Assessing the Ecological Water Level: The Case of Four Mediterranean Lakes

Petriki, O., D. Zervas, Ch. Doulgeris, D. Bobori. 2020. Assessing the Ecological Water Level: The Case of Four Mediterranean Lakes. Water: 12, 2977. doi:10.3390/w12112977The ecological water regime in lake water bodies refers to the water levels that enable the fulfillment of the ecosystem’s multiple functions. Therefore, assessing the ecological water regime necessitates the consideration of hydrological, economic, social, and ecological factors. The present research is focused on the assessment of the ecological water level of four Mediterranean natural lake ecosystems, considering their morphological and biological features. Initially, suggestions on the ecological water regime of the studied lakes were made based on an analysis of the lakes’ morphometry. Further, the ecological and biological requirements of the present fish fauna and aquatic macrophytic vegetation were considered. For the latter, mapping was conducted by extensive sampling according to international standards, in order to assess macrophyte composition, abundance, and chorology, as well as species sensitivity to water level fluctuations. The above guided the proposals on the optimal water level regime that should be met by each lake regarding the macrophytic and fish communities’ sustainability, also taking into account the unique hydromorphological features of each lake. The di erences in the outcoming results revealed that hydromorphological and biological approaches should be combined for assessing lakes’ ecological water regime

New Mediterranean Biodiversity Records (April, 2014)

According to reports, the following 16 species have extended their distribution to other Mediterranean areas or have made a new appearance in other regions. The first category includes the following organisms: The rare and common Indo-Pacific seaweed Codium arabicum (Lebanese coasts), the acari Thalassarachna affinis (Marmara Sea), and the non-indigenous nudibranch Flabellina rubrolineata, which has also been found in many other areas of the Aegean Sea. In addition, the rare sea slug Thecacera pennigera (Piccolo of Taranto), the fangtooth moray Enchelycore anatina (National Marine Park of Zakynthos, Ionian Sea), the carangid Seriola fasciata (Gulf of Antalya), Lagocephalus sceleratus (SE. Ionian Sea), the reticulated leatherjacket Stephanolepis diaspros (Slovenia, N. Adriatic Sea), the marbled stingray, Dasyatis marmorata (NE Levantine), the starry smooth-hound Mustelus asterias (Iskenderun Bay, NE Mediterranean), the cephalopod Ommastrephes bartramii (Ionian Sea) have also been reported. The Atlantic crab Dyspanopeus sayi has expanded to many Italian areas and the blue crab Callinectes sapidus to a lake in N. Greece and in the S. Adriatic Sea. Finally, Farfantepenaeus aztecus has been found in the Ionian Sea, thus showing its wide expansion in the Mediterranean. The larval stages of Faccionella oxyrhyncha have been found, after many years, in the Aegean Sea and the first report of an existence on intersexual acari Litarachna duboscqi in Split(Adriatic Sea) was reported

Range expansion of Pachychilon macedonicum (Actinopterygii: Cypriniformes: Cyprinidae) in northern Greece

The cyprinid freshwater fish, Pachychilon macedonicum (Steindachner, 1892), is an endemic species in the Balkan Peninsula and has a restricted distribution in Greece. Here, we report new records of the species out of its known natural range, namely at the Mpogdanas Stream (drainage area of lakes Koronia-Volvi, northern Greece), which now constitute a new eastern limit for the distribution of the species in southern Balkans. It appears that the new record is related to a human-mediated translocation

Portraying fisheries and ecological status of a Mediterranean lake

Background. Gaps of knowledge in lentic systems and discrepancies in official fishery statistics biased fisheries state and inhibits the development of conservation strategies. For that reason the integration of conventional (official data from fisheries landings) and unconventional (fishermen knowledge) sources of data, accompanied with the use of historical archives will outline the framework of the monitoring of freshwater resources.The presently reported study integrated local ecological knowledge of fishers, historical data, field surveys and scientific data to present better management options for a Mediterranean lentic system (Volvi Lake, northern Greece). Materials and methods. On-the-spot interviews were conducted with the professional fishers of Volvi Lake (northern Greece) in parallel with field surveys of environmental parameters during 2014–2015 and complemented with archival freshwater-related information. Results. The results of the presently reported study point to commercial fisheries as a declining activity, with little scope for a future, due to internal and external threats. This diagnostic can probably be generalized beyond the case study to other freshwater ecosystems in Europe, where decreasing fisheries productivity due to overfishing, habitat loss, and pollution, coupled with low economic productivity has led to an increased marginalisation of freshwater fisheries. Conclusion. The reported difficulties of freshwater fisheries could be bypassed through creation of fishers’ typology regarding their dependence on fisheries. Upgrading the methodological approach followed by the official reporting system in freshwaters might also facilitate the fulfilment of the requirements of the EU Water Framework Directive