Marine Wetlands Research Articles

Ecotoxicity of trace metal enrichment and the degrees of contaminated sediment and water from Riparian communities in Rivers State, Nigeria

This study assessed trace metal enrichment and contamination levels in Tema, Sangama, and Degema communities in Rivers State, Nigeria. Samples were collected monthly from October 2021 to April 2022. Trace metals such as Pb, Cu, Fe, Cd, Zn, and As were analysed using an Atomic Absorption Spectrophotometer (AAS). The contamination factor, degree of contamination and enrichment factor for trace metals were used to evaluate the impact of pollution levels. There was a descending order of heavy metal concentrations in water at the three stations: Fe > Cu > Zn > Cd > Pb. Sediment heavy metal concentrations were descending from Fe > Zn > Cu > Pb > Cd at the same stations. Heavy metal levels were consistently higher at Sangama. The result revealed that compared to Pb and Zn, Cd contamination was moderate to considerable. Fe contamination was relatively low, but Cu contamination was moderate to high. Water and sediment were contaminated to varying degrees. The contamination levels of Pb, Zn, and Cu were low to moderate. Sangama, Tema, and Degema all had varying degrees of contamination, with some areas having higher contamination levels. This study recommends the need for effective environmental management practices in these coastal marine wetlands.

Intrinsic and extrinsic drivers of organic matter processing along phosphorus and salinity gradients in coastal wetlands

Abstract Climate change is accelerating sea‐level rise and saltwater intrusion in coastal regions world‐wide and interacting with large‐scale changes in species composition in coastal wetlands. Quantifying macrophyte litter breakdown along freshwater‐to‐marine coastal gradients is needed to predict how carbon stores will respond to shifts in both macrophyte communities and water chemistry under changing environmental conditions. To test the interactive drivers of changing species identity and water chemistry, we performed a reciprocal transplant of four macrophyte litter species in seven sites along freshwater‐to‐marine gradients in the Florida Coastal Everglades. We measured surface water chemistry (dissolved organic carbon, total nitrogen and total phosphorus), litter chemistry (% nitrogen, % phosphorus, change in N:P molar ratio, % cellulose and % lignin as proxies for recalcitrance) and litter breakdown rates (k/degree‐day). Direct effects of salinity and surface water nutrients were the strongest drivers of k, but unexpectedly, litter chemistry did not correlate with litter k. However, salinity strongly correlated with changes in litter chemistry, whereby litter incubated in brackish and marine wetlands was more labile and gained more phosphorus compared with litter in freshwater marshes. Our results suggest that litter k in coastal wetlands is explained by species‐specific interactions among water and litter chemistries. Water nutrient availability was an important predictor of breakdown rates across species, but breakdown rates were only explained by the carbon recalcitrance of litter in the species with the slowest breakdown (Cladium jamaicense), indicating the importance of carbon structure, and species identity on breakdown rates. Synthesis. In oligotrophic ecosystems, nutrients are often the primary driver of organic matter breakdown. However, we found that variation in macrophyte breakdown rates in oligotrophic coastal wetlands was also explained by salinity and associated seawater chemistry, emphasising the need to understand how saltwater intrusion will alter organic matter processing in wetlands. Our results suggest that marine subsidies associated with sea‐level rise have the potential to accelerate leaf litter breakdown. The increase in breakdown rates could either be buffered or increase further as sea‐level rise also shifts macrophyte community composition to more or less recalcitrant species.

