Determining the Influence of Urbanization on Mangrove Zones of Northeastern Brazil: Characterization of Ceará State Coastal Zone Organic Matter Inputs

Mounier, Stéphane; Marins, Rozane Valente; Lacerda, Luiz Drude de

doi:10.1007/978-3-319-73016-5_10

Cited by 8 publications

(10 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lacerda et al [ 8 ] associated higher Diss-Hg concentrations and fluxes in the dry season with extremely low rainfall and the operation of dams, reducing sediment transport and augmenting the residence time of the fluvial water mass in the estuary, increasing the reactivity of Hg, which includes the most bioavailable organic Hg forms, favoring the incorporation by the biota and biomagnification in the food chain. Extensive and expanding mangroves favor this by producing large amounts of dissolved organic matter [ 49 ] with a large Hg complexing capacity, as observed previously in the Jaguaribe estuary and in other mangrove-dominated semiarid estuaries [ 6 , 40 , 50 ].…”

Section: Resultsmentioning

confidence: 93%

Mercury Sources, Emissions, Distribution and Bioavailability along an Estuarine Gradient under Semiarid Conditions in Northeast Brazil

Moura

Lacerda

2022

IJERPH

View full text Add to dashboard Cite

In the semiarid coast of northeast Brazil, climate change and changes in land use in drainage basins affect river hydrodynamics and hydrochemistry, modifying the estuarine environment and its biogeochemistry and increasing the mobilization of mercury (Hg). This is particularly relevant to the largest semiarid-encroached basin of the region, the Jaguaribe River. Major Hg sources to the Jaguaribe estuary are solid waste disposal, sewage and shrimp farming, the latter emitting effluents directly into the estuary. Total annual emission reaches 300 kg. In that estuary, the distribution of Hg in sediment and suspended particulate matter decreases seaward, whereas dissolved Hg concentrations increase sharply seaward, suggesting higher mobilization at the marine-influenced, mangrove-dominated portion of the estuary, mostly in the dry season. Concentrations of Hg in rooted macrophytes respond to Hg concentrations in sediment, being higher in the fluvial endmember of the estuary, whereas in floating aquatic macrophytes, Hg concentrations followed dissolved Hg concentrations in water and were also higher in the dry season. Animals (fish and crustaceans) also showed higher concentrations and bioaccumulation in the marine-influenced portion of the estuary. The variability of Hg concentrations in plants and sediments agrees with continental sources of Hg. However, Hg fractionation in water and contents in the animals respond to higher Hg availability in the marine-dominated end of the estuary. The results suggest that the impact of anthropogenic sources on Hg bioavailability is modulated by regional and global environmental changes and results from a conjunction of biological, ecological and hydrological characteristics. Finally, increasing aridity due to global warming, observed in northeast Brazil, as well as in other semiarid littorals worldwide, in addition to increased water overuse, augment Hg bioavailability and environmental risk and exposure of the local biota and the tradition of human populations exploiting the estuary’s biological resources.

show abstract

Section: Resultsmentioning

confidence: 93%

Mercury Sources, Emissions, Distribution and Bioavailability along an Estuarine Gradient under Semiarid Conditions in Northeast Brazil

Moura

Lacerda

2022

IJERPH

View full text Add to dashboard Cite

show abstract

“…This is clearly shown by the sharp increase in the Ia/Ic ratio from station 4 to 1 (Figure 1B). This suggests a higher production of young organic matter at the end of the fluvial end-member of the estuary, where mangroves abound, and its eventual flushing by tidal waters to the marine-influenced area (Mounier et al, 2018). The "younger" nature of the organic matter produced increases the metal complexing capacity of the DOC, as shown by the Hg speciation in mangrove pore waters (Figure 1A).…”

Section: Increasing the Production Of Young Organic Matter By Mangrov...mentioning

confidence: 98%

“…(A) Hg speciation in pore waters in a mangrove-dominated area showing increasing organic matter-Hg complex production, adapted from Mounier et al (2001) and Marins et al (1997). (B) Ia/Ic ratio matrices according to Coble (1996) and adapted from Mounier et al (2018). Moura and Lacerda (2018).…”

Section: Increasing the Production Of Young Organic Matter By Mangrov...mentioning

confidence: 99%

An Arctic Paradox: Response of Fluvial Hg Inputs and Bioavailability to Global Climate Change in an Extreme Coastal Environment

