Bedford Institute Of Oceanography Research Articles

REMEMBERING THE MARINE ECOLOGY LABORATORY, BEDFORD INSTITUTE OF OCEANOGRAPHY, 1965-1987: AN HISTORICAL AND PERSONAL PERSPECTIVE

The Marine Ecology Laboratory (MEL) was one of the principal federal scientific laboratories at the Bedford Institute of Oceanography (BIO) in Dartmouth, NS. Created in 1965 as an independent laboratory under the Fisheries Research Board of Canada, it grew out of the previous Atlantic Oceanographic Group with the broad mandate to study the structure and dynamics of marine ecosystems supporting marine fisheries. With time, it developed a well-rounded program of basic and applied ecological research and earned an international reputation for excellence. In 1987, it fell victim to a major reorganization of the Department of Fisheries and Oceans, driven by Ottawa managers, and was closed despite widespread protest from the scientific community. However, once the dust had settled from this unfortunate incident and, despite declining resources, ecological research at BIO continued to flourish under a new organizational structure.

Remembering Hudson-70

Hudson-70 was the last big multidisciplinary global oceanographic expedition. Organized by the Bedford Institute of Oceanography (BIO), based in Nova Scotia, this epic eleven-month voyage lasted from November 1969 to October 1970, involved 128 scientists from five countries, and traversed five oceans. Enroute, the CSS Hudson steamed 56,000 nautical miles and became the first ship to circumnavigate the Americas. A huge amount of new oceanographic information in all disciplines was collected in environments ranging from tropical to polar. Major highlights are summarized. General overviews of the expedition were published in three books and the results of individual studies were reported in over 50 scientific publications. Hudson-70 was a major Canadian oceanographic accomplishment, truly worthy of celebrating fifty years later.

D.N. Nettleship, D.C. Gordon, C.F.M. Lewis and M.P. Latremouille, eds., Voyage of Discovery: Fifty Years of Marine Research at Canada’s Bedford Institute of Oceanography (Dartmouth, Nova Scotia: BIO-Oceans Association, 2014), 444 pp.

D.N. Nettleship, D.C. Gordon, C.F.M. Lewis and M.P. Latremouille, eds., Voyage of Discovery: Fifty Years of Marine Research at Canada’s Bedford Institute of Oceanography (Dartmouth, Nova Scotia: BIO-Oceans Association, 2014), 444 pp.

Reconstructing the distribution of the non-native sea anemone, Diadumene lineata (Actiniaria), in the Canadian Maritimes: Local extinction in New Brunswick and no regional range expansion in Nova Scotia since its initial detection

Since its first observations in New Brunswick (Sam Orr’s Pond) and Nova Scotia (Bedford Institute of Oceanography in Dartmouth) in 2009 and 2013, respectively, Diadumene lineata has been observed spreading to new locations in the Canadian Maritimes. In 2017 and 2018, regional surveys for non-native species did not detect D. lineata in New Brunswick, suggesting local extinction. Recent surveys also did not detect D. lineata in Prince Edward Island. However, between 2013 and 2018, D. lineata was detected in Nova Scotia (in chronological order) from Lunenburg Harbour (Lunenburg), Hermans Island (Lunenburg), Black Rock Beach (Halifax), Oak Island Marina (Chester), and Dartmouth Yacht Club (Dartmouth). These new observations combine to reconstruct the known recent distribution of this non-native sea anemone in the Canadian Maritimes. Further, after five years since its first detection in Nova Scotia, the regional distribution of D. lineata remained unchanged, restricted to a region of approximately 100 km between Halifax and Lunenburg. Although the primary focus is on D. lineata, additional records of the non-native macroalga, Codium fragile, from Sam Orr’s Pond and the native sea anemone, Metridium senile, fouling dock structures throughout the Canadian Maritimes are included in this report as M. senile commonly overlaps in habitat with D. lineata.

Technology Development at the Bedford Institute of Oceanography, 1962-1986

This paper explores the relationship between technology and discovery in oceanography, examining examples of instrumentation development at the Bedford Institute of Oceanography (BIO). Between 1962 and 1986, BIO researchers and technicians initiated a wave of rapid technological development, while also adopting technology developed elsewhere. These developments were abridge into the digital age as BIO staff incorporated computer hardware and software into instrument development. This paper summarizes these developments, their impact on the work of the Institute, and factors that influenced this work, and how they changed over time BIO emerged as a world-class oceanographic institution.