Spartina alterniflora invasion differentially alters microbial residues and their contribution to soil organic C in coastal marsh and mangrove wetlands

Coastal wetlands play a critical role in global carbon (C) cycling while they are frequently challenged by exotic plant invasion. Microbial residues are increasingly recognized as the key constituent of stable soil organic C (SOC) but their responses to plant invasion in coastal wetlands remain largely unknown. Here, we investigated the effect of Spartina alterniflora invasion on microbial residues and their contribution to SOC in coastal wetland ecosystems with distinct native species (Phragmites australis (marsh), Kandelia candel or Avicennia marina). S. alterniflora invasion differentially altered microbial residue C accumulation in three coastal wetlands. Overall, the invasion of S. alterniflora significantly increased microbial residue C accumulation (17.8%) in marsh with native P. australis, while it showed negative or minor impacts on mangroves with K. candel and A. marine communities, despite nuanced site-specific differences. The divergent responses of microbial residues could be related to changes in edaphic conditions and plant inputs along with plant invasion process. Invasion of mangrove and marsh communities by S. alterniflora triggered divergent fungal and bacterial residue responses, leading to contrasting fungal to bacterial C ratios in invaded marsh and mangrove wetlands. The proportion of microbial residues in SOC pool was enhanced to some extent, with an increase by 14.4%, 33.0% and 1.9% in P. australis, K. candel and A. marine wetlands, respectively, despite inconsistent variations in total SOC with S. alterniflora invasion. This has an implication for an elevated preservation of microbial residue C relative to the other organic C fractions in the invaded coastal wetlands. These findings highlight the importance of anabolic microbial C sequestration process for the maintenance of wetland soil C, which may impact C cycling and balance in coastal wetland ecosystem subjected to S. alterniflora invasion. Our work provides new insights to capture the properties and mechanisms of microbial control over C sequestration as well as SOC source configuration in coastal wetlands undergoing S. alterniflora invasion.

Coastal Biodiversity, Sustainable Livelihood and Ecological Scenarios in Marine Wetland of Asarama Andoni in Parts of Eastern Niger Delta Nigeria

Wetland ecosystems are very important natural environmental resource that forms part of the total wealth of a nation. The Asarama wetland in Andoni is amongst the important wetlands in coastal marine cosystems of the Niger Delta; fascinated by diverse rich biodiversity, wetland ecotypes of mangrove, mudflat, Nypa, estuary and fresh water forest habitats with range of critical ecosystem services they provide for mankind survival. The data gathering involved both primary and secondary sources of information. Result revealed diverse ecological scenarios: a livelihood system with diverse level of significant sources and benefit of the ecosystem services. Food, aquacultural practices and sea route logistic component of livelihood benefit from sources recorded significant (HS- 4) level of provisioning services, breeding / nursery benefit with high significant (HS- 4) level of supporting services among other levels recorded in Table 1. Ecological challenges revealed nypa palm invasion of the mangrove ecotypes and uncertainty of climatic relationship to hydrological tidal regime as natural scenarios; economic, social, institutional and infrastructural challenges as anthropogenic scenarios. Therefore a policy framework (legislature) as part of future directive and initiatives to enforce the practice of biodiversity priorities and sustainable livelihood is of immediate importance to Asarama - Andoni wetlands ecosystem. Keywords: Likert scale, provisioning, cultural, regulatory, supporting, natural, anthropogenic. DOI: 10.7176/JESD/13-24-03 Publication date: December 31 st 2022

A Review on Wetlands – Threats, Conservation, Strategies and Policies

Globally 64% of the wetlands have disappeared since 1970 and the loss is higher in Asia, about 5000 km2 annually due to agriculture, dam construction and other uses. In India, the loss is about 38% with the disappearance rate of 2-3% per year. Further dependence on these wetlands leads to either extinction or threatened the species including 21% of bird species, 37% of mammal species and 20% fresh water fish species. Wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water level. According to Ramsar convention the wetlands are classified as three types via., coastal/ marine wetlands, inland wetlands and human made wetlands. Worldwide, the freshwater wetland ecosystems are among the mostly heavily used, depended upon and exploited ecosystems for sustainability and well-being. The main causes of wetland loss have been classified into two types namely acute and chronic wetland loss. This loss in wetland area results in adverse impact on the key functions performed by wetlands. Hence, we have to conserve these wetlands by implementing effective legal framework and management strategies. In this context Ramsar convention is an important International Treaty for the Conservation and Sustainable use of Wetlands which was signed at a city of Iran (Ramsar) in 1971. There are currently over 2,400 Ramsar sites on the territories of 171 Ramsar Contracting Parties across the world. They cover over 2.5 million square kilometers, an area larger than Mexico.

