Benthic macrofaunal structure and secondary production in tropical estuaries on the Eastern Marine Ecoregion of Brazil

Abstract

Tropical estuaries are highly productive and support diverse benthic assemblages within mangroves and tidal flats habitats. Determining differences and similarities of benthic assemblages within estuarine habitats and between regional ecosystems may provide scientific support for management of those ecosystems. Here we studied three tropical estuaries in the Eastern Marine Ecoregion of Brazil to assess the spatial variability of benthic assemblages from vegetated (mangroves) and unvegetated (tidal flats) habitats. A nested sampling design was used to determine spatial scales of variability in benthic macrofaunal density, biomass and secondary production. Habitat differences in benthic assemblage composition were evident, with mangrove forests being dominated by annelids (Oligochaeta and Capitellidae) whereas peracarid crustaceans were also abundant on tidal flats. Macrofaunal biomass, density and secondary production also differed between habitats and among estuaries. Those differences were related both to the composition of benthic assemblages and to random spatial variability, underscoring the importance of hierarchical sampling in estuarine ecological studies. Given variable levels of human impacts and predicted climate change effects on tropical estuarine assemblages in Eastern Brazil, our data support the use of benthic secondary production to address long-term changes and improved management of estuaries in Eastern Brazil.

Land use impacts on benthic bioturbation potential and carbon burial in Brazilian mangrove ecosystems

“…Two estuaries represented pristine conditions (Piraquê-Açu [PA] and Benevente [BE]) and one is a eutrophic metropolitan estuary (Vitória Bay [VB]; Fig. 1) (Bissoli and Bernardino 2018;Hadlich et al 2018). The Benevente and Piraquê-Açu mangrove forests were sampled near the seaward region, whereas the Vitória Bay mangrove forest was sampled in the inner estuary as the seaward forests had been lost due to urbanization.…”

“…Benthic macrofauna (> 500 μm) were sampled (N = 120 samples) in each estuary during a campaign from August 2014 to September 2014, with macrofaunal abundance and total biomass (ash-free dry weight [AFDW]) estimated as in Bissoli and Bernardino (2018). In summary, benthic macrofaunal assemblages were sampled using a nested spatial design on vegetated (mangrove forests) and unvegetated (tidal flats) habitats in the mesohaline sectors (salinity between 18 and 5) of the three estuaries (ICMBIO sampling permit N 24700-1).…”

Peer Review #1 of "Chronic trace metals effects of mine tailings on estuarine assemblages revealed by environmental DNA (v0.1)"

“…The Rio Doce estuary (19°38′ to 19°45′S, 39°45′ to 39°55′W; Figure 1), is located on the Eastern Marine Ecoregion of Brazil that has two well-defined seasons, dry winter (April to September) and wet summer (October to March), with an average monthly rainfall of 145 mm and temperatures of 24 to 26 °C (Bernardino et al, 2018;Bissoli and Bernardino, 2018). The Rio Doce estuary has been altered by historical human occupation, but ecosystem health of the estuary was poorly known before the Samarco disaster that occurred in November 2015 (Bernardino et al, 2016;Gomes et al, 2017).…”

Evaluating the boundaries of marine biogeographic regions of the Southwestern Atlantic using halacarid mites (Halacaridae), meiobenthic organisms with a low dispersal potential

“…This division of coastal and shelf areas of the Brazilian coast greatly influenced subsequent studies on marine conservation and biogeography (e.g. Mantelatto et al, 2018, Huguenin et al, 2018, Bissoli & Bernardino, 2018.…”