Oil plume simulations: Tracking oil droplet size distribution and fluorescence within high-pressure release jets

ABSTRACT Optical measurements have been used during oil spill response for more than three decades to determine oil presence in slicks and plumes. Oil surveillance approaches range from simple (human eyeball) to the sophisticated (sensors on AUVs, aircraft, satellites). In situ fluorometers and particle size analyzers were deployed during the Deepwater Horizon (DWH) Gulf of Mexico oil spill to track shallow and deep subsea plumes. Uncertainties regarding instrument specifications and capabilities during DWH necessitated performance testing of sensors exposed to simulated, dispersed oil plumes. Seventy-two wave tank experiments were conducted at the Bedford Institute of Oceanography. Simulated were oil releases with varying parameters such as oil release rate, oil temperature (reservoir temp ~ 80 °C), water temperature (<8 °C and >15 °C), oil type, dispersant type (Corexit 9500 and Finasol OSR52) and dispersant to oil ratio (DOR). Plumes of Alaskan North Slope Crude (ANS), South Louisiana Crude (SLC) and IFO-120 oils were tracked using in situ fluorescence, droplet size distribution (DSD), total petroleum hydrocarbons (TPH) and benzene-toluene-ethylbenzene-xylene (BTEX). For the lighter SLC, bimodal droplet size with mean diameter < 70 μm was achieved for 1:20 and 1:100 DOR, regardless of water temperature. Similarly, the medium ANS crude exhibited mean droplet diameter <70 μm, but was bimodal only for the 1:20 treatment. Bimodal distribution was not achieved with the heavy IFO, but droplet < 70 μm were observed for 1:20 warm waters, indicating poor dispersibility of the high viscosity oil even for jet releases. Results offer valuable information on the behavior and dispersibility of oils over a range of viscosity, DOR and environmental conditions. Findings have implications for fate and transport models, where DSD, chemistry and fluorescence are all impacted by release variables. This research was supported by the Bureau of Safety and Environmental Enforcement.

Erodibility of aquaculture waste from different bottom substrates

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 8:575-584 (2016) - DOI: https://doi.org/10.3354/aei00199 Erodibility of aquaculture waste from different bottom substrates B. A. Law1,2,*, P. S. Hill2, T. G. Milligan1, V. Zions1 1Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, Nova Scotia B2Y 4A2, Canada 2Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, B3H 4J1, Canada *Corresponding author: brent.law@mar.dfo-mpo.gc.ca ABSTRACT: A laboratory study was carried out to examine the effect of bed sediment texture on the erodibility of salmon aquaculture waste fecal material and salmon feed pellets. Erodibility measurements of this material were made using a Gust microcosm erosion chamber and artificially composed substrates of mud, sand, sand and gravel, sand and cobble, and cobble. Results show that cumulative mass eroded (CME) and erodibility constant (M) can vary by up to an order of magnitude depending on substrate composition, with a mud substrate having higher CME and M values than those of substrates composed of sand, gravel and cobble. Findings from this study suggest that bottom sediment texture plays a major role in aquaculture waste resuspension and subsequent transport and that predictive models of the transport of aquaculture waste should include the erosion dynamics of bottom texture. KEY WORDS: Aquaculture · Erodibility · Waste transport · Bottom substrate Full text in pdf format Supplementary material PreviousCite this article as: Law BA, Hill PS, Milligan TG, Zions V (2016) Erodibility of aquaculture waste from different bottom substrates. Aquacult Environ Interact 8:575-584. https://doi.org/10.3354/aei00199 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 8. Online publication date: October 17, 2016 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2016 Inter-Research.