Retraction Note: Evaluation of mangrove wetland potential based on convolutional neural network and development of film and television cultural creative industry

Convolutional neural network is a deep learning network, which is more suitable for image and speech processing. Image classification is one of the main research areas of visual artificial intelligence, with many applications, such as scene detection and robot vision enhancement. This paper proposes a new convolutional neural network to evaluate the potential of mangrove wetlands and discusses the development of the network in the film and television cultural and creative industries. Mangrove wetland is a special type of marine wetland centered on mangrove plant communities in tropical and subtropical coasts and intertidal zones of estuaries. They play an important role and play an important role in providing food, protecting wild germplasm resources, and population survival. Over the years, due to population pressure and economic development, the quality of mangrove wetlands has declined, the area has shrunk, and the restoration of mangrove wetlands has become a global hot spot. The development of the film and television industry is an important way to promote China’s cultural innovation. It is essential for strengthening the country’s soft power and improving China’s international image. However, due to the influence of many factors, the development of China’s film and television cultural creation industry is slow, and the development process is lagging behind. In recent years, the country has considered the development level of the cultural industry as an important development strategy, and has been taking various measures to promote the development of the film and television cultural industry. The creative film and television industry should be aware of its responsibility for cultural dissemination, actively learn from foreign industry development experience, and explore a scientific development system that meets China’s development needs and actual national conditions.

Environmental Isolation of Candida auris from the Coastal Wetlands of Andaman Islands, India.

Candida auris is a multidrug resistant pathogen that presents a serious global threat to human health. As C. auris is a newly emerged pathogen, several questions regarding its ecological niche remain unexplored. While species closely related to C. auris have been detected in different environmental habitats, little is known about the natural habitat(s) of C. auris Here, we explored the virgin habitats around the very isolated Andaman Islands in the Indian Ocean for evidence of C. auris We sampled coastal wetlands, including rocky shores, sandy beaches, tidal marshes, and mangrove swamps, around the Andaman group of the Andaman & Nicobar Islands, Union Territory, in India. Forty-eight samples of sediment soil and seawater were collected from eight sampling sites representing the heterogeneity of intertidal habitats across the east and west coast of South Andaman district. C. auris was isolated from two of the eight sampling sites, a salt marsh and a sandy beach. Interestingly, both multidrug-susceptible and multidrug-resistant C. auris isolates were found in the sample. Whole-genome sequencing analysis clustered the C. auris isolates into clade I, showing close similarity to other isolates from South Asia. Isolation of C. auris from the tropical coastal environment suggests its association with the marine ecosystem. The fact that viable C. auris was detected in the marine habitat confirms C. auris survival in harsh wetlands. However, the ecological significance of C. auris in salt marsh wetland and sandy beaches to human infections remains to be explored.IMPORTANCECandida auris is a recently emerged multidrug-resistant fungal pathogen capable of causing severe infections in hospitalized patients. Despite its recognition as a human pathogen a decade ago, so far the natural ecological niche(s) of C. auris remains enigmatic. A previous hypothesis suggested that C. auris might be native to wetlands, that its emergence as a human pathogen might have been linked to global warming effects on wetlands, and that its enrichment in that ecological niche was favored by the ability of C. auris for thermal tolerance and salinity tolerance. To understand the mystery of environmental niches of C. auris, we explored the coastal wetland habitat around the very isolated Andaman Islands in the Indian Ocean. C. auris was isolated from the virgin habitats of salt marsh area with no human activity and from a sandy beach. C. auris isolation from the marine wetlands suggests that prior to its recognition as a human pathogen, it existed as an environmental fungus.

