bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment and monitoring of ecosystem health in the sea: A description of the Swedish monitoring system for coastal marine areas
Authors: Dave G. 
Published: October 2002

Abstract
Swedish coastal waters range in salinity from 0 psu (practical salinity units = o/oo) in the Bothnian Bay, which is part of the Baltic Sea, to 35 psu in the Skagerrak, which belongs to the North Sea and the Atlantic Ocean. Natural variations in ambient conditions include weather and climate due to latitudinal, seasonal and annual variations. Anthropogenic inputs of pollutants originate from local point sources and diffuse and distant sources. These inputs may cause local and regional as well as national and international problems. Therefore, local and regional monitoring programs are integrated into the Swedish national monitoring program, which is also co-coordinated with other national and international monitoring programs. The aim of this paper is to describe and assess the Swedish monitoring system for the marine and coastal environment and to discuss its strengths and weaknesses. The monitoring system incorporates a combination of chemical-physical and biological parameters. Measured parameters are accompanied with specific quality criteria. In most cases the criteria are based on an estimate of a ‘natural state’ and the appraisals are expressed on a scale of 1-5 (high, good, fair, poor and bad quality). Three major threats to the marine environment are eutrophication, toxic organic pollutants/metals and physical disturbance (exploitation of the coast). The parameters used to assess eutrophication are concentrations of nitrogen, phosphorus and silica, Secchi depth, concentration of chlorophyll, benthic fauna and macrovegetation. Metals and toxic organic pollutants are assessed based on their concentrations in sediment and selected organisms. The assessment of the degree of physical disturbance of coasts and seas is based on the number of buildings along the shoreline, physical disturbance along the shoreline, proportion of exploited/disturbed coastal water zones and jetty length. Other threats, which are also briefly discussed in this paper, are impact from the fishery and the potential toxic impact of contaminants, which are not being measured.
Zebrafish Danio rerio and roach Rutilus rutilus: Two species suitable for evaluating effects of endocrine disrupting chemicals?
Authors: Andersen Lene , Petersen Gitte I. , Gessbo Åsa , Örn Stefan , Holbech Henrik , Bjerregaard Poul , Norrgren Leif 
Published: October 2002

Abstract
Morphological studies of gonads from roach (Rutilus rutilus) in a small Swedish lake were performed. The lake is a potential recipient for drainage water from a refuse dumping area. All fishes were macroscopically identified as males, but histological examination of the gonads showed a high incidence of intersex. This high incidence might be caused by endocrine disrupting chemicals. The relationships between exposure to endocrine disrupters and intersex observations in wild fish is unknown and the effect of endocrine disrupters on zebrafish (Danio rerio) were evaluated in order to determine whether they might serve as a model laboratory species for effects of endocrine disrupting chemicals in wild fish.
Zebrafish were exposed from pre-blastula stage until sexual maturation to either standardised water (controls), 17a-methyltestosterone (1, 10 μg l-1) or 17b-estradiol (1, 10 μg l-1). Exposure to both concentrations of 17bestradiol caused a significant feminisation, while a significant increase in the proportions of males was found after exposure to 1 mg 17a-methyltestosterone l-1. Furthermore, exposure to 1 and 10 mg 17a-methyltestosterone l-1 caused development of intersex individuals. Additionally, sexually mature male zebrafish were exposed to 1 μg 17b-estradiol l-1. After 10 weeks of exposure the fish were transferred to non-contaminated water for two weeks. The control group was kept in standardised water for 12 weeks. At termination of the experiment, measurement of whole-body vitellogenin concentrations were performed. Exposure to 17b-estradiol caused a significant increase in whole body vitellogenin concentrations. After 2 weeks in water without addition of 17b-estradiol, the vitellogenin concentration was reduced by approximately 50%. Roach and zebrafish may share properties which makes these species suitable for further comparisons to evaluate effects of endocrine disrupting chemicals as well as domestic and industrial effluents containing hormone-like substances.
Burrowing mayflies (Hexagenia) as indicators of ecosystem health
Authors: Edsall Thomas A. 
Published: October 2002

