Pluriannual Watershed Discharges of Hg into a Tropical Semi-Arid Estuary of the Jaguaribe River, NE Brazil

Lacerda, Luiz Drude de; Dias, Francisco; Marins, Rozane Valente; Soares, Talita M.; Godoy, José M.; Godoy, Maria Luiza D.P.

doi:10.5935/0103-5053.20130216

Cited by 14 publications

(29 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lacerda et al (2013) also found lower concentrations of Hg-D in the Jaguaribe River proper (0.3-3.8 ng l −1 ) and noted slightly higher Hg concentrations in the TSS (13.1-129.8 ng g −1 ). The Hg concentrations in bottom sediments varied from 2.9 to 38.3 ng g −1 , with the highest concentrations also measured at the cage stations and the lowest concentrations measured farthest from the farm.…”

Section: Estimated An Emissionmentioning

confidence: 79%

Emission factor and balance of mercury in fish farms in an artificial reservoir in NE Brazil

Oliveira

Lacerda

Peres

et al. 2015

Environ Sci Pollut Res

View full text Add to dashboard Cite

This paper estimated the mercury (Hg), emission factor, and mass balance from caged fish farming in the Castanhão Reservoir, NE Brazil, based on monitoring of a typical farm of Nile tilapia (Oreochromis niloticus). The total Hg input to the farm reached 1.45 gHg ha(-1) year(-1), from which 0.21 gHg ha(-1) year(-1) was exported out as fish biomass, ultimately resulting in an emission factor of 1.24 gHg ha(-1) year(-1) for the reservoir or approximately 8.27 mgHg ton fish(-1) year(-1) produced. Most of the input came from aquafeeds with concentrations varying from 1.4 to 31.1 ng g(-1), depending on the type of aquafeed. The Hg concentrations in fish were very low and varied from 1.0 to 2.9 ng g(-1). These values are two orders of magnitude lower than the legal limit for human consumption. The estimated total annual discharge of Hg from farming into the reservoir is 174 g for 18,000 tons of fish produced and may reach 387 g when the reservoir reaches its total capacity (40,000 tons), which is expected to occur in 2020. The mass balance, considering the deposition and accumulation rates, showed that approximately 40% of the total Hg input accumulate in farm sediments (0.72 g ha(-1) year(-1)), which is approximately 60% of the deposition rate estimated through the sediment traps and suggests that 0.54 gHg ha(-1) year(-1) could eventually be transported out of the farm to the reservoir. Notwithstanding these facts, the total annual input of Hg from fish farming to the Castanhão Reservoir is less than 1.0% of the total input from anthropogenic sources.

show abstract

Section: Estimated An Emissionmentioning

confidence: 79%

Emission factor and balance of mercury in fish farms in an artificial reservoir in NE Brazil

Oliveira

Lacerda

Peres

et al. 2015

Environ Sci Pollut Res

View full text Add to dashboard Cite

show abstract

“…Additionally, increasing temperature may allow mangrove expansion poleward, as suggested by some observations (Jennerjahn et al, ; Saintilan et al, ). However, indirect impacts related to global sea‐level rise—such as increasing frequency of extreme climatic events, strengthening of oceanic forcing upon continental shelves, and, consequently, upon estuaries (Ellison, ; Lacerda et al, ), as well as anomalies of rainfall regimes—seem more significant as sources of environmental pressures on mangroves (Lovelock et al, ). All these stressors interact among themselves and with other anthropogenic drivers, in particular damming and pollutant emissions.…”

Section: Neotropical Mangroves In the Recent Anthropocenementioning

confidence: 99%

Neotropical mangroves: Conservation and sustainable use in a scenario of global climate change

Lacerda

Borges

Ferreira

2019

Aquatic Conservation

View full text Add to dashboard Cite

This study assesses the evolution of major anthropogenic drivers of environmental impacts on Neotropical mangroves, the changes in the environmental pressures acting upon them, and the respective societal responses during the past 40 years. It reviews the impacts of new drivers, in particular those resulting from global climate change and the expansion in aquaculture and the effectiveness of local societal responses aimed at addressing them. Adaptation and mitigation actions are proposed to cope with the impacts and their socio‐economic consequences for Latin America and Caribbean mangroves. By comparing the situation in Latin America and the Caribbean with other regions, the knowledge gaps and priority research needs are discussed to support delineating a preliminary unifying framework to address the environmental pressures affecting mangroves. This scenario necessarily includes the interaction of climate change with human interventions and their effects on ecosystem goods and services, as well as their respective adaptation and management options. Results show that drivers of environmental impacts have changed in the past 40 years, reducing the effectiveness of some important societal responses towards conservation and sustainable management with a great potential to increase rates of mangrove deforestation and conversion to human uses. Although efforts in conservation and restoration have contributed to decreasing pressure on these ecosystems, the coupling of old drivers, such as damming, with climate change, and the appearance of new drivers in the region, such as shrimp aquaculture, may eclipse the gains made through these conservation efforts. Despite the negative trend, we discuss some successful efforts to curb negative impacts of human activities on mangroves. We also recommend regional assessments based on primary sources in the representative mangrove‐bearing countries throughout the continent to allow the upscaling of their experiences towards a regional response to the challenges facing Neotropical mangrove conservation and sustainable use.