Nitrogen and Phosphorus Export After Flooding of Agricultural Land by Coastal Managed Realignment

Climate-driven sea level rise has severe consequences for drained agricultural areas near coasts. The least productive of these can be restored into marine wetlands of high ecological quality by managed realignment. This study assessed the nitrogen (N) and phosphorus (P) balance in a 214 ha coastal lagoon formed after flooding of agricultural land by managed realignment. N and P loss from the soils was monitored over a 5-year period after flooding using three independent approaches: (1) temporal changes in N and P inventories of the soil; (2) flux of dissolved inorganic N and P from the flooded soil; and (3) tidal N and P exchange across the outer boundary in the form of particulate and dissolved nutrients. All three approaches showed similar initial release and tidal export of N and P the first year(s) after flooding followed by decreasing rates. The annual loss ranged from 157 to 299 kg N ha−1 yr−1 and 29 to 63 kg P ha−1 yr−1 during the first year. N loss decreased rapidly after the first 2 years and reached a level of 28–65 kg N ha−1 yr−1, while P loss declined after the first year and remained stable and relatively high at 18–32 kg P ha−1 yr−1 thereafter. High N and P export after implementing managed realignment of agricultural land may deteriorate environmental conditions in the adjacent marine recipients for at least 5 years. Particularly small and stagnant water bodies vulnerable to eutrophication should be avoided as recipients.

Carbohydrate metabolism genes dominant in a subtropical marine mangrove ecosystem revealed by metagenomics analysis.

Mangrove sediment microorganisms play a vital role in the energy transformation and element cycling in marine wetland ecosystems. Using metagenomics analysis strategy, we compared the taxonomic structure and gene profile of the mangrove and non-mangrove sediment samples at the subtropical estuary in Beibu Gulf, South China Sea. Proteobacteria, Bacteroidetes, and Firmicutes were the most abundant bacterial phyla. Archaeal family Methanosarcinaceae and bacterial genera Vibrio and Dehalococcoides were significantly higher in the mangrove sediments than in the nonmangrove sediments. Functional analysis showed that "Carbohydrate metabolism" was the most abundant metabolic category. The feature of carbohydrate-active enzymes (CZs) was analyzed using the Carbohydrate-Active EnZymes Database. The significant differences of CZs between mangrove and non-mangrove sediments, were attributed to the amounts of polyphenol oxidase (EC 1.10.3.-), hexosyltransferase (EC 2.4.1.-), and β-N-acetylhexosaminidase (EC 3.2.1.52), which were higher in the mangrove sediment samples. Principal component analysis indicated that the microbial community and gene profile between mangrove and non-mangrove sediments were distinct. Redundancy analysis showed that total organic carbon is a significant factor that affects the microbial community and gene distribution. The results indicated that the mangrove ecosystem with massive amounts of organic carbon may promote the richness of carbohydrate metabolism genes and enhance the degradation and utilization of carbohydrates in the mangrove sediments.

Salipaludibacillus halalkaliphilus sp. nov., a moderately haloalkaliphilic bacterium from a coastal-marine wetland.

A Gram-stain-positive, endospore-forming rod-shaped non-motile, moderately halophilic and alkaliphilic bacterium, strain GASy1T, was isolated from a water sample from Gomishan, a marine wetland in Iran. GASy1T required at least 0.5 % (w/v) NaCl for growth and was able to grow at NaCl concentrations of up to 15 % (w/v), with optimum growth occurring at 5 % (w/v) NaCl. The optimum pH and temperature for growth were pH 8.5-9.0 and 30 °C, respectively, while it was able to grow over a pH range and a temperature range of 7.5-10.0 and 4-40 °C, respectively. GASy1T was catalase-positive and oxidase-negative. Analysis of 16S rRNA gene sequences revealed that GASy1T represents a member of the genus Salipaludibacillus, family Bacillaceae within the order Bacillales, showing 97.4 % sequence similarity to Salipaludibacillus neizhouensis JSM 071004T, and 96.2 and 95.7 % sequence similarity to Salipaludibacillus agaradhaerens AC 13T and Salipaludibacillus aurantiacus S9T, respectively. The DNA G+C content of GASy1T was 38.8 mol%. The polar lipids of the strain were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and two unidentified phospholipids and its major cellular fatty acids were anteiso-C15 : 0, C16 : 0 and iso-C15 : 0. The isoprenoid quinone was MK-7. DNA-DNA hybridization experiments revealed a low level of relatedness between GASy1T and Salipaludibacillus neizhouensis IBRC-M 10892T (18 %). On the basis of a combination of phenotypic, chemotaxonomic and phylogenetic features, GASy1T represents a novel species of the genus Salipaludibacillus, for which the name Salipaludibacillus halalkaliphilus sp. nov. is proposed. The type strain of Salipaludibacillus halalkaliphilus is GASy1T (=IBRC M 10902T=LMG 28385T).

