WHOI silhouette DIGITIZER version 1.0 user’s guide

WHOI Silhouette DIGITIZER is a MATLAB-based computer program for measuring the lengths of marine organisms in the macrozooplankton size range. DIGITIZER displays a scanned photographic image of a seawater slurry containing large numbers of marine organisms, upon which is superimposed a reference grid. DIGITIZER then allows you to measure the organisms' lengths using the cursor on the computer screen. DIGITIZER automatically calculates each organism’s biomass and generates spreadsheet compatible output listings of basic statistics derived from the data. DIGITIZER also produces text files of lengths, weights, and size-frequency histograms.Funding was provided by the National Science Foundation under Grant Nos. OCE-9806381, OCE-9940880, and OCE-0095069

Copepods from warm-core ring 82-H

See Supplementary information.txt for information regarding how access and use the files in WHOI-89-24-data.zipNet tows were collected with a Multiple Opening/Closing Net Environmental Sampling System (MOCNESS) carrying twenty 1-m2 nets in October 1982 in and near warm-core ring 82-H in the North Atlantic (RV/Knorr cruise 98). This report includes the species list and abundance tables of the copepods found in five of the tows. There are four types of abundance tables: raw data, standardized to #/1000 m3 , integrated #/m2 to 1000 m depth, and cumulative percents over the depth of the tows.Funding was provided by the National Science Foundation through grant Number OCE 80-12748, OCE 85-08350, OCE 87-09962, OCE 80-19055, and OCE 80-17271

Seasonality and stable isotopes in planktonic foraminifera off Cape Cod, Massachusetts

Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 20 (2005): PA4011, doi:10.1029/2005PA001150.Monthly samples of stratified plankton tows taken from the slope waters off Cape Cod nearly 25 years ago are used to describe the seasonal succession of planktonic foraminifera and their oxygen isotope ratios. The 15°C seasonal cycle of sea surface temperature (SST) accounts for a diverse mixture of tropical to subpolar species. Summer samples include various Globigerinoides and Neogloboquadrina dutertrei, whereas winter and early spring species include Globigerina bulloides and Neogloboquadrina pachyderma (dextral). Globorotalia inflata lives all year but at varying water depths. Compared with the fauna in 1960–1961 (described by R. Cifelli), our samples seem warmer. Because sea surface salinity varies little during the year, δ18O is mostly a function of SST. Throughout the year, there are always species present with δ18O close to the calculated isotopic equilibrium of carbonate with surface seawater. This raises the possibility that seasonality can be estimated directly from the range of δ18O in a sediment sample provided that the δ18O-salinity relationship is the same as today.Funding was provided by NSF grant OCE-0117149

Drawings and descriptions of some deep-sea copepods living above the Guaymas Basin hydrothermal vent field

This report includes brief descriptions and illustrations of some of the copepods found in two bathypelagic MOCNESS samples. The MOCNESS was towed horizontally at an altitude of 100-200 m above the bottom in waters 1900 to 2000 m deep near hydrothermal vents in the southern trough of the Guaymas Basin, Gulf of California. Some copepods from one Alvin dive plankton tow collected three to four meters from the bottom in the vent field (2000 m depth) are also included.Funding was provided by the National Science Foundation through Grant No. OCE-8709962

Determining dominant scatterers of sound in mixed zooplankton populations

Author Posting. © Acoustical Society of America, 2007. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 122 (2007): 3304-3326, doi:10.1121/1.2793613.High-frequency acoustic scattering techniques have been used to investigate dominant scatterers in mixed zooplankton populations. Volume backscattering was measured in the Gulf of Maine at 43, 120, 200, and 420 kHz. Zooplankton composition and size were determined using net and video sampling techniques, and water properties were determined using conductivity, temperature, and depth sensors. Dominant scatterers have been identified using recently developed scattering models for zooplankton and microstructure. Microstructure generally did not contribute to the scattering. At certain locations, gas-bearing zooplankton, that account for a small fraction of the total abundance and biomass, dominated the scattering at all frequencies. At these locations, acoustically inferred size agreed well with size determined from the net samples. Significant differences between the acoustic, net, and video estimates of abundance for these zooplankton are most likely due to limitations of the net and video techniques. No other type of biological scatterer ever dominated the scattering at all frequencies. Copepods, fluid-like zooplankton that account for most of the abundance and biomass, dominated at select locations only at the highest frequencies. At these locations, acoustically inferred abundance agreed well with net and video estimates. A general approach for the difficult problem of interpreting high-frequency acoustic scattering in mixed zooplankton populations is described.This research was supported in part by the U.S. GLOBEC program, NOAA (Grant nos. NA17RJ1223 and NA67RJ0148), the James S. Cole and Cecily C. Selby Endowed Funds, the Penzance Endowed Fund for Support of Assistant Scientists, and the Adams Chair at the Woods Hole Oceanographic Institution. A selected number of focused experiments were also funded by the ONR (Grant No. N00014-98-1-0362)

