Gunta Springe

The STAR project: context, objectives and approaches

STAR is a European Commission Framework V project (EVK1-CT-2001-00089). The project aim is to provide practical advice and solutions with regard to many of the issues associated with the Water Framework Directive. This paper provides a context for the STAR research programme through a review of the requirements of the directive and the Common Implementation Strategy responsible for guiding its implementation. The scientific and strategic objectives of STAR are set out in the form of a series of research questions and the reader is referred to the papers in this volume that address those objectives, which include: (a) Which methods or biological quality elements are best able to indicate certain stressors? (b) Which method can be used on which scale? (c) Which method is suited for early and late warnings? (d) How are different assessment methods affected by errors and uncertainty? (e) How can data from different assessment methods be intercalibrated? (f) How can the cost-effectiveness of field and laboratory protocols be optimised? (g) How can boundaries of the five classes of Ecological Status be best set? (h) What contribution can STAR make to the development of European standards? The methodological approaches adopted to meet these objectives are described. These include the selection of the 22 stream-types and 263 sites sampled in 11 countries, the sampling protocols used to sample and survey phytobenthos, macrophytes, macroinvertebrates, fish and hydromorphology, the quality control and uncertainty analyses that were applied, including training, replicate sampling and audit of performance, the development of bespoke software and the project outputs. This paper provides the detailed background information to be referred to in conjunction with most of the other papers in this volume. These papers are divided into seven sections: (1) typology, (2) organism groups, (3) macrophytes and diatoms, (4) hydromorphology, (5) tools for assessing European streams with macroinvertebrates, (6) intercalibration and comparison and (7) errors and uncertainty. The principal findings of the papers in each section and their relevance to the Water Framework Directive are synthesised in short summary papers at the beginning of each section. Additional outputs, including all sampling and laboratory protocols and project deliverables, together with a range of freely downloadable software are available from the project website at www.eu_star.at.

Biological quality metrics: their variability and appropriate scale for assessing Streams

The concept of spatial scale is at the research frontier in ecology, and although focus has been placed on trying to determine the role of spatial scale in structuring communities, there still is a further need to standardize which organism groups are to be used at which scale and under which circumstances in environmental assessment. This paper contributes to the understanding of the variability at different spatial scales (reach, stream, river basin) of metrics characterizing communities of different biological quality elements (macrophytes, fishes, macroinvertebrates and benthic diatoms) as defined by the Water Framework Directive. For this purpose, high-quality reaches from medium-sized lowland streams of Latvia, Ecoregion 15 (Baltic) were sampled using a nested hierarchical sampling design: (river basin → stream → reach). The variability of metrics within the different groups of biological quality elements confirmed that large-bodied organisms (macrophytes and fish) were less variable than small-bodied organisms (macroinvertebrates and benthic diatoms) at reach, stream and river basin scales. Single metrics of biological quality elements had the largest variation at the reach scale compared with stream and basin scales. There were no significant correlations between biodiversity indices of the different organism groups. The correlation between diversity indices (Shannon’s and Simpson’s) of the biological quality eleme (macrophytes, fish, benthic macroinvertebrates and benthic diatoms) and a number of measured environmental variables varied among the different organism groups. Relationships between diversity indices and environmental factors were established for all groups of biological quality elements. Our results showed that metrics of macrophytes and fish could be used for assessing ecological quality at the river basin scale, whereas metrics of macroinvertebrates and benthic diatoms were most appropriate at a smaller scale.

The search for reference conditions for stream vegetation in northern Europe

Summary 1. The European Water Framework Directive provides a framework for improving the ecological quality of stream ecosystems, with deviation from reference used as a measure of ecological status. 2. Here we examine the possibility of using less impacted stream sites from Latvia, Lithuania and Poland to establish a Danish reference network for macrophyte assemblages, and as a guiding image for identification of possible references sites within Denmark. Both approaches were evaluated using historical Danish records. 3. Four different macrophyte assemblages were identified for mid‐sized streams in the Central and Eastern Lowland ecoregions. Macrophyte assemblages could not be delineated using physical stream site characteristics; however a gradual change in assemblage composition was attributed to differences in alkalinity and human impact. 4. Assemblages of contemporary vegetation in Denmark were quite similar to those found in Polish, Latvian and Lithuanian streams (26–35%). However, more importantly, from species‐based predictions we noted higher similarity, particularly with Latvian and Lithuanian streams, before intensive land use commenced in Denmark (c. 1900). These results show that stream sites from these three countries can be considered in a Danish reference network. 5. Two of the four macrophyte assemblages comprised species such as Fontinalis antipyretica, Myriophyllum spicatum, Nuphar lutea, Potamogeton alpinus and P. perfoliatus that have a very scattered occurrence in the contemporary vegetation in Denmark. These groups were closely associated with the predictions from historic records, thereby lending support the conjecture that these assemblages could be part of the guiding image for the identification of potential reference sites within Denmark.

