Length-based estimates of growth parameters and mortality rates of fish populations from a coastal zone in the Southeastern Brazil

Abstract

Small-scale fisheries in Brazil contribute to a significant share of total fish production, accessing a large variety of species. Life history parameters from these resources are important for their management and conservation, based on primary data. The objective of this article is to generate growth parameters and mortality rates of ten fish populations from a coastal zone in Southeastern Brazil. Monthly samples were taken between January 2011 and November 2014 from landings of the beach-seine fishery in an area adjacent to the entrance of the Guanabara Bay. All fishes were measured (total length) and weighed. The length-weight relationships (LWR) were estimated by linear regression analysis on log-transformed data of the equation: W = aLb. The Von Bertalanffy Growth Function (VBGF) was fitted to size-at-age data to obtain growth parameters (K, L∞). The length-converted catch curve was used for estimating the instantaneous total mortality (Z). Taylor’s equations provided an independent estimate of the natural mortality (M) and longevity. The difference between Z and M derived Fishing mortality (F). A total of 2,938 individuals from ten fish species were used to determine the length-weight relationships. Harengulaclupeola (Cuvier, 1829) has a new maximum length record for the FishBase LWR database. Sardinellabrasiliensis (Steindachner, 1879) presented the smallest and largest size recorded for LWR observed in the literature and FishBase database. Upeneusparvus showed the greatest total length, while Trichiuruslepturus Linnaeus, 1758, Orthopristisruber (Cuvier, 1830) and Dactylopterusvolitans (Linnaeus, 1758) presented the smallest sizes for LWR in FishBase. The other species showed parameters within the expected values for each group. The performance index combining information from K and L∞ presented values between 2.32 and 3.76 and were considered appropriate for the populations evaluated. Fishing was the primary source of mortality for Caranxcrysos (Mitchill, 1815), Eucinostomusargenteus Baird & Girard, 1855, S.brasiliensis and U.parvus, and less important for Cynoscionjamaicensis (Vaillant & Bocourt, 1883), D.volitans, O.ruber, Selenesetapinnis (Mitchill, 1815), T.lepturus and H.clupeola. The parameters generated may be used for the management and conservation of the species’ stocks.

Growth, Mortality and Exploitation Rates of African Moonfish (Selene dorsalis, Gill 1863) Encountered in the Coast of Ghana (West Africa)

“…The growth rate estimated for this study (0.76 year -1 ) was higher than recorded for other related species like Selene setapinnis (0.49 year -1 ) [24] but lower than the growth estimate for Selene peruviana (0.95 year -1 ) [25]. The growth rate (k) from the current study signifies that S. dorsalis in Ghana's coastal waters exhibited a fast growth rate, evinced by the low longevity of 3.72 years (Table 2).…”

“…Adaptations to local conditions and exploitation levels may have caused the variations observed in the fishing mortality rate as compared to other studies carried out on other related species [32]. From the present study, the natural mortality rate (1.21 year -1 ) was lower than the fishing mortality rate (2.11 year -1 ) unlike the related species Selene setapinnis which had its natural mortality rate (0.94 year -1 ) higher than the fishing rate (0.28 year -1 ) [24]. This suggests that unlike Selene setapinnis, the S. dorsalis species in the coastal waters of Ghana are more prone to fishing gears than naturally induced mortality situations caused by age, predation, lack of food, spawning stress, diseases, and pollution [27].…”

“…The asymptotic length of S. dorsalis (22.2 cm TL) varied compared to other related species like Selene setapinnis (36.84 cm TL) [24] and Selene peruviana (21 cm TL) [25]. According to [26], growth parameters are very sensitive to samples as such, larger individuals tend to increase the asymptotic length as growth rate decreases, hence, individual size ranges play a key role in estimating the asymptotic length.…”

Length at first sexual maturity of economically important fishes in the Brazilian Northeast Coast

“…When considering fishes from both sexes that are economically important in the North Coast of Maranhão, Brazil (Table 1) The species O. palometa (Berry and Smith-Vaniz, 1978;Duque-Nivia et al, 1995), L. synagris (Freitas, 2009;Lessa et al, 2004;Trindade-Santos and Freire, 2015) and B. bagre (Véras and Almeida, 2016) had a higher L50 than that calculated in previous studies. The species M. furnieri (Carneiro et al, 2005;Haimovici and Ignacio, 2005;Santos et al, 2015), T. lepturus (Magro, 2005;CMFRI, 2016;Costa et al, 2018) and M. curema (Araújo and Silva, 2013; Trindade-Santos and Freire, 2015) had similar or lower L50 compared to other studies. S. setappinis showed significant variation when comparing its L50 with other studies in Brazil (Bastos et al, 2005;Costa et al, 2018).…”

“…The species M. furnieri (Carneiro et al, 2005;Haimovici and Ignacio, 2005;Santos et al, 2015), T. lepturus (Magro, 2005;CMFRI, 2016;Costa et al, 2018) and M. curema (Araújo and Silva, 2013; Trindade-Santos and Freire, 2015) had similar or lower L50 compared to other studies. S. setappinis showed significant variation when comparing its L50 with other studies in Brazil (Bastos et al, 2005;Costa et al, 2018). N. microps, G. luteus, and P. crenulatus have no L50 information from previous studies.…”