Dinâmica populacional do camarão “barba-ruça” Artemesia longinaris Spence Bate, 1888 (Crustacea, Decapoda, Penaeidae) em dois períodos distintos (intervalo de 20 anos) no litoral sudeste do Brasil
Carregando...
Arquivos
Data
2017-02-21
Autores
Bernardo, Camila Hipolito
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Artemesia longinaris Spence Bate, 1888 é considerada uma espécie monotípica endêmica das zonas costeiras do Atlântico Sul Ocidental. Vem sendo recentemente explorada comercialmente devido à queda nos estoques dos camarões de maior interesse comercial. Esse estudo visou comparar a distribuição espaço temporal da A. longinaris em um intervalo de 20 anos (novembro/1988 a outubro/ 1989 e novembro/2008 a outubro/2009) na Enseada da Fortaleza, em Ubatuba, São Paulo. Em ambos os períodos os indivíduos e fatores ambientais (temperatura e salinidade da água de fundo e superfície, sedimento) foram coletados em 7 transectos. Uma RDA foi feita para relacionar os fatores ambientais com a abundância dos indivíduos. O teste de Mann-Whitney foi realizado para comparar fatores ambientais e abundância dos indivíduos entre os dois períodos. Foram coletados de 3088 espécimes no primeiro período e 1252 no segundo, não havendo diferença significativa entre os períodos (p>0,05). Apesar de não apontada estatisticamente houve uma redução do número de indivíduos entre os períodos. Segundo resultados da RDA, uma forte correlação negativa entre a abundância e a classe C (silte+argila) do sedimento, mostrou que o aumento desse tipo de sedimento no segundo período, pode ter contribuído para a redução do número de indivíduos. Aliado a isso, houve menores reflexos da massa ACAS nesta enseada, ocasionando uma redução do número de indivíduos. Esta massa de água reduz as temperaturas de fundo, sendo que a espécie em estudo possui uma história evolutiva vinculada a águas oceânicas frias. Além das condições do sedimento e reflexos da ACAS, a intensa atividade de pesca de arrasto de camarão na região de Ubatuba pode ter contribuído para a redução do número de indivíduos, pois como já é sabido, a pesca de arrasto é considerada uma atividade predatória e causa desestabilização da comunidade bentônica. Em ambos os períodos a espécie se concentrou nos transectos mais profundos (I, VI e VII) onde as características ambientais eram mais favoráveis (temperatura baixa e salinidade alta). O conhecimento sobre a distribuição ecológica desta espécie é importante para que haja um manejo sustentável dos estoques pesqueiros. A Enseada da Fortaleza é desde 8 de outubro de 2008, uma Área de Proteção Ambiental (APA), que visa a preservação dessa biodiversidade. Estudos futuros poderão mostrar se o estoque do camarão A. longinaris está se recuperando devidos às medidas de proteção estabelecidas na região.
Artemesia longinaris Spence Bate, 1888 is considered a monotypic species endemic to the coastal areas of the Western South Atlantic. It has recently been commercially exploited due to the fall in stocks of shrimps of major commercial interest. This study aimed at comparing the temporal distribution of A. longinaris over a period of 20 years (November / 1988 to October / 1989 and November / 2008 to October / 2009) at Fortaleza Bay in Ubatuba, São Paulo. In both periods the individuals and environmental factors (temperature and salinity of the bottom and surface water, sediment) were collected in 7 transects. An RDA was made to relate environmental factors to the abundance of individuals. The Mann-Whitney test was performed to compare environmental factors and abundance of individuals between the two periods. There were collected 3088 specimens in the first period and 1252 specimens in the second, with no significant difference between the periods (p> 0.05). Although not statistically indicated, there was a reduction in the number of individuals between the periods. According to the results of the GDR, a strong negative correlation between the abundance and class C (silt + clay) of the sediment showed that the increase of this type of sediment in the second period may have contributed to the reduction of the number of individuals. Along with this, there were smaller reflexes of the ACAS mass in this cove, causing a reduction in the number of individuals. This body of water reduces background temperatures, and the species under study has an evolutionary history linked to cold oceanic waters. In addition to the ACAS sediment and reflex conditions, the intense shrimp trawling activity in the Ubatuba region may have contributed to a reduction in the number of individuals, since, as is well known, trawling is considered a predatory activity and causes destabilization of the benthic community. In both periods the species was concentrated in the deeper transects (I, VI and VII) where the environmental characteristics were more favorable (low temperature and high salinity). Knowledge about the ecological distribution of this species is important for sustainable management of fish stocks. The Fortress Cove is since October 8, 2008, an Environmental Protection Area (APA), which aims to preserve this biodiversity. Future studies could show whether the shrimp A. longinaris stock is recovering due to the protection measures established in the region.
Artemesia longinaris Spence Bate, 1888 is considered a monotypic species endemic to the coastal areas of the Western South Atlantic. It has recently been commercially exploited due to the fall in stocks of shrimps of major commercial interest. This study aimed at comparing the temporal distribution of A. longinaris over a period of 20 years (November / 1988 to October / 1989 and November / 2008 to October / 2009) at Fortaleza Bay in Ubatuba, São Paulo. In both periods the individuals and environmental factors (temperature and salinity of the bottom and surface water, sediment) were collected in 7 transects. An RDA was made to relate environmental factors to the abundance of individuals. The Mann-Whitney test was performed to compare environmental factors and abundance of individuals between the two periods. There were collected 3088 specimens in the first period and 1252 specimens in the second, with no significant difference between the periods (p> 0.05). Although not statistically indicated, there was a reduction in the number of individuals between the periods. According to the results of the GDR, a strong negative correlation between the abundance and class C (silt + clay) of the sediment showed that the increase of this type of sediment in the second period may have contributed to the reduction of the number of individuals. Along with this, there were smaller reflexes of the ACAS mass in this cove, causing a reduction in the number of individuals. This body of water reduces background temperatures, and the species under study has an evolutionary history linked to cold oceanic waters. In addition to the ACAS sediment and reflex conditions, the intense shrimp trawling activity in the Ubatuba region may have contributed to a reduction in the number of individuals, since, as is well known, trawling is considered a predatory activity and causes destabilization of the benthic community. In both periods the species was concentrated in the deeper transects (I, VI and VII) where the environmental characteristics were more favorable (low temperature and high salinity). Knowledge about the ecological distribution of this species is important for sustainable management of fish stocks. The Fortress Cove is since October 8, 2008, an Environmental Protection Area (APA), which aims to preserve this biodiversity. Future studies could show whether the shrimp A. longinaris stock is recovering due to the protection measures established in the region.
Descrição
Palavras-chave
pesca de arrasto, APA, variáveis ambientais