Salinity variability along the eastern continental shelf of Canada and the United States, 1973–2013

Continental shelf waters located off the east coast of Canada and the United States are part of a long shelf current system that is partly comprised of colder, less-saline waters originating from high latitudes, including waters from the North Atlantic sub-polar gyre, along with ice-melt and freshwater input from local rivers. A 41-year analysis (1973–2013) of near-surface salinity (NSS) using three hydrographic datasets (Bedford Institute of Oceanography “Climate”, NOAA/ESDIM, and Canadian Marine Environmental Data Service (MEDS)) allowed an examination of NSS variability within 11 continental shelf sub-regions, extending from the southern Newfoundland Shelf of eastern Canada to the DelMarVa/Hatteras Shelf of the United States. Although the periods of record containing sufficient data vary between sub-regions, regional mean NSS values are lowest within the Gulf of St. Lawrence and highest on the DelMarVa/Hatteras shelf, with largest annual variability within the Gulf of St. Lawrence. After removal of outliers, long-term linear trends computed from annual mean NSS were detected along the Newfoundland Shelf (+0.011y−1), Western Scotian Shelf (−0.007y−1), Gulf of Maine (−0.014y−1), Georges Bank (−0.011y−1), and DelMarVa/Hatteras Shelf (+0.024y−1). A long-term quadratic fit to annual mean NSS from the Eastern Scotian Shelf displays a salinity increase through 1992 of +0.026y−1, decreasing thereafter until 2013 by −0.028y−1. A quadratic fit for the Western Grand Banks displays a NSS increase through 2007 of +0.022y−1, decreasing thereafter through 2013 by −0.006 y−1. Annual mean NSS from the Eastern Grand Banks, Tail of the Grand Banks, Gulf of St. Lawrence, and Middle Atlantic Bight display no long-term trends. Inter-annual variability (IAV) of NSS residuals shows similar small mean squared error (mse) of 0.02–0.04 for the four northern-most sub-regions (Newfoundland Shelf, Eastern, Tail and Western Grand Banks) and are correlated at 0-year lag. IAV of NSS residuals (mse) are larger for the Gulf of St. Lawrence (~0.19), Eastern and Western Scotian Shelf (~0.09–0.06), Gulf of Maine and Georges Bank (~0.08–0.06), Middle Atlantic Bight (~0.19), and maximal for the DelMarVa/Hatteras Shelf (~0.36), and are also correlated at 0-year lag, but are uncorrelated with the four northern-most sub-regions. Consideration of a simple “flux variation” model that includes along-shelf, altimeter-derived velocity anomalies measured upstream on the Western Scotian Shelf and the positive along-shelf mean salinity gradient between the Eastern Scotian Shelf and the DelMarVa/Hatteras Shelf, may explain the synchronous nature of NSS residuals for the southern-most 6 sub-regions. Furthermore, the flux variation model results in calculated NSS residuals that are within a factor of two of observed NSS residuals for the southern-most DelMarVa/Hatteras Shelf. Co-varying broad-scale coastal sea level and shelf break front position anomalies also support the flux variation model, as do CMV Oleander temperature anomalies across a limited Middle Atlantic Bight shelf region. Overall, the relationships between along-shelf observations of NSS and other shelf parameters support an existing wind-driven dynamical shelf model. Specifically, a flux variation model is able to describe IAV of NSS along a section of the Canadian and U.S shelf for periods greater than one year. In the future, this model may be able to provide useful indices of regime change as noted within the Northeast Shelf Large Marine Ecosystem by other workers.

Anomalous ecosystem dynamics following the apparent collapse of a keystone forage species

