Seasonal cholera caused by Vibrio cholerae serogroups O1 and O139 in the coastal aquatic environment of Bangladesh

Since Vibrio cholerae O139 first appeared in 1992, both O1 El Tor and O139 have been recognized as the epidemic serogroups, although their geographic distribution, endemicity, and reservoir are not fully understood. To address this lack of information, a study of the epidemiology and ecology of V. cholerae O1 and O139 was carried out in two coastal areas, Bakerganj and Mathbaria, Bangladesh, where cholera occurs seasonally. The results of a biweekly clinical study (January 2004 to May 2005), employing culture methods, and of an ecological study (monthly in Bakerganj and biweekly in Mathbaria from March 2004 to May 2005), employing direct and enrichment culture, colony blot hybridization, and direct fluorescent-antibody methods, showed that cholera is endemic in both Bakerganj and Mathbaria and that V. cholerae O1, O139, and non-O1/non-O139 are autochthonous to the aquatic environment. Although V. cholerae O1 and O139 were isolated from both areas, most noteworthy was the isolation of V. cholerae O139 in March, July, and September 2004 in Mathbaria, where seasonal cholera was clinically linked only to V. cholerae O1. In Mathbaria, V. cholerae O139 emerged as the sole cause of a significant outbreak of cholera in March 2005. V. cholerae O1 reemerged clinically in April 2005 and established dominance over V. cholerae O139, continuing to cause cholera in Mathbaria. In conclusion, the epidemic potential and coastal aquatic reservoir for V. cholerae O139 have been demonstrated. Based on the results of this study, the coastal ecosystem of the Bay of Bengal is concluded to be a significant reservoir for the epidemic serogroups of V. cholerae.     

Impacts of Florida red tides on coastal communities

Over the last few decades, scientific research has helped to describe the disease neurotoxic shellfish poisoning (NSP) by identifying the causative organism, Karenia brevis, and by characterizing the disease-causing toxins, a suite of polyether toxins called brevetoxins. In addition to causing disease in exposed human populations, K. brevis blooms and associated management responses have been linked to other effects on coastal communities. Some of these effects are negative, such as the loss of tourism dollars and the increased burden on local health care services caused by increases in human disease incidence. However, some of the effects are positive, such as the significant improvement in detecting brevetoxins in environmental samples and clinical specimens. This review discusses the health and economic effects from K. brevis blooms on Florida coastal communities and the current efforts to identify the data needed to assess social and cultural effects.     

Impacts on the deep-sea ecosystem by a severe coastal storm

Major coastal storms, associated with strong winds, high waves and intensified currents, and occasionally with heavy rains and flash floods, are mostly known because of the serious damage they can cause along the shoreline and the threats they pose to navigation. However, there is a profound lack of knowledge on the deep-sea impacts of severe coastal storms. Concurrent measurements of key parameters along the coast and in the deep-sea are extremely rare. Here we present a unique data set showing how one of the most extreme coastal storms of the last decades lashing the Western Mediterranean Sea rapidly impacted the deep-sea ecosystem. The storm peaked the 26(th) of December 2008 leading to the remobilization of a shallow-water reservoir of marine organic carbon associated with fine particles and resulting in its redistribution across the deep basin. The storm also initiated the movement of large amounts of coarse shelf sediment, which abraded and buried benthic communities. Our findings demonstrate, first, that severe coastal storms are highly efficient in transporting organic carbon from shallow water to deep water, thus contributing to its sequestration and, second, that natural, intermittent atmospheric drivers sensitive to global climate change have the potential to tremendously impact the largest and least known ecosystem on Earth, the deep-sea ecosystem.     