Water Environment Assessment as an Ecological Red Line Management Tool for Marine Wetland Protection.

A ‘red line’ was established, identifying an area requiring for ecological protection in Tianjin, China. Within the protected area of the red line area, the Qilihai wetland is an important ecotope with complex ecological functions, although the ecosystem is seriously disturbed due to anthropogenic activities in the surrounding areas. This study assesses the water quality status of the Qilihai wetlands to identify the pollution sources and potential improvements based on the ecological red line policy, to improve and protect the waters of the Qilihai wetlands. An indicator system was established to assess water quality status using single factor evaluation and a comprehensive evaluation method, supported by data from 2010 to 2013. Assessment results show that not all indicators met the requirement of the Environmental Quality Standards for Surface Water (GB3838-2002) and that overall, waters in the Qilihai wetland were seriously polluted. Based on these findings we propose restrictions on all polluting anthropogenic activities in the red line area and implementation of restoration projects to improve water quality.

The economic value of wetlands in developing countries: A meta-regression analysis

This paper presents the first comprehensive synthesis of economic valuations of wetlands in developing countries. Meta-regression analysis (MRA) is applied to 1432 estimates of the economic value of 379 distinct wetlands from 50 countries. We find that wetlands are a normal good, wetland size has a negative effect on wetland values, and urban wetlands and marine wetlands are more valuable than other wetlands. Wetland values estimated by stated preferences are lower than those estimated by market price methods. The MRA benefit transfer function has a median transfer error of 17%. Overall, MRA appears to be useful for deriving the economic value of wetlands at policy sites in developing nations.

Impact of Plant Invasion and Increasing Floods on Total Soil Phosphorus and its Fractions in the Minjiang River Estuarine Wetlands, China

Plant invasion and increased flooding intensity projected by climate change models can change the soil capacity of marine wetland to store P. This is a key question to the nutrient balances and eutrophication processes of coastal areas, especially in China coastal area that is receiving the freshwaters of a country in fast economical developing process. We studied the impact of changes in flooding intensity and plant invasion on total soil-P concentrations in the Minjiang River estuarine wetland. Flooding had a weak positive effect on soil P-fractions concentrations, but this effect was largely counteracted by the negative effect of salinity. Soil clay concentration and pH, both of which were related more with species community composition than with flooding intensity, were directly related to the P-fraction concentrations. The replacement of the native mangrove community by the invasive plant Phragmites australis was related to a decrease in the soil capacity to store P. A suitable management to maintain this wetland area in optimum conditions to act as a natural eutrophication buffer should tend to favor mangrove communities in the new areas that reach more than 220 days y-1 of flooding, and a combination of the three tall-grasses communities below this level of flooding.