Abstract
Three State of the Lakes Ecosystem Conferences have been held since 1996 to encourage the development of Great Lakes indicators of ecosystem health for use in reporting on progress in restoring and maintaining the chemical, physical and biological integrity of the Great Lakes ecosystem. Here we report on the development of an indicator based on burrowing mayflies, Hexagenia (Ephemeroptera: Ephemeridae), using production and biomass as the indicator metrics. Burrowing mayflies were selected because they (1) were historically abundant in unpolluted, soft-bottomed mesotrophic habitats throughout the Great Lakes, (2) are intolerant of and were extirpated by pollution in most of those habitats during the 1940s to1950s, (3) have shown the ability to recover in one of those habitats following pollution abatement, (4) are ecologically important as bioturbators of lakebed sediments and as trophic integrators that link detrital energy resources directly to fishes that feed preferentially on them, and (5) have highly visible mating flights, which carry the message directly to an informed public that the source water body is healthy. In addition, their annual production can be estimated from their mean annual biomass by the sizefrequency method. Productivity and biomass can also could be estimated with a ‘cohort-direct’ method, using the biomass of mature nymphs collected in May or early June from the cohort that is about to emerge as subimagos in late June or early July. Although both the size-frequency and cohort-direct methods provide reliable estimates of productivity and biomass, the latter method greatly reduces sample collection and processing effort and thus makes it feasible to use Hexagenia as an indicator of ecosystem health in surveys requiring the collection of large numbers of samples.
Development of multimetric indices of biotic integrity for riverine and palustrine wetland plant communities along Southern Lake Michigan
Authors: Simon Thomas P. , Stewart Paul M. , Rothrock Paul E. 
Published: October 2002

Riverine and palustrine wetland plant communities were examined in order to propose a multimetric plant index of biotic integrity. The objectives were to determine the structural and functional attributes of these wetland plant communities, calibrate reference conditions in assessing aquatic plant communities, provide methods for further development and testing of the index, and present a case study. The index is based on a rapid assessment method using the information collected from a species list and cover estimates. Sampling was done using a modified relevé
sampling approach with a modified Braun-Blanquet Cover Abundance Scale Method for estimating percent cover. More than 20 characteristics of aquatic plant communities were evaluated and 12 metrics in five categories were developed. Structural metrics focused on community composition, key indicator species such as number of Carex and Potamogeton species, and guild type. Functional metrics included sensitivity and tolerance measures; percent emergent, pioneer, and obligate wetland species; and the number of weed species as a substitute metric. Abundance was estimated based on evenness of average cover densities. Individual condition was suggested as a measure of the lowest extremes of biotic integrity. Palustrine study sites ranged across a disturbance gradient from ‘least-impacted’ to ‘poor'; riverine study sites ranged from high quality to some of the most degraded riverine sites in the Great Lakes region. Ninety-five species of aquatic vascular plants were found in 42 families. The most common families were Cyperaceae (15 species), Polygonaceae (9 species), and Juncaceae (6 species). Fourteen submergent, four floating, two woody and 75 emergent aquatic plant taxa were found. Five species were on the endangered, threatened, or rare list for the State of Indiana. Sites receiving the highest index scores included several of the a priori least-impacted sites while the lowest scores were located near-field to a large industrial landfill. The index will need to be further validated and tested but shows potential as a rapid index of biotic integrity using aquatic plant assemblages.
The status of the macroinvertebrate community in the St. Croix River, Minnesota and Wisconsin: An examination of ecological health using techniques of multivariate analysis
Authors: Boyle Terence P. , Strand Matthew 
Published: October 2002

