Control by fiddler crabs (Uca vocans) and plant roots (Avicennia marina) on carbon, iron, and sulfur biogeochemistry in mangrove sediment (original) (raw)
Journal of Coastal Research, 2008
MACHADO, W.; SANTELLI, R.E.; CARVALHO, M.F.; MOLISANI, M.M.; BARRETO, R.C., and LACERDA, L.D., 2008. Relation of reactive sulfides with organic carbon, iron, and manganese in anaerobic mangrove sediments: implications for sediment suitability to trap trace metals. Journal of Coastal Research, 24(4C), 25-32. West Palm Beach (Florida), ISSN 0749-0208.
Wetlands Ecology and Management, 2018
The land crab Cardisoma guanhumi is one of the most common species in mangroves of the American Atlantic coast and Caribbean islands however, studies of its effects on the physical and chemical soil properties are scarce. This study compares specific physicochemical properties of soil between C. guanhumi burrows (B) and adjacent zones (AZ), and provides the first insights on their role as an ecosystem engineer in mangroves. The study was conducted in an estuarine system dominated by Rhizophora mangle, located at the Río Chico estuary, Miranda state of Venezuela. Random soil samples were taken digging each burrow until reaching the bottom and at the same depth for AZ. Data analysis was carried out using Bayesian inference. Credible mean differences between B and AZ, were found for sand (B = 26.53 ± 10.76, AZ = 17.25 ± 5.7%), silt (B = 73.16 ± 10.77, AZ = 82.42 ± 5.69%), pH (B = 8.71 ± 0.36, AZ = 9.12 ± 0.30), soil organic matter (SOM, B = 0.43 ± 0.21, AZ = 0.17 ± 0.06%), total N (TN, B = 786 ± 232, AZ = 529 ± 107 lg g-1), Mg (B = 4.42 ± 0.60, AZ = 3.48 ± 0.71 cmol c kg-1) and K (B = 0.12 ± 0.05 AZ = 0.06 ± 0.02 cmol c kg-1). Chemical variables as SOM, K, Mg and TN showed the highest values of effect size ([ 1.4). With the exception of the pH, all chemicals variables-which were different between B and AZ-showed strong and decisive evidences of correlations with SOM. When SOM variable was controlled, the relationships between pH-TN, TN-K and Mg-K decreased, even though the correlation evidence between each pair remained. Differences in chemical contents found in B respect to AZ suggest that the activities of C. guanhumi (feeding, moulting, excretion and defecation) within their burrows promote the spatial heterogeneity of mangrove soils.
The government of Saudi Arabia launched the Jazan Economic City (JEC) at Baish near Jezan city in 2006. However, there is a concern that immense industrial and urban development at JEC will seriously impact the coastal mangrove habitats. To explore the related environmental stresses on mangrove forests near JEC, the present study was conducted at three locations characterized as one close to an industrial port, one close to shrimp aquacultures, and one further from immediate human impacts: (1) to assess the vertical distribution of the sediment bulk density (SBD), sediment organic carbon (SOC) concentration, and SOC density in two polluted mangrove (Avicennia marina) locations in comparison with a non-polluted location along the southern Red Sea coast of Saudi Arabia; and (2) to estimate the SOC pool and carbon sequestration rate (CSR) of these locations. We hypothesise that each of the above-mentioned parameters varied between the polluted and non-polluted locations. In total, 400 sediment samples were collected and analysed to determine the SBD, the SOC concentration, density and pool, and the CSR, to reveal significant variation between the polluted and non-polluted mangrove locations in terms of the total mean values of the SBD, the SOC concentration, density and pool, and the CSR. An increase in SBD with a decrease in concentration and density of SOC is evident with an increase in depth at both polluted and non-polluted mangrove locations. The SOC pool at the non-polluted location (11.5 kg C m −2 ) is significantly (p < 0.05) larger than the SOC pool at the polluted locations (9.9 kg C m −2 ). Similarly, the average CSR at the non-polluted location (5.1 g C m −2 yr −1 ) is significantly (p < 0.001) greater than the average CRS at the polluted locations (4.4 g C m −2 yr −1 ). Thus, there is an urgent need to implement climate mitigation projects in order to manage and restore the mangrove ecosystems along the coastal regions of Saudi Arabia, and protect and conserve the present SOC pools.
