This database contains climatic, hydrologic, water quality and biological information for the Lake Beysehir catchment, Turkey. The dataset includes meteorological data (precipitation, air temperature, wind speed, solar radiation, relative humidity), discharges for the main inflows and lake outflow, lake water level, water chemistry data for inflows and lake. In addition, lake biological data (phytoplankton, zooplankton, fish and macrophyte) is avaiable. Data was compiled during the METU-DPT-TEAB project, EU-FP7 REFRESH project and EU-FP7 MARS project . More information on this dataset can be found in the Freshwater Metadatabase - MARS_09 (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=MARS_09).
Biomass distribution among size classes follows a power law where the Log-abundance of taxa scales to Log-size with a slope that responds to environmental abiotic and biotic conditions. The interactions between ecological mechanisms controlling the slope of locally realized size-abundance relationships (SAR) are however not well understood. Here we tested how warming, nutrient levels, and grazing affect the slope of phytoplankton community SARs in decadal time-series from eight Swiss lakes of the peri-alpine region, which underwent environmental forcing due to climate change and oligotrophication. We expected rising temperature to have a negative effect on slope (favoring small phytoplankton), and increasing nutrient levels and grazing pressure to have a positive effect (benefiting large phytoplankton). Using a random forest approach to extract robust patterns from the noisy data, we found that the effects of temperature (direct and indirect through water column stability), nutrient availability (phosphorus and total biomass), and large herbivore (copepods and daphnids) grazing and selectivity on slope were non-linear and interactive. Increasing water temperature or total grazing pressure, and decreasing phosphorus levels, had a positive effect on slope (favoring large phytoplankton, which are predominantly mixotrophic in the lake dataset). Our results therefore showed patterns that were opposite to the expected long-term effects of temperature and nutrient levels, and support a paradigm in which (i) small phototrophic phytoplankton appear to be favored under high nutrients levels, low temperature and low grazing, and (ii) large mixotrophic algae are favored under oligotrophic conditions when temperature and grazing pressure are high. The effects of temperature were stronger under nutrient limitation, and the effects of nutrients and grazing were stronger at high temperature. Our study shows that the phytoplankton local SARs in lakes respond to both the independent and the interactive effects of resources, grazing and water temperature in a complex, unexpected way, and observations from long-term studies can deviate significantly from general theoretical expectations.
Individual-level variation arising from responses to environmental gradients influences population and community dynamics. How such responses empirically relate to the mechanisms that govern species coexistence is, however, poorly understood. Previous results from lake phytoplankton communities suggested that the evenness of organismal traits in multiple dimensions increases with resource limitation, possibly due to resource partitioning at the individual level. Here we experimentally tested the emergence of this pattern by growing two phytoplankton species (Pseudokirchneriella subcapitata and Microcystis aeruginosa) under a gradient of light intensity, in monoculture and jointly. Under low light (resource) conditions, the populations diversified into a wide range of phenotypes, which were evenly distributed in multidimensional trait space (defined by four pigment-related trait dimensions), consistent with the observed field pattern. Our interpretation is that under conditions of light limitation, individual phytoplankton cells alter photosynthetic traits to reduce overlap in light acquisition, acquiring unexploited resources and thereby likely maximising individual success. Our results provide prime experimental evidence that resource limitation increases the evenness of conspecific and heterospecific microbial phenotypes along trait axes, advancing our understanding of trait-based coexistence.
The Dual Scripps Plankton Camera (DSPC) is a new approach for automated in-situ monitoring of phyto- and zooplankton communities based on a dual magnification dark-field imaging microscope. Here, we present the DSPC and its associated image processing while evaluating its capabilities in i) detecting and characterizing plankton species of different size and taxonomic categories and ii) measuring their abundance in both laboratory and field applications. In the laboratory, body size and abundance estimates by the DSPC significantly and robustly scaled with measurements derived by microscopy. In the field, a DSPC installed permanently at 3 m depth in Lake Greifensee (Switzerland) delivered images of plankton individuals, colonies, and heterospecific aggregates at hourly timescales without disrupting natural arrangements of interacting organisms, their microenvironment or their behavior. The DSPC was able to track the dynamics of taxa, mostly at the genus level, in the size range between ∼10 μm to ∼ 1 cm, covering many components of the planktonic food web (including parasites and potentially toxic cyanobacteria). Comparing data from the field-deployed DSPC to traditional sampling and microscopy revealed a general overall agreement in estimates of plankton diversity and abundances. The most significant disagreements between traditional methods and the DSPC resided in the measurements of zooplankton community properties. Our data suggest that the DSPC is better equipped to study the dynamics and demography of heterogeneously distributed organisms such as zooplankton, because high temporal resolution and continuous sampling offer more information and less variability in taxa detection and quantification than traditional sampling. Time series collected by the DSPC depicted ecological succession patterns, algal bloom dynamics and diel fluctuations with a temporal frequency and morphological resolution that was never observed by traditional methods. Access to high frequency, reproducible and real-time data of a large spectrum of the planktonic ecosystem can expand our understanding of both applied and fundamental plankton ecology. Our work leads us to conclude that the utilization of the DSPC is robust for both research and water quality monitoring and suitable for stable long-term deployments.