Chemical Composition Analysis, Antimicrobial Activity and Cytotoxicity Screening of Moss Extracts (Moss Phytochemistry)

Mosses have been neglected as a study subject for a long time. Recent research shows that mosses contain remarkable and unique substances with high biological activity. The aim of this study, accordingly, was to analyze the composition of mosses and to screen their antimicrobial and anticancer activity. The total concentration of polyphenols and carbohydrates, the amount of dry residue and the radical scavenging activity were determined for a preliminary evaluation of the chemical composition of moss extracts. In order to analyze and identify the substances present in mosses, two types of extrahents (chloroform, ethanol) and the GC/MS and LC-TOF-MS methods were used. The antimicrobial activity was tested on four bacteria strains, and the anticancer activity on six cancer cell lines. The obtained results show the presence of a high number of primary (fatty acids and amino acids), but mainly secondary metabolites in moss extracts—including, sterols, terpenoids, polyphenols and others—and a high activity with respect to the studied test organisms.

Trends of natural organic matter concentrations in river waters of Latvia

This study revealed significant (P < 0.1and P < 0.05) increasing trends of total organic carbon (TOC) and water colour in most of the studied Latvian rivers during the last decade. However, over longer time periods, there were pronounced oscillations of TOC concentrations, similar to patterns of long-term changes of river discharge regime. On a yearly basis, there was a positive correlation between parameters of organic matter concentration and discharge in all selected rivers (rS = 0.540–0.803; P < 0.01). The impact of discharge on concentrations of organic matter could be masked by other factors, such as changes in precipitation, biological processes, soil types or land use.

Evaluation of plankton communities in small highly humic bog lakes in Latvia

This paper reports the results of a study performed at the Teici State Reserve in Latvia The results indicated that algal communities in brown water lakes were formed by species that were tolerant to a low pH and high humic substance concentration. The composition of the species of phytoplankton and zooplankton was comparatively simple. A significant correlation was found between the number of species of phytoplankton, zooplankton, and the pH value. Similarly there was a clear relationship between the taxonomic composition of phytoplankton, zooplankton, and the trophic state of the lakes. Dyseutrophic lakes were characterized by comparatively higher biodiversity of planktonic communities than dystrophic lakes. There was also a correlation between humic substance concentration and total bacterial numbers, and humic substance concentration and total number of zooplankton, respectively. The composition of the species, the biomass of phytoplankton and zooplankton, as well as the numbers of bacterioplankton, were specific for humic lakes and could assist in the identification of the unaffected state of bog lakes ecosystems.

Effects of changing climate on European stream invertebrate communities: a long-term data analysis

Long-term observations on riverine benthic invertebrate communities enable assessments of the potential impacts of global change on stream ecosystems. Besides increasing average temperatures, many studies predict greater temperature extremes and intense precipitation events as a consequence of climate change. In this study we examined long-term observation data (10-32years) of 26 streams and rivers from four ecoregions in the European Long-Term Ecological Research (LTER) network, to investigate invertebrate community responses to changing climatic conditions. We used functional trait and multi-taxonomic analyses and combined examinations of general long-term changes in communities with detailed analyses of the impact of different climatic drivers (i.e., various temperature and precipitation variables) by focusing on the response of communities to climatic conditions of the previous year. Taxa and ecoregions differed substantially in their response to climate change conditions. We did not observe any trend of changes in total taxonomic richness or overall abundance over time or with increasing temperatures, which reflects a compensatory turnover in the composition of communities; sensitive Plecoptera decreased in response to warmer years and Ephemeroptera increased in northern regions. Invasive species increased with an increasing number of extreme days which also caused an apparent upstream community movement. The observed changes in functional feeding group diversity indicate that climate change may be associated with changes in trophic interactions within aquatic food webs. These findings highlight the vulnerability of riverine ecosystems to climate change and emphasize the need to further explore the interactive effects of climate change variables with other local stressors to develop appropriate conservation measures.