Nutrient dynamics in mangrove crab burrow sediments subjected to anthropogenic input
Bioturbation by burrowing macroinvertebrates has a major impact on sediment properties, pollutant redistribution, and biogeochemical cycling. We assessed the impact of bioturbation on the nutrient dynamics and organic matter of sediments receiving anthropogenic inputs in the Manko wetland, located in southern Okinawa, Japan. We compared sediments that were and were not subjected to the activities of the tidal-flat crab Helice formosensis. The fatty acid composition of sediments indicated that different sources contributed to the organic matter profile. Agricultural and domestic waste discharge seemed to induce a high amount of green macroalgae and bacteria in the tidal flat. Sediments without crabs exhibited 2.1-2.4× more NH 4 -N release, which was associated with a low C/N ratio during the summer. In the crab burrow sediments, NO 3 -N concentrations were 1.4-1.9× more pronounced during winter. A significant correlation existed between NO 3 -N and NO 2 -N concentrations in sediments of the burrow chamber (r = 0.837, p b 0.02) and the mixed zone of burrow opening shaft and chamber (r = 0.885, p b 0.01). We suggest that burrow wall sediments provide ideal conditions for nitrate reduction (denitrification). H. formosensis thus contributes to balancing the effects of anthropogenic inputs by removing nitrogen loads in sediments.
Geoderma, 2014
A semi-arid mangrove estuary system in the northeast Brazilian coast (Ceará state) was selected for this study to (i) evaluate the impact of shrimp farm nutrient-rich wastewater effluents on the soil geochemistry and organic carbon (OC) storage and (ii) estimate the total amount of OC stored in mangrove soils (0-40 cm). Wastewateraffected mangrove forests were referred to as WAM and undisturbed areas as Non-WAM. Redox conditions and OC content were statistically correlated (P b 0.05) with seasonality and type of land use (WAM vs. Non-WAM). Eh values were from anoxic to oxic conditions in the wet season (from -5 to 68 mV in WAM and from b40 to N 400 mV in Non-WAM soils) and significantly higher (from 66 to 411 mV) in the dry season (P b 0.01). OC contents (0-40 cm soil depth) were significantly higher (P b 0.01) in the wet season than the dry season, and higher in Non-WAM soils than in WAM soils (values of 8.1 and 6.7 kg m -2 in the wet and dry seasons, respectively, for Non-WAM, and values of 3.8 and 2.9 kg m -2 in the wet and dry seasons, respectively, for WAM soils; P b 0.01). Iron partitioning was significantly dependent (P b 0.05) on type of land use, with a smaller degree of pyritization and lower Fe-pyrite presence in WAM soils compared to Non-WAM soils. Basal respiration of soil sediments was significantly influenced (P b 0.01) by type of land use with highest CO 2 flux rates measured in the WAM soils (mean values of 0.20 mg CO 2 h -1 -g -1 C vs. 0.04 mg CO 2 h -1 -g -1 C). The OC storage reduction in WAM soils was potentially caused (i) by an increase in microbial activity induced by loading of nutrient-rich effluents and (ii) by an increase of strong electron acceptors [e.g., NO 3 -] that promote a decrease in pyrite concentration and hence a reduction in soil OC burial. The current estimated OC stored in mangrove soils (0-40 cm) in the state of Ceará is approximately 1 million t.
Review: Biogeochemical process in mangrove ecosystem
International Journal of Bonorowo Wetlands
The mangrove ecosystem, one of the unique and distinctive aquatic ecosystems, is located in the tidal areas of the coast coastal areas in the tropics and subtropics. Mangrove ecosystems have many ecological, environmental, and social benefits. Mangrove forests have the potential to become a potential resource. This review aims to determine the process and function of the biogeochemical cycle in the mangrove ecosystem. The research method used in this research is descriptive qualitative research methods and tends to use inductive analysis. The biogeochemical cycle acts as a cycle that cannot be separated from the mangrove ecosystem. Biogeochemistry is the process of circulating chemical elements or compounds that occur repeatedly and continuously. Biogeochemistry plays a role in maintaining environmental stability and maintaining life on earth. The biogeochemical cycle consists of energy flow and nutrient cycling. Energy flows consist of food chains and food webs. The nutrient cycles include water, carbon, nitrogen, phosphorus, and sulfur. Various chemical elements resulting from the cycle process are needed to survive living things in the mangrove ecosystem.