Impacts of flood control schemes on inland fisheries in Bangladesh: guidelines for mitigation

Flood control, drainage and irrigation (FCDI) schemes are widespread in Bangladesh. They are built to control water levels to improve agricultural production based on high yielding varieties (HYV) of rice that cannot tolerate rapid inundation or that require irrigation, and to provide protection from extreme flood events. The benefits to the agricultural sector can be significant. At some sites in Bangladesh, farmers report up to 80% more agricultural production inside the schemes than outside. However, fish production and species richness is typically lowered by these structures. Fish yields inside a typical flood control compartment can be 50% lower than outside, with up to 25 species of fish absent or less abundant. Lower rates of recruitment of migratory whitefish species, whose lateral migrations are obstructed by the embankments, were found to be largely responsible for these differences. With a risk of more extreme flooding during the monsoon season but hotter and more arid dry season conditions predicted as a consequence of climate change, more FCDI schemes may need to be constructed to provide flood protection and to meet increasing irrigation needs. Based on fisheries monitoring and mark-recapture studies undertaken at 3 sluice gates, nine recommendations for operating sluice gates to mitigate the impacts of FCDI schemes on fish production and biodiversity are described. These recommendations aim to improve the access of migratory whitefish to modified floodplains and to improve or sustain the production of resident (non-migratory) blackfish whilst minimising agricultural sector losses. Guest editors: R. L. Welcomme & G. Marmulla Hydropower, Flood Control and Water Abstraction: Implications for Fish and Fisheries     

A differential proteomic approach to assess the effects of chemotherapeutics and production management strategy on giant tiger shrimp Penaeus monodon

The intensification of shrimp farming has been related to the increasing use of chemotherapeutics and potentially suboptimal rearing conditions. For the purpose of assessing the stress level of cultured giant tiger shrimp Penaeus monodon, a proteomic analysis (2D-DIGE) was performed on hemolymph. On the one hand, shrimp were exposed for 7 days to the antibiotics enrofloxacin or furazolidone via feed (4 g kg^?1) under laboratory conditions. On the other hand, shrimp were submitted to enrofloxacin directly in field conditions in Vietnam, for which two different culture systems were distinguished (intensive and improved extensive). No significant different protein abundance pattern was induced by antibiotics under laboratory conditions, while only one protein spot displayed a 1.53-fold reduction in intensity after exposure to enrofloxacin in improved extensive ponds. When we compared the proteome of shrimp bred either in intensive or in improved extensive system, we observed 9 protein spots displaying significant difference in abundance. Among them, 3 spots of hemocyanin were under-expressed in shrimp from improved extensive ponds. At the opposite 2 spots corresponding to Sarcoplasmic Calcium-binding Protein (SCP) were less abundant in hemolymph of shrimp from intensive ponds. These results demonstrate that the very subtle effects of tested antibiotics on patterns of hemolymph protein expression are overwhelmed by the effects of conditions encountered in different production management systems, such as different oxygen and nitric concentrations.     

State and management of wetlands in Bangladesh

Wetlands are a vital link between land and water in Bangladesh. A majority of the people of Bangladesh are critically dependent on wetlands. In this paper, the values of wetlands, causes and effects of wetlands degradation, as well as the present wetlands management approach, are analyzed and recommendations for wetlands management are suggested based on participatory rural appraisal (PRA), field visit, personal experience, and existing literature and information. Wetlands play a crucial role in maintaining the ecological balance of ecosystems, but wetlands habitat of Bangladesh is under constant threat due to increase of population, intensive agriculture, overfishing, siltation, pollution, ill-planned infrastructures, lack of institutional coordination, lack of awareness, etc. As a result biodiversity is reducing, many species of flora and fauna are threatened, wetlands-based ecosystem is degenerating, and the living conditions of local people are deteriorating as livelihoods, socioeconomic institutions, and cultural values are affected. Wetlands management is not addressed separately in water management activities of Bangladesh. In order to balance human needs and wetlands conservation, a mainly community-based wetlands management approach has been taken in Bangladesh, but this is not enough to prevent the degradation of wetlands. Therefore, Bangladesh now needs a comprehensive strategy combining political, economic, social, and technological approaches to stop further degradation of wetlands. Therefore, wetlands management should be incorporated into a system of integrated land and water use and, indeed, into the socioeconomic system of the country. Policies, strategies, and management plans for sustainable use and conservation of wetlands of Bangladesh must be based on solid knowledge and understanding of their ecological and socioeconomic functions and processes.     

