11.3 Living resources

Turkey is situated at the meeting point of Asia with Europe, at a short distance from Africa. Fauna and flora include, therefore, Asian and European and also African elements. The encounter and overlap of different biogeographical regions gives Turkey an outstanding importance as an area with a high number of plant and animal species including many endemic forms.

Living resources in Turkish lagoons have not been studied scientifically in detail yet. The most comprehensive studies are carried out by MoFAL under a World Bank Project concerning the Management and Development Strategies for Lagoons along the Turkish Coastline and their Rehabilitation in 1995–1997. More detailed studies were realised for four lagoons (Akyatan lagoon, Akgol-Paradeniz lagoon, Enez lagoon complex and Bafa lagoon complex) during the project.
More focus has been given to the lagoons of Homa (Alpaz and K?nac?gil, 1988; Onen and Yaramaz, 1992), Kucukcekmece (As?koglu, Gonenc and Basdemir, 1992; Gonenc, 1990), Koycegiz (Yerli, 1991; Erkakan and Yerli,1994), Karina (MARA, 1984; Cirik et al., 1992), Homa (Cirik et al., 1992), Camlik and Yelkoma (Dikel, 1990), Bafra (MARA, 1983; DSI, 1979; Uyan?k and Goksel, 1991; Gonulol, 1993), Gulluk (Egemen, 2004), Yumurtal?k and Akyatan (Kulan, 1984), Cardak-Burunici (MARA, 1989; MARA, 1996), Enez (MARA, 1994; Velioglu et al., 2008), Karacabey (Tatar, 1987), Homa and Karina (Yaramaz et al., 1992).

 

11.3.1 Flora

Phytoplankton: A predominance of freshwater species was reported during winter, due to the low salinity caused by precipitation and the discharge of drainage channels. A lower plankton density and composition was found in June-November due to high salinity values resulting from the high evaporation rate and absence of freshwater inflow. Marine species are present in all stations, but their relative abundance is higher in the area closer to the pass.
Diatoms (Bacillariophyta) are the most common group, followed by Cyanophyta, Chlorophyta and Dinophyta. Among diatoms, the species indicating brackish water conditions such as Navicula, Nitzschia closterium, Surirella fastuosa, Striatula unipunctata, Fragilaria capucina, Campylodiscus adriaticus, Surrirella striatula, Biddulphia pulchella were common throughout the year. Among Cyanophyta, Lyngbia and Gornphosphaeria were common in terms of geographical distribution and in all seasons, being more abundant during the hottest months. Since in Chlorophyta species, diversity increases with decreasing salinity, a larger number of species was observed in winter and spring.
The species composition is rather poor, being represented mainly by diatoms typical of brackish water conditions, such as Navicula, Nitzschia closterium, Nitzschia paradoxa and Surirella fastuosa, which are also the most common species together with Pleurosignia sp.
Aquatic vegetation: The vegetation mainly occupies the widest part of the lagoon, between the pass and the freshwater outlet of the drainage channel – about 1/3 of its total surface. In this area, an estimated 70 percent of the bottom is covered by submerged plants.
The plants form a thick mattress, which occupies the entire water column. Since the tallest plants are longer than the water depth, they remain on the surface over the submerged strata. The lower strata of this environment are therefore at risk of anoxia and do not provide favorable conditions for the fauna. Moreover, the vegetal biomass is so dense that it uses up the nutrients available in the water, reducing them to the planktonic fraction, and contributing to its depleted state. This reflects on the higher levels of the food chain as it means that less nourishment and nourishment of inferior nutritional quality is made available to those benthic organisms, which, in turn, represent an optimal feed for many fish species of commercial importance. The vegetation cover gradually disappears westward with almost none in the western corner of the lagoon.
The species consist mainly of dense meadows of Ruppia spiralis and Potamogeton pectinatin, Potarnogeton crispus, Chary vulgaris, Myryophyllum spicatum, Ceratophyllum dernersum, Phragmites australis, Juncus acutus, Nymphaea alba occurs, Chara hispida, Phragmites comunis, Juncus litoralis the latter more abundant in the area closer to the outlet of the drainage channel. These species are indicators of confined environment, according to the scheme of quantitative biological organization of coastal lagoons proposed by Guelorget (Perthuisot, 1983). In particular Ruppia spiralis, a monocotyledon with a high tolerance to salinity variation (between 1.5 and 80 ppt), indicates a zone where the influence of seawater is reduced to a minimum and corresponds to zone four of the freshwater sub-area of their classification scheme. Potamogeton pectinatin indicates quasi-freshwater conditions and characterizes zone five of the sub-area of the same scheme, i.e. a lagoon area closer to the continental environment than to the marine environment. Scattered patches of Zostera marina appear in the area near the pass. No significant presence of green algae (Chlorophyceae) of the genera Ulva, Enteromorpha and Chaetomorpha was observed. This is probably due to the scarce nutrient load (N and P) available, which is almost completely used by the aforementioned macrophytes.
Other plant species are Pinus nigra, Cistus cretius, Cyclamen trochopteranthum, Hyacinthus arientalis, Iris xanthospuria, Lunipus orientalis, Lunipus angustifolius, Nerium oleander, Pinus brutia and Sternbergia eischeriana.

