Woody vegetation encroachment has become a major threat to tallgrass prairie streams mainly because of fire suppression. This process converts prairie streams from open to closed canopy systems. The effects of these riparian changes are poorly understood, but the relative importance of basal resources presumably shifts from primarily autochthonous to allochthonous with increasing canopy cover, potentially altering macroinvertebrate functional structure and production. To assess the effects of woody vegetation encroachment on stream ecosystem structure and function, riparian trees were removed from two headwater stream reaches on the Konza Prairie Biological Station (KPBS) in eastern Kansas. Experimental stream reaches were compared to streams with naturally open and closed canopies before and after the manipulation. Benthic organic matter and macroinvertebrates were collected monthly from each reach for one year before and one year after woody vegetation removal. Total community production in canopy removal reaches ranged from 8.9-10.2 g AFDM m-2 y-1 before riparian removal, and this increased significantly to 13.4-14.5 g AFDM m-2 y-1 after riparian removal. Scraper production in canopy removal reaches was 2.8-3.9 g AFDM m-2 y-1 before riparian removal, and increased significantly to 6.0-8.7 g AFDM m-2 y-1 after riparian removal, presumably due to enhanced food availability. Total community production in naturally open reaches ranged from 7.6-12.6 g AFDM m-2 y-1 before riparian removal and decreased to 6.5-9.8 g AFDM m-2 y-1 after riparian removal. Riparian forest removal altered macroinvertebrate production and functional structure, but higher macroinvertebrate production in canopy removal reaches compared to naturally open reaches suggested natural conditions were not restored one year after riparian removal. However, macroinvertebrate communities in naturally open and canopy removal reaches became more similar after riparian removal. Functional structure, based on production, in naturally open and canopy removal reaches after riparian removal was dominated by scrapers (45-60% of total production), with similar proportions of collector-gatherers (12-26%) and predators (15-25%). Collector-filterers and shredders contributed < 9% of total production in naturally open and canopy removal reaches after riparian removal. Results demonstrate that woody vegetation encroachment and riparian forest removal significantly influence tallgrass prairie stream structure and function. Information from this study can help inform and guide management, restoration, and conservation of remaining tallgrass prairie streams.

This study represents the first shift in multivoltine life history of Cheumatopsyche species from a wastewater treatment plant (WWTP) in North America. Populations of C. lasia were examined upstream and downstream of the Denton’s Pecan Creek WWTP August 2009 through November 2010. C. lasia is multivoltine in Pecan Creek with three cohorts observed upstream of the WWTP and four possible cohorts downstream. A fourth generation was possible downstream as thermal inputs from WWTP effluent resulted in elevated water temperatures that allowed larval development to progress through the winter producing a cohort ready to emerge in spring. Production of C. lasia was 5 times greater downstream of the WWTP with secondary production estimates of 1.3 g m-2 yr-1 and 4.88- 6.51 g m-2 yr-1, respectively. Differences in abundance were due to increased habitat availability downstream of the WWTP in addition to continuous stream flow from inputs of wastewater effluent. Results also suggest that C. lasia is important for energy transfer in semiarid urban prairie streams and may serve as a potential conduit for the transfer of energy along with emergent contaminants to terrestrial ecosystems. These finding highlight the need for more quantitative accounts of population dynamics (voltinism, development rates, secondary production, and P/B) of aquatic insect species to fully understand the ecology and energy dynamics of urban systems.