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 553:185-202 (2016) - DOI: https://doi.org/10.3354/meps11761 Anomalous ecosystem dynamics following the apparent collapse of a keystone forage species Kenneth T. Frank1,2,*, Brian Petrie1, Daniel Boyce2, William C. Leggett2 1Fisheries and Oceans Canada, Bedford Institute of Oceanography, Ocean Sciences Division, Dartmouth, Nova Scotia B2Y 4A2, Canada 2Department of Biology, Queen’s University, Kingston, Ontario K7L 3N6, Canada *Corresponding author: kenneth.frank@dfo-mpo.gc.ca ABSTRACT: Major groundfish populations in the western Atlantic north of Georges Bank/Western Scotian Shelf experienced near-total population collapses beginning in the late 1980s-early 1990s. Explosive increases in the abundance of their pelagic fish and invertebrate prey (notably capelin, sand lance, herring, shrimp and snow crab) generally followed. However, several investigators have concluded, based on the results of annual acoustic surveys, that the lightly exploited capelin stock in the Newfoundland/Labrador (NL) region experienced a sudden 6.8 Mt (98%) decline in biomass from 1990 to 1991 coincident with the groundfish collapse. Given the enormity, duration and unexpected nature of this decline, it was characterized as a collapse. The contrasting response of this capelin stock to the groundfish collapse relative to other North Atlantic (NA) ecosystems prompted us to undertake systematic analyses of the NL ecosystem. The reported capelin collapse in NL should have induced significant responses of trophically linked species, as have been reported in other NA ecosystems. We found little evidence of changes in the population abundance, diet and condition of marine mammals, cod, seabirds and zooplankton, in indexes of the areal occupancy and spawning biomass of capelin, or of environmental effects. These results strongly support the hypothesis that the reported collapse did not occur. Profound seasonal distribution changes, a fixed in time and space acoustic survey in a restricted portion of the distributional range of capelin, and the possibility that NL capelin stock has become less migratory provide a more robust and consistent explanation of the observations. KEY WORDS: Forage fish · Stock collapse · Ecosystem response · North Atlantic · Acoustic surveys · Migration Full text in pdf format Supplementary material PreviousNextCite this article as: Frank KT, Petrie B, Boyce D, Leggett WC (2016) Anomalous ecosystem dynamics following the apparent collapse of a keystone forage species. Mar Ecol Prog Ser 553:185-202. https://doi.org/10.3354/meps11761 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 553. Online publication date: July 14, 2016 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2016 Inter-Research.

Monitoring the North Atlantic using ocean colour data

The Remote Sensing Unit (RSU) at the Bedford Institute of Oceanography (BIO) has been monitoring the North Atlantic using ocean colour products for decades. Optical sensors used include CZCS, POLDER, SeaWiFS, MODIS/Aqua and MERIS. The monitoring area is defined by the Atlantic Zone Monitoring Program (AZMP) but certain products extend into Arctic waters, and all-Canadian waters which include the Pacific coast. RSU provides Level 3 images for various products in several formats and a range of temporal and spatial resolutions. Basic statistics for pre-defined areas of interest are compiled for each product. Climatologies and anomaly maps are also routinely produced, and custom products are delivered by request. RSU is involved in the generation of Level 4 products, such as characterizing the phenology of spring and fall phytoplankton blooms, computing primary production, using ocean colour to aid in EBSA (Ecologically and Biologically Significant Area) definition and developing habitat suitability maps. Upcoming operational products include maps of diatom distribution, biogeochemical province boundaries, and products from sensors such as VIIRS (Visible Infrared Imaging Radiometer Suite), OLCI (Ocean Land Colour Instrument), and PACE (Pre-Aerosol, Clouds and ocean Ecosystem) hyperspectral microsatellite mission.

Voyage of Discovery – Fifty Years of Marine Research at Canada's Bedford Institute of Oceanography

Voyage of Discovery – Fifty Years of Marine Research at Canada's Bedford Institute of Oceanography

Reproductive periodicity and larval vertical migration behavior of European green crab Carcinus maenas in a non-native habitat

