Distribution and annual variation of Trichodesmium thiebautii Gomont ex Gomont (Oscillatoriales - Cyanophyta) in tropical waters of Northeastern Brazil (Western Atlantic)

Abstract

Studies about Trichodesmium thiebautii Gomont ex Gomont and the relations of its spatial and temporal distribution with the hydrological conditions were developed in the continental shelf of the coast of Pernambuco, Brazil. The samples were collected during the rainy (July 2005) and the dry (November 2006) seasons, on the surface and bottom, at six sampling points, distributed along two profiles perpendicular to the coast of Gaibú and Serrambi beaches. The collection points were approximately 5, 10 and 20 miles from the coast, corresponding to the isobaths of 10, 20 and 30 meters. T. thiebautii occurred in bothl periods, with less density in areas closer to the coast and higher further from the coast. The correlation of T. thiebautii was positive with pH and dissolved oxygen during the rainy season and with salinity and dissolved oxygen during the dry season. No correlation was observed with the nutrient salts.

Microplankton Community Composition Associated With Toxic Trichodesmium Aggregations in the Southwest Atlantic Ocean

“…The association between the harpacticoid Macrosetella gracilis and Trichodesmium colonies are thought to benefit the zooplankton, since trichomes were reported containing eggs and larvae attached, and served as food and substrate (Björnberg, 1965;O'Neil et al, 1996). Understanding the microbial community structure surrounding Trichodesmium aggregations is therefore an important key to understand its ecology and species interactions, especially in understudied regions such as the South Atlantic Ocean where the genus is often reported (Gianesella-Galvão, 1995;Rörig et al, 1998;Carvalho et al, 2008;Monteiro et al, 2010Monteiro et al, , 2012. Recent works from our group have identified colonies in the Southwest Atlantic Ocean associated with iron-rich dust particles (Bif and Yunes, 2017) and producing toxins (Detoni et al, 2016a); however, the association of these potentially toxic aggregations with other microbial communities was never assessed.…”

Ocorrência e coexistência de cianobactérias diazotróficas no Canal de São Sebastião-SP com o aumento da pluviosidade

“…Florações de Trichodesmium spp. foram registradas nas regiões Norte (Naithirithi et al, 2005), Nordeste (Koening e Macedo, 1999;Koening et al, 2009;Proença et al, 2009;Monteiro et al, 2010;Monteiro et al, 2012),…”