Um estudo de distribuição temporal, proporção sexual e densidade de caranguejos do gênero Uca foi realizado no estuário dos rios Piraquê-Açu e Piraquê-Mirim, Santa Cruz, Espírito Santo, Brazil. A população de caranguejos presentes em 06 áreas dividias em 90 quadrados de 0.75 m² foi coletada mensalmente durante o período de Julho/2012 à Maio/2013. Os caranguejos foram coletados por escavação manual das tocas, identificados e sexados. A temperatura do ar e da água variou entre 21 a 27°C e 22 a 28°C, respectivamente, enquanto que a salinidade variou de 21 a 35. Um total de 5.391 espécimes foi coletado, sendo 2.823 machos e 2.568 fêmeas (sendo 40 ovadas). A densidade média para a população de Uca sp. (subgênero leptuca) variou de 18,01 ± 1,29 (Maio/13) a 62,22 ± 1,51 ind.m-² (Novembro/12), para Uca thayeri de 3,67 ± 0,63 (Julho/12) a 15,29 ± 1,44 ind.m-² (Janeiro/13) e para a população Uca maracoani de 0,83 ± 0,27 ind.m-² (Julho/13) a 10,31 ± 0,73 (Novembro/12). A proporção sexual foi 1:1 para cada espécie estudada. A análise de correspondência canônica indicou que houve influência dos fatores ambientais na densidade dos caranguejos. Entretanto, as variáveis abióticas não foram limitantes para a distribuição das espécies estudadas. A produção secundária para a população de Uca sp. (subgênero leptuca) variou de 7,34 para 50,89 g PSLC m-1 ano-1, para Uca thayeri de 12,10 para 27,65 g PSLC m-1 ano-1 e para a população Uca maracoani de 1,70 para 8,83 g PSLC m-1 ano-1. A análise de regressão multivariada indicou que para a espécie Uca sp. (subgênero leptuca) a quantidade clorofila-a está relacionada com a produtividade desta espécie e para as demais espécies nenhuma das variáveis abióticas estudadas estaria relacionada com sua produtividade. / The temporal distribution, sex ratio and density of the fiddler crab Uca spp. was studied in populations living in the Piraquê-Açu and Piraquê-Mirim estuaries, Santa Cruz, Espírito Santo State, Brazil. Ninety 0.75 m² in 06 areas were used to obtain monthly samples from July 2012 to May 2013. The crabs were collected manually through excavation of burrows, identified and sexed. Air and water temperatures varied from 21 to 27°C and 22 to 28°C, respectively, and the salinity from 21 to 35. A total of 5,391 fiddler crabs were collected, with 2,823 males and 2,568 females (40 ovigerous). The average densities for the three species found were 18,01 ± 1,29 (May/13) to 62,22 ± 1,51 ind.m-² (November/12), 3,67 ± 0,63 (July/12) to 15,29 ± 1,44 ind.m-² (January/13) for Uca thayeri and 0,83 ± 0,27 ind.m-² (July/13) to 10,31 ± 0,73 (November/12) for Uca maracoani. Sex ratio (male:female) was 1:1. Canonical correspondence analysis showed that abiotic factors can influence crab density, but do not limit species distribution. The average secondary production of the Uca sp. population ranged from 7.34 to 50.89 g PSLC m-1 y-1, for Uca thayeri ranged between 12.10 to 27.65 g PSLC m-1 y-1 and for Uca maracoani from 1.70 to 8.83 g PSLC m-1 y-1. The multiple regression shows the chlorophyll-a may influence Uca sp. (subgênero leptuca) productivity. For the Uca thayeri and Uca maracoani species not a single abiotic factor tested had an influence in productivity.