Abstract
A statistical procedure that integrates physical, chemical and biological data is used to operationally define and analyze ecological health. Benthic macroinvertebrates collected from May through September from eight locations along the St. Croix River in Minnesota and Wisconsin were analyzed by canonical correspondence analyses. A sequential multivariate analysis procedure was developed that included: 1) determining which environmental variables explained the most variation in the taxonomic data, individually and collectively, 2) running canonical correspondence analyses on the taxonomic data along with environmental variables chosen from a stepwise forward selection procedure, 3) performing a cluster analysis of the taxonomic data in sampling times to determine artificial biological seasons, and 4) analyzing the seasonal data (three time intervals) separately, as in steps 1 and 2. Changes in community structure were significantly associated with changes in environmental factors (physical and chemical) that varied in time and space. The variables found to be significant were largely those expected to be associated with the variations in the structure of benthic macroinvertebrate community in an unimpacted river. A slight influence of nitrogen could be detected in agricultural areas.
Assessing atrazine pollution potential to a drinking water reservoir using remote sensing and geographic information system modeling
Authors: Atkinson S. F. , Waller W.T. , Crooks T.J. 
Published: October 2002

Abstract
Water quality monitoring by the City of Dallas, Texas (US) and the Institute of Applied Science, University of North Texas, has recently shown elevated atrazine concentrations in the watershed of a large drinking water reservoir in the Dallas-Fort Worth metropolitan area serving over 3,000,000 people. Atrazine is under investigation by numerous researchers as an environmental estrogen that may be involved in increasing breast cancer incidence in humans and impacting health and reproductive systems in wildlife. Since treatment technologies for atrazine removal from finished drinking water can be expensive and provide no protection to aquatic ecosystem health, watershed managers are currently seeking proactive methods to reduce the amount of atrazine entering water supply systems.
The most viable approach for reducing atrazine in a drinking water reservoir begins with understanding the distribution and extent of landuse in the watershed where atrazine may be applied. Understanding the spatial distribution of areas potentially contributing atrazine runoff facilitates developing an effective atrazine reduction program of the best management practices that are appropriate to a particular region. Using remotely sensed satellite imagery and geographic information system modeling, an analysis of the spatial distribution of landuse, soil erodibility, and surface slope information in a large watershed in north central Texas was conducted. An ‘atrazine pollution potential’ model was developed and applied to over 224,000 hectares draining into Lake Lewisville which provides drinking water to Dallas and surrounding communities. Model results compared well with in situ water quality measurements of atrazine, and point to areas most in need of best management practice implementation.
A methodology for identifying and classifying aquatic biodiversity investment areas: Application in the Great Lakes basin
Authors: Morrison Heather A. , Minns Charles K. , Koonce Joseph F. 
Published: October 2002

Abstract
A scientifically defensible methodology for identifying areas of high biodiversity in aquatic environments is presented. Areas of high biodiversity or Aquatic Biodiversity Investment Areas are identified using a technique referred to as Habitat Supply Analysis. This technique uses the microhabitat features of an ecosystem in conjunction with information on the microhabitat preferences of fish to calculate the suitability of an area to fish. The method is structured so that the suitability of habitat to lifestages of fish, species of fish, groups of fish and fish assemblages can be evaluated. The methodology recognises that to some degree all areas within an aquatic system contribute to the maintenance of biodiversity. As such, a classification scheme is proposed to evaluate the potential versus the actual contribution of an area to the maintenance of biodiversity in an ecosystem. This classification scheme is designed to help prioritise habitat restoration and preservation efforts. Prototype evaluations of the methodology for identifying and classifying Aquatic Biodiversity Investment Areas are presented.
Thraustochytrids: A neglected agent of the marine microbial food chain
Authors: Kimura Hiroyuki , Naganuma Takeshi 
Published: October 2002