Effects of vegetation and sewage load on mangrove crab condition using experimental mesocosms
Estuarine, Coastal and Shelf Science, 2009
Constructed wetlands, especially mangroves, have been studied for their usefulness in sewage treatment but the effects of mangrove vegetation and a sewage load on mangrove macrofauna have been given little attention. Ocypodid crabs are important components of mangrove forests and constitute good bioindicators of the functioning of the ecosystem as a whole. In constructed mangrove mesocosms, three vegetation treatments (bare substratum, and Avicennia marina and Rhizophora mucronata seedlings) were subjected to 0, 20, 60 and 100% sewage loads from a nearby hotel. The physiological condition of introduced Uca annulipes and Uca inversa was evaluated in terms of their RNA/DNA ratio after one, five and twelve months, and used as an indicator of ecological function in the system. Crab condition in 0% sewage load was similar to that of wild crabs throughout, suggesting no significant effects of the mesocosms on their RNA/DNA ratio. Overall, both species coped well with the administered sewage loads, suggesting good ecological function in the system. Both species manifested similar patterns in RNA/DNA ratio, being more affected by seasonal fluctuations than by sewage load and vegetation presence and type. Higher RNA/DNA ratios were recorded in the long compared to the short rainy season. Sewage enhanced crab condition in the bare substratum and R. mucronata treatments, especially after one year, probably as a result of enhanced food availability. Uca inversa may be more sensitive to sewage pollution than U. annulipes. In A. marina, no difference in crab condition was observed between sewage loads, and this mangrove yielded the best reduction in sewage impacts. Our results support the usefulness of constructed mangrove areas in sewage treatment, especially if planted with A. marina and inhabited by physiologically healthy ocypodid crabs to enhance the system’s performance.
Grapsid crabs are one of the most abundant and potentially the most important group of macrofauna inhabiting mangrove forests. A field study was conducted in the Manko wetland (Okinawa Island, southern Japan) to investigate how the burrowing crab Helice formosensis affects the sedimentary fatty acid (FA) and physicochemical characteristics of subtropical mangrove sediments. Multi-dimensional scaling (MDS) results from FA profiles revealed clear differences between burrow compartments and sediments with and without crabs. The impacts of burrowing were demonstrated by higher percentages of bacterial, vascular plant, and macroalgal FA markers in the burrow compartments and crab sediment areas. Conductivity and redox potential were significantly higher in sediments of the burrow opening shaft than in the burrow chamber. We found a similar pattern in surface sediments with crabs, but not in surface sediments without crab habitats. These results suggest that H. formosensis significantly influences the physicochemical properties, FA composition, and organic matter profiles of its surrounding environment.
Soil Organic Carbon in Mangrove Ecosystems with Different Vegetation and Sedimentological Conditions
Journal of Marine Science and Engineering, 2015
A large number of studies have been conducted on organic carbon (OC) variation in mangrove ecosystems. However, few have examined its relationship with soil quality and stratigraphic condition. Mangrove OC characteristics would be explicitly understood if those two parameters were taken into account. The aim of this study was to examine mangrove OC characteristics qualitatively and quantitatively after distinguishing mangrove OC from other OC. Geological survey revealed that the underground of a mangrove ecosystem was composed of three layers: a top layer of mangrove origin and two underlying sublayers of geologic origin. The underlying sublayers were formed from different materials, as shown by X-ray fluorescence analysis. Despite a large thickness exceeding 700 cm in contrast to the 100 cm thickness of the mangrove mud layer, the sublayers had much lower OC stock. Mangrove mud layer formation started from the time of mangrove colonization, which dated back to between 1330 and 1820 14 C years BP, and OC stock in the mangrove mud layer was more than half of the total OC stock in the underground layers, which had been accumulating since 7200 14 C years BP. pH and redox potential (Eh) of the surface soils varied depending on vegetation type. In the surface soils, pH correlated to C% (r = −0.66, p < 0.01). C/N ratios varied widely from 3.9 to 34.3, indicating that mangrove OC had various sources. The pH
Influence of Edaphic factors on Mangrove Carbon.pdf
We evaluated the biomass and stored carbon in three dominant mangrove species of Indian Sundarbans in relation to specific soil parameters (soil salinity, pH, organic carbon, nitrate-nitrogen, phosphatephosphorus, sulphate-sulphur and potassium). The study was conducted in two sampling stations with contrasting physico-chemical variables preferably salinity. The growth and stored carbon was more in the species of Lothian Island (located in the western Indian Sundarbans) compared to Bonnie camp (located in the central Indian Sundarbans). ANOVA results identified soil salinity, organic carbon, nitrate-nitrogen and phosphate-phosphorus as the primary drivers influencing the growth and carbon storage potential of the selected species.