Length-weight regressions for zooplankton biomass calculations – A review and a suggestion for standard equations

Zooplankton biomass can be estimated through the use of equations that convert length of individuals to dry weight. The logarithmic transformation of these power equations follow the form Ln(W) =Ln(α) + β Ln(L) where L is length in mm, W is dry weight in ug, and α and β are species-specific values. Several sets of L-W equations have been developed for use in the Great Lakes region by agencies such as the Environmental Protection Agency (EPA) and Canada’s Department of Fisheries and Oceans (DFO). Since we collaborate with both agencies and require comparability with previously collected data, we reviewed these two sets of equations and the publications that were used to develop them. We offer a third Cornell Standard (CBFS STD) set that resolves many of the discrepancies seen in the other sets.Funded by the Great Lakes Restoration Initiative through the Environmental Protection Agency and the International Joint Commission

2010 Status of the Lake Ontario Lower Trophic Levels

This report presents data on the status of lower trophic level components of the Lake Ontario ecosystem (zooplankton, phytoplankton, nutrients) in 2010 and compares the 2010 data with available time series. Lower trophic levels are indicators of ecosystem health [as identified by the Lake Ontario Pelagic Community Health Indicator Committee (EPA 1993) and presented in the biennial State of the Lake Ecosystem Conference (SOLEC) reports] and determine the lake’s ability to support the prey fish upon which both wild and stocked salmonids depend. Understanding the production potential of lower trophic levels is also integral to ecosystem-based management. Continued evaluation of lower trophic levels is particularly important for fisheries management, as the observed declines in alewife and Chinook salmon in Lake Huron in 2003 may have been partly the result of changes in lower trophic levels (Barbiero et al. 2009)

BioTIME: A database of biodiversity time series for the Anthropocene.

MotivationThe BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables includedThe database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grainBioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2).Time period and grainBioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurementBioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.Software format.csv and .SQL

Dispersal and emerging ecological impacts of Ponto-Caspian species in the Laurentian Great Lakes

We describe, explain, and “predict” dispersal and ecosystem impacts of six Ponto-Caspian endemic species that recently invaded the Great Lakes via ballast water. The zebra mussel, Dreissena polymorpha, and quagga mussel, Dreissena bugensis, continue to colonize hard and soft substrates of the Great Lakes and are changing ecosystem function through mechanisms of ecosystem engineering (increased water clarity and reef building), fouling native mussels, high particle filtration rate with selective rejection of colonial cyanobacteria in pseudofeces, alteration of nutrient ratios, and facilitation of the rapid spread of their Ponto-Caspian associates, the benthic amphipod Echinogammarus ischnus and the round goby, Neogobius melanostomus, which feeds on zebra mussels. The tubenose goby, Proterorhinus marmoratus, which does not feed on zebra mussels, has not spread rapidly. Impacts of these benthic invaders vary with site: in some shallow areas, habitat changes and the Dreissena → round goby → piscivore food chain have improved conditions for certain native game fishes and waterfowl; in offshore waters, Dreissena is competing for settling algae with the native amphipod Diporeia spp., which are disappearing to the detriment of the native deep-water fish community. The predatory cladoceran Cercopagis pengoi may compete with small fishes for zooplankton and increase food-chain length

Analysis of Lake Ontario Lower Aquatic food web Assessment (LOLA 2003 and 2008) within the context of long-term ecological change