Um estudo de distribuição temporal, proporção sexual e densidade de caranguejos do gênero Uca foi realizado no estuário dos rios Piraquê-Açu e Piraquê-Mirim, Santa Cruz, Espírito Santo, Brazil. A população de caranguejos presentes em 06 áreas dividias em 90 quadrados de 0.75 m² foi coletada mensalmente durante o período de Julho/2012 à Maio/2013. Os caranguejos foram coletados por escavação manual das tocas, identificados e sexados. A temperatura do ar e da água variou entre 21 a 27°C e 22 a 28°C, respectivamente, enquanto que a salinidade variou de 21 a 35. Um total de 5.391 espécimes foi coletado, sendo 2.823 machos e 2.568 fêmeas (sendo 40 ovadas). A densidade média para a população de Uca sp. (subgênero leptuca) variou de 18,01 ± 1,29 (Maio/13) a 62,22 ± 1,51 ind.m-² (Novembro/12), para Uca thayeri de 3,67 ± 0,63 (Julho/12) a 15,29 ± 1,44 ind.m-² (Janeiro/13) e para a população Uca maracoani de 0,83 ± 0,27 ind.m-² (Julho/13) a 10,31 ± 0,73 (Novembro/12). A proporção sexual foi 1:1 para cada espécie estudada. A análise de correspondência canônica indicou que houve influência dos fatores ambientais na densidade dos caranguejos. Entretanto, as variáveis abióticas não foram limitantes para a distribuição das espécies estudadas. A produção secundária para a população de Uca sp. (subgênero leptuca) variou de 7,34 para 50,89 g PSLC m-1 ano-1, para Uca thayeri de 12,10 para 27,65 g PSLC m-1 ano-1 e para a população Uca maracoani de 1,70 para 8,83 g PSLC m-1 ano-1. A análise de regressão multivariada indicou que para a espécie Uca sp. (subgênero leptuca) a quantidade clorofila-a está relacionada com a produtividade desta espécie e para as demais espécies nenhuma das variáveis abióticas estudadas estaria relacionada com sua produtividade. / The temporal distribution, sex ratio and density of the fiddler crab Uca spp. was studied in populations living in the Piraquê-Açu and Piraquê-Mirim estuaries, Santa Cruz, Espírito Santo State, Brazil. Ninety 0.75 m² in 06 areas were used to obtain monthly samples from July 2012 to May 2013. The crabs were collected manually through excavation of burrows, identified and sexed. Air and water temperatures varied from 21 to 27°C and 22 to 28°C, respectively, and the salinity from 21 to 35. A total of 5,391 fiddler crabs were collected, with 2,823 males and 2,568 females (40 ovigerous). The average densities for the three species found were 18,01 ± 1,29 (May/13) to 62,22 ± 1,51 ind.m-² (November/12), 3,67 ± 0,63 (July/12) to 15,29 ± 1,44 ind.m-² (January/13) for Uca thayeri and 0,83 ± 0,27 ind.m-² (July/13) to 10,31 ± 0,73 (November/12) for Uca maracoani. Sex ratio (male:female) was 1:1. Canonical correspondence analysis showed that abiotic factors can influence crab density, but do not limit species distribution. The average secondary production of the Uca sp. population ranged from 7.34 to 50.89 g PSLC m-1 y-1, for Uca thayeri ranged between 12.10 to 27.65 g PSLC m-1 y-1 and for Uca maracoani from 1.70 to 8.83 g PSLC m-1 y-1. The multiple regression shows the chlorophyll-a may influence Uca sp. (subgênero leptuca) productivity. For the Uca thayeri and Uca maracoani species not a single abiotic factor tested had an influence in productivity.

<p>By concentrating materials and increasing the speed with which rainfall is conveyed off of the landscape, nearly all forms of land use change lead to predictable shifts in the hydrologic, thermal, and chemical regimes of receiving waters that can lead to the local extirpation of sensitive aquatic biota. In Central Appalachian river networks, alkaline mine drainage (AlkMD) derived from mountaintop removal mining for coal (MTM) noticeably simplifies macroinvertebrate communities. In this dissertation, I have used this distinct chemical regime shift as a platform to move beyond current understanding of chemical pollution in river networks. In Chapter Two, I applied a new model, the Hierarchical Diversity Decision Framework (HiDDeF) to a macroinvertebrate dataset along a gradient of AlkMD. By using this new modeling tool, I showed that current AlkMD water quality standards allow one-quarter of regional macroinvertebrates to decline to half of their maximum abundances. In Chapter Three, I conducted a field study in the Mud River, WV to understand how AlkMD influences patterns in aquatic insect production. This work revealed roughly 3-fold declines in annual production of sensitive taxa throughout the year in reaches affected by AlkMD. These declines were more severe during summer base flow when pollutant concentrations were higher, thereby preventing sensitive organisms from completing their life cycles. Finally, in Chapter Four I described the idea of chemical fragmentation in river networks by performing a geospatial analysis of chemical pollution in Central Appalachia. In this work I showed that the ~30% of headwaters that remain after MTM intensification over the last four decades support ~10% of macroinvertebrates not found in mined reaches. Collectively my work moves beyond the simple tools used to understand the static, local consequences of chemical pollution in freshwater ecosystems.</p> / Dissertation