Abstract
The base of the pelagic microbial food chain consists of bacterioplankton and mycoplankton (mostly thraustochytrids), the latter having drawn less attention. In a rather simplistic formulation, bacterioplankton is regarded as the harvester of autochthonous (marine) dissolved organic material exuded from phytoplankton, while mycoplankton is seen to be the scavenger of refractory dissolved organic material which is often allochthonous (riverine). This study presents a case study report on the abundance of thraustochytrids (mycoplankton) and bacterioplankton in the discharge area of River Shimanto, Northwestern Pacific, Japan. Thraustochytrid cells were stained with acriflavine and counted directly by epifluorescence microscopy. Thraustochytrids were found in the surface water at a density of 0.9 to 3.6 x 10 3 cells l -1 , with an overall average of 2.5 x 10 3 cells l -1 . Distribution of thraustochytrids was correlated to (or controlled by) river discharge as depicted by lowered salinity. On the other hand, abundance of bacterioplankton, 1.2 to 1.4 x 10 9 cells l -1 , showed no significant correlation with river discharge. Thraustochytrids may grow on terrestrial organic matter in the riverine input, which is often refractory to degradation, and play a role in enhancing carbon cycling in the estuarine and coastal areas.
Physical variables, carbon cycling and primary producer couplings in a shallow tropical lagoon (Barra Lagoon, Brazil)
Authors: Carmouze Jean-Pierre , Domingos Patricia 
Published: October 2002

Abstract
The Barra Lagoon (28°S and 43°W, 7 km², mean depth, 1m, salinities from 3 to 12 ) was investigated between October 1990 and August 1993. We report here a first synthesis of organic carbon metabolism, the phytoplankton community and their mutual interactions. Barra Lagoon exhibited a hypereutrophic state (high values of phytoplanktonic biomasses, diurnal metabolic rates, particulate and dissolved organic carbon concentrations). As with most shallow lagoons, Barra Lagoon was very sensitive to short-term meteorological changes which induced high day to day changes in organic carbon metabolism and severely dampened seasonal trends. But surprisingly, when consistent structural changes occurred, its total organic carbon metabolism was rapidly dampened by shifts from pelagic to benthic carbon metabolism and vice-versa. Seasonal auto/heterotrophic shifts of the ecosystem (generally autotrophy in summer and heterotrophy in winter) were not always verified. They were more strongly linked to growing and degeneration phases of pelagic and benthic algae. Biological activity was mainly controlled by the rate of nutrient in situ regeneration (low nutrient concentrations in water). In these conditions, small-size phytoplankton species predominated, as they are more efficient than large forms in sharing nutritive resources. Cyanophyceae were ecologically favoured by low transparency, nitrogen limitation and high nutrients regenerated in the water column, while small species of Dinophyceae and Chrysophyceae were promoted by a higher photic layer, nitrogen content and benthic nutrient regeneration. Extra input of nutrients (proceeding from fish-kill in February 1991, from decomposition of macro-algae after a temporary phase of colonization in August-September 1992, and from abundant rainfalls) induced an ephemeral growth of larger species at the expense of Cyanophyceae. Cyanophyceae lost their dominance also when temperature fell to 20°C.
The dynamics of nutrient enrichment and primary production related to recent changes in the ecosystem of the Black Sea
Authors: Yayla M. , Yilmaz A. , Morkoc E. 
Published: October 2002

Abstract
The data collected in the southern Black Sea during the period of July 1997 to September 1998 showed that light penetrated into the upper 20-35 m, with a downward attenuation coefficient varying between 0.1 and 0.25 m -1 . The chlorophyll-a concentration for the euphotic zone ranged from &lt;0.5 to 1.5 µg l -1 . Coherent sub-surface chlorophylla maxima formed near the base of the euphotic zone at all study points and a secondary one was observed at very low level of light (&lt;0.1% of the surface light) in the nearshore regions. Production rates were estimated in between 62 and 785 mg C m -2 d -1 in this period. Bioassay experiments (using extra nitrate, ammonia, phosphate, silicon and iron) showed that under optimum light conditions the phytoplankton population is nitrate limited in open waters. Phosphate seems to control the growth in the nearshore regions of the southern Black Sea. Silicon concentration also influenced the phytoplankton growth since the majority of the population was determined to be diatoms.
The diversity of benthic macroinvertebrates as an indicator of water quality and ecosystem health: a case study for Brazil
Authors: Barbosa F. A. R , Callisto M. , Galdean N. 
Published: October 2002

