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    Are introduced gibel carp Carassius gibelio in Turkey more invasive in artificial than in natural waters?
    (Wiley-Blackwell, 2012) Tarkan, Ali Serhan; Copp, Gordon H.; Karakuş, Nildeniz Top; Özdemir, Nedim; Önsoy, Bahadır; Bilge, Gökçen; Saç, Gülşah
    The underlying mechanisms responsible for ecological plasticity and consequent invasive character of non-native freshwater fish species, variations in growth and life history traits in gibel carp Carassius gibelio (Bloch) were compared in natural and artificial water bodies of Turkey. Females significantly outnumbered males in all natural and most artificial waters. Discriminate function analysis differentiated gibel populations into three separate groups (natural lakes, artificial water bodies and running waters), with significant differences among separated groups in growth index, standard length and age at maturity, relative fecundity and gonado-somatic index, but not in egg diameter and both generalised and relative condition. Growth features (e.g. growth index and relative condition) and reproductive features (e.g. relative and absolute fecundity) positively correlated with water body area. No correlations were found for any growth or life history trait with depth, latitude and altitude. With the exception of smaller size at maturity, all traits were higher in populations from artificial water bodies than those inhabiting running waters, suggesting gibel carp is required to exert more reproductive effort to invade natural ecosystems than artificial waters.
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    Economic costs of non-native species in Türkiye: A first national synthesis
    (Academic Press Ltd- Elsevier Science Ltd, 2024) Tarkan, Ali Serhan; Baycelebi, Esra; Giannetto, Daniela; Ozden, Emine Demir; Yazlik, Ays; Emiroglu, Ozgur; Aksu, Sadi
    Biological invasions are increasingly recognised as a major global change that erodes ecosystems, societal wellbeing, and economies. However, comprehensive analyses of their economic ramifications are missing for most national economies, despite rapidly escalating costs globally. T & uuml;rkiye is highly vulnerable to biological invasions owing to its extensive transport network and trade connections as well as its unique transcontinental position at the interface of Europe and Asia. This study presents the first analysis of the reported economic costs caused by biological invasions in T & uuml;rkiye. The InvaCost database which compiles invasive non-native species' monetary costs was used, complemented with cost searches specific to T & uuml;rkiye, to describe the spatial and taxonomic attributes of costly invasive non-native species, the types of costs, and their temporal trends. The total economic cost attributed to invasive non-native species in T & uuml;rkiye (from 202 cost reporting documents) amounted to US$ 4.1 billion from 1960 to 2022. However, cost data were only available for 87 out of 872 (10%) non-native species known for T & uuml;rkiye. Costs were biased towards a few hyper -costly non-native taxa, such as jellyfish, stink bugs, and locusts. Among impacted sectors, agriculture bore the highest total cost, reaching US$ 2.85 billion, followed by the fishery sector with a total cost of US$ 1.20 billion. Management (i.e., control and eradication) costs were, against expectations, substantially higher than reported damage costs (US$ 2.89 billion vs. US$ 28.4 million). Yearly costs incurred by non-native species rose exponentially over time, reaching US$ 504 million per year in 2020-2022 and are predicted to increase further in the next 10 years. A large deficit of cost records compared to other countries was also shown, suggesting a larger monetary underestimate than is typically observed. These findings underscore the need for improved cost recording as well as preventative management strategies to reduce future post -invasion management costs and help inform decisions to manage the economic burdens posed by invasive non-native species. These insights further emphasise the crucial role of standardised data in accurately estimating the costs associated with invasive non-native species for prioritisation and communication purposes.