Opportunities and challenges for mangrove carbon sequestration in the Mekong River Delta in Vietnam

Increasing value is attributed to mangroves due to their considerable capacity to sequester carbon, known as ‘blue carbon’. Assessments of opportunities and challenges associated with estimating the significance of carbon sequestered by mangroves need to consider a range of disciplinary perspectives, including the bio-physical science mangroves, social and economic issues of land use, local and international law, and the role of public and private finance. We undertook an interdisciplinary review based on available literature and fieldwork focused on parts of the Mekong River Delta (MRD). Preliminary estimates indicate mangrove biomass may be 70–150 t ha^?1, but considerably larger storage of carbon occurs in sediments beneath mangroves. These natural stores of carbon are compromised when mangroves are removed to accommodate anthropogenic activities. Mangroves are an important resource in the MRD that supplies multiple goods and services, and conservation or re-establishment of mangroves provides many benefits. International law and within-country environmental frameworks offer increasing scope to recognize the role that mangrove forests play through carbon sequestration, in order that these might lead to funding opportunities, both in public and private sectors. Such schemes need to have positive rather than negative impacts on the livelihoods of the many people living within and adjacent to these wetlands. Nevertheless, many challenges remain and it will require further targeted and coordinated scientific research, development of economic and social incentives to protect and restore mangroves, supportive law and policy mechanisms at global and national levels, and establishment of long-term financing for such endeavours.     

Characteristics of stone moroko population dynamics at different stages of naturalization in lake- and steam-type Dnieper reservoirs

The probable source of stone moroko, Pseudorasbora parva (Temminck & Schlegel, 1846), populations in lake- and stream-type Dnieper reservoirs was revealed. The dynamics and specific growth rates of these populations over 20 years were analyzed. The dynamic phase portrait method was used to determine the timing of stages in the process of invader naturalization and the periods when its populations were in equilibrium. The potential growth rates of P. parva populations in the Kremenchug and Dneprodzerzhinsk reservoirs were estimated.     

Common buzzards (Buteo buteo) bio-indicators of heavy metals pollution in Sicily (Italy)

The aim of this study was to evaluate the accumulation of toxic (As, Cd and Pb) and essential (Cu, Mn and Zn) metals in samples (feathers, liver, kidney, lung, intestine and muscle) of common buzzards (Buteo buteo) from Sicily, used as bio-indicators for monitoring environmental metals pollution. All samples of buzzards were collected at the “Recovery Center of Wild Fauna” of Palermo, through the Zooprophilactic Institute. The quantitative determinations of metals were carried out using an atomic absorbtion spectrophotometer (AAS). The results obtained showed the presence of metals in all samples analyzed. For toxic metals the highest levels of Pb and As were found in liver and those of Cd in kidney; for essential metals Zn levels were higher than Cu and Mn in all tissues analyzed. Significant differences are observed in metal levels between female and male and juvenile and adult bird samples.Highest metal levels found in liver, kidney and muscle can be considered indicative of chronic exposure to metals while the presence of metals in feathers can be consequential to storing and elimination processes. The results obtained suggest that common buzzards (Buteo buteo) may be very useful as bio-indicators for monitoring environmental pollution.     

Levels and congener pattern of polychlorinated biphenyl and organochlorine pesticide residues in bluefin tuna (Thunnus thynnus) from the Straits of Messina (Sicily, Italy)

The aim of this study is to assess the accumulation of OCs and PCBs in Thunnus thynnus and to elucidate the suitability of this species as a bioindicator for monitoring contaminations of these compounds in the marine ecosystems of the Straits of Messina. This investigation was conducted on fat, liver and muscle samples of 14 T. thynnus collected during April 2004. Quantitative determination of OCs and PCBs in the various samples examined has been carried out using GC-ECD and GC-MS. The results obtained show the presence of low concentrations of p,p'-DDE and PCB congeners (138, 153 and 180) in all fat, liver and muscle samples caught in the Straits of Messina. Concentrations of p,p'-DDE and PCB congeners (138, 153 and 180) in all the samples examined were below MRLs (CE n. 97/41, 1999/65 and 1999/71).     

Ecological tax reforms and environmental benefits in Italy and Sweden

The paper calculates the implications of including monetary measurements of environmental emission changes for the welfare impacts of ecological tax reforms in Italy and Sweden. Taxes on emissions of SO₂, NO_x and CO₂ are investigated. Country-specific computable equilibrium models are used for estimating net welfare changes of the introduction of these taxes, the incomes of which are used for reducing distorting labour taxes. The results indicate that the inclusion of environmental benefits reduces the costs of ecological tax reforms considerably for both countries, and may even turn into net welfare gains.     

Nationwide survey on the natural radionuclides in industrial raw minerals in South Korea

A Nationwide survey on the natural radioactivity in industrial raw mineral commodities (17 kinds of domestic and 18 kinds of imported) that are representative minerals used in production and consumption in South Korea was conducted. The target industrial minerals can be categorized into two groups. The first group covers non-metallic and metallic raw minerals with low levels of radioactivity such as clay, silica sand, carbonates, bituminous and anthracite coal, iron ores, ilmenite, rutile, and phosphate ore. The other group comprises minerals with high levels of radioactivity including zircon and monazite. One hundred and sixty-four domestic and imported samples were analysed by gamma-ray spectroscopy using an HPGe detector. The (40)K content ranges from <0.00131 to 2.69Bq g(-1), and (226)Ra and (232)Th range over <0.0006 to 0.630 and <0.0008 to 0.474Bq g(-1), respectively. There was no anthropogenic radioactive signal in any of the samples.     

Heavy metals in four fish species from the French coast of the Eastern English Channel and Southern Bight of the North Sea

Shallow coastal waters act as nurseries for various fish species and have been recognized as essential fish habitat. We studied heavy metal concentrations in four fish species (plaice, dab, flounder and cod) as an indicator of large-scale habitat quality. The study took place along the French coasts between the Eastern English Channel and the Southern Bight of the North Sea. All species show different concentrations of measured metals (e.g., Cd, Cu, Mn and Pb) in liver but not in muscle. The highest concentrations are found for the flounder and the lowest for cod which is consistent with their habitat and diet. Although our results do not highlight levels of appreciable pollution within the study area, inter-site differences are mainly observed in the muscle tissues and are generally in agreement with the known environmental data (e.g., anthropogenic pressure). However, in the Bay of Seine, one of the most contaminated estuaries in Europe, metal concentrations are in the same range or even lower than those found in fish collected from areas distant from any anthropogenic pressures. At one site, the comparisons of the Cd, Cu and Pb concentrations between healthy and diseased dabs have been carried out on the muscle and liver tissues. The results of this preliminary study show a relationship between metal concentrations and the pathological status of the fish. The use of fish health as indicator of habitat quality is discussed.