Lake Ontario is the 13th largest lake in the world with a surface area of 18,500 km² (Reynolds et al. 2000), has a population in the watershed of over 8 million, and provides a range of ecosystem services to the people in the watershed (freshwater for various uses, shipping, fisheries, and recreation). Currently, extensive surveys for each Great Lake occur on a rotating five-year schedule. This report presents the status of Lake Ontario’s lower trophic levels in 2008 and a detailed comparison with similarly collected in 2003 and with data collected by the collaborating agencies and Cornell University and discuss observed changes in relation to changes in nutrient concentration and food web configuration in Lake Ontario. There has been a spatial restructuring of the Lake Ontario offshore ecosystem through the increase in the deep chlorophyll layer and associated zooplankton. This has resulted in a Lake Ontario that in 2008 is more similar to Lakes Superior, Huron and Michigan than to the Lake Ontario of the 1990s. Major findings are Nutrients: Spring offshore total phosphorus and soluble reactive phosphorus increased from 2003 to 2008, but summer levels did not. Lake-wide average total phosphorus levels remained at or below the target level of 10 µg/L in all three seasons of 2008. Lake-wide nutrient concentrations have declined since the 1960s. However, phosphorus concentrations have been stable (~7-10 µg/L) since the mid-1990s. Spring silica was similar in 2003 and 2008 and was depleted by the summer in both years. This indicates continued spring diatom production in Lake Ontario. Phytoplankton: Summer epilimnetic chlorophyll-a increased by a factor of 2, the proportion of autotrophic algae increased, and summer water clarity declined from 2003 to 2008. Summer chlorophyll-a levels in 2008 were similar to the concentrations in the 1981-1995 time period. However, the trend towards mesotrophy in the summer of 2008 may be limited to that year as it was not followed by increased values in 2009 to 2011. Most of the chlorophyll in the water column was located in a deep chlorophyll layer in the thermocline. Zooplankton: Offshore epilimnetic zooplankton density and biomass declined from 2003 to 2008 by a factor of 5 to 12 in the summer and by a factor of 1.5 to 2.6 in the fall. This is consistent with long-term trends of declining epilimnetic zooplankton abundance including a larger decline in 2004-2005 coincident with an increase in the predatory Bythotrephes. Whole water column zooplankton density also declined from 2003 to 2008 in the summer and fall, but zooplankton biomass only declined in the fall. Large changes in whole water column zooplankton community composition occurred between 2003 and 2008 from a cyclopoid/bosminid dominated system in 2003 to a calanoid dominated system in 2008. Mysids, Diporeia and Mussels Mysid densities were similar in 2003 and 2008 indicating continued high biomass of mysids in Lake Ontario. In July of 2008, the biomass of Mysis diluviana was 17% of the crustacean zooplankton biomass in the offshore of Lake Ontario (depth >30m). Mysid densities appear stable in Lake Ontario. The native benthic amphipod Diporeia declined further in 2008 and is almost extirpated from Lake Ontario. Quagga mussels are very abundant as deep as 90 m, but populations in shallow water declined from 2003 to 2008. Few zebra mussels were present in either 2003 or 2008.Report for the GLRI funded project Improving Lake Ontario Environmental Management Decisions (Grant ID # 97220700-0