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 536:123-134 (2015) - DOI: https://doi.org/10.3354/meps11422 Reproductive periodicity and larval vertical migration behavior of European green crab Carcinus maenas in a non-native habitat Claudio DiBacco1,*, Thomas W. Therriault2 1Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, B2Y 4A2, Canada 2Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, BC, V9T 6N7, Canada *Corresponding author: claudio.dibacco@dfo-mpo.gc.ca ABSTRACT: The reproductive periodicity and vertical migration behavior of the European green crab Carcinus maenas in a non-native environment were characterized and the implications for invasion dynamics highlighted. Biweekly to monthly trap surveys in Pipestem Inlet, British Columbia, revealed ovigerous crabs from mid-February to June 2007. Concurrent meroplankton surveys confirmed green crab zoeae by mid-April, about 1 mo following peak abundance of ovigerous crabs (March 2007). All 4 zoeal stages of development were sampled between March and December 2007, but >95% were Stage I zoeae sampled between April and August. Vertical meroplankton surveys conducted in 2008 revealed diel-mediated vertical migratory (DVM) behavior; however the majority of sampled zoeae were aggregated near the pycnocline in surface outflowing waters. Negligible densities of post-Stage I zoeae (<1%) support the observation of zoeal export from Pipestem Inlet. Tidal-mediated vertical migratory behavior, characteristic in native European populations, was not observed in Pipestem Inlet. In contrast, low larval densities were sampled in surface (<1 m) and deep (>8 m) sampling strata. We hypothesize that low surface salinity (17-19 psu) and cold temperature (<12°C below the pycnocline) in deep strata constrained DVM. Our results highlight a need for better characterization of reproductive periodicity and zoeal migratory behavior in non-native habitats, which has implications for improving predictions of secondary spread and range expansion rates mediated via larval dispersal dynamics. KEY WORDS: Invasive · Non-native · European green crab · Carcinus maenas · Larval abundance · Dispersal · Reproductive periodicity · Vertical migration behavior Full text in pdf format PreviousNextCite this article as: DiBacco C, Therriault TW (2015) Reproductive periodicity and larval vertical migration behavior of European green crab Carcinus maenas in a non-native habitat. Mar Ecol Prog Ser 536:123-134. https://doi.org/10.3354/meps11422 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 536. Online publication date: September 29, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Simulation for Path Planning of SLOCUM Glider in Near-bottom Ocean Currents Using Heuristic Algorithms and Q-Learning

Addressing the need for exploration of benthic zones utilising autonomous underwater vehicles, this paper presents a simulation for an optimised path planning from the source node to the destination node of the autonomous underwater vehicle SLOCUM Glider in near-bottom ocean environment. Near-bottom ocean current data from the Bedford Institute of Oceanography, Canada, have been used for this simulation. A cost function is formulated to describe the dynamics of the autonomous underwater vehicle in near-bottom ocean currents. This cost function is then optimised using various biologically-inspired algorithms such as genetic algorithm, Ant Colony optimisation algorithm and particle swarm optimisation algorithm. The simulation of path planning is also performed using Q-learning technique and the results are compared with the biologically-inspired algorithms. The results clearly show that the Q-learning algorithm is better in computational complexity than the biologically-inspired algorithms. The ease of simulating the environment is also more in the case of Q-learning techniques. Hence this paper presents an effective path planning technique, which has been tested for the SLOCUM glider and it may be extended for use in any standard autonomous underwater vehicle. Defence Science Journal, Vol. 65, No. 3, May 2015, pp.220-225, DOI: http://dx.doi.org/10.14429/dsj.65.7855

SUBMERSIBLE OPTICAL SENSORS EXPOSED TO CHEMICALLY-DISPERSED CRUDE OIL: WAVE TANK SIMULATIONS FOR IMPROVED OIL SPILL MONITORING

In situ fluorometers were deployed during the Deepwater Horizon (DWH) Gulf of Mexico oil spill to provide critical measurements for tracking the subsea oil plume. In the wake of the spill, uncertainties regarding instrument specifications, capabilities and reliability necessitated performance testing of sensors (commonly used during spill response) exposed to simulated, dispersed oil plumes. Moreover, concerns on the applicability of laboratory calibrations (at high concentrations and insufficient mixing energies) to field conditions and on sensor reliability to detect dispersed oil persist. To address these uncertainties the performance of select commercially-available sensors (from Chelsea Technologies Group, Satlantic, Turner Designs, WetLabs Inc) was evaluated using a wave tank facility at the Bedford Institute of Oceanography in Halifax, Nova Scotia. Breaking waves were generated within the tank to simulate mixing energies and achieve dispersant effectiveness observed in the field. Presented here are the results of the sensors exposed to chemically-dispersed MC252 crude oil using Corexit 9500, DOR=1:20. Stepwise additions of dispersed oil (0.3 – 12 ppm) to the tank were used to establish linearity. Model 1 linear least squares regressions were calculated and applied to sensor data during validation experiments to simulate dilution of an oil plume. Dynamic ranges of the sensors, exposed to fresh and artificially weathered crude oil, were determined. Sensors were standardized against known oil volumes and measured Total Petroleum Hydrocarbons (TPH) and Benzene-Toluene-Ethylbenzene-Xylene (BTEX) values – both collected during spills, providing oil estimates during dilution experiments. Results were validated against particle size data (Sequoia LISST). All sensors estimated oil concentrations down to 300 ppb oil, refuting previous reports. Low percent differences and absolute errors between chemistry and sensor results were metrics to evaluate performance. Discussed will be the application of this vicarious calibration approach as a means to calibrate the DWH fine-scale fluorescence data into oil concentrations. This allows for filling in coarse-scale field chemistry data, improved assessment of DWH spill measurements mined from the NOAA NODC, and understanding the fate and transport of the DWH oil plume.