缺氧环境下自噬对肠黏膜屏障的影响

肠黏膜屏障是机体屏障系统的重要组成部分,可有效阻止肠道寄生菌及其毒素向肠腔外组织移位,防止机体受内源性微生物及其毒素的侵害.自噬在各种生命活动中发挥着重要作用.在缺血缺氧等应激状态下,自噬对细胞存活、清除细胞内衰老细胞器等起重要作用.缺氧可诱导自噬.多数情况下自噬被认为是细胞的一种保护作用,然而在某些条件下细胞过度自噬也能导致细胞凋亡.肠黏膜屏障损伤的研究是目前医学研究领域的一个重要课题,本文就自噬在缺氧环境下对肠黏膜屏障的影响做一综述.     

The influence of farming technique on cropland: A new approach for the Ecological Footprint

The relationship between farming management and the overexploitation of natural resources is often a theme of discussion in the environmental sciences. Moreover, farmers’ choices – driven by consumer demand – have a significant effect on the agricultural production system.The Ecological Footprint methodology as it currently implemented assumes that all cropland activities are sustained by the capacity of the ecosystem, basing both demand and capacity calculations on the exact same flow accounting. This causes some confusion in the evaluation of the ecological performance of farming because it appears that this activity has no consequences on the planet.This paper proposes a solution to this duality caused by the current methodological assumption about croplands, and investigates the influence of different farming techniques on Ecological Footprint results. Starting from the concept of an embodied footprint in production, we propose a new approach for the evaluation of farming performance. This approach permits an estimation of the impact of farming activity, linked to the farmers’ technique, and a calculation of the crop Footprint in reference to the production capacity of the natural system.Building on the central methodology of the Ecological Footprint, we provide a different evaluation system and show case study results for comparison.     

Correction to: Impacts of the regulatory environment for gene editing on delivering beneficial products

In Vitro Cellular & Developmental Biology - Plant -     

Biomonitoring of trace metal contamination in mangrove-lined Brazilian coastal systems using the oyster Crassostrea rhizophorae: comparative study of regions affected by oil, salt pond and shrimp farming activities

The oyster Crassostrea rhizophorae has been used as a biomonitor of trace metal contamination in two Brazilian coastal systems. C. rhizophorae were collected in January 1998 from 15 stations (from 4 coastal inlets (including 1 estuary) and 1 coastal beach) near Macau, Rio Grande do Norte (RN), Brazil, a region affected by the activities of the oil industry and salt manufacture in coastal salt ponds; oysters were also collected in September 1999 from 8 stations in the Curimatau estuary (RN), an estuary becoming increasingly affected by shrimp farming activities. C. rhizophorae is a net accumulator of trace metals and can be used as a biomonitor, the accumulated soft tissue concentrations representing integrated records of bioavailable metal over the life of the oyster. At Macau, significant differences in oyster accumulated concentrations (and hence bioavailabilities to the oyster) of Fe, Zn, Cu, and Mn were found between stations; raised zinc availabilities at the coastal site are in close proximity to oil industry activities but the very high availabilities of Fe, Cu and Mn in the Rio dos Cavalos estuary originate from an unknown source. In the Curimatau estuary, bioavailabilities of Mn, Pb and Cd, but particularly of Cu and Zn, to the oysters are raised at the two most downstream sites, the only sites below the effluent of a large shrimp farming enterprise. The oysters also act as a local food source, and concentrations of Zn, Cu and Pb of some of the oysters are above typical public health recommended limits.     

