Age, growth and mortality of poor cod (Trisopterus minutus L.) from the eastern Adriatic Sea

Abstract

The age, growth and mortality parameters for poor cod, Trisopterus minutus, from the eastern Adriatic were analyzed. Samples were collected monthly from January to December 2009 on a random basis, with a total of 1200 specimens analyzed (885 females and 315 males). The values of parameter b (the exponent of the arithmetic form of length-weight relationships) of males (2.97), females (3.01) and total sample (2.99) indicated isometric growth. Fish aged 1-6 years were present in the samples, including a high proportion of 2-year-old individuals. The oldest female was estimated to be 6 years old, while the oldest male was 5. The von Bertalanffy growth parameters were L¥ = 26.81, K = 0.186, and to = 1.41 for males; L¥ = 29.5, K = 0.197, and to = 1.33 for females; L¥ = 28.76, K = 0.194, and to = 1.34 for all specimens. This study revealed that poor cod is a relatively slow-growing fish with intensive growth during the first two years of life. Total and natural mortality were Z = 1.01 year-1 and M = 0.50 year-1, respectively. The exploitation rate, E = 0.50, revealed a high fishing pressure on the stock in the studied area.