Long-term Development of the Hydroecosystem of the Lake Engure and its Influencing Factors

Long-term Development of the Hydroecosystem of the Lake Engure and its Influencing Factors Investigations of water chemical composition and biota of Lake Engure have been carried out since 1995 by using standard methods for inland surface waters. Time series of air temperature and precipitation for the Mersrags meteorological station for the period 1928 to 2009 are used for the trend analysis. The results show that the long-term development of the hydroecosystem is related to such environmental factors as the lakes geographical location, basin and morphology, as well as the lakes history and relationship of biotic and abiotic factors. Engures ezera hidroekosistēmas ilgtermiņa attīstība un to ietekmējošie faktori Engures ezers ir lielākā reliktā ūdenstilpe Rīgas līča piekrastē. Tas ir sekls, morfometriski eitrofs caurplūstošs ezers. Ezers ir Ramsāres vieta, atrodas Engures dabas parkā, kas ir biologiski daudzveidīga teritorija. Ezera ilgtspējīgas attīstības iespējas saistītas ar vairākiem faktoriem. Engures ezerā ūdens ķīmiskā sastāva un planktisko un bentisko sabiedrību izpēte notiek kopš 1995.g., izmantojot hidroķīmiskās un hidrobiologiskās standartmetodes. 2010.g. veikta arī augstāko augu sabiedrību izpēte. Klimata datu analīzei izmantoti Latvijas Vides, geologijas un meteorologijas centra dati no Mērsraga meteorologiskās stacijas par laiku no 1928.g. līdz 2009.g, Rezultāti liecina, ka Engures ezera regionā notikusi būtiska gada vidējās temperatūras palielināšanās, temperatūras pieauguma tendences vērojamas arī vasarā un pavasarī. Būtiskas nokrišņu izmaiņas nav novērotas. Ezers joprojām ir dzidrūdens stāvoklī, fitoplanktona biomasas ir zemas un nav novērojamas izmaiņas dominējošo aļgu grupu struktūrā. No lokālajiem faktoriem visbūtiskāk ezera ekosistēmu ietekmējusi antropogēnā darbība - 19.gs. vidū izraktais Mērsraga kanāls, kas savieno ezeru ar Rīgas līci. Tas izmainījis ezera morfometriju un ietekmē ezera ziemeļu daļas ūdens ķīmisko sastāvu, kā arī organismu sabiedrību sugu sastāvu. Tikpat būtiska ir ezera geologija un ezerā ietekošās upes, kas ietekmē ūdens cietību, līdz ar to - fosfora atrašanos saistītā formā un mieturaļgu attīstību, kas kavē sedimentu resuspensiju. Fitoplanktons vāji izmanto saistīto fosforu un ezera eitrofikācija izpaužas pastiprinātā augstāko augu attīstība. Kopumā lokālo faktoru (gan antropogēno, gan dabisko) loma ir noteicoša pašreizējā ezera attīstības stadijā. Долгосрочное развитие озера Энгурес и влияющие на него факторы Озеро Энгуре - крупнейшее реликтовое озеро побережья Рижского залива. Мелководное, морфометрически эвтрофное проточное озеро. Озеро Энгуре является объектом Рамсарской конвенции, а также основной частью природного парка Энгуре, имеющего статус территории биологического разнообразия. Долговременное развитие озера связано с несколькими факторами. Относительно регулярные исследования химического состава вод, планктонных и бентосных сообществ озера с использованием стандартных гирохимических и гидробиологических методов проводятся с 1995 года. В 2010 году проведены картирование и анализ высшей водной растительности. Для анализа климатических показателей использованы данные Латвийского центра среды, геологии и метеорологии (станция наблюдений Мерсрагс) за период с 1928 по 2009 годы. Анализ результатов измерений показывают, что в регионе озера с 70-х годов прошлого века существенно увеличились средняя годовая температура воздуха, увеличились тренды средних температур весной и летом. Среднегодовое количество осадков значительно не изменилось. Озеро прозрачное, биомассы фитопланктона низкие и значительные изменения в структуре доминирующих групп водорослей не найдены. В историческом плане существенное антропогенное вмешательство в экосистему озера произошло в середине 19 века - прорытием канала, соединившего озеро с Рижским заливом. Это изменило морфометрию озера, периодическое проникновение солоноватых вод залива повлияло на химический состав, особенно северной части, а также отчасти на видовой состав сообществ организмов. На остальные части озера столь существенно влияют геологическое строение водосбора и приток рек в озеро, обуславливающий гидрокарбонатную жесткость воды, содержание фосфора в связанной форме, что в свою очередь влияет на развитие харовых водорослей, задерживающих ресуспенсию донных отложений. Форма связанного фосфора слабо используется фитопланктоном, поэтому главную роль в эвтрофировании озера на данном этапе принадлежит высшей водной растительности.