Toxigenic Vibrio cholerae in the aquatic environment of Mathbaria, Bangladesh

Toxigenic Vibrio cholerae, rarely isolated from the aquatic environment between cholera epidemics, can be detected in what is now understood to be a dormant stage, i.e., viable but nonculturable when standard bacteriological methods are used. In the research reported here, biofilms have proved to be a source of culturable V. cholerae, even in nonepidemic periods. Biweekly environmental surveillance for V. cholerae was carried out in Mathbaria, an area of cholera endemicity adjacent to the Bay of Bengal, with the focus on V. cholerae O1 and O139 Bengal. A total of 297 samples of water, phytoplankton, and zooplankton were collected between March and December 2004, yielding eight V. cholerae O1 and four O139 Bengal isolates. A combination of culture methods, multiplex-PCR, and direct fluorescent antibody (DFA) counting revealed the Mathbaria aquatic environment to be a reservoir for V. cholerae O1 and O139 Bengal. DFA results showed significant clumping of the bacteria during the interepidemic period for cholera, and the fluorescent micrographs revealed large numbers of V. cholerae O1 in thin films of exopolysaccharides (biofilm). A similar clumping of V. cholerae O1 was also observed in samples collected from Matlab, Bangladesh, where cholera also is endemic. Thus, the results of the study provided in situ evidence for V. cholerae O1 and O139 in the aquatic environment, predominantly as viable but nonculturable cells and culturable cells in biofilm consortia. The biofilm community is concluded to be an additional reservoir of cholera bacteria in the aquatic environment between seasonal epidemics of cholera in Bangladesh.     

Impacts of intensive dairy production on smallholder farm women in coastal Kenya

Welfare impacts of an intensive dairy technology package on women and their families are investigated on 32 smallholder crop-livestock farms in the sub-humid zone off Kilifi District, Coast Province, Kenya. Farms were stratified according to male or female extension contact. A female enumerator interviewed the wife or female head of household on each farm regarding her present and past household responsibilities and the affects of the intensive dairy enterprise on these duties and upon the welfare of the household. On three-quarters of the male contact farms, dairy operators were women. Across all farms, women performed half of all dairy-related activities, but only on female contact farms did income from the dairy enterprise accrue to women in proportion to their labor input. The equitable return of benefits to labor corresponded with better dairy unit performance on female contact farms, where women also indicated greater access to and autonomy over household resources and decision-making. Irrespective of extension contact, there was broad consensus among the women interviewed that intensive dairying has led to improved household welfare, primarily through increased household income and milk consumption. There was also wide agreement, however, that these gains have been achieved at the expense of more work for women. Women on female contact farms were observed spending dairy income on food for the household and childrens' schooling more often than their counterparts on male contact farms. Based on these and other findings, the study concludes that gender of the extension contact, dairy operator and farm owner were determinants of the intra-household impacts of intensive dairying on the smallholder farms in this study. Recommendations for design and delivery of livestock technologies for crop-based farming systems, with special emphasis on how to minimize negative impact on vulnerable household members, are inferred from study findings.Formerly International Livestock Research Institute, P.O. Box 30709, Nairobi, Kenya.     

Impact of integrated fish farming on antimicrobial resistance in a pond environment

Integrated fish farming combines livestock production with fish farming. Animal manure is shed directly into a fish pond as fertilizer and supports the growth of photosynthetic organisms. The livestock, mainly chickens and pigs, is often fed feed containing growth promoters. In this study we investigated the impact of integrated fish farming on the levels of antimicrobial-resistant bacteria in a pond environment. One integrated broiler chicken-fish farm was studied for 2 months immediately after the start of a new fish production cycle. A significant increase over time in the resistance to six different antimicrobials was found for the indicator organism Acinetobacter spp. isolated from composite water-sediment samples. The initial resistance levels prior to the new production cycle were 1 to 5%. After 2 months the levels of resistance to oxytetracycline and sulfamethoxazole reached 100%, and the levels of resistance to ciprofloxacin were more than 80%. The long-term effects of resistance on integrated farming were studied on seven additional farms. The resistance levels were particularly high among Enterococcus spp. and were also high among Acinetobacter spp. isolated from water-sediment samples compared to the resistance levels at four control farms. In conclusion, integrated fish farming seems to favor antimicrobial-resistant bacteria in the pond environment. This could be attributed to the selective pressure of antimicrobials in the pond environment and/or to the introduction of antimicrobial-resistant bacteria from animal manure. Potential risks to human health were not addressed in this study and remain to be elucidated.     

