Legacy and emerging antifouling biocide residues in a tropical estuarine system (Vitória state, SE, Brazil)

Abstract Aim: There are few studies dealing with the biogeochemical processes occurring in small estuaries receiving high sewage loading in tropical regions. The aim of this investigation was to characterize the biogeochemical behavior of nutrients in superficial waters collected at the Iguaçu estuarine system, during specific conditions (neap tide), located at the inner sector of a heavily eutrophicated embayment (Guanabara Bay, SE Brazil). Methods Physical and chemical variables were measured in situ (pH, temperature, conductivity, salinity, total dissolved solids, transparency, dissolved oxygen), whereas suspended particulate matter, chlorophyll a, phaepigments and nutrients (carbon, nitrogen and phosphorus forms) were measured in laboratory across the mesohaline estuarine gradient. Results The Iguaçu River mouth is in a high stage of eutrophication, considering nutrient concentrations, chlorophyll a and transparency of water column. Results indicate a transition from heterotrophic conditions to autotrophic conditions, since the nutrients concentrations showed a decreasing pattern along the saline gradient, while the chlorophyll an increased over the transects. The pH values and chlorophyll : phaeopigments ratios are significantly related to the amount and quality of organic matter contents, especially at transects under strong marine influence. More than 95% of the dissolved and total nitrogen concentrations are represented by NH4+ contributions, which are related to the ammonification of organic matter contents in this region, indicating the existence of untreated sewage loads in this area. Conclusion In this study, the Iguaçu River seemed to contribute with high inputs of nutrients that support important phytoplankton production at the inner regions of the bay related to the CO2 sink and autotrophic metabolism, showing the importance of verifying the biogeochemical behaviors of nutrients in estuarine areas, even in small scale.

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Phytoplankton community structure is governed by salinity gradient and nutrient composition in the tropical estuarine system

Continental Shelf Research ◽

10.1016/j.csr.2021.104643 ◽

2022 ◽

pp. 104643

Author(s):

M.D. Bharathi ◽

V. Venkataramana ◽

V.V.S.S. Sarma

Keyword(s):

Community Structure ◽

Phytoplankton Community ◽

Salinity Gradient ◽

Nutrient Composition ◽

Estuarine System ◽

Phytoplankton Community Structure ◽

Tropical Estuarine

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Nitrogen fixation and carbon uptake in a tropical estuarine system of Goa, western India

Journal of Sea Research ◽

10.1016/j.seares.2018.09.018 ◽

2019 ◽

Vol 144 ◽

pp. 16-21

Author(s):

Ayaz Ahmed ◽

Hema Naik ◽

Sarvesh S. Adel ◽

Pratirupa Bardhan ◽

Mangesh Gauns ◽

...

Keyword(s):

Nitrogen Fixation ◽

Carbon Uptake ◽

Western India ◽

Estuarine System ◽

Tropical Estuarine

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Geochemistry of intertidal sediment pore waters from the industrialized Santos-Cubatão Estuarine System, SE Brazil

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652012005000021 ◽

2012 ◽

Vol 84 (2) ◽

pp. 427-442 ◽

Cited By ~ 6

Author(s):

Winston F.O. Gonçalves ◽

Wanilson Luiz-Silva ◽

Wilson Machado ◽

Erico C. Nizoli ◽

Ricardo E. Santelli

Keyword(s):

Surface Water ◽

Pore Water ◽

Surface Waters ◽

Water Concentration ◽

Point Sources ◽

Intertidal Sediment ◽

Estuarine System ◽

Pore Waters ◽

Geochemical Composition ◽

Se Brazil

The geochemical composition of sediment pore water was investigated in comparison with the composition of sediment particles and surface water in an estuary within one of the most industrialized areas in Latin America (Santos-Cubatão estuarine system, SE Brazil). Pore and surface waters presented anomalously high levels of F-, NH4+, Fe, Mn and P due to two industrial point sources. In the summer, when SO4(2-)/Cl- ratios suggested an enhanced sulfate reduction, the higher dissolved levels observed in pore waters for some metals (e.g., Cu and Ni) were attributed to reductive dissolution of oxidized phases. Results evidenced that the risks of surface water concentration increase due to diffusion or advection from pore water are probably dependent on coupled influences of tidal pumping and groundwater inputs.

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The Mangrove Periwinkle Littoraria angulifera (Mollusca: Littorinidae) in the Urabá Gulf (Colombian Caribbean): Finding Ways in an Urbanizing Coast?

Frontiers in Marine Science ◽

10.3389/fmars.2021.641567 ◽

2021 ◽

Vol 8 ◽

Author(s):

Jhostin Ramos ◽

Marco Boto ◽

Juan Felipe Blanco-Libreros ◽

José M. Riascos

Keyword(s):

Urban Areas ◽

Size Structure ◽

Woody Debris ◽

Land Use Changes ◽

Estuarine System ◽

Mangrove Forests ◽

Demographic Traits ◽

Tropical Estuarine ◽

Anthropogenic Substrates ◽

Different Populations

Periwinkles (Littorinidae: genus Littoraria) are one of the very few molluscan clades showing an adaptive radiation closely associated to the mangrove habitat. However, pervasive land use changes associated to urbanization is prompting mangrove loss or degradation, with unknown consequences for mangrove-associated fauna. In the southern Colombian Caribbean, mangrove ecosystems have been encroached by human settlements and different populations of Littoraria angulifera (Lamarck, 1822) now inhabit anthropogenic intertidal substrates in urban areas, but the demographic traits of populations thriving in these novel environments are unknown. We studied the relative abundance and size structure of L. angulifera in remnant mangrove patches, woody debris and anthropogenic substrates (boulder seawalls and built structures) in 13 locations throughout the Urabá Gulf, a human-transformed tropical estuarine system. The abundance of L. angulifera was up to two orders of magnitude higher in anthropogenic than in quasi-natural or natural substrates. Snails also displayed a significant preference for wave protected positions in boulder seawalls and built structures exposed to heavy wave action, which was not previously reported in mangrove forests. Moreover, snail populations in anthropogenic substrate were consistently dominated by individuals of small sizes in comparison with mangroves or driftwood. We argue that the anthropogenic disturbances caused by the expansion of Turbo city during nearly one century in a coast formerly dominated by mangrove forests are providing novel and expanding habitats, whose quality might be good enough as to support high-density populations of L. angulifera. However, we hypothesize that shifted thermal regimes in hard and novel wave-exposed urban seascapes might also be prompting behavioral adjustments and the selection of smaller size ranges than those observed in mangrove forests.

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