This paper is a synthetic overview of some of the threats, risks, and integrated water management elements in freshwater ecosystems. The paper provides some discussion of human needs and water conservation issues related to freshwater systems: (1) introduction and background; (2) water basics and natural cycles; (3) freshwater roles in human cultures and civilizations; (4) water as a biosphere cornerstone; (5) climate as a hydrospheric ‘game changer’ from the perspective of freshwater; (6) human-induced stressors’ effects on freshwater ecosystem changes (pollution, habitat fragmentation, etc.); (7) freshwater ecosystems’ biological resources in the context of unsustainable exploitation/overexploitation; (8) invasive species, parasites, and diseases in freshwater systems; (9) freshwater ecosystems’ vegetation; (10) the relationship between human warfare and water. All of these issues and more create an extremely complex matrix of stressors that plays a driving role in changing freshwater ecosystems both qualitatively and quantitatively, as well as their capacity to offer sustainable products and services to human societies. Only internationally integrated policies, strategies, assessment, monitoring, management, protection, and conservation initiatives can diminish and hopefully stop the long-term deterioration of Earth’s freshwater resources and their associated secondary resources.

Records of mass fish deaths were found in different data sources for this study. A map of mass fish deaths in Turkey was also realized for the first time. We aimed to present a review of the distribution of mass fish deaths in the freshwater ecosystems of Turkey, mostly present in the Marmara Region and Aegean Sea Region, where there are intensive industrial and agricultural activities. Fish parasites generally occur in equilibrium with their hosts in natural environments. In the freshwater ecosystems of Turkey, which are highly affected by human activities and have extremely rich natural ichthyofauna, the negative effects of pollution on environmental parameters, which can directly affect the fish, and the emergence and overextension of fish parasites can cause a supplementary synergic direct negative effect transposition in mass fish deaths due to the deterioration of host immunity and to the wounds induced in fish where bacterial, viral, and fungal pathogens can be effective. Finally, these factors can influence the fish rate of survival and skew the structure of fish populations. Mass fish deaths have been frequently reported in Turkey, but are usually only explained by pollution as a single accepted anthropogenic stressor. Together with pollution, a supplementary induced bioecological stressor, the qualitative and quantitative characteristics of the fish parasites’ association variations should be assessed and monitored as potential complex precursor indicators of fish communities’ structural degradation and freshwater ecosystems’ dreadful conditions. Fish parasites as biomonitor species should be used to identify the effects of pollution in Turkish ecosystems, and not only in freshwater ecosystems, in the future. An optimum management plan for freshwater ecosystems should include all the physico-chemical factors, fish parasites, and fish elements involved in permanent assessment and monitoring activities.

This review presents the occurrence of 62 parasitic copepod species from 72 different fish species (64 wild, two cultured, seven from aquarium) from Turkey.The parasite species list is arranged by providing parasite species name, host fish, location of host fish capture and author, date of published record.All parasites and their hosts are confirmed with the recent systematic accounts and full taxonomic account according to literature and internet database. Siphonostomatoida with 47 species and Caligidae with 12 species are the dominant order and family among parasitic copepoda with regard to species diversity, host distribution and location.

New Information on the Hosts and Distribution of the Marine Fish LeechesTrachelobdella LubricaandPontobdella Muricata(Clitellata, Hirudinida): Fish leeches collected in the Aegean Sea, the Sea of Marmara and the Black Sea were examined.Trachelobdella lubrica(Grube, 1840) was recorded for the first time from the ballan wrasseLabrus bergylta(Osteichthyes, Labridae), marine breamDiplodus vulgaris(Osteichthyes, Sparidae) and the grouperEpinephelus aeneus(Osteichthyes, Serranidae) from aquiculture. The leeches of this species were found in the Aegean Sea and the Sea of Marmara on the body surface, in the mouth and gill cavities of their hosts. Leeches identified asPontobdella muricata(Linnaeus, 1758) were collected from the thornback rayRaja clavata(Chondrichthyes, Rajidae) in the Black Sea.

Revizuire a viermilor paraziți raportați la specii de pești de apă dulce din Turcia, cu noi înregistrări

An updated checklist carried out indicated the occurrence of 161 helminth species from wild marine fish species in Turkey, which includes 49 monogeneans, 63 digeneans, 18 cestodes, 17 nematodes, 11 acanthocephalans and three annelids, from 88 different fish (86 native, two migratory) species. Since the publication of the checklist of helminth parasites of marine fishes in Turkey over nine years ago (Öktener, 2005), there have been a number of new records. This update includes these additional records and has allowed the correction of those errors and omissions that were present in the previous version. The parasite species list is arranged by phylum and class, providing parasite species name, host fish, location of host fish capture and author, and date of published record. The host list consists of all parasite species listed by host species. All parasites and their hosts are confirmed with the recent systematic accounts and full taxonomic account