Evaluation of wildlife management through organic farming

Organic farming has often been suggested as a way of increasing biodiversity in agricultural landscapes, but literature reports a variable success. The drivers in play are multi-factorial and include the particular species groups under consideration, the precise form of organic management, the landscape structural and management context, the area and scale considered, and the historical context. Here ALMaSS, a comprehensive agent-based model simulation system, was used to produce an assessment of the impact of organic and conventional farm types, landscape structure, and management context for six common agricultural wildlife species. ALMaSS outputs can be expressed as a simple index of relative change in abundance and distribution, allowing easy comparison between scenarios. Results indicate that organic farming generally had a beneficial effect, but the degree was variable with all factors considered and there were strong interactions between factors. Targeted managements provided much greater impacts than changes in farm types. Predictions of biodiversity impacts depended on precise inputs, underlying both the view of this system as being complex, and the necessity for detailed knowledge. However, this combination of detailed modelling platform with a simple index of impact provides an easily interpreted method for objective evaluation of impacts of potential policy scenarios.     

Evaluation of Gracilaria caudata J. Agardh for bioremediation of nutrients from shrimp farming wastewater

The accelerated development of shrimp farming in Brazil in recent decades has caused negative impacts to the environment. The most evident effects resulting from this activity is the increase in organic material, the reduction in oxygen and the excessive rise in water nutrients. Thus, there is a need for finding alternative solutions that can mitigate the negative impacts caused by this activity. A potentially viable solution is the use of macroalgae to remove nutrients from the cultivation systems. This study examined in situ (shrimp pond), the growth and storage of nitrogen and phosphorous from the macroalga Gracilaria caudata. A short-term measurement experiment was also conducted to evaluate the bioremediation potential this species. These results showed positive values for biomass and growth during the study period, except at day 45 for the tubular nets and day 75 for the cages, when they reached lower values than those of the initial weight. The results obtained indicate that G. caudata may reach annual production of 59.16 ton ha⁻¹ of wet weight, which corresponds to 11.83 ton dry weight. Nitrogen and phosphorous content in the algal tissues increased with time. The mean for the period was 2.61 ± 0.26% and 0.20 ± 0.03% for the nitrogen and phosphorous, respectively. An estimate of the data showed that 1 ha of cultivated algae has the potential to remove 0.309 ton ha⁻¹ year⁻¹ of nitrogen and 0.024 ton ha⁻¹ year⁻¹ of phosphorous. The study of the biofiltration capacity of G. caudata showed a significant reduction in nutrients. The removal of NH₄–N was around 59.5%, NO₃–N 49.6% and PO₄–P 12.3% in 4 h. These results suggest that although G. caudata showed relatively modest growth rates, they can be cultivated together with shrimp and can contribute to the removal of nitrogen and phosphorous from the pond. Moreover, the capacity to efficiently remove nutrients demonstrated in laboratory experiments encourages the use of this alga as a bioremediation agent.     

Description of by-catch species from the coastal shrimp beam trawl fishery in Turkey

Seasonal landings and survey data from the Turkish shrimp beam trawl fishery were analyzed. A total of 32 valid hauls from twelve boats were analyzed 17 in autumn, 12 in spring and three in winter. The estimated by-catch to shrimp ratios exhibited a seasonal pattern, with autumn having the highest ratio. In total, the by-catch consisted of 57 species belonging to six groups of marine fauna, including Osteichthyes (25 species), Chondrichthyes (three species), Crustacea (six species), Mollusca (11 species), Cephalopoda (five species) and Echinodermata (seven species). The Osteichthyes form the most abundant (52.6%) by-catch group, followed by Crustacea > Chondrichthyes > Echinodermata > Cephalopoda > and Mollusca. Whiting, Merlangius merlangus euxinus and hake, Merluccius merluccius dominated in the commercially utilized part of the by-catch, while swimming crab, Leocarcinus depurator and gobies, Gobius bucchichi, G. niger dominated the discarded part of catches. The mean catch per unit effort (CPUE) obtained from all hauls was 5.91 ± 0.62 kg h⁻¹. There were no statistically significant differences among mean CPUE values per season (P   >   0.05).     

