Nonnative Species in British Columbia Eelgrass Beds Spread via Shellfish Aquaculture and Stay for the Mild Climate

Nonnative species cause economic and ecological impacts in habitats they invade, but there is little information on how they spread and become abundant. This is especially true for nonnative species in native Zostera marina eelgrass beds in coastal British Columbia, Canada, which play a vital role in estuarine ecosystems. We tested how nonnative species richness and abundance were related to both arrival vectors and environmental factors in northeast Pacific eelgrass. Using correlation tests and generalized linear models, we examined how nonnative macroinvertebrates (benthic, epifaunal, and large mobile) and some algae species were related to arrival vectors (shipping and aquaculture) and environmental factors (climate variables, human population density, and native richness and abundance). We found 12 nonnative species, 50 % with known negative impacts within eelgrass habitats. For benthic organisms, both nonnative richness and abundance were strongly correlated with shellfish aquaculture activities, and not with shipping activity. For epifaunal nonnative richness and abundance, neither vector was significantly correlated. Climate (temperature and salinity) helped explain nonnative richness but not abundance; there was no relationship of nonnative richness or abundance to native species richness and abundance or population density. Results suggest that aquaculture activities are responsible for many primary introductions of benthic nonnative species, and that temperature and salinity tolerances are responsible for post-introduction invasion success. While aquaculture and shipping vectors are becoming increasingly regulated to prevent further international spread of nonnative species, it will be important when managing nonnatives to consider secondary spread from intraregional transport through local shellfish aquaculture and shipping.     

Recent advances in aquaculture in Japan

Conclusions During the last ten years, aquaculture, especially mariculture has undergone remarkable expansion to counter-balance the gap between the supply and demand of fishery products in Japan. Its expansion has also been supported by the traditional preference of the Japanese people for seafood. Mariculture is now being forced to change its structure due to adverse economic circumstances such as the rise in the cost of energy, feeds and other materials for culture, low market prices, deterioration of environmental conditions, and many other factors. Before these constraints can be resolved, advanced scientific knowledge and technologies must be integrated to develop new types of aquaculture. Expansion of maricultural activities to more open-sea and off shore areas would be one route to follow. Technologies for the development of formulated diets not only for young but also for adults and larvae, establishment of feeding standards, prevention of epizootic diseases must support the establishment of modern aquaculture.The culture-based fisheries, or marine ranching, is becoming a subject for further development in Japan. Much research work has been conducted with a great degree of governmental support. Establishment of a net work of seedstock production farms has made it possible to carry out releasing experiments on a large scale. A newly integrated restoration system could be developed on the basis of these experiments, even though the profits resulting from the artificial restoration of stocks is not thouroughly verified at present. The commencement of a national scheme for culture-based fisheries would be a manifestation of the enthusiasm of the Japanese fish industry.     

The role of aquaculture in human nutrition

Aquaculture, the farming and husbandry of freshwater and marine organisms furnishes about 12% of the food man obtains from the waters of the globe. It is most important in Asia and has grown rapidly in the last decade. The development of aquaculture must rely on control over production sites, in most cases, and on the application of various bio-technical inputs. It dates back to antiquity and has relied on fish and molluscs as its mainstays. Freshwater species predominate among the former but increasing competition for the freshwater resources of the globe indicate that the cultivation of marine species (mariculture) will be of increasing importance. Many species are partly or fully cultured with very few having assumed domesticated, i.e., genetically improved status. The world's tropics with their warmer climate present greater development potential for aquaculture than the temperate zone, a fact that promises to make it especially valuable in policies to improve the diets of developing nations. An overview is given here over species and methods of aquaculture with the latter seen as a continuum having at one pole feedlot types of management with strong control over environmental variables and high inputs, also resulting in high yields, and at the other an approach that could be likened to pasturage. Feeding is not excluded in it but recycling and astute steering of ecological processes are equally if not more important management mechanisms here. Biological and engineering research in aquaculture is being pursued widely. However, pollution, site competition, security of tenure to a site and the like have to be addressed in equal measure for aquaculture to hold its promise of furnishing important quantities of high quality protein food.     

Constraints and perspectives in aquaculture development

Aquaculture can be considered as a rapidly growing industry in many parts of the world. The impressive overall upward trend in production is likely to continue for the rest of the century. However, aquaculture will still be a minor contributor to the world's protein supply, even though the projected annual output of about 30 million tons can be realized by the year 2000. Nevertheless, aquaculture can play an important role in many developing countries not only within the context of rural development, but also as a commercial activity that focuses on export markets. Progress in aquaculture will always be accompanied by a number of constraints that occur with or through expansion of this industry. Some of the most important problem areas are briefly addressed, including those related to environmental degradation, disease control, human health and competition for resources. Finally, gaps in science and technology as well as research priorities are identified.     

Environmental impacts of shrimp farming with special reference to the situation in the continental United States

Shrimp culture technology has resulted in development of a major shrimp farming industry worldwide. Without the shrimp farming industry, increasing demands for shrimp by consumers could not be met, resulting in increased pressure on wild shrimp resources. Unfortunately, there are realized and potential adverse environmental effects on estuarine ecosystems as a result of shrimp farming. The effects can be categorized as wetland destruction for construction of shrimp farms, hypernutrification of estuarine ecosystems by shrim pond effluent, “biological pollution” of native shrimp stocks through escapement of aquaculture stocks, water use and entrainment of estuarine biota, and impacts of shrimp farm chemicals on estuarine systems. While the shrimp farming industry in the United States is small, the United States is effectively addressing all the realized and potential environmental impacts through regulation and research at the federal and state levels. Areas of regulation and research include stringent prohibitions on wetland destruction, regulation of effluents and support of research to eliminate and/or reduce effluents, escapement prevention technology and development of high-health stocks, minimizing entrainment of estuarine biota through water conservation and screening technology, and regulation of chemical use in the shrimp farming industry and support of research on shrimp pathology and environmentally safe disease control. Work is still in progress and not all problems have been resolved to the complete satisfaction of shrimp farmers and estuarine conservationists. However, the situation in the United States should serve as a model of how to encourage sustainable economic development through commercial shrimp farming while abating adverse environmental impacts on estuarine systems. To further improve the situation, the development and adoption of “best management practices” for shrimp aquaculture are recommended.     

On the units of geographical economics

The new `geographical economics' introduced by Paul Krugman and others has been dismissed by geographers for a number of reasons, ranging from (mis)treatment of externalities to reliance on formal modelling. These criticisms may be appropriate, but they miss some underlying unit assumptions that cause geographical economics to deal poorly with issues of scale and space. The theories produced by Krugman and others rely on the economic units of the firm, industry and economy for analysis. In contrast, geographers often use spatial units which not only reveal different processes, but can also delimit the economic units. Acknowledgement of the difference in the assumed units of analysis between geographical economics and economic geography is necessary before any useful discourse between the two fields can occur.     

Differential Effects of Bivalves on Sediment Nitrogen Cycling in a Shallow Coastal Bay

In coastal ecosystems, suspension-feeding bivalves can remove nitrogen though uptake and assimilation or enhanced denitrification. Bivalves may also retain nitrogen through increased mineralization and dissimilatory nitrate reduction to ammonium (DNRA). This study investigated the effects of oyster reefs and clam aquaculture on denitrification, DNRA, and nutrient fluxes (NO _x , NH₄ ⁺, O₂). Core incubations were conducted seasonally on sediments adjacent to restored oyster reefs (Crassostrea virginica), clam aquaculture beds (Mercenaria mercenaria) which contained live clams, and bare sediments from Smith Island Bay, Virginia, USA. Denitrification was significantly higher at oyster reef sediments and clam aquaculture site than bare sediment in the summer; however, DNRA was not enhanced. The clam aquaculture site had the highest ammonium production due to clam excretion. While oyster reef and bare sediments exhibited seasonal differences in rate processes, there was no effect of season on denitrification, or dissimilatory nitrate reduction to ammonium (DNRA) or ammonium flux at the clam aquaculture site. This suggests that farm management practices or bivalve metabolism and excretion may override seasonal differences. When water column nitrate concentration was elevated, denitrification increased in clam aquaculture site and oyster reef sediments but not in bare sediment; DNRA was only stimulated at the clam aquaculture site. This, along with a significant and positive relationship between denitrification and sediment organic matter, suggests that labile carbon limited nitrate reduction at the bare sediment site. Bivalve systems can serve as either net sinks or sources of nitrogen to coastal ecosystems, depending mainly on the type of bivalve, location, and management practices.     

Cyanobacteria in aquaculture systems: linking the occurrence,abundance and toxicity with rising temperatures

The presence of toxic cyanobacteria in aquaculture systems is a matter of concern due to its capability to produce toxin known as microcystin. This study was carried out to determine the presence, abundance and toxic potential of cyanobacteria in selected aquaculture systems in Perak, Malaysia, as well as to identify the potential main trigger of toxic cyanobacterial blooms in aquaculture water. In this study, a total of 40 freshwater fish ponds were sampled from 10 different aquaculture farms in Perak, Malaysia. Results revealed that the most frequently found cyanobacterial taxa in Perak aquaculture water was Microcystis spp., where it was detected in all of the studied ponds. During the sampling period, 75 % of the sampled ponds water contained unsafe levels of microcystin with concentrations up to 295.86 µg MC-LR equivalent L^?1. This study also discovered that a combination of temperature and pH was the key environmental factor that triggered the proliferation and toxicity of cyanobacteria, whereby temperature was statistically proven to be a more powerful predictor in comparison with pH. This study has implied that cyanobacteria can present health risk to human through aquaculture fish consumption. Moreover, the risk posed by cyanobacteria in aquaculture systems will be amplified by the influence of global warming, with rising water temperatures up to 32 °C.     

From Headwaters to Coast: Influence of Human Activities on Water Quality of the Potomac River Estuary

The natural aging process of Chesapeake Bay and its tributary estuaries has been accelerated by human activities around the shoreline and within the watershed, increasing sediment and nutrient loads delivered to the bay. Riverine nutrients cause algal growth in the bay leading to reductions in light penetration with consequent declines in sea grass growth, smothering of bottom-dwelling organisms, and decreases in bottom-water dissolved oxygen as algal blooms decay. Historically, bay waters were filtered by oysters, but declines in oyster populations from overfishing and disease have led to higher concentrations of fine-sediment particles and phytoplankton in the water column. Assessments of water and biological resource quality in Chesapeake Bay and tributaries, such as the Potomac River, show a continual degraded state. In this paper, we pay tribute to Owen Bricker’s comprehensive, holistic scientific perspective using an approach that examines the connection between watershed and estuary. We evaluated nitrogen inputs from Potomac River headwaters, nutrient-related conditions within the estuary, and considered the use of shellfish aquaculture as an in-the-water nutrient management measure. Data from headwaters, nontidal, and estuarine portions of the Potomac River watershed and estuary were analyzed to examine the contribution from different parts of the watershed to total nitrogen loads to the estuary. An eutrophication model was applied to these data to evaluate eutrophication status and changes since the early 1990s and for comparison to regional and national conditions. A farm-scale aquaculture model was applied and results scaled to the estuary to determine the potential for shellfish (oyster) aquaculture to mediate eutrophication impacts. Results showed that (1) the contribution to nitrogen loads from headwater streams is small (about 2 %) of total inputs to the Potomac River Estuary; (2) eutrophic conditions in the Potomac River Estuary have improved in the upper estuary since the early 1990s, but have worsened in the lower estuary. The overall system-wide eutrophication impact is high, despite a decrease in nitrogen loads from the upper basin and declining surface water nitrate nitrogen concentrations over that period; (3) eutrophic conditions in the Potomac River Estuary are representative of Chesapeake Bay region and other US estuaries; moderate to high levels of nutrient-related degradation occur in about 65 % of US estuaries, particularly river-dominated low-flow systems such as the Potomac River Estuary; and (4) shellfish (oyster) aquaculture could remove eutrophication impacts directly from the estuary through harvest but should be considered a complement—not a substitute—for land-based measures. The total nitrogen load could be removed if 40 % of the Potomac River Estuary bottom was in shellfish cultivation; a combination of aquaculture and restoration of oyster reefs may provide larger benefits.     

A multidisciplinary approach to evaluating impacts of shellfish aquaculture on benthic communities

The impact of suspended mussel culture (Mytilus edulis, M. trossulus) on the benthos of a small Nova Scotia cove (7 m depth) was assessed using meehods involving both benthic metabolism and community structure. Due to deposition of mussel feces and pseudofeces, sedimentation rate was higher under the mussel culture lines than at an adjacent reference site of similar sediment texture. Porewater profiles of sediment sulfate and sulfide indicated greater anaerobic metabolism at the mussel site than at the reference site, but sulfide was absent from the upper centimeters of sediments under the mussels. Seasonal measures of sediment oxygen demand showed little change between sites, but maximum rates of ammonium release at the mussel site were twice the highest rates measured at the reference site. Abundance of benthic macrofauna was higher at the reference site, but biomass was generally lower. Biomass at the mussel site was dominated by molluscs (Ilyanassa spp. andNucula tenuisulcata), that were attracted to mussels fallen from the culture and/or enriched organic matter due to biodeposition. Species diversity was lower at the reference site due to the dominance of the polychaeteNephtys neotena. Abundance-biomass comparisons (ABC method) of faunal analysis did not indicate any impact of biodeposition at this site: however, disturbance did not result in a typical assemblage of small opportunistic species anticipated with this method. Cluster analysis of macrofauna usually provided a clear separation between the sites. Since the contruction of a causeway (1968), foraminifera species composition showed a temporal response to temperature changes in the cove by shifting toward calcareous species, but assemblages downcore showed little or no relationship to aquaculture impacts. Although there is a shift toward anaerobic metabolism at the mussel lines, the impact of mussels falling to the sediments was more noticeable in benthic community structure than was any impact due to organic sedimentation or hypoxia. In general the impact of aquaculture on the benthos appeared to be minor. Furtyher assesment of these consequences may mandate both taxonomic and energetic approaches to impact assessment.     

Impacts of saline water irrigation and shrimp pond discharges on the surrounding waters of a coastal district in the Mekong delta of Vietnam

This study discusses impacts of saline water irrigation and shrimp pond discharges on the surrounding waters in the coastal Cai Nuoc district, Mekong delta of Vietnam where the landscape was re-shaped by shrimp aquaculture since 2000. Sampling took place at the end of the wet season of 2009 in the district (as aquaculture sites) and a nearby freshwater-dominated reference site. The aquaculture sites showed significantly higher salinities and organic loadings (biochemical oxygen demand, chemical oxygen demand) but lower dissolved nutrients (NO₃–N, NO₂–N, and PO₄–P), total iron, and phytoplankton diversity compared to the reference site. Irrigation of saline waters has exacerbated salinization, leading to significant biological changes in the surrounding waters. Impacts of shrimp pond discharges on the surrounding waters were not very dramatic in terms of organic loadings and nutrients. The increase in organic loadings in the surrounding waters was mostly due to contribution from other pollution sources, such as domestic/industrial discharges and runoff. Enhanced salinization and changes in nutrients resulted in a decline in species richness and diversity, and a change in the evenness of the phytoplankton community. Besides, the composition of zooplankton and zoobenthos were also restructured. The mild impacts of shrimp pond discharges on the surrounding waters were primarily due to the limited inputs for shrimp aquaculture in this area.     

The effect of aquaculture practices on the benthic macroinvertebrate community of a lagoon system in the Bay of Cádiz (southwestern Spain)

Monthly quantitative Ekman-Birge grab sampling was used to characterize and compare the composition and structure of the benthic macroinvertebrate community inhabiting semi-enclosed polyculture lagoons (SPL) (three sampling sites) and enclosed monoculture ponds (EMP) (two sampling sites) of a lagoonal system of the Bay of Cádiz. The two areas differed considerably in habitat characteristics and aquaculture management. The SPL area was characterized by low rates of water exchange, low fish densities, and the presence of a macroalgal cover. In the EMP area, there was a complete exchange of water daily (by pumping) and a supply of food pellets, density of fish was high, and no vegetative cover was present. There were considerable differences in species composition between habitats with different culture methods: 11 of the 21 most abundant species were exclusive to one or the other. Several epibenthic species were abundant in the polyculture lagoon but were low in density or were absent in monoculture ponds. Some infaunal species, on the other hand, were more abundant in the monoculture ponds. Univeriate measures of community structure (abundance and biomass, Margalef’s species richness, Shannon-Wiener diversity, and Pielou’s evenness indices) did not indicate significant differences between the SPL and EMP areas. Conversely, the abundance-biomass comparison (ABC) method indicated that, on average, the macrobenthic community was moderately disturbed in the SPL and undisturbed in the EMP areas. Multidimensional scaling (MDS) ordination and hierarchical cluster analysis (Bray-Curtis similarity measure) revealed the occurrence of two main benthic assemblages that corresponded to the aquaculture methods. The different rates of water exchange for the two aquaculture practices seem to have contributed to differences in the composition and structure of the benthic communities.     

The social relations of catfish production in Vietnam

The growth of intensive export-oriented Pangasius catfish production in Vietnam’s Mekong Delta is unparalleled in terms of rapidity and scale by any other agricultural sector, with production climbing from a low base to more than 1 million tons in a single decade. This paper examines the effects of this remarkable change on the rural class structure in locations where catfish farming has boomed, and analyses the role of local state-society relations in mediating outcomes resulting from the integration of local actors into the global value chain. We conclude that private economic activity is deeply embedded in informal relations with the state bureaucracy in Vietnam, with the result that the expansion of catfish aquaculture has generally acted to reproduce and entrench existing class relations rather leading to a radical reconfiguration of the rural class structure.     

胜利油田采油污水综合特征及利用评价

胜利油田作为我国石油的重要赋存区,其地热资源也相当丰富。在节能减排的背景下,采油产生的污水由于其相对较高的温度,除了用于回注开采层提高石油采收率,还能用于供暖、洗浴等。通过采集胜利油田济阳坳陷探区19个典型采油联合站分离出的采油污水,分析其水化学组分和微量元素,总结了采油污水的基本水化学特征以及腐蚀性和结垢性趋势。研究结果表明,本次采集的采油污水属于咸水-卤水,矿化度最高可达59.7gL-1,其中锂和锶的含量达到了作为矿水的要求。综合腐蚀性系数和拉申指数评价方法得出采油污水属于强腐蚀性水。结垢性评价结果表明,这些采油污水不会形成碳酸钙垢,也不具备二氧化硅的结垢条件,仅滨南和河口采油厂采油污水有硫酸钙结垢的可能性,综合利用前需要及时预防和处理。采油污水可以用于开采层回注、供暖、洗浴、温室大棚和水产养殖等,一方面可以减少环境污染,另一方面还能改善能源结构,具有良好的社会和经济效益。在综合利用采油污水时,需要考虑其腐蚀性和结垢性,选择合适的预处理方式及管道。     

电解脱氮除磷技术在海产养殖废水治理中的研究

海产养殖迅速发展造成水域富营养化、赤潮频发,海产养殖废水污染的治理迫在眉睫。为解决此问题将电解脱氮除磷技术应用在海产养殖废水处理中,并探讨电压、pH、极板间距和电解时间对脱氮除磷去除率的影响。结果表明:脱氮除磷的去除率与电压成正相关,与极板间距成负相关。在电压为30V,极板间距10cm,pH为7时,NH_4~+-N、NO_3~--N和TP的去除率达到最大分别为72%、90%、85%。     

The role of economic sectoral structure as a policy mechanism towards more resilient peripheral regions: the case of South Africa

The role of economic sectoral structure in regional growth and development is widely acknowledged. However, there has been scarce reflection on its role as a policy instrument, particularly for peripheral regions. In reaction, this paper investigates the role of economic sectoral structure as a policy instrument towards more resilient peripheral regions. Through a multiple country policy analysis, the paper determines to what degree economic sectoral structure is reflected in regional development policies of 18 countries with predominantly rural characteristics and lagging regions. Moreover, the role of economic sectoral structure towards more resilient regions is quantified and measured for a specific peripheral region case in South Africa as developing country exhibiting poor economic resilience. The paper highlights related variety as a key ingredient for a region to reach a state of dynamic stability between adaptation and adaptability towards enhanced long-term resilience capacity of the peripheral region. The research concludes that policy focus should support the maintenance of the sectors and industries of comparative advantage on the regional scale, but strongly focus on sectoral comparative advantage within the national scale (if present) to establish a more robust region. This will establish and strengthen the identified peripheral growth centres as centres of national competitiveness and specialisation. Primary policy actions as emanated from the literature and the multiple country policy analysis will promote more efficient sectoral composition as key towards more resilient peripheral regions. It is acknowledged that these policy actions must be informed by a detailed regional economic analysis for different peripheral regions to determine inherent and latent economic potential and link with interdependent industries. This paper will highlight that regional policy should become more explicit by exploiting the role of economic and natural resources as growth engines for the peripheral regional economy in a more effective way through a multi-centred territorial structure.

     

The Influence of Oyster Farming on Sediment Bacterial Communities

Aquaculture currently provides half of all fish for human consumption, and this proportion is expected to increase to meet the growing global demand for protein. As aquaculture, including oyster farming, expands, it is increasingly important to understand effects on coastal ecosystems. The broad-scale ecological effects of oyster aquaculture are well documented; however, less is known regarding the influence of oyster aquaculture on sediment bacterial communities. To better understand this relationship, we compared three different oyster farming practices that varied in oyster biomass and proximity of oysters to the sediment. We used high-throughput sequencing and quantitative polymerase chain reaction to examine the effect of oyster farming on sediment bacterial communities. We examined the entire bacterial community and looked specifically at bacteria that support essential estuarine ecosystem services (denitrifiers), as well as bacteria that can be detrimental to human health (members of the Vibrio genus). We found that oyster biomass increased Vibrio richness and sediment carbon content, which influenced bacterial community composition. When compared to reference sites, the overall abundance of bacteria was increased by the bottom planting method, but the associated increases in denitrifiers and Vibrio were not significant. We were unable to detect V. parahaemolyticus, V. vulnificus, or V. cholera, the three most common Vibrio pathogens, in any sample, suggesting that oyster farming did not enhance these potential human pathogens in sediments at the time of sampling. These results highlight how differences in oyster farming practice can affect sediment bacterial communities, and the ecosystem services they provide.     

中国浅海贝藻养殖对海洋碳循环的贡献

中国是浅海贝藻养殖的第一大国,年产量超过1 000万t。根据贝藻养殖产量、贝藻体内碳元素的含量及其贝类能量收支,推算出2002年中国海水养殖的贝类和藻类使浅海生态系统的碳可达300多万t,并通过收获从海中移出至少120万t的碳。该结果不仅为探讨全球“遗漏的碳汇”问题提供了一个新的线索,同时也证明了浅海的贝类和藻类养殖活动直接或间接地使用了大量的海洋碳,提高了浅海生态系统吸收大气CO2的能力。另外,贝藻的养殖活动与浅海生态系统的碳循环之间关系复杂,相互作用明显,因此,它的生物地球化学过程是一个值得深入研究的科学问题。     

互锚式薄壁挡土墙影响因素分析

针对日益增多的高填方路堤,提出了一种新型的挡土墙结构--互锚式薄壁挡土墙,它具有成本低廉、结构合理、施工方便的特点,有利于保护环境,具有广泛地应用前景。在现场测试的基础上进行有限元分析,总结出拉筋应力、侧向土压力、侧向位移等指标的可能影响因素,为这种新结构的设计及优化提供了理论依据。     

Diversity of marine and brackish water nitrite-oxidizing consortia developed for activating nitrifying bioreactors in aquaculture

Nitrite is a well-known toxicant in aquaculture, produced as intermediate in nitrification. Two nitrite-oxidizing bacterial consortia, one from marine environment and the other from brackish water, were developed by enrichment technique at National Centre for Aquatic Animal Health, for removal of nitrite from recirculating aquaculture systems. In the present study, bacterial diversity of the consortia was assessed based on 16S ribosomal RNA and the functional gene analysis. Clone libraries of 16S ribosomal RNA gene and nitrite oxidoreductase A gene were constructed, and amplified ribosomal DNA restriction analysis was carried out to cluster the clones. Dendrograms generated through molecular characterization showed 29 and 27 clusters in marine and brackish water consortia, respectively. Phylogenetic analyses of representative clones from each cluster depicted profound diversity in the consortia consisting autotrophic nitrifiers belonging to Proteobacteria, anaerobic ammonia oxidizers, Actinobacteria, Bacteroidetes and heterotrophic denitrifiers. Functional gene analysis corroborated with the presence of specific nitrite oxidizers. Quantitative polymerase chain reaction showed the abundance of nitrite oxidizers in the order of 1.51 ± 0.38 × 10⁹/g and 4.88 ± 0.42 × 10⁷/g in marine and brackish water consortia, respectively. Diversity indices and pattern of distribution of organisms within the consortia were analyzed using Geneious, VITCOMIC, Mega 5 and Primer software. The marine nitrite-oxidizing consortium showed higher Shannon–Wiener diversity and mean population diversity than brackish water consortium, suggesting that the former was having more diverse flora and higher potential to be used as startup cultures for activating nitrifying bioreactors subsequent to acclimatization to the required salinity.