11.3.2 Aquatic fauna

Zooplankton: As for phytoplankton, the great variations in salinity create the conditions for an alternation of coastal marine species such as Oitliana nana and Acartia clattsi, and inland species such as Brachionus plicatilis and Brachionus angularis. Rotifers were abundant in winter, with prevalent freshwater conditions, whereas bivalve larvae replaced them in spring and summer.
The species composition is not rich, being represented mostly by rotifers of the genera Brachionus, Keratella and Synchaeta. Cladocera and copepoda are the other groups represented in the samples. Zooplankton plays an important role in the production dynamics of the lagoon as it represents the suitable feeding for many larval and post larval stages of commercially important fish species such as mullets, seabream, seabass and sand smelt. Other zooplanktons are Keratella quadrata, Polyarthra vulgaris, Daphnia galeata, Bosmina longirostris, Chydorus piger, Cyclops vicinius and Calanipora aquaedulcis.
Benthos: Among Anellida, the most common species was Hediste diversicolor and Polydora ciliata. The molluscs were represented mostly by the bivalves Cerastoderma glaucunt and Abra alba and the gastropod Pyrenella conica. The group of crustacea was the richest in species with Gammarus aequicauda, Gantmarus subtypicus and Corphium orientale the most diffused. The chironomid larvae form the third group of benthic organisms with four species identified, of which Dicrotendipes tritonuts was the commonest.
The benthos of lagoons is very homogenous and relatively scarce. The number of species, which is never high as less than a dozen species, were found in even the richest stations, decreases from the zone near the pass to the inner parts of the lagoon, where only chironomid larvae and the bivalve molluscs Cerastoderma glaucum and Abra alba were found (Guelorget and Perthuisot, 1983). Other important benthos species are: Hediste diversicolor, Polydora ciliata, Cerastoderma glaucunt, Abra alba, Pyrenella conica, Gammarus aequicauda, Gantmarus subtypicus, Corphium orientale, Dicrotendipes tritonuts, Oligochaeta, Polychaeta, Nematoda, Gastropods (genus Planorbis, Gyraulus, Valvata, Physa and Radix), Bivalves (genus Unio and Anodonta, Teodoxus sp., Cerastoderma glaucum, Polypedilum sp., Fleura lacustris, Theodoxus anatolica, Gyraulus albus, Potamopyrgus sp., Cerastoderma glaucum, Iharix sp., Heteromastus filiformis, Palaemonetes antennarius and Chara hispida.
Crustacea: The Mediterranean and Aegean lagoons host a large population of the blue crab, Callinectes sapidus. At present, it is not exploited because demand for it collapsed after the closure of the only processing plant for crab meat, located near Karatas. Its abundance now represents a pest for the fishing industry since the crabs enter the fishing installation and damage the fish, thus lowering their commercial value. Their abundance in the catches also means that it takes a longer time to process the fish for selling. Other species observed are the common prawn Palaemon sp. and the crab Carcinus mediterraneus in the area closer to the pass. None of them are exploited by the tenant (Table IX).

Table IX: Main crustacean species in Turkish lagoons
Blue crab Callinectes sapidus
Common prawn Palaernon sp.
Crab Carcinus mediterraneus
White claw crayfish Astacus leptodactylus

Fish: The typical Mediterranean brackish water fish fauna, mainly characterized by grey mullets (several species), seabass (Dicentrarchus labrax), gilthead seabream (Sparus aurata) and eel (Anguilla anguilla). Some marine species such as Diplodus sargus and Mullus barbatus are also present, but confined to the area more influenced by seawater.
In the period from February to April, large numbers of fish fry and fingerlings migrate into the lagoon. During the April survey seabass, seabream, mullets and sole fry were observed. Despite the large number of migrating juvenile soles (Solea kleini), larger specimens appear to be absent from lagoon catches for the most part (Table X).

Table X: Main fish species in Turkish lagoons

European seabass Dicentrarchus labrax
Gilthead seabream Sparus aurata
European Eel Anguilla anguilla
White seabream Diplodus sargus
Red porgy Pagrus pagrus
Red mullet Mullus barbatus
Klein's sole Solea kleini
Common carp Cyprinus carpio
Pike-perch Stizostedion lucioperca
Striped Mullet Mugil cephalus
Golden grey mullet Liza aurata
Thin Lipped Grey Mullet Liza ramada
Redbelly Tilapia Tilapia zilli

11.3.3 Wildlife

Water birds: The main breeding birds of the Turkish lagoons are marbled teal, Marmaronetta angustirostris, and the ducks, Aythya nyroca, Holycon smymensis and Cryle rudis, which are threatened on a global basis.
Other breeding birds which enable lagoons and its immediate surroundings to be classified as a "wetland of national importance" include the purple gallinule, Porphyrio porphyrio, the collared pratincole, Glareola pratincola, the spur-winged plover, Hoplopterus spinosus, the stone curlew, Burhinus oedicnernus, the marsh harrier ,Circus aeruginosus, the Kentish plover, Charadrius alexandrinus, the little tern, Sterna albifrons, the black francolin, Francolinus francolinus,
Holycon smymensis and C. rudis.
The sandy beach along the seashore of the Akyatan lagoon is one of the most important nesting beaches of marine turtles in the Mediterranean. It is one of the two most important Mediterranean nesting beaches of the green turtle Chelonia mydas, which is classified as “threatened” on a global basis. Loggerhead turtles Caretta caretta (classified as “endangered”) also nest, although in smaller numbers (Baran and Kasparek, 1988).
The fallow deer, Dania damn, live in the afforestation area between the lagoon and the sea. The population originated from three individuals that escaped from captivity in 1987/88. Today's population is 23. Although this is not a natural population, it is of great interest as fallow deer is native to Turkey and this may be a good example of re-introduction. The origin of the escapees should be revealed. The badger, Meles meles, is also found in the forest. Jackals Canis aureus are found particularly in the dune areas. The long-tailed mongoose Herpestes ichneumon is relatively common along the Akyatan shores.
Koycegiz is a location where the Nile turtle (Trionyx triunguis) can be spotted. It is a turtle with a soft shell, thence also called African soft-shell turtle, which is about one meter in size. It is a protected, thermophile species. Consequently, it is often seen near the thermal springs along the fault line. The species occurs near the sea, in lagoons, lakes, rivers and canals, both in fresh and brackish waters. The Nile turtle is mainly aquatic and will only leave the water for short periods to rest in the sun. In the Koycegiz-Dalyan SEPA, oviposition takes place at the brackish waterside of Iztuzu Beach.