Regional sustainability assessment framework for integrated coastal zone management: Satoumi,ecosystem services approach,and inclusive wealth

This study proposes a novel regional sustainability assessment framework for integrated coastal zone management (ICZM). Various ICZM indicators have been developed, but their management insights are not always clear. Our framework integrates three separately developed approaches with an explicit reflection of stakeholders’ values: Satoumi (a Japanese concept of socio-ecological production landscapes, SEPLs), ecosystem services approach (ESA), and inclusive wealth (IW). We suggest that the integration of Satoumi, a uniquely Japanese concept, with the ESA and IW complements each other and increases the effectiveness of all three approaches when applied to ICZM and decision making. Satoumi describes the desired state of a coastal zone. The ESA translates Satoumi into IW and helps explain which changes to ecosystems contribute to the asset quality (i.e., shadow prices). As a sustainability indicator, IW differs from other ecological indicators because it comprises human, natural, and manufactured capital assets and incorporates shadow prices to weigh the contribution of each asset to the present value of social welfare. Shadow prices may capture the quality of capital assets in terms of how much people value them, and can therefore be a direct management target for realizing a desired coastal zone. We propose adding two sustainability criteria, desired state and strong sustainability, to the original IW to make it operational. The framework was tested in Japan’s Seto Inland Sea, and the results were analyzed in depth. Based on the outcomes, we discuss the insights for ICZM and future research. While Satoumi is a Japanese concept, the framework could be applied to other countries where similar SEPLs exist.     

Critical factors influencing the occurrence of Vibrio cholerae in the environment of Bangladesh

The occurrence of outbreaks of cholera in Africa in 1970 and in Latin America in 1991, mainly in coastal communities, and the appearance of the new serotype Vibrio cholerae O139 in India and subsequently in Bangladesh have stimulated efforts to understand environmental factors influencing the growth and geographic distribution of epidemic Vibrio cholerae serotypes. Because of the severity of recent epidemics, cholera is now being considered by some infectious disease investigators as a "reemerging" disease, prompting new work on the ecology of vibrios. Epidemiological and ecological surveillance for cholera has been under way in four rural, geographically separated locations in Bangladesh for the past 4 years, during which both clinical and environmental samples were collected at biweekly intervals. The clinical epidemiology portion of the research has been published (Sack et al., J. Infect. Dis. 187:96-101, 2003). The results of environmental sampling and analysis of the environmental and clinical data have revealed significant correlations of water temperature, water depth, rainfall, conductivity, and copepod counts with the occurrence of cholera toxin-producing bacteria (presumably V. cholerae). The lag periods between increases or decreases in units of factors, such as temperature and salinity, and occurrence of cholera correlate with biological parameters, e.g., plankton population blooms. The new information on the ecology of V. cholerae is proving useful in developing environmental models for the prediction of cholera epidemics.     

Assimilation of inorganic nutrients from salmon (Salmo salar) farming by the macroalgae (Saccharina latissima) in an exposed coastal environment: implications for integrated multi-trophic aquaculture

This paper investigated the assimilation of dissolved inorganic nitrogen (DIN) in Saccharina latissima in proximity to salmon cages in coastal waters. The bioassays were performed on plants from three stations located in the vicinity of a salmon farm (Salmo salar) in exposed waters at Tristein (63° 52′ N, 9° 37′ E) in Central Norway. The growth, the C and N content, and the nitrogen isotope ratios (δ¹⁵N) of S. latissima were monitored over 1 year. The DIN concentrations in seawater were higher at the salmon farm stations than at the reference station during the winter, and the N/P ratio at the salmon farm stations was higher from September to January and in June. S. latissima at the salmon farm stations grew faster than at the reference station. The length of S. latissima increased by 50 % when integrated with the salmon farm compared to the reference station. The N content of S. latissima was positively correlated to the DIN concentration in seawater (p?<?0.05), but the increased N supply from salmon did not result in N accumulation in S. latissima at the salmon farm station because of the dilution by a higher growth rate. The δ¹⁵N in S. latissima was higher at the salmon farm station from April to June and changed in the direction of the δ¹⁵N signature in urine. This indicated that N in S. latissima at the salmon farm station partly originated from the salmon. One hectare of S. latissima may absorb 0.8～1.2 t N during one growth season. Large-scale cultivation of S. latissima should be considered to mitigate the environmental effects of DIN wastes from salmon farms.