Voyage of Discovery: Fifty Years of Marine Research at Canada’s Bedford Institute of Oceanography

The BIO–Oceans Association announces the forthcoming publication of Voyage of Discovery Fifty Years of Marine Research at Canada’sBedford Institute of OceanographyEdited by D.N. Nettleship, D.C. Gordon, C.F.M. Lewis and M.P. Latremouille

Proteomic Analysis of Eggs from Mytilus edulis Females Differing in Mitochondrial DNA Transmission Mode

Many bivalves have an unusual mechanism of mitochondrial DNA (mtDNA) inheritance called doubly uniparental inheritance (DUI) in which distinctly different genomes are inherited through the female (F genome) and male (M genome) lineages. In fertilized eggs that will develop into male embryos, the sperm mitochondria remain in an aggregation, which is believed to be delivered to the primordial germ cells and passed to the next generation through the sperm. In fertilized eggs that will develop into female embryos, the sperm mitochondria are dispersed throughout the developing embryo and make little if any contribution to the next generation. The frequency of embryos with the aggregated or dispersed mitochondrial type varies among females. Previous models of DUI have predicted that maternal nuclear factors cause molecular differences among unfertilized eggs from females producing embryos with predominantly dispersed or aggregated mitochondria. We test this hypothesis using females of each of the two types from a natural population. We have found small, yet detectable, differences of the predicted type at the proteome level. We also provide evidence that eggs of females giving the dispersed pattern have consistently lower expression for different proteasome subunits than eggs of females giving the aggregated pattern. These results, combined with those of an earlier study in which we used hatchery lines of Mytilus, and with a transcriptomic study in a clam that has the DUI system of mtDNA transmission, reinforce the hypothesis that the ubiquitin-proteasome system plays a key role in the mechanism of DUI and sex determination in bivalves. We also report that eggs of females giving the dispersed pattern have higher expression for arginine kinase and enolase, enzymes involved in energy production, whereas ferritin, which is involved in iron homeostasis, has lower expression. We discuss these results in the context of genetic models for DUI and suggest experimental methods for further understanding the role of these proteins in DUI.

Voyage of Discovery: Fifty Years of Marine Research at Canada’s Bedford Institute of Oceanography

VOYAGE OF DISCOVERY will summarize BIO research results on theoceanography of Arctic and Eastern Canada. It will be the most extensivesurvey of the history and scientific accomplishments of the Bedford Instituteof Oceanography under one cover.

O Canada, o quanta qualia

ESEP Ethics in Science and Environmental Politics Contact the journal RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections ESEP 12:1-4 (2012) - DOI: https://doi.org/10.3354/esep00119 AS I SEE IT O Canada, o quanta qualia William K. W. Li* Department of Fisheries and Oceans, Bedford Institute of Oceanography, Dartmouth, Nova Scotia B2Y 4A2, Canada *Email: bill.li@dfo-mpo.gc.ca ABSTRACT: The ecological effects of warming and freshening ocean waters in the Arctic have been discerned, but narratives are needed to unify these objective scientific states of material being with subjective humanistic states of ideal knowing. Here, the physicality of nature and the spirituality of humanity point towards a putative unification that transcends two self-consistent but non-overlapping frames of reference. KEY WORDS: Arctic · Complexity · Science philosophy · Simplicity Full text in pdf format NextCite this article as: Li WKW (2012) O Canada, o quanta qualia. Ethics Sci Environ Polit 12:1-4. https://doi.org/10.3354/esep00119 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESEP Vol. 12, No. 1. Online publication date: January 02, 2012 Print ISSN: 1863-5415; Online ISSN: 1611-8014 Copyright © 2012 Inter-Research.

