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 = aL^b. 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.

Studies on age and growth of fish populations have direct application in fisheries and contribute for policies of conservation. Our aim was update information on the Micropogonias furnieri growth parameters based on sagittae otoliths annulis readings, and we expected that the studied population from Southeast Brazil can reach more longevity than the reported in the available literature. We examined 286 individuals between August-2010 and July-2011 from Ubatuba Bay, SP. The Total Length ranged 200-480 mm. The determined growth parameters were: Males, L_∞ =523.4mm, k = 0.05×year^-1, t₀ = -8.78 year; Females L_∞ = 573.5mm, k = 0.06 × year^-1, t₀ = -7.49 year. The MI and % of edge type evidenced the formation of one ring per year during autumn/winter, coinciding with low temperature and low growth rate. These results differed from those reported for the Vazzoler’s Population I (summer), and we detected higher longevity (45-48 years) as compared with the recorded in the available information.

The bluefish, Pomatomus saltatrix (Linnaeus, 1766), was used as a species-specific model to study morphometric relationships between otolith size and relative growth variables. Length-weight relationships between Otolith (Length-OL, Height-OH, and Weight-OW) and fish measurements (Total Length-TL and Total Weight-TW) were determined for fishes captured monthly during the year 2015 off the southeastern coast of Brazil. The ANCOVA and Kruskal-Wallis analysis did not indicate significant differences in the relative growth constants between sexes and length frequency distributions (p > 0.05). The condition factor also did not present significant differences between sexes, and right and left otolith measurements (p > 0.05). A total of 398 specimens were sampled: TL = 43.6-67.0 cm, TW = 365-2400 g, OL = 9.65-15.25 mm, OH = 3.65 - 5.45 mm and OW = 0.03-0.11 g. The LWR for grouped sexes was TW = 0.050TL^2.55 and otoliths OW = 6.17E-05OL^2.59. The best adjustments were TL vs OL (r² = 0.90); OL vs OW (r² = 0.90); TW vs OW (r² = 0.81); and TW vs OL (r² = 0.80). These results showed that such relationships are helpful tools for predicting the fish size and weight from otoliths, which may be used in food habits and paleontology studies, and other fisheries management applications.

Um estoque pesqueiro pode ser definido como conjunto de indivíduos de uma espécie sob processo de explotação em determinada região, apresentando características locais intrínsecas como interação com o ambiente e parâmetros de história de vida (^{Sparre & Venema, 1997}; ^{Begg & Waldman, 1999}). A importância de se definir os limites de um estoque, conhecer sua dinâmica e história de vida reside no fato de esse conhecimento permitir a aplicação de estratégias de manejo que visem otimizar a explotação do recurso e mantê-lo disponível perpetuamente (^{Sparre & Venema, 1997}; ^{Vaz-dos-Santos et al., 2007}). Para tal, são necessárias pesquisas científicas com objetivo de entender o comportamento das espécies perante as condições ambientais e de explotação, bem como acompanhar permanentemente, a médio e longo prazo, de modo a aplicar ações emergenciais quando necessário. Estudos morfométricos e morfológicos de otólitos têm sido utilizados na identificação de várias espécies marinhas de importância ecológico-econômica em diversas regiões (^{Castonguay et al., 1991}; ^{Campana & Casselman, 1993}; ^{Tuset et al., 2003}; ^{Mahe et al., 2016}), inclusive ao largo da costa do Brasil (^{Monteiro et al., 2005}; ^{Rondon et al., 2014}; ^{Santos et al., 2017}; ^{Soeth et al., 2019}).

The physical habitat simulation sub-routine of the Instream Flow Incremental Methodology (IFIM) uses hydraulic modeling and suitability indices of target fish species to predict how differences in-stream flows affect the microhabitat occupation by fish species. This habitat modelling approach was adopted to assess the ecological effects of running flows on three neotropical fish species of different orders (Bryconamericus ornaticeps , Ancistrus multispinis and Geophagus brasiliensis ).The study encompassed two reaches of an Atlantic Forest stream in Southeastern Brazil where topographic and hydraulic (depth, velocity and type of substrate) characteristics were measured to implement one-dimensional hydraulic simulation. Sub aquatic observation of fish was performed to collect data on microhabitat use and these data were used to develop habitat suitability curves that were used in the habitat simulation to obtain the habitat suitability index (HSI) and weighted usable area (WUA) versus flow curves. Upon these curves minimum and optimum environmental flows for the target fish species were proposed. Bryconamericus ornaticeps and A. multispinis selected microhabitats around 0.6 m depth, whereas G. brasiliensis showed a wider suitable range (0.35-0.9 m). All the three species were mainly observed in microhabitat with low flow velocity (0.1 m/s). Bryconamericus ornaticeps selected more frequently coarse substrate (e.g. boulders) but it appeared also over sandy substrate, whereas A. multispinis and G. brasiliensis selected preferably boulders. The range of 0.65-0.85 m³/s was found as the optimum to meet the needs of the three fish species. Our results agree with the necessary objective information to perform grounded management actions in the frame of a management program aiming at ecosystem conservation. Thereby it can be considered a successful pilot study in environmental flow assessment in an Atlantic Forest stream of Brazil.