Kaptai Lake was a special freshwater habitat with a diverse fish population from the very beginning. A total of 76 fish species from 10 orders was found in Kaptai lake, among them Siluriformes (catfish) was the 2nd most dominant order, contributing 15 species (Suman et al., 2021). It is economically significant as a food fish, ornamental fish, and sport fish (Jin et al., 2016). Catfish are a prominent freshwater fish fauna abundantly found in Bangladesh (Rahman, 2005). According to the BFDC (2020) report, a total of 36 valuable fish species are harvested for commercial purposes, of which ayre (Sperata sp.) is among them. The Ayre (Sperata aor and S. seenghala), belongs to the order Siluriformes and family Bagaridae (Rahman, 1989). Due to its incredible nutritional value with strong protein content, low number of intramuscular bones (Chondar, 1999; Talwar & Jhingran, 1991), high market price, and widespread popularity (Chondar, 1999; Khawja, 1966), it has been regarded as one of the most loved culinary fishes.
For various causes, these catfish species attempts to spawn failed, resulting in a drop in recruitment. As part of a fish protection program, all fishing is restricted in Kaptai Lake from May through July each year. Currently, no harvest management plan, area-based regional management plan and ex-situ conservation strategies are in place (Rema Devi and Raghavan 2011). In India and Bangladesh, S. aor and S. seenghala are reported as vulnerable primarily because of several factors, including siltation brought on by deforestation, overfishing, the indiscriminate killing of supplemental fingerlings, and the use of various types of destructive fishing techniques, such as fish aggregation devices (FAD), and the effects of climate change have led to a significant decline in the availability of these fish in lake environments over the past 20 years (Ahmed and Hambrey, 1999). Moreover, ayre (Sperata sp.) has been in a decreasing trend. According to (BFDC)’s landing records 2019-2023, every year about 10-12% ayre have decreased from the previous landing data of these fishes. It has been stated that long-whiskered catfish, Sperata aor; giant river catfish, Sperata seenghala are easily stressed because it is susceptible to changes in water quality; it is challenging to make spawn through induced breeding (Rahman et al., 2005; Khan et al., 2016).
The growth pattern is often used to identify variations in growth and condition indices of fish throughout the year. Furthermore, the assessment of fish output and biomass heavily relies on the accurate estimation of growth patterns. Various dynamic mathematical models, such as the Beverton and Holt models (1957, 1966), have been extensively used in formulating management strategies to evaluate potential yields and stock biomass at different stages of fishing methods (Dadzie et al., 2017). These models require knowledge of fish population growth, recruitment, mortality, relative yield per recruit, exploitation, and maximum sustainable yield. The various dynamic pool models have been used to estimate fish ages and define fishery management techniques in most tropical and semi-tropical environments. However, it is likely to analyze fish population dynamics in temperate waterbodies by improving stock assessment methodologies. However, stock assessment is essential for providing fisheries researchers with the statistics required for a fish stock's management plan and defining the historical and current stock status of fish. Information on exploitation status and length-based stock assessment of ayre and gulsha is very scanty.. Therefore, capture from wild population is still fulfilling total demand in the local markets. So the appropriate management of capture fisheries of S. seenghala and S. aor is very essential.
Kaptai Lake was a special freshwater habitat with a diverse fish population from the very beginning. A total of 76 fish species from 10 orders was found in Kaptai lake, among them Siluriformes (catfish) was the 2nd most dominant order, contributing 15 species (Suman et al., 2021). It is economically significant as a food fish, ornamental fish, and sport fish (Jin et al., 2016). Catfish are a prominent freshwater fish fauna abundantly found in Bangladesh (Rahman, 2005). According to the BFDC (2020) report, a total of 36 valuable fish species are harvested for commercial purposes, of which ayre (Sperata sp.) is among them. The Ayre (Sperata aor and S. seenghala), belongs to the order Siluriformes and family Bagaridae (Rahman, 1989). Due to its incredible nutritional value with strong protein content, low number of intramuscular bones (Chondar, 1999; Talwar & Jhingran, 1991), high market price, and widespread popularity (Chondar, 1999; Khawja, 1966), it has been regarded as one of the most loved culinary fishes.
For various causes, these catfish species attempts to spawn failed, resulting in a drop in recruitment. As part of a fish protection program, all fishing is restricted in Kaptai Lake from May through July each year. Currently, no harvest management plan, area-based regional management plan and ex-situ conservation strategies are in place (Rema Devi and Raghavan 2011). In India and Bangladesh, S. aor and S. seenghala are reported as vulnerable primarily because of several factors, including siltation brought on by deforestation, overfishing, the indiscriminate killing of supplemental fingerlings, and the use of various types of destructive fishing techniques, such as fish aggregation devices (FAD), and the effects of climate change have led to a significant decline in the availability of these fish in lake environments over the past 20 years (Ahmed and Hambrey, 1999). Moreover, ayre (Sperata sp.) has been in a decreasing trend. According to (BFDC)’s landing records 2019-2023, every year about 10-12% ayre have decreased from the previous landing data of these fishes. It has been stated that long-whiskered catfish, Sperata aor; giant river catfish, Sperata seenghala are easily stressed because it is susceptible to changes in water quality; it is challenging to make spawn through induced breeding (Rahman et al., 2005; Khan et al., 2016).
The growth pattern is often used to identify variations in growth and condition indices of fish throughout the year. Furthermore, the assessment of fish output and biomass heavily relies on the accurate estimation of growth patterns. Various dynamic mathematical models, such as the Beverton and Holt models (1957, 1966), have been extensively used in formulating management strategies to evaluate potential yields and stock biomass at different stages of fishing methods (Dadzie et al., 2017). These models require knowledge of fish population growth, recruitment, mortality, relative yield per recruit, exploitation, and maximum sustainable yield. The various dynamic pool models have been used to estimate fish ages and define fishery management techniques in most tropical and semi-tropical environments. However, it is likely to analyze fish population dynamics in temperate waterbodies by improving stock assessment methodologies. However, stock assessment is essential for providing fisheries researchers with the statistics required for a fish stock's management plan and defining the historical and current stock status of fish. Information on exploitation status and length-based stock assessment of ayre and gulsha is very scanty.. Therefore, capture from wild population is still fulfilling total demand in the local markets. So the appropriate management of capture fisheries of S. seenghala and S. aor is very essential.
Objectives
i. To estimate the population parameters of two long-whishkered catfish (Sperata seenghala and Sperata aor) in Kaptai lake
ii. To assess the stock of two long-whishkered catfish (Sperata seenghala and Sperata aor) in Kaptai lake
Planning and Implementation: Cabinet Division, A2I, BCC, DoICT and BASIS
Technical Assistance:
