Laboratory experiment to determine the potential of two macroalgae from the Russian Far-East as biofilters for integrated multi-trophic aquaculture (IMTA)

Two local macroalgal species (Undaria pinnatifida and Gracilaria vermiculophylla) were tested in laboratory experiments to determine their nutrient uptake potential and their physiological response to waste water effluents from a mariculture project on bivalve mollusks (mussels). No negative effects on the growth and photosynthesis rates of the algae were detected. High nutrient uptake rates and high nutrient removal efficiency were measured in both tested species. We propose that U. pinnatifida be introduced into IMTA systems during the cold-water season to remove nutrients from cultured animals. The culture of this species can be alternated with that of G. vermiculophylla during warm-water season in order to provide a longer biofiltration period.     

人工鱼礁建设对浙江嵊泗海域营养盐与水质的影响

根据2003-2007年对嵊泗人工鱼礁海域11个航次调查所获得的实验数据,运用鱼礁区和对照区相比较的方法,分析了该海域不同季节氮、磷营养盐和水质在投放人工鱼礁后的变化,并对海域水质状况进行评价。结果表明,无机氮大多数处于阈值范围或低于最小阈值,活性磷酸盐含量则严重超标,N/P值范围为0.6280-14.8273,嵊泗海域处于氮限制,溶解氧不成为该海域浮游生物的生长限制因子。投放人工鱼礁后,生态效应不能在短期里得以体现,鱼礁区的水质情况要好于对照区,海域对P的富集强度大于N,人工鱼礁建设对再生生产力影响较大,对新生产力的贡献很小。       

Integrated treatment of farm effluents in New Zealand’s dairy operations

Maintaining growth through intensification in the New Zealand dairy industry is a challenge for various reasons, in particular sustainably managing the large volumes of effluent. Dairy farm effluents have traditionally been treated using two-pond systems that are effective in the removal of carbon and suspended solids, however limited in their ability to remove nutrients. In the past these nutrient-rich two-pond treated effluents were disposed of in surface waters. Current environmental concerns associated with the direct discharge of these effluents to surface waters has prompted in developing technologies to either minimise the nutrient content of the effluent or apply effluents to land. Here, we discuss various approaches and methods of treatment that enable producers to sustainably manage farm effluents, including advanced pond treatment systems, stripping techniques to reduce nutrient concentration, land application strategies involving nutrient budgeting models to minimise environmental degradation and enhance fodder quality. We also discuss alternative uses of farm effluents to produce energy and animal feed.     

Discharge of disinfected wastewater in recipient aquatic systems: fate of allochthonous bacterial and autochthonous protozoa populations

The discharge of disinfected effluents affects the bacterivorous ability of protozoa and the effect depends on the disinfectant applied. Chlorine provokes a decrease in the number of protozoa and a delay in the bacterivorous ability. The discharge of ozonated and peracetic acid-treated wastewater provokes only an initial slight decrease in bacterivorous ability. No correlation was found between toxicity values detected using the Microtox^™ assay and the effect of disinfected effluents on freshwater protozoa populations. After the disinfection processes, recipient systems (fresh and marine water) have different effects on the survival of Escherichia coli populations discharged to them. The effect of the freshwater recipient system is less negative than the effect provoked by sea-water, and the differences detected depend on the disinfection treatment applied. The wastewater bacterial population as a whole is able to grow after discharge of disinfected wastewater to receiving waters. However, in the absence of predation or competition, the recipient systems exert selection, with rod-shaped bacteria predominating.     

The role of fish in the regulation of nutrient cycling in Lake Balaton, Hungary

SUMMARY. 1. In 1984 an enclosure experiment was carried out in order to elucidate the importance of nutrient supply from fish to phytoplankton during the critical summer period in eutrophic Lake Balaton. One enclosure was stocked with fish and the other left empty.
2. Two peaks were recorded in primary production reaching maximum values in the fish enclosure.
3. In the enclosure with fish, inorganic nitrogen concentrations increased gradually till the end of the experiment, with ammonia making up the largest component. Lower dissolved phosphorus concentrations in the fish enclosure, with its higher primary production rate, may indicate an intense cycling of this nutrient.
4. The biological and chemical changes occurring in the enclosure suggest that bream removal can be an effective tool in water quality control for Lake Balaton.     

Some positive and negative effects of stocking whitefish on the ecosystem redevelopment of Hjarbæk Fjord,Denmark

In 1984 the County of Viborg introduced a large-scale programme to improve the water quality in Hjarbæk Fjord, a freshwater fjord cut off from the sea in 1964. Measures were taken to reduce the discharges of nutrients from various sources. To reduce the nuisance of chironomids a large release of whitefish (Coregonus lavaretus L.) was incorporated in the programme. The effects of these efforts on the fish, benthos and plankton communities were studied during a period of five years. The whitefish established a self-reproducing population with a very good growth rate, and may have created quantitative and qualitative changes in the plankton community. Observed changes in the benthos community may also be related to predation by whitefish. The study did not confirm that whitefish could actually control the population of chironomids and diminish, thus, the nuisance caused by them. The stocking of whitefish created an exploitable fish stock of a valuable fish species in the hypertrophic Hjarbæk Fjord.

     

Impact of acidification and eutrophication on the distribution of fish species in shallow and lentic soft waters of The Netherlands: an historical perspective

The species richness and composition of fish assemblages were examined in lentic soft waters in The Netherlands. The selected bodies of water reflected a large variation in geomorphological and limnological factors. In total, 24 fish species were encountered in Dutch soft waters. During 1983–1984 Esox lucius, Perca fluviatilis, Rutilus rutilus, Scardinius erythrophthalmus, Tinca tinca and Umbra pygmaea were quite common. In slightly acid and alkaline waters (pH≥5) Rutilus rutilus, Scardinius erythrophthalmus, Perca fluviatilis, Ictalurus nebulosus and Cyprinus carpio accounted for about 90% of the total number of specimens in the catches. Strongly acid waters (pH < 5) generally were fishless. If fish were present in these waters, however, the catches mainly consisted of Umbra pygmaea. Only in a few strongly acid systems were other species collected. The lowest pH at which certain fish species occurred varied from 3.1 to 7.0. In particular, Umbra pygmaea was extremely acid-tolerant. The percentage of waters which harboured fish as well as the average number offish species per water decreased steeply between pH 6 and 4. The sampled waters showed remarkable differences in their fish assemblages. With hierarchical classification, six groups of waters could be distinquished with respect to their fish fauna. The site groups are defined and characterized physico-chemically and their fish assemblages described. Multivariate analysis showed that the structure of fish communities is strongly related to the pH, the alkalinity, trophic level and the ionic composition of the water. Comparison of historical and recent data on the occurrence of fish strongly indicated that in many sampling sites fish species or even entire fish assemblages had disappeared. Ordination of available data also illustrated recent changes in community structure. At least 67% of the nowadays extremely acid waters formerly harboured fish populations. The impoverishment of fish communities or the total loss of fish were primarily caused by cultural acidification. Limited nutrient enrichment of soft waters only resulted in minor alterations of fish assemblages.     

Ecology and distribution of diatoms in Biscayne Bay,Florida (USA): Implications for bioassessment and paleoenvironmental studies

The spatial and temporal distribution of planktonic, sediment-associated and epiphytic diatoms among 58 sites in Biscayne Bay, Florida was examined in order to identify diatom taxa indicative of different salinity and water quality conditions, geographic locations and habitat types. Assessments were made in contrasting wet and dry seasons in order to develop robust assessment models for salinity and water quality for this region. We found that diatom assemblages differed between nearshore and offshore locations, especially during the wet season when salinity and nutrient gradients were steepest. In the dry season, habitat structure was primary determinant of diatom assemblage composition. Among a suite of physicochemical variables, water depth and sediment total phosphorus (STP) were most strongly associated with diatom assemblage composition in the dry season, while salinity and water total phosphorus (TP) were more important in the wet season. We used indicator species analysis (ISA) to identify taxa that were most abundant and frequent at nearshore and offshore locations, in planktonic, epiphytic and benthic habitats and in contrasting salinity and water quality regimes. Because surface water concentrations of salts, total phosphorus, nitrogen (TN) and organic carbon (TOC) are partly controlled by water management in this region, diatom-based models were produced to infer these variables in modern and retrospective assessments of management-driven changes. Weighted averaging (WA) and weighted averaging partial least squares (WA-PLS) regressions produced reliable estimates of salinity, TP, TN and TOC from diatoms (r² = 0.92, 0.77, 0.77 and 0.71, respectively). Because of their sensitivity to salinity, nutrient and TOC concentrations diatom assemblages should be useful in developing protective nutrient criteria for estuaries and coastal waters of Florida.     

Enclosures study of trophic level interactions in the mesotrophic part of Lake Balaton

Enclosures, open to the bottom sediments and to the atmosphere, containing about 17 m³ of lake water in the mesotrophic area of Lake Balaton, were used to elucidate the role of the benthivorous fish bream (Ambramis brama L.) in the lake during 1984–1986.Throughout the whole period water was less transparent in the enclosure containing fish, which strongly influenced the concentrations of suspended solids and chlorophyll a.Both phytoplankton biomass and production readily responded to nutrient increase in the enclosure with fish. In 1985 diatoms were replaced by cyanobacteria whereas in 1986, at a lower fish stocking, a shift in algal structure towards chlorophytes was observed.Egested organic substances and the resuspension of sediment particles by fish increased bacterial production.     

鲢鱼的放养对水质影响的研究进展

鲢鱼的放养对水质影响的研究进展董双林（华东师范大学生物系,上海２０００６２）ＥｆｆｅｃｔｏｆＳｉｌｖｅｒＣａｒｐＳｔｏｃｋｉｎｇｏｎＷａｔｅｒＱｕａｌｉｔｙｇ：ＲｅｓｅａｒｃｈＡｄｖａｎｃｅｓ．￥ＤｏｎｇＳｈｕａｎｇｌｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＢ...     

Effects of entrapment and cooling water discharge by the Bergum Power Station on 0+ fish in the Bergumermeer

The numbers, distribution and size of 0+ fish in Bergumermeer and in the cooling water system of the Bergum Power Station were registered from 1978 to 1981. An exponentially decreased vulnerability to entrapment by the power station was found with increasing size of fish. Because of the large water intake in relation to the lake volume, entrainment mortality of fish larvae in May and June is large and probably of the same order of magnitude as the natural mortality. In the same period the Bergumermeer can be supplied with large amounts of fish larvae, immigrating passively with the water current. Impingement mortality later on in the season is insignificant compared with natural mortality. The heated effluents from the power station influence the distribution and the size of 0+ fish in the lake. Year-class strength of pikeperch may be improved due to the larger size of 0+ pikeperch. Less water intake as a possibility to minimize entrainment is discussed.     

微生物在水环境污染物降解中的应用

每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中,因此,地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂,除草剂、烃等)的严重挑战,特别是近年来随着集约化养殖的发展,废水污染问题日益突出,并且随着分析手段的进步,能够检测到被排入水环境中的化学污染物质也越来越多,这些化学污染物对水环境中的生物产生有害影响.但是,微生物在污染控制上具有许多重要的作用.因此,本文对微生物在水环境污染物降解中的应用进行了评论.结果表明微生物主要是应用在水产养殖水中,而在其它的水体系(如河、湖、海)的应用较少.     

微生物在水环境污染物降解中的应用（英文稿）

每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中, 因此, 地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂、除草剂、烃等)的严重挑战, 特别是近年来随着集约化养殖的发展, 废水污染问题日益突出, 并且随着分析手段的进步, 能够检测到被排入水环境中的化学污染物质也越来越多, 这些化学污染物对水环境中的生物产生有害影响。但是, 微生物在污染控制上具有许多重要的作用。因此, 本文对微生物在水环境污染物降解中的应用进行了评论。结果表明微生物主要是应用在水产养殖水中, 而在其它的水体系(如河、湖、海)的应用较少。     

微生物在水环境污染物降解中的应用

每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中, 因此, 地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂、除草剂、烃等)的严重挑战, 特别是近年来随着集约化养殖的发展, 废水污染问题日益突出, 并且随着分析手段的进步, 能够检测到被排入水环境中的化学污染物质也越来越多, 这些化学污染物对水环境中的生物产生有害影响。但是, 微生物在污染控制上具有许多重要的作用。因此, 本文对微生物在水环境污染物降解中的应用进行了评论。结果表明微生物主要是应用在水产养殖水中, 而在其它的水体系(如河、湖、海)的应用较少。     

Environmental Effects of Marine Fish Pond Culture in the Ria Formosa (Southern Portugal)

Macrobenthic organisms, sediment and water characteristics were analysed in two fish farms in the Ria Formosa at control sites, near the outflows and inside the decantation ponds, in winter and summer 2001. Both farms operate under semi-intensive and intensive regimes. Statistical analysis reveals a very localised effect of fish farms near the outflow of the semi-intensive ponds, with an increase of density of small-sized organisms. The fish farms released high concentrations of nutrients and relatively low quantities of suspended solids. The effects of the effluents on the sediment were significant in the immediate vicinity of discharge point-source. The effects were localized mainly because all farms operate near the sea inlets, where water renewal rates are higher to ensure good fish production, thus permitting a important flushing of waste water. The effects of the effluents were more pronounced in summer because of the farms’ higher productivity at that time of the year. The decantation ponds, obligatory for the intensive regime, were apparently efficient in removing part of the solid waste. However, semi-intensive fish farms represent important sources of dissolved nutrients in the Ria Formosa and the joint effect of several fish farms in a semi-enclosed coastal system may be considerable.     

From Bacteria to Fish: Ecological Consequences of Seasonal Hypoxia in a Great Lakes Estuary

The occurrence of bottom-water hypoxia is increasing in bodies of water around the world. Hypoxia is of concern due to the way it negatively impacts lakes and estuaries at the whole ecosystem level. During 2015, we examined the influence of hypoxia on the Muskegon Lake ecosystem by collecting surface- and bottom-water nutrient samples, bacterial abundance counts, benthic fish community information, and performing profiles of chlorophyll and phycocyanin as proxies for phytoplankton and cyanobacterial growth, respectively. Several significant changes occurred in the bottom waters of the Muskegon Lake ecosystem as a result of hypoxia. Lake-wide concentrations of soluble reactive phosphorus (SRP) and total phosphorus increased with decreasing dissolved oxygen (DO). Bacterial abundance was significantly lower when DO was less than 2.2 mg L^?1. Whereas there were no drastic changes in surface chlorophyll a concentration through the season, phycocyanin increased threefold during and following a series of major wind-mixing events. Phycocyanin remained elevated for over 1.5 months despite several strong wind events, suggesting that high SRP concentrations in the bottom waters may have mixed into the surface waters, sustaining the bloom. The fish assemblage in the hypolimnion also changed in association with hypoxia. Overall fish abundance, number of species, and maximum length all decreased in catch as a function of bottom DO concentrations. The link between hypoxia and wind events appears to serve as a positive feedback loop by continuing internal loading and cyanobacterial blooms in the lake, while simultaneously eroding habitat quality for benthic fish.     

Sediment and Water Nutrient Characteristics in Patches of Submerged Macrophytes in Running Waters

(1) The relative importance of sediments and water as nutrient sources for submerged macrophytes in running waters is poorly understood. Here we present water and sediment nutrient characteristics within macrophyte patches in Bavarian rivers. (2) No significant differences between early (June/July) and late summer (August/September) sediment nutrient characteristics could be detected within macrophyte patches. Therefore, a single sediment sample per macrophyte patch was considered to be sufficient for characterising nutrient concentrations during the main growing season in running waters. (3) Sediment TP (total phosphorus) is not a useful parameter for predicting trophic status in running waters. Sediment porewater SRP (soluble reactive phosphorus) concentration is not correlated to water body SRP or TP concentration; nor is it correlated with sediment TP content. Potamogeton coloratus, a oligotrophic species, is associated with low overlying and porewater SRP concentrations but high sediment TP content. Eutrophic species, such as Potamogeton pectinatus, are associated with low sediment TP. (4) It is hypothesized that Chara hispida primarily takes up sediment ammonia for nitrogen nutrition. (5) Nutrient characteristics of the water body and the sediment of eight macrophyte species in Bavarian rivers are described.     

Evaluation of water productivity and fish yield in sewage-fed vis-à-vis fertilized based carp culture

Reuse of wastewater in aquaculture provides a scope to enhance water productivity of the system. Quantification of nutrient inputs incorporated through treated domestic sewage with varying dosages viz. 79.3 x 10(5)lha(-1) and 67.7 x 10(5)lha(-1) and water productivity in a controlled carp culture system were assessed in comparison to those involved in a fertilized based one, with a view to correlate among physical, chemical and biological processes involved in fish yield under the systems. The net water productivities were measured on the basis of net return values (in Indian rupees; INR) from the carp production systems at a stocking density @ 5000 per ha with four species combination. Selected relevant water parameters such as dissolved oxygen, total alkalinity, biochemical oxygen demand (BOD5) in sewage effluent and fertilizer based systems were monitored along with certain biological parameters viz. gross primary productivity, fish production and water productivity. The nutrient inputs in terms of total ammonia-nitrogen (TAN) in effluents, total nitrogen (TN) in fertilizers and phosphorus (P2O5) in both effluents and fertilizers were found significantly correlated with biological production. The results of the experiment revealed that the sewage incorporation at 79.3 x 10(5)lha(-1) yielded similar gross fish production as recorded from fertilizer based system, whereas net water productivity using sewage as nutrient source was found 64% higher than that of a fertilizer based system.     

Water Quality Conditions Associated with Cattle Grazing and Recreation on National Forest Lands

There is substantial concern that microbial and nutrient pollution by cattle on public lands degrades water quality, threatening human and ecological health. Given the importance of clean water on multiple-use landscapes, additional research is required to document and examine potential water quality issues across common resource use activities. During the 2011 grazing-recreation season, we conducted a cross sectional survey of water quality conditions associated with cattle grazing and/or recreation on 12 public lands grazing allotments in California. Our specific study objectives were to 1) quantify fecal indicator bacteria (FIB; fecal coliform and E. coli), total nitrogen, nitrate, ammonium, total phosphorus, and soluble-reactive phosphorus concentrations in surface waters; 2) compare results to a) water quality regulatory benchmarks, b) recommended maximum nutrient concentrations, and c) estimates of nutrient background concentrations; and 3) examine relationships between water quality, environmental conditions, cattle grazing, and recreation. Nutrient concentrations observed throughout the grazing-recreation season were at least one order of magnitude below levels of ecological concern, and were similar to U.S. Environmental Protection Agency (USEPA) estimates for background water quality conditions in the region. The relative percentage of FIB regulatory benchmark exceedances widely varied under individual regional and national water quality standards. Relative to USEPA’s national E. coli FIB benchmarks–the most contemporary and relevant standards for this study–over 90% of the 743 samples collected were below recommended criteria values. FIB concentrations were significantly greater when stream flow was low or stagnant, water was turbid, and when cattle were actively observed at sampling. Recreation sites had the lowest mean FIB, total nitrogen, and soluble-reactive phosphorus concentrations, and there were no significant differences in FIB and nutrient concentrations between key grazing areas and non-concentrated use areas. Our results suggest cattle grazing, recreation, and provisioning of clean water can be compatible goals across these national forest lands.     

Elver (Anguilla anguilla L.) stockings in a Swedish thermal effluent-recaptures, growth and body condition

Stockings of elvers (Anguilla anguilla L.) were made in 1982 and 1984 in a Swedish cooling water effluent area at the coast of the Baltic proper. The elvers were tagged using radioactive europium isotopes; recaptures were made by yearly samplings from 1983–1989. Détéction of eels tagged by this technique was found to be possible for at least 7 years after stocking. At the end of the study, 3.5 % and 1.3 %, respectively, of the stockings were recaptured in our own sampling programme. Growth of the introduced eels was faster than reported in studies on comparable populations. As high temperatures have a potential to change vital physiological functions, body condition, fat content and size distribution were studied in the stocking area, in two additional cooling water effluents, and in two reference areas along a salinity gradient from the Baltic to the northern Kattegat! where Atlantic waters have a major influence. Although there were indications of early sexual maturation in warm waters, the high survival of introduced eels, their tendency to stay in the stocking area, the fast growth and the positive effect on quality paramétérs such as fat content speaks in favour of an allocation of eel management to thermal discharge areas.