Reversible effects of fertilizer use on population trends of waterbirds in Europe

Nutrients are often limiting primary productivity, and fertilizer use by agriculture increases primary and secondary productivity in marine environments. High levels of eutrophication due to fertilizer use can have negative effects on the distribution and the abundance of many organisms including waterbirds inhabiting freshwater and marine wetlands. Because nutrients, in particular phosphorus, can be stored in sediment, reversal of effects of eutrophication can take considerably longer time than the period during which effects of eutrophication build up. We quantified the effects of fertilizer use on 50 species of freshwater and coastal waterbirds monitored across Europe during 1982–2008 during the increase and the decrease phase of fertilizer use. More species were negatively affected by fertilizer use, and use of marine habitats during winter was the single-most important predictor of negative trends. The relative effect of fertilizer use on abundance of waterbird species was consistent during the increase and the decrease phase of fertilizer use. The effects of fertilizer use were statistically independent of the effects of climate change. Reversal of the effect of fertilizer use on population trends of waterbirds was almost three times as slow as the build-up of effects of nutrients on population size. These findings have management implications for the extent and the duration of fertilizer policies at local, national and international levels since these policies will partly determine the population trends and the population sizes of waterbirds.

Diet of the Chilean flamingo Phoenicopterus chilensis (Phoenicopteriformes: Phoenicopteridae) in a coastal wetland in Chiloé, southern Chile

BackgroundThe geographical distribution of the Chilean flamingo (Phoenicopterus chilensis) includes the southern-central Neotropics. Despite its wide distribution, currently there is no dietary information on its southern distribution range. From June to September 2011, we quantified the diet and prey availability of the Chilean flamingo in the marine wetland of Caulín (41°48' S, 73°37' W), southern Chile.ResultsThe prey availability related to both plankton and benthos were four species of copepods, four polychaetes, one foraminifera, and two amphipods. The diet of the Chilean flamingo was composed of foraminifera (Ammonia beccarii), copepods (Harpacticus sp.) and polychaetes. The most abundant prey items from feces of flamingos were Ammonia beccarii and Harpacticus sp. The diameter of A. beccarii consumed by flamingos ranged between 400 and 900 μm, while its width varied between 100 and 300 μm. The width of Harpacticus sp. consumed ranged between 160 and 260 μm. The similarity between flamingo diet and prey availability was 0.553. The diversity of prey organisms in the benthos was higher than that observed from plankton and feces of birds. A. beccarii was preferred over other prey consumed by flamingos. This preference is not related to the size of Harpacticus sp. but to their ability to swim and escape from flamingos.ConclusionsThe dietary similarity of the Chilean flamingo versus the availability of prey in the environment (plankton and benthos) was 55%, indicating that the Chilean flamingo is a partially selective predator.

Salinispirillum marinum gen. nov., sp. nov., a haloalkaliphilic bacterium in the family 'Saccharospirillaceae'.

A novel Gram-staining-negative, motile, non-pigmented, facultatively anaerobic, spirillum-shaped, halophilic and alkaliphilic bacterium, designated strain GCWy1(T), was isolated from water of the coastal-marine wetland Gomishan in Iran. The strain was able to grow at NaCl concentrations of 1-10% (w/v) and optimal growth was achieved at 3% (w/v). The optimum pH and temperature for growth were pH 8.5 and 30 °C, while the strain was able to grow at pH 7.5-10 and 4-40 °C. Phylogenetic analysis based on the comparison of the 16S rRNA gene sequence placed the isolate within the class Gammaproteobacteria as a separate deep branch, with 92.1% or lower sequence similarity to representatives of the genera Saccharospirillum and Reinekea and less than 91.0% sequence similarity with other remotely related genera. The major cellular fatty acids of the isolate were C(18 : 1)ω7c, C(16:0) and C(17 : 0), and the major components of its polar lipid profile were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The cells of strain GCWy1(T) contained the isoprenoid quinones Q-9 and Q-8 (81% and 2%, respectively). The G+C content of the genomic DNA of this strain was 52.3 mol%. On the basis of 16S rRNA gene sequence analysis in combination with chemotaxonomic and phenotypic data, strain GCWy1(T) represents a novel species in a new genus in the family 'Saccharospirillaceae', order Oceanospirillales, for which the name Salinispirillum marinum gen. nov., sp. nov. is proposed. The type strain of the type species is GCWy1(T) ( = IBRC-M 10765(T) =CECT 8342(T)).

