Biological parameters and current status of European eel (Anguilla anguillaLinnaeus, 1758) from Asi River, Northeastern Mediterranean region, Turkey

Abstract

The biological characteristics of eels from the Asi River, Turkey, were assessed between December 2017 and November 2018. Eels were sampled monthly using fyke nets (operated by professional fishermen), yielding a total of 509 specimens. Total length and weight were measured, sex, age and maturity stages (silver or yellow eel) were determined. Catch Per Unit Effort (CPUE) was calculated for both biomass per unit effort and numbers caught on a monthly and annual basis. The length‐weight relationships (LWRs) of silver and yellow eel was W = 0.009*TL3.22 (n = 262) and W = 0.0106*L3.09 (n = 247), respectively. The age of the sampled fish ranged from year class II to VI. Von Bertalanffy growth parameters were estimated as L∞=69.25 cm, K = 0.43 1/year, t0= −0.41 and phi prime index (ǿ)= 3.31 for all samples. The overall eel fishing mortality rate (F) was 0.31 year‐1, and the exploitation and survival rates of silver stage eels were estimated with 30% and 39%, respectively.

Length-Weight Relationship and Condition Factor of Prussian Carp (Carassius gibelio, Bloch, 1782) from Asi River

“…Although the Asi River is an important area in terms of species diversity, this region has important fish stock problems due to seasonal water shortages and overfishing (Demirci & Yalçın Özdilek, 2010Demirci et al, 2020). Therefore, monitoring and protection of fish populations in this region is essential for a sustainable ecosystem and fisheries.…”

“…To date, there are various species, both native and invasive, belonging to different families in the Asi River (Demirci & Demirci, 2009;Bayçelebi, 2020). Some biological parameters of Barbus luteus (Gökçek & Akyurt, 2008), Capoeta capoeta (Demirci & Yalçın Özdilek, 2010), Alburnus orontis, Chondrostoma kinzelbachi (Özcan & Altun, 2015), Capoeta barroisi (Demirci & Yalçın Özdilek, 2015), Garra rufa (Demirci et al, 2016), Capoeta angorae (Alagöz Ergüden & Turan, 2017), Anguilla anguilla (Demirci et al, 2020), Barbus lorteti (Demirci & Yalçın Özdilek, 2021), Salaria fluviatilis (Alagöz Ergüden, 2021a), Garra turcica (Alagöz Ergüden, 2021b), Clarias gariepinus (Şimşek et al, 2022) have been assessed in previous studies. Since Cyprinidae family carries commercial importance in the Asi River (Demirci & Demirci, 2009), information regarding its population characteristics is important for the establishment of proper management strategies.…”

First record of economically important big-scale sand smelt (Atherina boyeri Risso, 1810, Pisces: Atherinidae) with some biological parameters from Reyhanlı Dam Lake, Türkiye

“…In the Asi River basin, intensive amateur and commercial fishing activities are carried out by the public. Target species in this intense catch are stressed species, including Anguilla anguilla, Clarias gariepinus and Cyprinid species (Demirci & Demirci 2009;Demirci et al 2020;Şimşek et al 2022). In this sense, A. boyeri may become a new economic target species for regional fisheries.…”

Biological traits of a data deficient species in the Asi River: Barbus lorteti (Sauvage, 1882)

“…The river rose from the Bekaa Valley in Lebanon and reached after in Syria. 94 km of its water were located in the borders of Turkey (Yalçın Özdilek et al, 2006;Demirci et al, 2020). In the last set, it flowed into Mediterrenean from Samandag (Yalcin, 1999;Demirci et al, 2012;Demirci et al, 2016).…”