2020

Self Cite

View full text Add to dashboard Cite

Global climate change interacts with regional alterations of land use in coastal basins and promotes rapid changes in the biogeochemistry of the coastal zone. These changes are generally stronger in extreme environments such as polar and semiarid regions. In these environments, biogeochemical changes result in a greater transfer of pollutants from the continent to the sea with resultant contamination of marine biota. In semiarid regions, there is a reduction in continental runoff and bulk pollutant transport, but paradoxically, there is an increase in the export of more bioavailable pollutants, resulting in higher contamination of the marine biota. In tropical latitudes, mangroves dominate coastal and estuarine environments and respond rapidly to environmental changes. The semiarid coast of Brazil is strongly affected by climate change. A major environmental response is altered hydrodynamics, generally involving decreasing continental runoff to the ocean, caused by reducing annual rainfall and damming of rivers. Also, strengthening of marine forcing due to heat accumulation in the South Atlantic Ocean and rising sea level pushes shelf and coastal waters into estuaries. Basin and oceanic processes undergo positive feedback, which causes an increase in the water residence time in estuaries, an extension of saline intrusion landward, accumulation of sediments in the inner reaches of estuaries, and the expansion of mangrove areas, particularly over the past 50 years. Expansion of mangroves means an expansion of sulfate reduction metabolism, which produces large amounts of dissolved organic carbon, characterized by a high capacity for forming organo-metallic complexes of high environmental significance. Dissolved and particulate Hg concentrations and fluxes are greater from the river to the estuary than from the estuary to the sea, producing an accumulation of particulate Hg in the estuary. Particulate Hg export may occur only during extremely rainy periods, and Hg is eventually deposited is shelf sediments, displaying low bioavailability. Export of dissolved, reactive, and DOC-bound Hg is practically nonexistent during rainy periods but increases by two orders of magnitude during the progressively longer dry periods. These highly bioavailable forms of Hg will enter food webs in the lower estuary and coastal areas, increasing contamination of the biota and human exposure to Hg.

show abstract

“…In marine tropical oligotrophic ecosystems, absorption and fluorescence properties of CDOM remain scarce compared to lakes or coastal areas (e.g., Zhang et al, 2009Zhang et al, , 2013. Weathering of soils is a source of fluorescent CDOM in rivers and coastal ecosytems (Mounier et al, 2018). In shallow coastal tropical ecosystems, CDOM absorption is typically low due to strong solar photobleaching (Nelson et al, 1998;Swan et al, 2012) that significantly influences the biogeochemical cycles of DOM through photodegradation (Osburn et al, 2012;Hu et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Impact of Contrasted Weather Conditions on CDOM Absorption/Fluorescence and Biogeochemistry in the Eastern Lagoon of New Caledonia

et al. 2020

View full text Add to dashboard Cite

New Caledonia (Southwest Pacific), like all tropical Pacific Island countries, is impacted by weather events, climate change, and local anthropogenic forcing. Strong erosion of particles and dissolved organic matter (DOM) from ultramafic rocks, associated with trace metals dissemination (i.e., nickel, manganese and cobalt), potentially affects lagoon waters and coral reefs surrounding the main island. The CALIOPE (CALedonian Inherent Optical PropErties) cruises were performed along the Eastern Lagoon of New Caledonia (ELNC) (400 km, 13 transects from Bay to open ocean, 51 stations) during contrasted meteorological conditions: a dry period (October 2011), a windy situation (March 2014), and a strong rainy event (March 2016). CDOM absorption and fluorescence (FDOM), particulate absorption, backscattering, suspended particulate matter (SPM), total chlorophyll a (TChla), nutrients (NOx), pigment and phytoplankton composition were measured. Among the four CDOM fluorophores, the humic-like component (λ Ex /λ Em : 235/460 nm), assimilated to a photoproduct of terrestrial organic matter, had relatively low fluorescence compared to protein-like fluorophores. As CDOM absorption, particulate absorption, backscattering, SPM, total chlorophyll a (TChla) and nutrient (NOx) concentrations, this humic-like material generally showed the highest values during rainfall events, the latter inducing an increase in riverine terrigeneous inputs and change toward higher phytoplankton size classes. The tyrosine 1-like (λ Ex /λ Em : 220, 275/304 nm) and tryptophan-like fluorophores (λ Ex /λ Em : 230, 300/352 nm) were strongly influenced by wind displaying a 7-fold and 3-fold increase, respectively in windy situation compared to calm conditions. These increases could be related to enhancements of autochthonous biological activities (highest mean concentrations of Synechococcus spp., phycoerythrin, pico-and nano-eukaryotes, heterotrophic bacteria and nanoplankton observed in wind condition) through the inputs of organic and mineral materials issued from the wind-induced sediment resuspension, atmospheric deposition and water mass mixing. By contrast, the tyrosine 2-like fluorophore (λ Ex /λ Em : 245, 275/304 nm) substantially increased during rain events and presented the lowest values

show abstract

Determining the Influence of Urbanization on Mangrove Zones of Northeastern Brazil: Characterization of Ceará State Coastal Zone Organic Matter Inputs

Cited by 8 publications

References 20 publications

Mercury Sources, Emissions, Distribution and Bioavailability along an Estuarine Gradient under Semiarid Conditions in Northeast Brazil

Mercury Sources, Emissions, Distribution and Bioavailability along an Estuarine Gradient under Semiarid Conditions in Northeast Brazil

An Arctic Paradox: Response of Fluvial Hg Inputs and Bioavailability to Global Climate Change in an Extreme Coastal Environment

Impact of Contrasted Weather Conditions on CDOM Absorption/Fluorescence and Biogeochemistry in the Eastern Lagoon of New Caledonia

Contact Info

Product

Resources

About