Cyclobacterium halophilum sp. nov., a marine bacterium isolated from a coastal-marine wetland

A novel Gram-stain-negative, slightly halophilic bacterium, designated strain GASx41(T), was isolated from soil of the coastal-marine wetland Gomishan in Iran. Cells of strain GASx41(T) were curved, ring-like or horseshoe-shaped rods and non-motile. Strain GASx41(T) was strictly aerobic, and catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 1-10% (w/v), with optimum growth occurring at 2.5-3% (w/v) NaCl. The optimum temperature and pH for growth were 25-30 °C and pH 7.5-8.0. On the basis of 16S rRNA gene sequence analysis, strain GASx41(T) was shown to belong to the genus Cyclobacterium within the phylum Bacteroidetes and showed closest phylogenetic similarity to 'Cyclobacterium jeungdonense' HMD3055 (98.0%). The DNA G+C content of strain GASx41(T) was 48.1 mol%. The major cellular fatty acids of strain GASx41(T) were iso-C15 : 0, summed feature 4 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), anteiso-C15 : 0 2-OH, anteiso-C15 : 0 and iso-C17 : 0 3-OH, and its polar lipid pattern consisted of phosphatidylethanolamine, phosphatidylcholine and 12 unknown lipids. The only quinone present was menaquinone 7 (MK-7). All these features confirmed the placement of isolate GASx41(T) within the genus Cyclobacterium. On the basis of evidence from this study, a novel species of the genus Cyclobacterium, Cyclobacterium halophilum sp. nov., is proposed, with strain GASx41(T) ( = IBRC-M 10761(T) = CECT 8341(T)) as the type strain.

갯지렁이(Perinereis aibuhitensis)에서 분리한 Bacillus spp.의 생리생화학적 특성 분석

본 연구에서는 연안 갯벌에서 유기물 분해능이 매우 우수한 것으로 알려진 갯지렁이(Perinereis aibuhitensis)에 내생하고 있는 균주 중 호기성과 혐기성 조건에서 생장 가능한 5 종류의 Bacillus 균주 CBW3, CBW4, CBW9, CBW14 그리고 EBW10를 선별하여 그 특성을 비교 분석하였다. 16S rRNA 염기서열에 기초하여 동정한 결과, CBW3과 CBW14는 B. nanhaiensis, B. arsenicus 그리고 B. barbaricus와 99.8% 이상의 높은 상동성을, CBW4, CBW9 그리고 EBW10 균주는 B. anthracis, B. algicoa 그리고 B. thuringiensis와 각각 92.7%, 99.8% 그리고 99.8%의 상동성을 보였다. 이들 대부분 균주들의 생장온도 범위는 <TEX>$4-45^{\circ}C$</TEX>, 염도는 0-17%, pH는 5-9 범위로 매우 다양하게 나타났다. 모든 균주들이 casein, starch 분해 효소를 가지고 있었으며 특히 균주 EBW10은 시험한 모든 고분자 물질을 분해할 수 있는 protease, amylase, cellulase. lipase 등의 효소 활성을 가지고 있을 가능성이 높음을 제시해주었다. 대상 균주 5 종 모두 alkaline phosphatase 활성을 가지며, CBW3, CBW4 그리고 EBW10은 acid phospatase 활성을 동시에 가지고 있었으며, CBW3, CBW14, EBW10은 esterase (C4) 활성을, CBW3, CBW9, EBW10은 CBW4는 esterase lipase (C8) 활성을 나타냈다. 지방산 분석 결과 CBW3, CBW9, CBW14, EBW10 균주에서는 anteiso <TEX>$C_{15:0}$</TEX>이 균주에 따라 차이가 있었지만 약 42.8%에서 55.7%까지 가장 많은 비율을 차지하는 지방산으로 분석되었고, 오직 CBW4에서만 iso <TEX>$C_{15:0}$</TEX>이 전체 지방산의 46.9%로 가장 많은 비율로 나타났다. This study compared the characteristics of five Bacillus strains capable of aerobic and anaerobic growth, CBW3, CBW4, CBW9, CBW14 and EBW10. They were isolated and selected from a polychaete, Perinereis aibuhitensis, which is known as a good degrader of organic compounds in marine wetland. Based on a 16S rRNA sequence, CBW3 and CBW14 were found to share more than 99.8% similarity with B. nanhaiensis, B. arsenicus and B. barbaricus. CBW4, CBW9 and EBW10 shared 92.7%, 99.8%, and 99.8% similarity with B. anthracis, B. algicoa and B. thuringiensis, respectively. The temperature, salinity, and pH ranges of the cell growth of the Bacillus strains were <TEX>$4-45^{\circ}C$</TEX>, 0-17%, and pH 5-pH 9, respectively. All Bacillus strains were found to exhibit enzyme activities for the degradation of casein and starch. Notably, strain EBW10 exhibited the enzyme activities for all the tested macromolecules, DNA, casein, starch, cellulose, and four kinds of Tweens, which suggests the possibility that it had protease, amylase, cellulose, and lipase. All five Bacillus strains had alkaline phosphatase activities, and the strains CBW3, CBW4, and EBW10 also had acid phospatase. Strains CBW3 and EBW10 exhibited the enzyme activities both for esterase (C4) and esterase lipase (C8). The analysis of fatty acids revealed that in all strains, major fatty acids were anteiso <TEX>$C_{15:0}$</TEX> and iso <TEX>$C_{15:0}$</TEX>.

