Role of light and photophysiological properties on phytoplankton succession during the spring bloom in the north-western Mediterranean Sea

This study aimed to determine the role of light on the succession of the phytoplankton community during the spring bloom in the northwestern Mediterranean Sea. To this end, three successive Lagrangian experiments were carried out between March and April 2003. The three experiments correspond to distinct phases of the bloom development (pre-bloom, bloom peak and post-bloom, respectively) and therefore to different trophic conditions. Phytoplankton (sampled on a daily scale) was grouped in size-based classes (pico and nano+micro) each of them were characterised in terms of chemotaxonomic composition, primary production and photophysiological properties. The phytoplankton community evolved with time changing in both size-class dominance and specie/group dominance within each size class. The bloom peak was characterised by highly dynamic condition (i.e. vertical mixing) and by the dominance of both small (pico) and large (nano and micro) diatoms, as a result of their capacity to photoacclimate to changing light regimes (‘physiological plasticity’). Concluding, we suggest that the physiological adaptation to light is the main factor driving the succession of the phytoplankton community during the first phases of the bloom (until the onset of thermal stratification) in the western Mediterranean Sea.

The meso-scale response of subarctic North Pacific seabird community structure to lower trophic level abundance and diversity

Understanding the mechanisms that structure communities and influence biodiversity are fundamental goals of ecology. To test the hypothesis that the abundance and diversity of upper-trophic level predators (seabirds) is related to the underlying abundance and diversity of their prey (zooplankton) and ecosystem-wide energy availability (primary production), we initiated a monitoring program in 2002 that jointly and repeatedly surveys seabird and zooplankton populations across a 7,500 km British Columbia-Bering Sea-Japan transect. Seabird distributions were recorded by a single observer (MH) using a strip-width technique, mesozooplankton samples were collected with a Continuous Plankton Recorder, and primary production levels were derived using the appropriate satellite parameters and the Vertically Generalized Production Model (Behrenfeld and Falkowski 1997). Each trophic level showed clear spatio-temporal patterns over the course of the study. The strongest relationship between seabird abundance and diversity and the lower trophic levels was observed in March/April ('spring') and significant relationships were also found through June/July ('summer'). No discernable relationships were observed during the September/October ('fall') months. Overall, mesozooplankton abundance and biomass explained the dominant portion of seabird abundance and diversity indices (richness, Simpson's Index, and evenness), while primary production was only related to seabird richness. These findings underscore the notion that perturbations of ocean productivity and lower trophic level ecosystem constituents influenced by climate change, such as shifts in timing (phenology) and synchronicity (match-mismatch), could impart far-reaching consequences throughout the marine food web.

Enhancement of primary production in the North Atlantic outside of the spring bloom, identified by remote sensing of ocean colour and temperature

The heterogeneity in phytoplankton production in the North Atlantic after the spring bloom is poorly understood. We analysed merged microwave and infrared satellite sea surface temperature (SST) data and ocean colour phytoplankton size class biomass, primary production (PP) and new production (ExP) derived from SeaWiFS data, to assess the spatial and temporal frequency of surface thermal fronts and areas of enhanced PP and ExP. Strong and persistent surface thermal fronts occurred at the Reykjanes Ridge (RR) and sub-polar front (SPF), which sustain high PP and ExP and, outside of the spring bloom, account for 9% and 15% of the total production in the North Atlantic. When normalised by area, PP at the SPF is four times higher than the RR. Analysis of 13 years of satellite ocean colour data from SeaWiFS, and compared with MODIS-Aqua and MERIS, showed that there was no increase in Chla from 1998 to 2002, which then decreased in all areas from 2002 to 2007 and was most pronounced in the RR. These time series also illustrated that the SPF exhibited the highest PP and the lowest variation in Chla over the ocean colour record. This implies that the SPF provides a high and consistent supply of carbon to the benthos irrespective of fluctuations in the North Atlantic Oscillation.

High-resolution view of the spring bloom initiation and net community production in the Subantarctic Southern Ocean using glider data

In the Southern Ocean, there is increasing evidence that seasonal to subseasonal temporal scales, and meso- to submesoscales play an important role in understanding the sensitivity of ocean primary productivity to climate change. This drives the need for a high-resolution approach to re- solving biogeochemical processes. In this study, 5.5 months of continuous, high-resolution (3 h, 2 km horizontal resolution) glider data from spring to summer in the Atlantic Subantarctic Zone is used to investigate: (i) the mechanisms that drive bloom initiation and high growth rates in the region and (ii) the seasonal evolution of water column production and respiration. Bloom initiation dates were analysed in the context of upper ocean boundary layer physics highlighting sensitivities of different bloom detection methods to different environmental processes. Model results show that in early spring (September to mid-November) increased rates of net community production (NCP) are strongly affected by meso- to submesoscale features. In late spring/early summer (late-November to mid-December) seasonal shoaling of the mixed layer drives a more spatially homogenous bloom with maximum rates of NCP and chlorophyll biomass. A comparison of biomass accumulation rates with a study in the North Atlantic highlights the sensitivity of phytoplankton growth to fine-scale dynamics and emphasizes the need to sample the ocean at high resolution to accurately resolve phytoplankton phenology and improve our ability to estimate the sensitivity of the biological carbon pump to climate change.