A “Rosetta Stone” for Metazoan Zooplankton: DNA Barcode Analysis of Species Diversity of the Sargasso Sea (Northwest Atlantic Ocean)

Species diversity of the metazoan holozooplankton assemblage of the Sargasso Sea, Northwest Atlantic Ocean, was examined through coordinated morphological taxonomic identification of species and DNA sequencing of a ∼650 base-pair region of mitochondrial cytochrome oxidase I (mtCOI) as a DNA barcode (i.e., short sequence for species recognition and discrimination). Zooplankton collections were made from the surface to 5,000 meters during April, 2006 on the R/V R.H. Brown. Samples were examined by a ship-board team of morphological taxonomists; DNA barcoding was carried out in both ship-board and land-based DNA sequencing laboratories. DNA barcodes were determined for a total of 297 individuals of 175 holozooplankton species in four phyla, including: Cnidaria (Hydromedusae, 4 species; Siphonophora, 47); Arthropoda (Amphipoda, 10; Copepoda, 34; Decapoda, 9; Euphausiacea, 10; Mysidacea, 1; Ostracoda, 27); and Mollusca (Cephalopoda, 8; Heteropoda, 6; Pteropoda, 15); and Chaetognatha (4). Thirty species of fish (Teleostei) were also barcoded. For all seven zooplankton groups for which sufficient data were available, Kimura-2-Parameter genetic distances were significantly lower between individuals of the same species (mean=0.0114; S.D. 0.0117) than between individuals of different species within the same group (mean=0.3166; S.D. 0.0378). This difference, known as the barcode gap, ensures that mtCOI sequences are reliable characters for species identification for the oceanic holozooplankton assemblage. In addition, DNA barcodes allow recognition of new or undescribed species, reveal cryptic species within known taxa, and inform phylogeographic and population genetic studies of geographic variation. The growing database of “gold standard” DNA barcodes serves as a Rosetta Stone for marine zooplankton, providing the key for decoding species diversity by linking species names, morphology, and DNA sequence variation. In light of the pivotal position of zooplankton in ocean food webs, their usefulness as rapid responders to environmental change, and the increasing scarcity of taxonomists, the use of DNA barcodes is an important and useful approach for rapid analysis of species diversity and distribution in the pelagic community

Phenology in Calanus funmarchicus; hypotheses about control mechanisms

Calanus finmarchicus (Gunnerus) stratify narrowly near 500 m depth during their fifth copepodite resting phase in North Atlantic Slope Water off southern New England, USA. They probably achieve this by migration to a specific, daytime isolume. Photoperiod information provided by light intensity at depth could serve as a cure for termination of the resting phase. Population data on tooth formation and gonad growth show that the resting stock prepares for termination in late winter and matures in February-March. Photoperiods are lengthening throughout that seasonal interval, and might cue arousal. An endogenous, 'long-range' timer that cues arousal after an interval of rest is another possible mechanism

Planktonic foraminifera and their stable isotope record of MICNESS samples off Cape Cod

Monthly samples of stratified plankton tows taken from the slope waters off Cape Cod nearly 25 years ago are used to describe the seasonal succession of planktonic foraminifera and their oxygen isotope ratios. The 15°C seasonal cycle of sea surface temperature (SST) accounts for a diverse mixture of tropical to subpolar species. Summer samples include various Globigerinoides and Neogloboquadrina dutertrei, whereas winter and early spring species include Globigerina bulloides and Neogloboquadrina pachyderma (dextral). Globorotalia inflata lives all year but at varying water depths. Compared with the fauna in 1960-1961 (described by R. Cifelli), our samples seem warmer. Because sea surface salinity varies little during the year, d18O is mostly a function of SST. Throughout the year, there are always species present with d18O close to the calculated isotopic equilibrium of carbonate with surface seawater. This raises the possibility that seasonality can be estimated directly from the range of d18O in a sediment sample provided that the d18O-salinity relationship is the same as today