Sediment accretion and organic carbon burial relative to sea-level rise and storm events in two mangrove forests in Everglades National Park

The goal of this investigation was to examine how sediment accretion and organic carbon (OC) burial rates in mangrove forests respond to climate change. Specifically, will the accretion rates keep pace with sea-level rise, and what is the source and fate of OC in the system? Mass accumulation, accretion and OC burial rates were determined via 210 Pb dating (i.e. 100 year time scale) on sediment cores collected from two mangrove forest sites within Everglades National Park, Florida (USA). Enhanced mass accumulation, accretion and OC burial rates were found in an upper layer that corresponded to a well-documented storm surge deposit. Accretion rates were 5.9 and 6.5 mm yr − 1 within the storm deposit compared to overall rates of 2.5 and 3.6 mm yr − 1 . These rates were found to be matching or exceeding average sea-level rise reported for Key West, Florida. Organic carbon burial rates were 260 and 393 g m − 2 yr − 1 within the storm deposit compared to 151 and 168 g m − 2 yr − 1 overall burial rates. The overall rates are similar to global estimates for OC burial in marine wetlands. With tropical storms being a frequent occurrence in this region the resulting storm surge deposits are an important mechanism for maintaining both overall accretion and OC burial rates. Enhanced OC burial rates within the storm deposit could be due to an increase in productivity created from higher concentrations of phosphorus within storm-delivered sediments and/or from the deposition of allochthonous OC. Climate change-amplified storms and sea-level rise could damage mangrove forests, exposing previously buried OC to oxidation and contribute to increasing atmospheric CO 2 concentrations. However, the processes described here provide a mechanism whereby oxidation of OC would be limited and the overall OC reservoir maintained within the mangrove forest sediments. ► Sediment accretion and OC burial rates were determined from two mangrove forests. ► Enhanced rates were found in a layer that corresponded to a storm surge deposit. ► Accretion rates were 2.5 and 3.6 mm yr − 1 and matching or exceeding sea-level rise. ► Organic carbon burial rates were 151 and 168 g m − 2 yr − 1 .

Design and Energy Analysis for Eco-Community Based on Constructed Marine Wetland

A design concept of eco-community based on constructed marine wetland is proposed. Constructed marine wetland can clean up seawater, which is not only helpful to reduce the corrosion of seawater on the pipeline of the seawater heat pump system, but also remove the thermal impact of discharged cooling water on ocean. Energy analysis simulation of a typical coastal eco-community in Xiamen city is conducted. This investigation shows that the eco-community has higher efficiency of energy and water usage than conventional chiller with cooling tower system.