From cytometry to macroecology: a quarter century quest in microbial oceanography

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 57:239-251 (2009) - DOI: https://doi.org/10.3354/ame01328 AME Special: 'Rassoulzadegan at Villefranche-sur-Mer: 3 decades of aquatic microbial ecology' From cytometry to macroecology: a quarter century quest in microbial oceanography William K. W. Li* Ocean Research and Monitoring Section, Bedford Institute of Oceanography, PO Box 1006, Dartmouth, Nova Scotia, Canada, B2Y 4A2 *Email: lib@mar.dfo-mpo.gc.ca A quarter of a century has passed since the contemporary ecological role of water column microbes was first articulated. It was also about a quarter of a century ago that 2 other seemingly unrelated developments first appeared: the application of flow cytometry for analysis of marine microbes and the statistical approach of macroecology for the analysis of complex ecological systems. These two developments now meet at the interface of microbial oceanography. The combination of these developments, termed cytometric macroecology, provides an avenue to explore general theories of ecology and biogeography, as well as a means to address environmental issues of long-term change. This case study examines the abundance of picoeukaryotic phytoplankton from weekly to multiyear time scales and from local to global space scales. Cytometric macroecology identifies patterns of regularity arising from flexible contingent circumstances, some of which—like anthropogenic disruptions—are of special interest because they appear outside the bounds of natural variability. KEY WORDS:Bacteria · Cytometry · Ecological provinces · Macroecology · Picoeukaryotes · Phytoplankton · Prochlorococcus · Synechococcus Full text in pdf format PreviousNextCite this article as: Li WKW (2009) From cytometry to macroecology: a quarter century quest in microbial oceanography. Aquat Microb Ecol 57:239-251. https://doi.org/10.3354/ame01328 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 57, No. 3. Online publication date: November 24, 2009 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2009 Inter-Research.

Interannual variability of the shelf-slope front position between 75° and 50° W

The shelf-slope front (SSF) is a continuous shelf-break front running from the Tail of the Grand Banks to Cape Hatteras, North Carolina, separating colder and less-saline continental shelf waters from warmer and more saline slope waters. Time series containing mean monthly SSF positions were produced along each of 26 longitude lines between 75° and 50°W by workers located at Bedford Institute of Oceanography by digitizing individual frontal charts and computing mean monthly latitudinal positions over a 29-year (1973–2001) period. After removing seasonal variability at each longitude, interannual variability (IAV) of the SSF position at each longitude was computed as the annual mean of all monthly SSF position anomalies for each year over the 29-year period. Despite some missing data, a longitude-time plot reveals alternating bands of offshore (late-1970s, late-1980s, late-1990s) and onshore (early-1980s, early-1990s, early-2000s) annual mean SSF anomaly values, exhibiting a period of approximately 10 years. Annual mean SSF anomaly amplitudes are largest in the east, with maxima of O (± 100 km) located east of 60° W for years when data are available. Empirical orthogonal function (EOF) modes 1–4 (accounting for > 90% of the variance) form a set of basis functions that describe the SSF anomaly data and allow reconstruction of the entire data set since missing data are relatively few (14%). A complex empirical orthogonal function (CEOF) analysis using the “reconstructed” data reveals a wavelength scale of approximately 20° of longitude, a distance nearly equal to the entire study domain, along with steady, westward phase propagation of SSF anomalies over approximately the same distance. Speed calculations for the westward-propagating features yield a value of approximately 1.2 to 2.4 cm s − 1 (1 to 2 km d − 1 ), with annual mean SSF anomalies thus requiring about 4 years to propagate from the Tail of the Grand Banks in the east to Cape Hatteras, North Carolina, in the west. This propagation speed and the timing of the SSF positional anomalies at the Tail of the Grand Banks for the 29-year study period are in agreement with speeds computed for the propagation of quasi-decadal salinity anomalies through the Labrador Sea and the time of their arrival at the Tail of the Grand Banks. The small westward SSF anomaly propagation speed is an order of magnitude smaller than the associated currents, in agreement with a highly damped flow-through system originating from both Davis Strait and the West Greenland Current as discussed by other workers. Observations from both southern and northern portions of the study domain, within both continental shelf and slope waters, show that interannual changes in the volume of shelf water along with shelf water bulk properties exhibit a strong relationship with IAV of the SSF position over long time periods.