Sets of names used for analysis of algal samples in the USGS NAWQA, EPA NARS, and ANSP projects A common set of names is important for maximizing taxonomic consistency among analysts and comparability among datasets. Academy phycologists and collaborators, with support from the USGS, US EPA, and several state agencies, have developed and maintained a set of taxa names for use in agency sponsored projects and elsewhere. The current set of names (2011) has evolved from initial sets over the past 15-20 years. Many phycologists at several institutions have contributed to expanding and updating the names. Much of this work was supported by the USGS and documented in USGS NAWQA Workshop reports. The first set of names, or “taxonomic systems”, was developed in 1994. Names have been updated about every 3 years, typically as part of USGS NAWQA taxonomic workshops. More information on this dataset can be found in the Freshwater Metadatabase - BFE_73 (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=BFE_73).
The ANSP Algae Image Database contains light micrograph images of diatom taxa from rivers throughout the USA. Many taxa are represented. There are multiple images of several to help represent within-taxon variability. The images were made primarily by ANSP Patrick Center Phycology Section staff as part of their routine analysis of algal samples. Purposes of the database are to: provide a set of reference images for ANSP algal analysts and collaborators to help them maintain consistency in taxonomic identifications help document names of taxa used in papers and reports by providing easy access to representative images make images available to other phycologists as a resource to help with identifications The set of images available here is not meant to be comprehensive or to be taxonomically definitive, but only to show representative specimens that can be used to supplement image resources in the published taxonomic literature. Read the documentation to learn more about the database and how to search for and view images. More images will be added on a regular basis. More information on this dataset can be found in the Freshwater Metadatabase - BFE_71 (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=BFE_71).
Phytoplankton and cyanobacteria. This dataset is associated with the following publication: Chen, K., J. Lu, and J. Allen. 12 Community structures of phytoplankton with emphasis of toxic cyanobacteria in an Ohio inland lake during bloom season. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH. Ecomed Verlagsgesellschaft AG, Landsberg, GERMANY, 9(11): 1-29, (2017).
The PLANKTON*NET data provider at the Alfred Wegener Institute for Polar and Marine Research is an open access repository for plankton-related information. It covers all types of phytoplankton and zooplankton from marine and freshwater areas. PLANKTON*NET's greatest strength is its comprehensiveness as for the different taxa image information as well as taxonomic descriptions can be archived. PLANKTON*NET also contains a glossary with accompanying images to illustrate the term definitions. PLANKTON*NET therefore presents a vital tool for the preservation of historic data sets as well as the archival of current research results. Because interoperability with international biodiversity data providers (e.g. GBIF) is one of our aims, the architecture behind the new planktonnet@awi repository is observation centric and allows for mulitple assignment of assets (images, references, animations, etc) to any given observation. In addition, images can be grouped in sets and/or assigned tags to satisfy user-specific needs . Sets (and respective images) of relevance to the scientific community and/or general public have been assigned a persistant digital object identifier (DOI) for the purpose of long-term preservation (e.g. set "Plankton*Net celebrates 50 years of Roman Treaties", handle: 10013/de.awi.planktonnet.set.495) More information on this dataset can be found in the Freshwater Metadatabase - BFE_70 (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=BFE_70).
collection of sites with both biological and abiotic information - biological data covers all quality elements (macroinvertebrates, macrophytes, diatoms, other benthic algae, fish, and phytoplancton) - abiotic data comprises hydromorphological info (Gew�sserstrukturkartierung), physico-chemical info, and information about landcovering in catchment area primary aim was to aquire complete site information (complete set of environmental data and data from all organism groups), but finally the datasets turned out to be quite fregmentary More information on this dataset can be found in the Freshwater Metadatabase - BF_W_76-R-CAl (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=BF_W_76-R-CAl).