Fish assemblage structure on sandy beaches with different anthropogenic influences and proximity of spawning grounds

Abstract

Fish assemblages in an insular (preserved) and a continental (disturbed) sandy beach were compared to assess any changes that could be attributed to anthropogenic influences and/or the proximity of the fish spawning grounds. We expected that the closer geographical position to the spawning grounds and the small amount of anthropogenic disturbance on the insular beach would be likely to provide more suitable conditions for early fish development compared with the continental beach. A total of 192 samples (96 in each beach) were taken, yielding 68 fish species, mostly young‐of‐the‐year. Fish assemblage structure differed significantly between the two beaches. Moreover, the insular beach had higher number of species, number of individuals and biomass compared with the continental beach. The commercially important Clupeiformes Harengula clupeola, Anchoa tricolor and Anchoa januaria, Perciformes Micropogonias furnieri and Mugiliformes Mugil liza were typical species on the insular beach, partitioning the seasonal use of the beach. On the other hand, a few abundant non‐commercial species, mainly the Atheriniformes Atherinella brasiliensis and the Perciformes Eucinostomus argenteus and Diapterus rhombeus, occurred all year round at the continental beach. The high fish richness and abundance and the more conspicuous species turnover across seasons on the insular beach are probable indications of more complex and dynamic organization of the communities favored by better geographical position and less anthropogenic disturbance in the area.

Juvenile fish use of the shallow zone of beaches of the Cananéia-Iguape coastal system, southeastern Brazil

“…Although juveniles of Gerreidae are among the most abundant groups in the coastal ecosystems, including those caught in beach seine samples (ARAÚJO; SANTOS, 1999;FÉLIX et al, 2007a;2007b;SOUZA-CONCEIÇÃO et al, 2013;PEREIRA et al, 2014), they were only sampled in the larval stage in the study area. Araújo and Santos (1999) found that juvenile gerreids prefer less-turbid regions, with mud and moderate organic matter substrates, while GODEFROID et al (1999; found 98% of gerreids in the larval stage, corroborating the findings of this study.…”

“…Unfortunately, this period is the one with the greatest tourism impact. PEREIRA et al (2014) indicated that less anthropogenic disturbance on the beach results in greater fish richness and abundance. It is also important to note that many of the species studied are commercially important, emphasizing the necessity of coastal habitat preservation for better fishery management.…”

Gonadal development and fecundity of the smooth weakfish Cynoscion leiarchus (Teleostei: Perciformes: Sciaenidae) in a tropical Brazilian bay

“…Our records on postovulatory follicles in this study suggest that the Sepetiba Bay might be used as reproductive grounds by at least part of the population of C. leiarchus. Furthermore, the occurrence of young-of-the-year of this species in great numbers at the nearshore waters of the bay was reported by Pessanha & aRaújo (2003) and PeReiRa et al (2015). However, more studies are necessary to confirm this hypothesis.…”

Life-history traits of Chloroscombrus chrysurus (Actinopterygii: Perciformes: Carangidae) in tropical waters of the Atlantic Ocean

“…For many tropical species, a strong relation between rainfall and growth has been previously reported (Bwanika et al 2007, Ong et al 2015, Sousa et al 2015, Efitre et al 2016. This relation results, mainly, from changes caused by rainfall in water physicochemical parameters (i.e., turbidity, salinity, and light penetration) and productivity levels (Barletta et al 2005, Pereira et al 2015, as these changes may provide better feeding condition for fish (Bergenius et al 2005).…”