Climate change due to global warming have effects upon sustainable use of natural resources. Climatic parameters such as temperature, evaporation and precipitation obtained from 3 meteorological observation stations, and streamflow data of Kocabaş Stream were used to understand the effects of global warming on annual streamflow of Kocabaş Stream. Change years were determined and trend analysis was applied for climatic parameters and streamflow of the river. As specified in the results of analyses it could be enunciated that there was a visible increase in temperature and evaporation, and that there was a decrease in precipitation and annual streamflow of the river. Change year was determined as 1981 for streamflow of the river and trend analysis results showed that the streamflow has a decreasing trend and the annual amount of this decrease is predicted to be 0.025005 m³ s^-1. Trend analysis results for climatic parameters showed that there is a decreasing trend in precipitation and increasing trends in temperature and evaporation. The paper indicates that the effects of climate change on annual streamflow of the river could be variable and that many effects such as agricultural activities, anthropogenic effects, and geographical location should be considered in predicting of climate change effects on river systems.

Zebra midyeleri, Dreissena polymorpha (Pallas, 1771) hidroelektrik ve nükleer güç sistemlerinde su akışını engellediğinden zararlı bir istilacı epibiont türü olarak kabul edilir. D. polymorpha suyun temizlenmesi, su görünürlüğünün arttırılması ve kirleticilerin filtrelenmesi olarak rapor edilmesine rağmen, bazı balıkların ve sucul türlerin popülasyonu ve büyüklüğü üzerinde olumsuz etkilere sahiptir. Bu çalışmada, zebra midyesi Türkiye’deki bazı su kaynaklarındaki tatlısu ıstakozu üzerinde ilk defa gözlemlenmiştir. Bireyler Türkiye’deki iki doğal göl (Çıldır Gölü, Eğirdir Gölü) ve beş göletten (Altınyazı Baraj Gölü, Keban Baraj Gölü, Küçükçekmece Gölü, Karpuzlu Baraj Gölü, Kadıköy Baraj Gölü) toplanmıştır. Bu çalışmada, kerevitlerin farklı vücut bölümlerine zebra midyesinin tutunması belgelenmiştir. Cochran’s Q test sonuçları; kerevitin değişik bölümlerine tutunan midye sayılarının farklılık gösterdiğini ortaya koydu (P=0.000) (P <0.001). Zebra midyelerin tatlısu ıstakozlarının üzerinde tutunma bölgeleri arasında farklılığın tespit edilmesinin konakçı açısından bazı olumsuzluklara neden olabileceği düşünülmektedir. Özellikle carapax bölgesinde yoğun tutunmaların; hareket (beslenme, çiftleşme, predatörlerden kaçınma ve barınma). Pleopodal bölgedeki midye bireyleri ise yumurta tutunumu ve taşınımını zorlaştırabilir. Bu çalışma Türkiye sularındaki Astacus leptodactylus üzerinde Dreissena polymorpha ’nın varlığı ile ilgili ilk rapordur.

This paper includes three exotic polychaeta species, Hydroides dianthus (Verrill, 1873), Polydora cornuta Bosc, 1802, and Pseudopolydora paucibranchiata (Okuda, 1937), found during benthic samplings in Çardak Lagoon (Turkish Straits). The sampling was collected from the sandy and silty bottoms known to be polluted by sewage discharges. A total of 45 specimens of exotic polychaetes (H. dianthus: 1; P. cornuta: 4; P. paucibranchiata: 40) were found. The correlation values between the annual average values of the nutrients and the polychaeta abundance showed that the highest positive relationships with the abundance were between sand content, total phosphate, and pH. P. cornuta was the most observed species with a frequency index value of 75%, while H. dianthus was represented with a single species in the study area. Albeit the previous studies, P. paucibranchiata was observed most abundantly in the sampling station having low organic matter amounts. The study showed that opportunistic polychaetes observed in Çardak Lagoon mostly preferred organically poor sediments.

The present study aims to determine the diet composition of Eriphia verrucosa using an informative and uninformative approach in which the stomach content results were assigned as prior based on this model. A stable isotope mixing model and stomach content analysis were used together to determine the diet and prey-predator relationships of E. verrucosa. A total of 24 crabs and benthic material were collected from depths between 1.5 and 2 m in the Strait of Çanakkale in July, 2020. The contribution of two different diets was assessed both by prior assignment (informative) and uninformative. According to the stomach content analyses, among the prey, Echinodermata contributed 37% to the diet, followed by Mollusca, especially Gastropoda (18%). In the uninformative model without prior assignment and in the informative model (prior assignment), Gastropoda contributed the most to the diet (57, 66%, respectively).