Yetiştiriciliğe Konu Olan Beş Yabancı Sucul Türün Türkiye’deki İstilacılık Potansiyelinin Değerlendirilmesi

Abstract

ABSTRACT

EVALUATION OF THE INVASIVENESS POTENTIAL OF FIVE NON -NATIVE AQUATIC SPECIES SUBJECTED TO AQUACULTURE IN TÜRKİYE

Derya ÖZCAN

Master of Science, Department of Biology Supervisor: Prof. Dr. Fitnat Güler EKMEKÇİ May 2024, 200 pages

Aquaculture, which is of great importance in food supply, economy and employment, is also one of the important vectors for the introduction and spread of non-native species. It is important to know the invasion potential of species that are unwittingly or intentionally moved out of their natural distribution areas, as they may cause more damage than benefit in the long term. In this thesis, giant freshwater shrimp (Macrobrachium rosenbergii), Pacific white shrimp (Penaeus vannamei), Pacific oyster (Magallana gigas), Atlantic salmon (Salmo salar) and Nile tilapia (Oreochromis niloticus), which are not native to Turkey, were evaluated using the Aquatic Species Invasiveness Screening Kit (AS-ISK). With the AS-ISK, a valid screening and assessment consisting of 55 questions, the first 49 of which are basic risk assessment (BRA) and the last six of which are climate change assessment (CCA), was carried out for each species specific to the identified risk region, and an answer, confidence level and justification were provided for each question. For fish species, the threshold value of 28 was determined for Turkey, and for the species in the Malacostraca and Bivalvia classes, the threshold values of 15 and 15.1 determined globally for marine and brackish water invertebrates, respectively, were used. After the survey was completed, both a Basic Risk Assessment (BRA) and Climate Change Assessment (CCA) score and a BRA+CCA (composite) score were obtained for each species and their invasiveness potential was ranked. According to the study results, in terms of invasiveness potential in the Marmara Region; Pacific oyster (M. gigas), Nile tilapia (O. niloticus) and giant freshwater shrimp (M. rosenbergii) are "high risk" with scores of BRA: 37, BRA: 32 and BRA: 19.5, respectively, in the Mediterranean Region; Pacific shrimp (P. vannamei) is “high risk” with a BRA score of 25, in the Aegean Region; giant freshwater shrimp (M. rosenbergii) is “high risk” with a BRA score of 20.5, in the Black Sea Region; Pacific oyster (M. gigas) is considered “high risk” with a BRA score of 36, and Atlantic salmon (S. salar) is considered “medium risk” with a BRA score of 22. In terms of invasion potential, only S. salar is predicted to be negatively affected by the projected climate changes in the Risk Assessment Zones, while the other four species, the lowest degree at M. rosenbergii, are predicted to be positively affected. Keywords: Aquaculture, Invasive, Macrobrachium rosenbergii, Penaeus vannamei, Magallana gigas, Salmo salar, Oreochromis niloticus, AS-ISK