Temporal variability of the estuarine macrofauna of the Patos Lagoon, Brazil

Rosa, L.C. & Bemvenuti, C.E. 2007. Would be the benthic macrofauna of the soft-bottoms influenced by increase in the habitat structural complexity? The Patos Lagoon estuary as a case study. Braz. J. Aquat. Sci. Technol. 11(1):51-56. ISSN 1808-7035. The main objective of this study was to evaluate the influence of vegetated beds on macrofauna community structure of the estuarine soft bottoms of the Patos Lagoon, southern Brazil. Comparative analyses were made by faunal samples collected inside and outside in two kinds of vegetated beds: a sea grass meadows during the summer period and, an algal mats at winter one. The presence of theses vegetated beds had essentially favoring highest densities of epifaunal organisms by increase of substratum for fixation and feeding, which could to result at decrease of evenness and, consequently, of the diversity of macrofauna inside these beds such as registered at summer survey. Differences in the both evenness and diversity at winter survey as well in the composition and number of species at both times were not observed among habitats. These results indicate that the increase at structural complexity of habitat promoted by presence of vegetated beds not necessarily favoring the increase of the macrofauna diversity of the estuarine region of the Patos Lagoon.

Section: Discussionunclassified

Seria a macrofauna bentônica de fundos não consolidados influenciada pelo aumento na complexidade estrutural do habitat? o caso do estuário da Lagoa dos Patos

Rosa

Bemvenuti

2008

“…Devido às condições climáticas locais, o período de cultivo do camarão marinho fica restrito aos meses de verão (Freitas, 2006;Poersch et al, 2006), onde além de temperaturas mais elevadas, a baixa pluviosidade favorece maior salinização da água estuarina local devido ao aporte da água marinha (Poersch et al, 2006;Rosa & Bemvenuti, 2006). Durante o resto do ano, os viveiros permanecem secos, exceto pelo acúmulo ocasional de água da chuva, o que poderia favorecer a ocorrência de organismos límnicos como Chironomidae, os quais foram observados apenas no inicio do cultivo (Tab.…”

Section: Discussionunclassified

“…A comunidade da macrofauna estuarina da Lagoa dos Patos é caracterizada por baixa riqueza de espécies (Bemvenuti, 1997), sendo os planos de águas rasas (i.e., < 1 m) dominados por organismos infaunais como o tanaidáceo K. schubartii e os poliquetas L. acuta, N. fluviatilis e H. similis (Bemvenuti, 1997;Rosa, 2003;Rosa & Bemvenuti, 2006). Na região estuarina, essa comunidade apresenta marcada sazonalidade nos padrões de abundância, onde elevadas densidades registradas nas áreas rasas são resultantes do recrutamento de novos indivíduos após intensa atividade reprodutiva desencadeada pelo aumento da temperatura a partir do final da primavera (Bemvenuti, 1997;Rosa, 2003;Rosa & Bemvenuti, 2006).…”

Section: Discussionunclassified

“…As características de uma laguna "estrangulada" (sensu Kjerfve, 1986) e a baixa amplitude das marés astronômicas (< 0,4m) fazem com que o regime de salinidade da região estuarina seja fortemente influenciado pela ação dos ventos e pela taxa de pluviosidade na bacia de drenagem da Lagoa dos Patos (Kantin, 1983;Costa et al, 1998). Períodos de menor pluviosidade, como observados durante o verão e inicio do outono, associados a ventos do quadrante sul favorecem a intrusão da cunha salina ao interior do estuário resultando em elevados valores de salinidade (Rosa & Bemvenuti, 2006). O estudo foi realizado na fazenda Carcibrás, situada na porção mediana do estuário (Lat.…”

Section: Methodsunclassified

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Macrofauna associada a um cultivo semi-intensivo de Litopenaeus vannamei (Boone, 1931) no estuário da Lagoa dos Patos (sul do Brasil)

Rosa

Freitas²,

Niencheski

2009

2 ) compared to natural environment (6spp. and 40 ind./0.008m 2 ). However, the biomass values at sedimentary basin (mean = 0.06 g/0.008m 2 ) were twice higher than natural environment. At pond, low richness of macrofauna seems related to absence of previous pond preparation; while shrimp predation and/or disturbance resulting in low densities after begin of culture. Otherwise, the presence of a biota relatively abundant and with high biomass at sedimentary basin could contribute to increase effluent quality of the shrimp farm.

“…Estes organismos participam de diversos processos ecológicos, exercendo um papel fundamental no funcionamento do ecossistema como um todo. Recebem nutrientes de origem continental e do plâncton, transmitem energia para os elos superiores da cadeia trófica e contribuem na reciclagem de nutrientes, servindo de alimento a uma grande variedade de espécies, muitas destas de importância econômica (Rosa & Bemvenuti, 2006).…”

Section: Introductionunclassified

Distribuição Espacial da Macrofauna e Sua Interação Com o Sedimento no Parque Aquícola da Enseada da Armação do Itapocoroy/SC

Martins¹,

Almeida²

2014

The distribution of the benthic macrofauna of Itapocoroy Bay, Santa Catarina on Brazilian south coast and the factors that influence it were analyzed within 50 sampling stations determined in a grid, covering the whole extent of this area. Two temporal sampling were done -one in July 2010 and the other in February 2011. Numeric describers of the community were associated with sediment characteristics, depth, salinity and temperature according to multivariate statistical analysis. A total of 4338 organisms were collected With 97 species identified and classified in Polychaeta, Crustacea and Mollusca. Four faunal assemblages were found, and their spatial distribution was mainly related to depth and sediment characteristics. The first assemblage was the deepest and showed higher concentration of fine sediments, dominated by Kinbergonuphis sp. The second assemblage located under the mussel farm showed high heterogeneity of sediments and was dominated by Ampelisca spp. The third assemblage, shallower and with pebble concentration, was dominated by species of the Syllidae family. The fourth assemblage was characterized by well sorted sediment with high percentage of sand, dominated by Prionospio sp. 1. Although this bay is a sheltered site, the distribution of sediments showed that high energetic hydrodynamics processes operate inside it, which is able to avoid the formation of biodeposits. Nevertheless, the constant supply of organic matter and shell fragments accumulation from mussel farms are a source of stress, increasing the abundance and diversity values near the mussel farms.