Anthropogenic influence on the water quality in Guanabara Bay, Rio de Janeiro, Brazil

Guanabara Bay is a 384-km² coastal bay with 70% of the population of the metropolitan area of Rio de Janeiro located within its drainage basin. The water quality of the Bay is impacted by domestic and industrial runoff, of which only 15% has been adequately treated. However, based on a 14-year monitoring program, the water quality for most of Guanabara Bay remains acceptable because of intense tidal flushing, and we failed to find a worsening of conditions during the 14-year study. The inner shallow regions of the Bay, the western and northwestern parts, receive most of the drainage from metropolitan Rio de Janeiro. It is here that the water quality is alarmingly poor, characterized by hypertrophic conditions and occasional hypoxic events. Fecal coliform counts in these inner reaches of the Bay are 4–100 times higher than the maximum acceptable count for recreational waters. Hypertrophic conditions prevail in Guanabara Bay, which is characterized by low dissolved oxygen, high biochemical oxygen demand, peaks in fecal coliform, and extremely high chlorophyll-a concentrations, which reflect high quantities of nutrients entering the system. These anthropogenic pressures are a threat to planktonic and benthic communities and are reminiscent of San Francisco Bay 30 years ago. The Guanabara Bay water quality could be returned to pre-1950 conditions, but it would require sufficient political will and economic investment to ensure that at least 80–90% of the domestic and industrial sewage were treated adequately. Electronic Publication     

Geochronology of anthropogenic radionuclides in Ribeira Bay sediments, Rio de Janeiro, Brazil

Ribeira Bay is located approximately 130 km south of the city of Rio de Janeiro and receives discharges of liquid effluent from the Angra dos Reis nuclear power plant (NPP) site, where two pressurized water reactors are located. To test whether the presence of anthropogenic radionuclides in sediments in Ribeira Bay could be correlated to the NPP operations, we sampled seven sediment cores and determined accumulation rates and chronologies. Only one sediment core did not exhibit a superficial mixing layer; this sample was used for dating purposes. Cesium-137 and ²⁰⁷Bi were observed in this sediment profile, but their presence was associated with atmospheric fall-out rather than the nearby NPP. The exponential decay of ²¹⁰Pb concentration with sediment layer depth was verified below a superficial mixing layer for all other sediment cores. Calculated accumulation rates ranged from 1.2 mm y⁻¹ in the inner bay to 6.2 mm y⁻¹ close to its entrance.     

Evaluating the cost of flood damage based on changes in extreme rainfall in Japan

We estimated the cost of flood damage using numerical simulations based on digital map data and the flood control economy investigation manual submitted by the Ministry of Land, Infrastructure, Transportation, and Tourism in Japan. The simulation was carried out using a flood model incorporating representative precipitation data for all of Japan. The economic predictions, which estimate flood damage caused by extreme rainfall for the return periods of 5, 10, 30 50, and 100 years, are as follows: (1) the cost of flood damage increases nearly linearly with increases in extreme precipitation; (2) assuming that flood protection is completed for a 50-year return period of extreme rainfall, the benefit of flood protection for a 100-year return period of rainfall is estimated to be 210 billion USD; (3) the average annual expected damage cost for flooding is predicted to be approximately 10 billion USD per year, based on the probability of precipitation for a return period of 100 years and assuming that flood control infrastructures will be completed within the 50-year return period and will be able to protect from flooding with a 50-year return period; (4) urban and rural areas are predicted to suffer high and low costs of damage, respectively. These findings will help to derive measures to enhance flood protection resulting from climate change.     

Social contrasts and land use conflicts in the context of sustainable development and management needs: a case study from an estuarine area at northeastern Brazil

This paper discusses the misuses of estuaries in Northeast of Brazil and the social contrasts there found. The several kinds of impacts promoted by capitalist enterprises in one side and by traditional population, who uses estuary areas at another side, are in complete disagreement with the ethic of sustainable development. Our intention is to demonstrate how these aspects occur in the River Paraíba do Norte estuary, in the State of Paraíba. Observing the conditions of infrastructure besides the multiple ways to handle along with the extension of the estuary, we could recognize 59 focus of conflict between the incorrect use and sustainable mode. Most of the uses concern to traditional artisan fishing, slums and recreational marinas, reflecting the great social contrast between rich and poor people settled in area studied. Ecological and social implications of these conflicting uses are discussed and measures to improve the situation are suggested.     

The use of DPSIR framework to evaluate sustainability in coastal areas. Case study: Guanabara Bay basin,Rio de Janeiro,Brazil

The Guanabara Bay basin, SE Brazil, is shown as an experimental site to evaluate development and sustainability in coastal areas. We developed a Driver–Pressure–State–Impact–Response (DPSIR) framework in a practical context to integrate natural and socio-economic indicators. Sustainability reflects public policies towards the utilization of natural resources. Cost-benefit analysis (CBA) included in DPSIR evaluates losses and benefits resulting from such policies. CBA has some limitations due to the difficulty of valuating environmental goods and services. Instead of valuating them we propose to combine sustainability indicators and defensive expenditures for the implementation of public policies. This approach agrees with the environmental conservation paradigm implicit in sustainable development. It allows an estimation of the physical natural capital depreciation (PNCD), by using it to correct the gross domestic product (GDP) of the study area, and demonstrating the present non-sustainable characteristics of the current policies applied to the area.     

Human appropriation of net primary production (HANPP) in Nova Scotia,Canada

Photosynthetically fixed energy from the sun, in the form of net primary production, ultimately supports the majority of life on earth. Given the importance of this energy source, we calculate the human appropriation of net primary production (HANPP) for the province of Nova Scotia, Canada. We find that over 25% of potentially available production is appropriated by humans through harvest (forestry and agriculture) and land cover change. The level of appropriation in Nova Scotia is close to the global average, when methodological differences between studies are taken into account, but substantially less than in Austria and India where detailed surveys have also been conducted. Furthermore, HANPP is not distributed evenly throughout the province, but is instead concentrated in the north-central counties, where appropriation reaches 50%. We discuss the implications of these results, and the novel method used to obtain them, in the context of biophysical assessment and the species-energy hypothesis.     

Current state and long-term changes of the <Emphasis Type="Italic">Crenomytilus grayanus</Emphasis> community in Vostok Bay,Sea of Japan

The composition and structure of the Gray mussel (Crenomytilus grayanus) community in Vostok Bay of the Sea of Japan have been studied. A total of 165 species have been identified in the macrobenthos. Its species composition has changed insignificantly since the 1970s. The total biomass of the biocenosis has decreased, and the size-age composition of the C. grayanus population has changed due to poaching. The trophic structure of the community has also changed, with the Shannon indices of species diversity and equitability (E) becoming lower, due to intensive organic pollution of Vostok Bay resulting from increasing recreational activities and sewage discharge.