et al., 2007; Stoumboudi, 2009). Deterioration in the fish population would represent a decline in ecological status of the river and thus failure to meet obligations under the Water Frame Directive. For these reasons, the above program is actually going on, with the aim to survey and eventually improve habitat and population conditions of the fish seriously damaged during and after the dam building.

If, on one hand, the natural downstream habitat of Gadouras was negatively affected by the dam construction, on the other hand recent surveys confirm that L. ghigii inhabits abundantly and reproduces in the new artificial lake. Furthermore, after the overflow occurred during winter 2011, small sized specimens were observed in April and May 2011 along the downstream course.

It is to be noted that in the past, the above mentioned canals created by the Italians for agricultural purposes, were very useful refuges for Gizani during the dry periods (Author, personal observation).

Concluding, today the main threats to the endemic to Gizani populations are draught, water abstraction, degradation of habitats (Table 1), but also the risk of inbreeding in numerically reduced populations, alien introductions, parasites and pollution are to be considered. In the outflow of Apolakkia stream, Gizani were infected by Lernaea cyprinacea, probably introduced by alien fish species introduced, like carps (Stoumboudi and Cowx, 203).

Table 1. Occurrence, state and threats of Ladigesocypris ghigii populations in principal streams and lakes of Rhodes Island (Source: Stoumboudi and Cowx, 2003, modified).
Stream/Lake	Presence/ absence	Status	Threats
Gadouras	+	Very good (upper stream).	Affected by dam construction (downstream).
Kontaris	+	Good.
Loutanis	+	Good. Enhanced by refuge.
Lardos	+	Good?
Seven Springs-Loutanis	+	Good
Apolakkia	+	Critically endangered.	Water abstraction. Inbreeding.
Pelemonis	+	Critically endangered.	Water abstraction. Inbreeding.
Chas	+	Critically endangered.	Water abstraction. Inbreeding.
Makaris	+	Critically endangered.	Water abstraction. Inbreeding.
Argiros	+	Critically endangered.	Water abstraction. Inbreeding.
Kremastinos	+	Critically endangered.	Water abstraction. Inbreeding.
Paradisiotis	+	Critically endangered.	Water abstraction. Inbreeding.
Eleoussa reservoir	+	Good. Protected in a semi-natural habitat.	Inbreeding. Aliens.
Platis	-
Butterfly Valley stream	-
Artificial Lake of Seven Springs	+	Good?	Instable conditions, sometimes the lake is voluntary emptied.
Lake Nani	-
Artificial Lake of Apolakkia	-
Artificial Lake of Gadouras	+

Conclusions

Since the positive economic results of the touristic development achieved between the 60s and 70s, the type of development undertaken successively in the island of Rhodes was and is clearly addressed to satisfy an “unlimited” increase of mass tourism. It favoured consequently the increment of the capacity of the island to host more and more tourists, accompanied by the increment of related services, with an obvious increase of needs in terrestrial and aquatic resources and energy and paralleled by increase of economic well-being.

The general trend of environmental degradation observed in the last years in Rhodes does not involve only the freshwater systems. Let us express freely, this trend of environmental degradation occurs at all levels, including the land and also the sea, where disturbances and alterations produced by human activities are observed. Deleterious interventions on/into the coastal and inland environment are no more few “spots”, but they are assuming a continuous aspect. Their total sum appears more evident and touchable than in other Mediterranean regions, being concentrated in the reduced space of a medium sized island.

Environmental management through a clear delimitation and planning of a) boundaries of the beds, banks and estuaries of streams and rivers, b) of beaches and coastal zones, c) of land use for different purposes (building, industry, agriculture, forests, grazing) results or inexistent or, if it theoretically exists, practically is rarely applied. Probably, only archeological areas are subjected to true delimitations, although, sometimes, also these could be overpassed. This situation leads to the impossibility to discern between legality and illegality of the various human interferences on the territory.

The island is quickly loosing natural landscapes, natural habitats for flora and fauna and beauties. The architecture used does not take into account the morphology of the land, consequently most of the recent buildings are not inserted harmoniously into the landscape, but detached from it and also from eventual local style. And this is demonstrated by the characteristic practice to “gain building land”, vertically and horizontally, through flattening of what is “high”, i.e. hills, or through excavation of what is rocky, along the coasts, in the interland and inland. A very recent example of the absence of land planning use is the installation of wind turbines and photovoltaic panels without rules.

Looking at the inhabitants of the island and the visitors, few show surprise and disappointment and react to the impoverishment of the environmental quality, while most seem generally to be not able to observe critically, and to distinguish and realize changes and disturbances to optical view and to natural richness and beauties, or they unconditionally accept whatever situation appears. Only through knowledge of the history, culture and environment, and acquisition of a critical capacity of observation, respect of natural environment and its resources may be achieved.

Concerning water resources, on our opinion, it is important to underline that the damlake of Gadouras should not to be considered the final solution for satisfying a further and continuous increasing in freshwater demand and/or consume by humans, i.e. in view of further development of the touristic industry and increase of population and needs: water management needs a re-planning in view of climatic changes versus tropicalization of climate in south Europe and desertification already prospected by scientific studies (ANPA, 2001; Iosefides and Politidis, 2005; EEA, 2008).

On our opinion, other various actions of politico-administrative character are furthermore recommended: encourage and support installation of desalination systems, mainly in the waterless islands, encourage and support recycling of water, survey-control of illegal drills and surface pumping, rehabilitation of the artificial lake of Apolakkia and other smaller reservoirs, official severe restrictions of water use during summer (with punishments-fines) by local administrations, insistent and repeated efforts aimed to educate people, visitors and tourist managers for a correct domestic use of water.

The status of Gizani populations, the lilliputian symbol of Rhodes freshwater, is an index of the freshwater status of the island. According to Mamuris et al. (2005), on the base of genetic studies and the characteristics of the species, Gizani populations should be managed separately and their stocking is not recommended, while conservation actions should be addressed towards a rational management of “water resources and restoration/preservation of the aquatic habitat of the species”.

The protection and conservation of Gizani, is important not only because this fish exists only in the delicate and vulnerable hydrobiotopes of Rhodes, but also because it is a part of the actual biodiversity living on the hearth, which is the result of hundreds millions years of evolution history. The viability of our planet and the protection of its natural richness represent our ethic duty in front of future generations.

Although the pressure for greater development especially for mass tourism is continuously degrading the natural coastal and inland environment, the nature of the island, even today, reveals unexpected and incredible beauties and surprising diversified features at short distance one from the other, that should be protected, on our vision, in a manner similar to the NATURA 2000 sites already existing, improving their organization with official regulations for their management. On the other hand, authorities should urgently take decisions for the application of actions aimed to correct and adjust the many mistakes already made.

References

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Freshwater environment on Rhodes and the endangered fish by Maria Corsini-Foka

Karaman M.S., 1972. Revision einiger kleinwuhsiger Cyprinidengattungen Phoxinellus, Leucaspius, Acanthobrama usw. aus Sudeuropa, Kleinasien, Vorder-Asien und Nordafrika. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut 69: 115-155.