Made available in DSpace on 2016-06-02T19:31:48Z (GMT). No. of bitstreams: 1 2872.pdf: 6249209 bytes, checksum: f31460c647c1aca2560d572231c4fbbd (MD5) Previous issue date: 2010-02-22 / Financiadora de Estudos e Projetos / The UHE-Furnas is a reservoir built in 1963 for hydroelectricity generation, but also exploited for multiple purposes. In the last decades it has been subject to continuous antropic impacts as the discharges of domestic and industrial non-treated effluents and the agricultural runoff, thus undergoing progressive nutrient enrichment. Rotifera is an important component group of the zooplankton community, playing relevant role in the transfer of energy and matter in freshwater food chains. Studies on their diversity and productivity can contribute to the understanding of the reservoir as a whole and contribute for the conservation of aquatic biota. The objective of this work was to analyze the spatial seasonal changes of Rotifera species composition, diversity and production, verifying its relationships with the abiotic factors. Rotifera assemblages were sampled monthly in four localities and six points at the Sapucaí compartment of Furnas Reservoir, including four points in the limnetic and two in the littoral region, during the period between August 2006 and July 2007. The main physical and chemical variables were measured in situ and samples were taken for nutrients and chlorophyll a quantification. The Sapucaí compartment had low nutrient concentrations characterizing an oligotrophic system. The Rotifera assemblage was composed by 51 taxa of common occurrence in tropical regions. The highest species richness and population equitability were recorded in the dry period, but there were no significant changes in assemblages composition among sites. Mean production was 31.79 &#956;g PS. m-3.day-1 in the rainy season and 14.27 &#956;gPS. m-3.day-1. The species that contributed most to the production were Conochilus unicornis and Trichocerca chattoni, in the rainy season and C. unicornis, Plationus patulus and Collotheca sp in the dry period. The highest values were recorded in spring-summer seasons, realted to the increases on phytoplankton biomass. The mean P:B ratio was 0.51 corresponding to a turnover time of 1.96 days. Production values obtained for Rotifera were in the range of values reported in the literature for this group, in other oligotrophic reservoirs. Despite its small sizes and biomass when compared to other zooplankton groups, Rotifera assemblages had high biomass turnover rates thus playing important role in nutrient cycling and energy transfer in UHE-Furnas Reservoir. / O reservatório da UHE de Furnas foi construído em 1963 para produção de energia elétrica, mas é utilizado para múltiplos fins. Nas últimas décadas vem sofrendo progressivo processo de degradação ambiental devido às ações antrópicas, principalmente a descarga de efluentes domésticos, industriais e agrícolas, com gradual enriquecimento por nutrientes. Os Rotifera, um dos principais grupos componentes da comunidade zooplanctônica, desempenham um importante papel na transferência de energia e matéria nas cadeias alimentares. O estudo da sua diversidade e produtividade pode contribuir para o entendimento do funcionamento dos ecossistemas como um todo e a conservação da biota aquática. O objetivo deste trabalho foi analisar as variações temporais e espaciais na composição, diversidade, biomassa e produção secundária dos rotíferos e verificar as relações destas com as características abióticas. Mensalmente foram amostrados seis pontos do reservatório de Furnas, na porção Sapucaí, sendo dois situados na região litorânea e quatro na região limnética, no período de agosto de 2006 a julho de 2007. As principais variáveis físicas e químicas da coluna d água foram medidas in situ e amostras de água foram coletadas para determinação de nutrientes e clorofila a. A baixa concentração de nutrientes e de material em suspensão caracterizou este compartimento como um sistema oligotrófico. Foram identificados 51 táxons, com composição típica de regiões tropicais. A maior riqueza e uniformidade foram obtidas no período seco, não havendo diferenças espaciais com relação à composição das espécies. A produção média dos rotíferos no período chuvoso foi 31,79 &#956;g PS. m-3.dia-1 e no período seco foi de 14,27 &#956;gPS.m-3.dia-1. As espécies que mais contribuíram para a produção foram Conochilus unicornis e Trichocerca chattoni, no período chuvoso e C. unicornis, Plationus patulus e Collotheca sp. no período seco. Os maiores valores foram registrados nos meses de primavera e verão, relacionados em parte com os aumentos na biomassa do fitoplâncton. A razão P:B foi em média 0,51, que corresponde a um tempo de renovação de 1,96 dias. Os valores de produção de Rotifera enquadram-se na faixa de valores relatados na literatura para outros reservatórios oligotróficos. Apesar de menor tamanho corporal, menor biomassa, comparados aos outros grupos zooplanctônicos, os Rotifera apresentaram altas taxas de renovação, desempenhando, portanto um importante papel na ciclagem de nutrientes e transferência de energia no reservatório da UHE de Furnas.