show abstract

“…The effects of climate change on increasing Hg contamination have been particularly enhanced in ecosystems exposed to climatic extremes, mainly in the transition (estuarine) ecosystems [ 1 , 3 , 41 , 48 ]. Continental runoff in semiarid regions is affected by land use and global climate change, leading to the increasing accumulation of particulate Hg in estuaries and increasing export of dissolved Hg to the ocean [ 49 ]. This scenario is especially relevant in the food webs of tropical aquatic ecosystems, especially in the estuaries and continental shelf of the northeastern regions of Brazil, being already subject to semiarid conditions, but drought events are now intensifying in terms of frequency and duration of episodes.…”

Section: Introductionmentioning

confidence: 99%

“…In the semiarid region of NE Brazil, similarly to that recently verified in the Artic [ 52 , 53 , 54 , 55 ], the regional and global drivers responsible for increasing continental runoff and diminishing fluvial discharges to the Western Equatorial South Atlantic Ocean are strengthening due to global warming [ 56 ]. Lacerda et al [ 49 ] verified in 2009 that during the rainy season, a positive net flux to the ocean occurred but, even during the extreme rainy period, marine waters contributed significantly to the total flow, mostly from the estuary to the sea, with a much larger flow compared to flow from the fluvial to the estuary. The same study reported that during the dry season, the discharge to the ocean was mostly due to tidal waters entering the estuary, with a small contribution from the higher basin.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, it is crucial to analyze climate change's effects on the intensification of some mechanisms triggering higher Hg bioaccumulation in the aquatic ecosystems of this region. Seawater intrusion will promote not only higher resuspension processes, but also longer water residence time in the dry season, favoring intra-estuary reactions of continental and marine-born materials brought in by fluvial and tidal flows (Lacerda et al, 2013), thus leading to an increase in bioaccumulation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Chronological Trends and Mercury Bioaccumulation in an Aquatic Semiarid Ecosystem under a Global Climate Change Scenario in the Northeastern Coast of Brazil

Morgado

Santos

Sampaio

et al. 2021

Animals

View full text Add to dashboard Cite

Due to global warming, in the northeastern semiarid coastal regions of Brazil, regional and global drivers are responsible for decreasing continental runoff and increasing estuarine water residence time, which promotes a greater mobilization of bioavailable mercury (Hg) and allows increasing fluxes and/or bioavailability of this toxic trace element and an acceleration of biogeochemical transformation of Hg. In this work, an application of dendrochemistry analysis (annular tree rings analysis) was developed for the reconstruction of the historical pattern of mercury contamination in a contaminated area, quantifying chronological Hg contamination trends in a tropical semiarid ecosystem (Ceará River Estuary, northeastern coast of Brazil) through registration of mercury concentration on growth rings in specimens of Rhizophora mangle L. and using the assessment in sediments as a support for the comparison of profiles of contamination. The comparison with sediments from the same place lends credibility to this type of analysis, as well as the relationship to the historical profile of contamination in the region, when compared with local data about industries and ecological situation of sampling sites. In order to evaluate the consequences of the described increase in Hg bioavailability and bioaccumulation in aquatic biota, and to assess the biological significance of Hg concentrations in sediments to fish and wildlife, muscle and liver from a bioindicator fish species, S. testudineus, were also analyzed. The results of this work reinforce the indicators previously described in the semiarid NE region of Brazil, which showed that global climate change and some anthropogenic factors are key drivers of Hg exposure and biomagnification for wildlife and humans. Considering the Hg concentration present in the top layers of sediment (~20 cm around 15 to 20 years) with the outer layers in the tree ring cores and in the sediment’s cores from Pacoti estuary and the Ceará estuary, overall the data indicate an increase in mercury in recent years in the Hg surface sediments, especially associated with the fine sediment fraction, mainly due to the increased capacity of small particles to adsorb Hg. There was revealed a positive and significant correlation (p < 0.05) between Hg trends in sediments and Hg trends in annular tree rings. This shared Hg pattern reflects local environmental conditions. The Hg concentration values in S. testudineus from both study areas are not restrictive to human consumption, being below the legislated European limit for Hg in foodstuffs. The results from S. testudineus muscles analysis suggest a significant and linear increase in Hg burden with increasing fish length, indicating that the specimens are accumulating Hg as they grow. The results from both rivers show an increase in BSAF with fish growth. The [Hg] liver/[Hg] muscles ratio >1, which indicates that the S. testudineus from both study areas are experiencing an increase in Hg bioavailability. Possible climate-induced shifts in these aquatic systems processes are inducing a greater mobilization of bioavailable Hg, which could allow an acceleration of the biogeochemical transformation of Hg.

show abstract

Pluriannual Watershed Discharges of Hg into a Tropical Semi-Arid Estuary of the Jaguaribe River, NE Brazil

Cited by 14 publications

References 0 publications

Emission factor and balance of mercury in fish farms in an artificial reservoir in NE Brazil

Emission factor and balance of mercury in fish farms in an artificial reservoir in NE Brazil

Neotropical mangroves: Conservation and sustainable use in a scenario of global climate change

Chronological Trends and Mercury Bioaccumulation in an Aquatic Semiarid Ecosystem under a Global Climate Change Scenario in the Northeastern Coast of Brazil

Contact Info

Product

Resources

About