Abstract
The state of Minas Gerais still has some nearly pristine aquatic ecosystems, thus representing strategic aquatic resources for Brazil. Rivers and creeks of Serra do Cipó (19° -20°S, 43° -44°W) constitute an example of natural ecosystems in preserved conditions where a broad research project was initiated in 1996 aimed at the assessment of aquatic biodiversity and water quality characterisation. This area is the natural water division between the hydrographic basins of Doce and São Francisco rivers, two of the most important watersheds of Minas Gerais. The main goal of this study was to assess the diversity of benthic macroinvertebrate communities and use them as bioindicators of water quality. A secondary goal was to classify the benthic communities into three categories: 1) non-affected communities: those preserving a pristine structure, which are significant for fragile ecosystems, 2) median-affected communities: those receiving some degree of impacts, formed by a mixture of stenotopic and euritopic populations capable of adapting to new conditions thus reflecting the ecosystem's resilience, and 3) heavily-affected communities: those with very poor diversity, generally subject to severe human impact with destructive effects, but that are still important for the functioning of these degraded ecosystems.
Toxicity and mutagenecity of urban wastewater treated with different purifying processes
Authors: Sánchez Mata José D. , Fernández Virginia , Chordi Andrés , Tejedor Carmen 
Published: October 2002

Abstract
The toxicity and mutagenecity of 1000-fold concentrates of 5 litre samples of wastewater from five different towns (containing 500, 600, 15000, 50000 and 190000 inhabitants) with different sewage treatment processes were determined. Two kinds of samples, including municipal wastewater entering the sewage treatment plants and the effluents discharged into the environment were analysed. After concentration through resins, overall toxicity was evaluated using the bioassay employing Photobacterium phosphoreum and samples were classified according to Vasseur et al. (1986) as 'Non-toxic', 'Slightly toxic', 'Toxic' or 'Highly toxic'. Mutagenecity was evaluated using the mutagenecity index determined by the Ames test, and samples were classified as 'Non-mutagenic', 'Slightly mutagenic', or 'Mutagenic', according to the 'two-fold' rule. The results obtained varied considerably; such that in some plants the toxicity values decreased during treatment whereas in others they remained unmodified or increased. None of the extracts analysed proved to be mutagenic. The data on toxicity and mutagenecity of the samples are apparently not correlated.
Status of the Guadiana Estuary (south Portugal) during 1996-1998: An ecohydrological approach
Authors: Chícharo M. A. , Chícharo L. M. , Galvão H. , Barbosa A. , Marques M. H. , Andrade J. P. , Esteves E. , Miguel C. , Gouveia I. 
Published: October 2002

Abstract
The aims of this study were to monitor basic hydrological and ecological characteristics of the Guadiana Estuary (1996-1998) before the construction of the Alqueva dam. This work was carried out to determine how environmental factors affect seasonal and tidal variations of plankton populations in the estuary. The available information on the subcatchment of the estuary (e.g., urban, agricultural and forested areas) was integrated into a geographic information system-based software program. Mean monthly river flow varied markedly on a seasonal and yearly basis. River flow near Mértola (ca 50 km upstream from the mouth) reached 3400 2 10 6 m 3 in winter and decreased to 42 2 10 6 m 3 in summer. With respect to nutrients, nitrogen to phosphorus ratios indicated some limitation by phosphorus, except at the end of summer, when nitrogen limitation appeared. During this period, cyanobacterial blooms usually occurred in the upper/middle estuary. Estuarine Turbidity Maximum may significantly influence the retention of zooplankton in the estuary. The fish larval life cycle, especially sensitive to environmental alterations, showed high ratios of ribonucleic to desoxyribonucleic acids indicating good physiological condition. It was concluded that an ecohydrological approach, allowing integration of different elements from the cellular to the habitat level into a geographic information system, can contribute to a better understanding of the processes that influence the aquatic biota of the estuary. The approach will be a useful assessment tool for monitoring the estuary following dam completion.