Tese(doutorado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2011. / Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-10-17T13:22:32Z No. of bitstreams: 1 Tatiana.pdf: 800712 bytes, checksum: 8a3d4e20ee5c684b5100fb7af1f23e95 (MD5) / Approved for entry into archive by Sabrina Andrade (sabrinabeatriz@ibest.com.br) on 2013-10-17T16:37:23Z (GMT) No. of bitstreams: 1 Tatiana.pdf: 800712 bytes, checksum: 8a3d4e20ee5c684b5100fb7af1f23e95 (MD5) / Made available in DSpace on 2013-10-17T16:37:23Z (GMT). No. of bitstreams: 1 Tatiana.pdf: 800712 bytes, checksum: 8a3d4e20ee5c684b5100fb7af1f23e95 (MD5) Previous issue date: 2011 / O objetivo desta tese foi estimar a produção secundária em ambientes aquáticos, com enfoque no estuário da Lagoa dos Patos (Rio Grande, RS, Brasil). Os crustáceos são dominantes no zooplâncton da região em estudo, sendo utilizados como base das análises realizadas. A produção secundária foi estimada através de modelos matemáticos e do método enzimático. Para a aplicação dos modelos matemáticos, foram realizadas coletas em 5 pontos do estuário nas 4 estações do ano. Os resultados obtidos foram utilizados para estimativa da produção secundária através dos modelos de Huntley & Lopes (1992) e Hirst & Bunker (2003). Durante as coletas, também foram obtidas amostras de água do ambiente para a determinação da taxa de decaimento da atividade da quitobiase, parâmetro utilizado para estimativa da produção secundária através do método enzimático, o qual está baseado na atividade da quitobiase liberada na água durante a muda de crustáceos. Para aplicação deste método, foram realizados experimentos em laboratório para determinar as características da quitobiase do copépode Acartia tonsa, principal representante do grupo Copepoda do zooplâncton no estuário da Lagoa dos Patos. Os resultados de produção de carbono obtidos através dos modelos matemáticos e do método enzimático foram comparados. Por fim, foram realizados experimentos utilizando-se metodologias já bem definidas de estimativa de crescimento, como a análise de coorte em náuplios e produção de ovos de adultos de A. longiremis coletadas no Saanich Inlet (BC, Canadá), sendo que os resultados obtidos foram comparados àqueles do congênere A. tonsa. Os resultados apresentados nesta tese contribuem tanto com dados de produção secundária para o estuário da Lagoa dos Patos, bem como indicam a aplicação do método da quitobiase também em águas estuarinas. / The aim of this thesis was to estimate the secondary production in aquatic environments with focus on the Patos Lagoon estuary (Rio Grande, RS, Brazil). Crustaceans are dominants in the zooplankton of the study area, being employed in the analyses performed. Secondary production was estimated using mathematical models and the enzymatic method. Zooplankton sampling was seasonally performed in 5 sites at the Patos Lagoon estuary for the application of the mathematical methods. Results obtained were used to estimate the secondary production through the models described by Huntley & Lopes (1992) and Hirst & Bunker (2003). During zooplankton collection, water samples were also obtained for determination of the rate of chitobiase activity decay, parameter used in the secondary production estimation employing the enzymatic method. This method is based on the activity of the chitobiase released during the crustacean molting process. For the application of the enzymatic method, laboratory experiments were performed to characterize the chitobiase do the copepod Acartia tonsa, major representative of Copepoda in the zooplankton of the Patos Lagoon estuary. Data of carbon production generated using the mathematical models and the enzymatic method were compared. Finally, experiments were performed employing known methodologies based on cohort analysis and egg production in the copepod A. longiremis collected at the Saanich Inlet (BC, Canada). Results obtained were compared to those for the congener A. tonsa. Results presented in this thesis contribute with secondary production data for the Patos Lagoon estuary and indicate the application of the chitobiase method for estimation of secondary production also in estuarine waters.

Acid rain alters freshwater pH and ion composition, preventing organisms from performing essential bodily functions causing mortality. Macroinvertebrate communities in acidified streams are characterized by species loss in response to physiological stress and altered food quality resulting from the degradation of microbial (e.g., fungi on leaves) communities. Although freshwater acidification in the U.S. is lessening following reduced industrial emissions, little is known about macroinvertebrate recovery. Often, biotic recovery is assessed by looking at changes to what taxa and how many individuals are present in the community (e.g., richness, density). While providing a metric for change, changes in "who" is there (i.e., richness) doesn't necessarily tell us changes in "what" they are doing (i.e., function). The relationship between diversity and function requires linking a "who" to their "what" with direct measurements or as indicated by their traits. Traits are attributes of an organism that aggregate biological, morphological, and behavioral information and may relate to their success in a particular environment. For example, taxa that cannot survive with stream drying (not desiccation resistant) may only be found in streams with permanent water. Trait-based taxonomic metrics could bridge "who" and "what" and expand the impact of stream recovery assessments. My objective was to assess trends over time in water chemistry and macroinvertebrate taxonomic and trait richness and density following reduced industrial emissions. To do so, I studied two long-term data sets from Shenandoah National Park to assess trends in water chemistry and macroinvertebrate taxa and trait composition over a 30-year period to identify taxa and traits that are sensitive to acidification. I also measured how much biomass macroinvertebrates produced in a year (i.e., secondary production) in two streams (1 acidified; 1 not acidified) to determine taxa and traits that are functionally sensitive to acidification. I used these structural and functional measures of sensitivity to determine if changes in trait richness or density predict changes in the function of that trait (e.g., secondary production). Changes over time show that streams have some recovery from acid rain with increasing stream pH and a greater number of taxa and traits present in the community. Changes in taxa were greater than changes in traits over time. While this result was expected as multiple taxa make up each trait category, it may also suggest minimal or delayed functional recovery over time. Still, macroinvertebrate secondary production indicated that function did differ with differences in acidification. Therefore, observed small changes in traits over time mirror prior studies that found other variables, such as competition for food or space, delay or inhibit macroinvertebrates from returning to the recovering streams. Additionally, there were similarities between traits changing over time and the secondary production of traits that differed between more and less acidified streams. Taxa characterized by long life spans and large body size (e.g., semivoltine, long adult life, slow seasonal development) appeared to be the most sensitive to changes in acidification. These findings suggest that some compositional attributes, like taxonomic or trait richness, may predict functional changes measured as secondary production while others, such as density, do not. / Master of Science in Life Sciences / Acid rain causes the acidification of freshwater stream water observed as decreased stream pH and decreased ability of watershed soils to neutralize or "soak up" acidic inputs before they enter the stream. These changes in stream water chemistry inhibit the ability of aquatic animals to perform essential bodily functions resulting in mortality. The total number of aquatic insect taxa and total number of individuals in the community have been found to decrease in response to acidification. Although freshwater acidification is lessening following reduced industrial emissions, little is known about if and how aquatic insects can recover. Often, aquatic insect recovery is assessed through looking at changes to what taxa and how many individuals are present in the community. While providing a metric for change, changes in "who" is there (i.e., richness) doesn't necessarily tell us changes in "what" they are doing (i.e., function). The relationship between diversity and function requires linking a "who" to their "what". This is often done by assessing changes in the taxa present but also looking at how the composition of traits associated with those taxa also change. Traits or taxa-specific characteristics aggregate biological, morphological, and behavioral information and may relate to their ability to live in a given environment. For example, taxa that rely on filtering and consuming fine particles may only be found in faster flowing streams where they function to remove fine particulates. Trait-based assessments could link "who" and "what" to expand our understanding of how stream ecosystems change with a stressor. My objective was to assess recovery of streams in Shenandoah National Park following reduced industrial emissions. To do so, I studied two long-term (1987-2017) data sets from to assess trends in water chemistry and macroinvertebrate taxa and traits. This enabled me to determine "who" is changing in these streams over time. I also measured how much insect biomass s produced in a year (i.e., secondary production) in two streams (1 more acidic; 1 less acidic) to determine what taxa and traits alter "what" (e.g., secondary production) they are doing. I found that long-term trends indicate some recovery from acid rain with improving water quality and an increased number of insect taxa and traits present in the community over time. Changes in insect taxa were greater than changes in their traits suggesting that stream acidification did not greatly alter "what" the insects are doing greatly to begin with or that recovery may be delayed. In contrast, my secondary production study showed that "what" macroinvertebrates are doing does differ in more or less acidic streams. Therefore, our observed minimal changes in traits over time suggest that other variables, such as competition for food or space, delay or inhibit macroinvertebrates from returning to the recovering streams. Additionally, there were similarities between traits changing over time and traits that were different in the more or less acidic streams. Taxa characterized by long life spans and large body size (e.g., semivoltine, long adult life, slow seasonal development) appeared to be the most affected by differences or changes in stream water acidity. These findings suggest that changes in "who" can predict changes in "what" to some degree though static metrics of abundance do not always reflect the function of the taxa or community.

A composição, distribuição, abundância, biomassa e produção secundária do zooplâncton do Sistema estuarino de Santos foram estudadas na baía de Santos (4 estações), canal de Santos (3 estações) e canal da Bertioga (4 estações), entre novembro de 2004 e outubro de 2005, em relação à temperatura, salinidade, material em suspensão, nutrientes dissolvidos e clorofila-a. Nas 114 amostras analisadas, o zooplâncton foi constituído de 101 táxons distribuídos em 10 filos: Arthropoda (subfilo Crustacea), Annelida (classe Polychaeta), Bryozoa, Chaetognatha, Chordata (subfilo Tunicata), Cnidaria, Ctenophora, Echinodermata, Mollusca e Phoronida, sendo o primeiro dominante. Os copépodes constituíram, em média, 85,5% do zooplâncton total. A comunidade zooplanctônica das três áreas incluiu táxons estuarinos, costeiros e oceânicos, sendo dominantes Oithona hebes, Oithona oswaldocruzi, Acartia lilljeborgi, Acartia tonsa, Bestiolina similis, Balanus spp. (náuplios), Paracalanus quasimodo, Paracalanus spp. (copepoditos), Parvocalanus scotti, Euterpina acutifrons, Pseudodiaptomus acutus, Oikopleura dioica e as larvas de Polydora spp., Aonides spp., Spionidae e Bivalvia. A abundância, biomassa e a produção secundária zooplanctônica foram maiores no canal da Bertioga, enquanto a produtividade foi maior na baía de Santos. Esses fatores estiveram associados, principalmente, à salinidade, temperatura da água e material em suspensão total. / The zooplankton´s composition, distribution, abundance, biomass and secondary production of Santos estuarine system were studied on Santos bay (4 stations), Santos channel (3 stations) and Bertioga channel (4 stations) between November 2004 and October 2005 in relation to temperature, salinity, suspended matter, dissolved nutrients and chlorophyll-a. On the 114 analyzed samples, zooplankton was constituted of 101 taxa distributed among 10 phyla: Arthropoda (subphylum Crustacea), Annelida (class Polychaeta), Bryozoa, Chaetognatha, Chordata (subphylum Tunicata), Cnidaria, Ctenophora, Echinodermata, Mollusca and Phoronida, being Arthropoda the dominant phylum. Copepoda (subphylum Crustacea) constituted on average 85,5% of total zooplankton. The zooplankton community among the three areas included estuarine, coastal and oceanic taxa, being Oithona hebes, Oithona oswaldocruzi, Acartia lilljeborgi, Acartia tonsa, Bestiolina similis, Balanus spp. (naupli), Paracalanus quasimodo, Paracalanus spp. (copepodite), Parvocalanus scotti, Euterpina acutifrons, Pseudodiaptomus acutus, Oikopleura dioica and the larvae of Polydora spp., Aonides spp., Spionidae and Bivalvia dominant. The abundance, biomass and zooplanktonic secondary production were higher on Bertioga channel, whereas the productivity was higher on Santos bay. These factors were associated mainly to salinity, water temperature and total suspended matter.

A composição, distribuição, abundância, biomassa e produção secundária do zooplâncton do Sistema estuarino de Santos foram estudadas na baía de Santos (4 estações), canal de Santos (3 estações) e canal da Bertioga (4 estações), entre novembro de 2004 e outubro de 2005, em relação à temperatura, salinidade, material em suspensão, nutrientes dissolvidos e clorofila-a. Nas 114 amostras analisadas, o zooplâncton foi constituído de 101 táxons distribuídos em 10 filos: Arthropoda (subfilo Crustacea), Annelida (classe Polychaeta), Bryozoa, Chaetognatha, Chordata (subfilo Tunicata), Cnidaria, Ctenophora, Echinodermata, Mollusca e Phoronida, sendo o primeiro dominante. Os copépodes constituíram, em média, 85,5% do zooplâncton total. A comunidade zooplanctônica das três áreas incluiu táxons estuarinos, costeiros e oceânicos, sendo dominantes Oithona hebes, Oithona oswaldocruzi, Acartia lilljeborgi, Acartia tonsa, Bestiolina similis, Balanus spp. (náuplios), Paracalanus quasimodo, Paracalanus spp. (copepoditos), Parvocalanus scotti, Euterpina acutifrons, Pseudodiaptomus acutus, Oikopleura dioica e as larvas de Polydora spp., Aonides spp., Spionidae e Bivalvia. A abundância, biomassa e a produção secundária zooplanctônica foram maiores no canal da Bertioga, enquanto a produtividade foi maior na baía de Santos. Esses fatores estiveram associados, principalmente, à salinidade, temperatura da água e material em suspensão total. / The zooplankton´s composition, distribution, abundance, biomass and secondary production of Santos estuarine system were studied on Santos bay (4 stations), Santos channel (3 stations) and Bertioga channel (4 stations) between November 2004 and October 2005 in relation to temperature, salinity, suspended matter, dissolved nutrients and chlorophyll-a. On the 114 analyzed samples, zooplankton was constituted of 101 taxa distributed among 10 phyla: Arthropoda (subphylum Crustacea), Annelida (class Polychaeta), Bryozoa, Chaetognatha, Chordata (subphylum Tunicata), Cnidaria, Ctenophora, Echinodermata, Mollusca and Phoronida, being Arthropoda the dominant phylum. Copepoda (subphylum Crustacea) constituted on average 85,5% of total zooplankton. The zooplankton community among the three areas included estuarine, coastal and oceanic taxa, being Oithona hebes, Oithona oswaldocruzi, Acartia lilljeborgi, Acartia tonsa, Bestiolina similis, Balanus spp. (naupli), Paracalanus quasimodo, Paracalanus spp. (copepodite), Parvocalanus scotti, Euterpina acutifrons, Pseudodiaptomus acutus, Oikopleura dioica and the larvae of Polydora spp., Aonides spp., Spionidae and Bivalvia dominant. The abundance, biomass and zooplanktonic secondary production were higher on Bertioga channel, whereas the productivity was higher on Santos bay. These factors were associated mainly to salinity, water temperature and total suspended matter.