Fish assemblage structure in a port region of the Amazonic coast

Abstract

The fish assemblage structure in a port area in São Marcos Bay (Amazonic coast) was evaluated based on the spatial and temporal distributions to identify potential changes in response to anthropic pressure increases associated with industrial and port activities in region. The samples were taken between March 2011 and November 2015. The ichthyofauna was represented by a total of 56 species, distributed in 15 orders and 29 families. Captures were dominated by Genyatremus luteus (Bloch, 1790), but Sciades proops (Valenciennes, 1840) was the most representative in terms of biomass. Seasonal distributions of fish assemblage did not reveal significant differences. However, there was a difference between catch sites, abundance, biomass and Shannon diversity index was higher in the Site 1 and evenness in Site 4. The analysis NMDS and the test ANOSIM between months and between sampling sites, based on species composition, revealed a seasonal differentiation associated with the rainy and drought months, as well as spatial differentiation, in function of a depth gradient and hydrodynamics, resulting from greater distance from mangrove areas. The low diversity recorded may be a reflection of port activities that historically occur in the area investigated. However, there was still a maintenance of regional diversity throughout the period under analysis. Thus, temporal and spatial scales become important for the detection and understanding of fish biodiversity in an Amazonian estuary, reflecting, the importance of mangroves for the maintenance of the ichthyofaunistic diversity in the area. In this context, the present study may subsidize possible conservation projects in the area since information of this nature is almost non-existent for estuarine fish from the Maranhão Amazon.

Stable isotope evidence for dietary diversification in the pre-Columbian Amazon

“…Lying in the transition between Amazon and Northeastern vegetation 52 , the region has a tropical climate with dry (January to June) and rainy (June to December) seasons, with species from the Amazon forest, caatinga, and cerrado biomes, and extensive restinga and mangrove ecosystems along the coast which are important nurseries for aquatic organisms 53 . The coastal environment is highly dynamic and shows relatively high biological productivity and biomass with limited seasonal variability due to the combination of semidiurnal macro-tidal regimes, mangrove vegetation, and freshwater input (notably in São Marcos Bay) 35 . This has favoured fish and shellfish exploitation by groups on the island since at least the Middle and Late Holocene 54 , during the spread of ceramic artefacts associated with the Mina tradition.…”

“…The δ 13 C and δ 15 N values for fish (n = 11) were statistically distinguishable from terrestrial mammals (n = 23, p < 0.01, F = 617.8 for δ 13 C, p < 0.01, F = 44.52 for δ 15 N, One-way Anova) and ranged from − 12.3 to − 8.9 ‰ and from + 7.5 to + 12.5 ‰, respectively. Some of the remains could be identified as catfish (Ariidae), which is a common taxa in the region 35 . The high δ 13 C values observed are typical of fish from marine ecosystems 36 and are also comparable with other marine taxa from the southwestern Atlantic Ocean 30,37 .…”

Caracterização Da Pesca Com Rede Serreira No Município De Raposa-Ma = Characterization of Fishing With Drift Gillnet in the Municipality of Raposa-Ma

“…A família Scombridae, que é constituída por peixes que habitam mares tropicais e temperados, foi registrada como mais representativa e importante em trabalhos realizados na Costa Norte do Brasil (Lima, Fonteles-Filho, and Chellappa 2007;Silva et al 2018;Silva Júnior et al 2013;Soares, Castro, and Silva-Júnior 2006; M. R. J. Sousa, Castro, and Silva 2011)"ISSN":"2526-7639","abstract":"Lima JTAX, Fonteles-Filho AA, & Chellappa S (2007. Entretanto, no presente estudo, 21,6% da captura pertenciam à família Sciaenidae, que é constituída por peixes costeiros, comumente encontrados em águas rasas da plataforma continental (Figueiredo & Menezes, 2000).…”

“…Como observado na análise de constância de captura, a maior parte dos pescados desembarcados não apresenta ocorrência ao longo de todos os meses do ano. Esse quadro pode ser justificado pelo fato da região onde ocorre a atividade ser considerada área de passagem/migração de várias espécies (Silva et al 2018;da Silva Castro et al 2019; M. R. de J. Sousa, de Castro, and Silva 2011)especialmente os ambientes estuarinos, impõe a necessidade de implementar metodologias para avaliação dos índices de degradação dessas áreas. Estudos em níveis de comunidade têm se mostrado efi cientes em análises ambientais, já que refl etem respostas em conjuntos de espécies, demonstrando possíveis alterações em cadeias alimentares, relações inter e intra-específi cas que infl uenciam diretamente na fauna existente na área.…”

The southernmost record and an update of the geographical range of the Atlantic chupare, Styracura schmardae (Chondrichthyes: Myliobatiformes)

“…The specimen was morphologically identified based on the following diagnostic characters proposed by Stehmann et al (1978), indicated in the original description (Werner, 1904) State; see Figure 1). This area comprises estuaries, other sandy or muddy bottoms, and reef environments located on the coastlines of the Brazilian States of Pará (Barthem, 1985;Camargo & Isaac, 2001;Freitas et al, 2019b;Pinheiro & Frédou, 2004;Rodrigues-Filho et al, 2020;Santo et al, 2005;Silva et al, 2016), Maranhão (Almeida et al, 2011;Aragão et al, 2019;Guimarães-Costa et al, 2019;Lessa, 1986;Martins-Juras et al, 1987;Nunes et al, 2005Nunes et al, , 2011Rocha & Rosa, 2001;Silva et al, 2018), Piauí (Aragão et al, 2019;Guimarães-Costa et al, 2019;Mai et al, 2012;Melo et al, 2016) and…”