An unusually large phytoplankton spring bloom drives rapid changes in benthic diversity and ecosystem function

In 2012, the Western English Channel experienced an unusually large and long-lived phytoplankton spring bloom. When compared with data from the past 20 years, average phytoplankton biomass at Station L4 (part of the Western Channel Observatory) was approximately 3× greater and lasted 50% longer than any previous year. Regular (mostly weekly) box core samples were collected from this site before, during and after the bloom to determine its impact on macrofaunal abundance, diversity, biomass, community structure and function. The spring bloom of 2012 was shown to support a large and rapid response in the majority of benthic taxa and functional groups. However, key differences in the precise nature of this response, as well as in its timing, was observed between different macrofauna feeding groups. Deposit feeders responded almost instantly at the start of the bloom, primarily thorough an increase in abundance. Suspension feeders and opportunistic/predatory/carnivorous taxa responded slightly more slowly and primarily with an increase in biomass. At the end of the bloom a rapid decline in macrobenthic abundance, diversity and biomass closely followed the decline in phytoplankton biomass. With suspension feeders showing evidence of this decline a few weeks before deposit feeders, it was concluded that this collapse in benthic communities was driven primarily by food availability and competition. However, it is possible that environmental hypoxia and the presence of toxic benthic cyanobacteria could also have contributed to this decline. This study shows evidence for strong benthic–pelagic coupling at L4; a shallow (50 m), coastal, fine-sand habitat. It also demonstrates that in such habitats, it is not just planktonic organisms that demonstrate clear community phenology. Different functional groups within the benthic assemblage will respond to the spring bloom in specific manner, with implications for key ecosystem functions and processes, such as secondary production and bioturbation. Only by taking integrated benthic and pelagic observations over such fine temporal scales (weekly) was the current study able to identify the intimate structure of the benthic response. Similar studies from other habitats and under different bloom conditions are urgently needed to fully appreciate the strength of benthic–pelagic coupling in shallow coastal environments.

LibQUAL+ Survey 2004 @ Queen's University Library : analysis of results

Queen's University Library was one of 202 libraries, including 57 members of the Association of Research Libraries (ARL), to survey its users in spring 2004 using the LibQUAL+ survey instrument. LibQUAL+ was designed by ARL to assist libraries in assessing the quality of their services and identifying areas for improvement. # Overall: Queen's scored higher than the average for all ARL participants and 1st among the 2004 Canadian participants. This relatively high rating is due to very high scores in the dimensions of Library as Place and Affect of Service. However, there is considerable need for improvement in the area of Information Control where Queen's rated well below the ARL average. # Affect of Service: Queen's strong overall ratings are supported by the many respondent comments praising customer service throughout the system. The ratings and survey comments indicate greatest appreciation by faculty and more experienced students (e.g. graduate students) for the instruction and on-site services provided by the libraries. The ratings also indicate that undergraduates, growing up with the web, want and expected to be able to access library resources independently and do not value these services as highly. The comments also indicated some specific areas for improvement throughout the library system. # Library as Place : All Queen's libraries except for Law ranked well above the ARL and Canadian averages. Overall, Library as Place ranked lowest in importance among the service dimensions for all ARL participants including Queen's. Comparative analysis of LibQUAL results since the survey began shows a decline in “desired” ratings for Library as Place. However, undergraduates continue to give strong "desired" ratings to certain aspects of Library as Place and a relatively high rating for "minimum expected" service. The comments from Queen's survey respondents and ARL's analyses of focus groups indicate that undergraduates value the library much more as a place to study and work with peers rather than for its on-site resources and services. # Information Control: This is the area in greatest need of attention. While it ranked highest in importance for all user groups by a wide margin, Queen's performed poorly in this category. Overall, Queen's ranked far below both the ARL average and the top three Canadian scores. However, the major dissatisfaction was concentrated in the humanities/social sciences (Stauffer primary users) and the health sciences (Bracken primary users) where the overall rating of perceived service quality ranked below the minimum expected service rating. Primary users of the Education, Engineering/Science and Law libraries rated this service dimension higher than the ARL average. The great success of the Canadian National Site License Program (CNSLP) is reflected in the high overall rating generated by Engineering/Science Library users. The low ratings from the humanities and social sciences are supported by respondents' comments and are generally consistent with other ARL participants.

The librarian is in: a consultation model for information literacy formative assessment

Formative assessment was introduced in Rehabilitation Therapy students’ information literacy programs in Fall Term 2006 in the course OT/PT 892: Evidence-Based Practice. It was subsequently employed in the Winter Term 2008 and again in the Spring Term 2008. Formative assessment during student/librarian face-to-face consultations was one of a variety of teaching techniques used in the program. Other techniques included: a required reading; an interactive hands-on searching session; and a summative assessment of the final revised search strategy assignment (these techniques varied somewhat over the 3 classes). With the 2008 entrance class, this course content moved to OT/PT 898: Critical Enquiry, largely in Module 3: Reviewing the Literature. One of the Critical Enquiry’s learning objectives is: “recognize and reflect on the complexity of gathering evidence to inform decision-making.”