BioTIME: A database of biodiversity time series for the Anthropocene

Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record. Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km(2) (158 cm(2)) to 100 km(2) (1,000,000,000,000 cm(2)). Time period and grainBio: TIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year. Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.European Research Council; EU [AdG-250189, PoC-727440, ERC-SyG-2013-610028]; Natural Environmental Research Council [NE/L002531/1]; National Science Foundation [DEB-1237733, DEB-1456729, 9714103, 0632263, 0856516, 1432277, DEB 9705814, BSR-8811902, DEB 9411973, DEB 0080538, DEB 0218039, DEB 0620910, DEB 0963447, DEB-1546686, DEB-129764]; National Science Foundation (LTER) [DEB-1235828, DEB-1440297, DBI-0620409, DEB-9910514, DEB-1237517, OCE-0417412, OCE-1026851, OCE-1236905, OCE-1637396, DEB 1440409, DEB-0832652, DEB-0936498, DEB-0620652, DEB-1234162, DEB-0823293, OCE-9982105, OCE-0620276, OCE-1232779]; Fundacao para a Ciencia e Tecnologia [POPH/FSE SFRH/BD/90469/2012, SFRH/BD/84030/2012, PTDC/BIA-BIC/111184/2009]; Ciencia sem Fronteiras/CAPES [1091/13-1]; Instituto Milenio de Oceanografia [IC120019]; ARC Centre of Excellence [CE0561432]; NSERC Canada; CONICYT/FONDECYT [1160026, ICM PO5-002, 11110351, 1151094, 1070808, 1130511]; RSF [14-50-00029]; Gordon and Betty Moore Foundation [GBMF4563]; Catalan Government; Marie Curie Individual Fellowship [QLK5-CT2002-51518, MERG-CT-2004-022065]; CNPq [306170/2015-9, 475434/2010-2, 403809/2012-6, 561897/2010, 306595-2014-1]; FAPESP (Sao Paulo Research Foundation) [2015/10714-6, 2015/06743-0, 2008/10049-9, 2013/50714-0, 1999/09635-0 e 2013/50718-5]; EU CLIMOOR [ENV4-CT97-0694]; VULCAN [EVK2-CT2000-00094]; DFG [120/10-2]; Polar Continental Shelf Program; CENPES - PETROBRAS; FAPERJ [E-26/110.114/ 2013]; German Academic Exchange Service; New Zealand Department of Conservation; Wellcome Trust [105621/Z/14/Z]; Smithsonian Atherton Seidell Fund; Botanic Gardens and Parks Authority; Research Council of Norway; Conselleria de Innovacio, Hisenda i Economia; Yukon Government Herschel Island-Qikiqtaruk Territorial Park; UK Natural Environment Research Council ShrubTundra Grant [NE/M016323/1]; IPY; Memorial University; ArcticNet; Netherlands Organization for Scientific Research in the Tropics NWO [W84-194]; Ciencias sem Fronteiras and Coordenacao de Pessoal de Nivel Superior (CAPES, Brazil) [1091/13-1]; U.S. Fish and Wildlife Service/State Wildlife federal grant [T-15]; Australian Research Council Centre of Excellence for Coral Reef Studies [CE140100020]; Australian Research Council Future Fellowship [FT110100609]; University of Lodz; NSF DEB [1353139]; Catalan Government fellowships (DURSI) [1998FI-00596, 2001BEAI200208]; MECD Post-doctoral fellowship [EX2002-0022]; FONDECYT [1141037]; FONDAP [15150003]; [SFRH/BD/80488/2011]; [PD/BD/52597/2014]; [REN2000-0278/CCI]; [REN2001-003/GLO]; [CGL2016-79835-P]; [AGAUR SGR-2014453]; [SGR-2017-1005]; [FCT - SFRH / BPD / 82259 / 2011]; [OCE 95-21184]; [OCE-0099226]; [OCE 03-5234]; [OCE-0623874]; [OCE-1031061]; [OCE-1336206]; [DEB-1354563]; [OPP-1440435]12 month embargo; published online: 24 July 2018This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Are rare species useful species? Obstacles to the conservation of tree diversity in the dry forest zone agro-ecosystems of Mesoamerica

Aim To test the potential to conserve rare dry forest tree and shrub species circa situm.Location Oaxaca, Mexico and Southern Honduras.Methods Local uses (timber, posts and firewood) of species were determined principally through semistructured interviews with 20 rural householders in each of four communities in Honduras and four in Oaxaca. Tree and shrub diversity inventories were carried out in a total of 227 forest patches and parcels of farmland in those eight communities. Species’ conservation priorities were determined using the star system of Hawthorne (1996) and IUCN listings.Results Despite a large number of useful species, remarkably few were also conservation priorities. Useful species were found to be substitutable as is illustrated by Bombacopsis quinata, Cordia alliodora, Guaiacum sanctum and G. coulteri.Conclusions In these areas, circa situm conservation is inhibited by the lack of species that are both rare and useful. Usefulness must be interpreted as a function of substitutability. Natural regeneration provides an abundance of diversity, farmers are unlikely to invest in the management of a species when suitable substitutes are freely available. The key to conserving rare species may be in maintaining or enhancing the value of the landscape elements in which they are found