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Objectives: Existing information on Arctic marine food web structure is fragmented. Integrating data across research programs is an important strategy for building a baseline understanding of food web structure and function in many Arctic regions. Naturally-occurring stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) measured directly in the tissues of organisms are a commonly-employed method for estimating food web structure. The objective of the current dataset was to synthesize disparate δ15N, and secondarily δ13C, data in the Canadian Beaufort continental shelf region relevant to trophic and ecological studies at the local and pan-Arctic scales. Data description: The dataset presented here contains nitrogen and carbon stable isotope ratios (δ15N, δ13C) measured in marine organisms from the Canadian Beaufort continental shelf region between 1983 and 2013, gathered from 27 published and unpublished sources with associated sampling metadata. A total of 1077 entries were collected, summarizing 8859 individual organisms/samples representing 333 taxa across the Arctic food web, from top marine mammal predators to primary producers. [ABSTRACT FROM AUTHOR]

• Sex-specific beluga body condition models account for size, age, location, and year. • Belugas from entrapment events can serve as thresholds for body condition indicators. • Spatial variability was detected and requires consideration in the use of indicators. • This study aims to develop blubber thickness and girth as body condition indicators. Monitoring marine protected areas requires simplifying complex marine ecosystems into a suite of indicators. The Tarium Niryutait Marine Protected Area (TN MPA), the first MPA in the Canadian Arctic is located in the Inuvialuit Settlement Region, NT and is selecting indicators for monitoring. Proposed health indicators for the TN MPA species of interest, the Eastern Beaufort Sea (EBS) beluga, include the body condition metrics blubber thickness and girth. Sex-specific body condition models for both metrics were developed to account for age, size, location, and timing of harvest from belugas harvested from 2000 to 2015. Models were tested to determine if the spatial variation is detected in the condition of belugas between the three areas of the TN MPA and between belugas harvested inside to outside of the TN MPA. Lastly, we assessed belugas from entrapment events to determine if indicator thresholds could be developed. Three of the indicators (girth male, girth female, blubber thickness male) contain both temporal and spatial factors, signalling the significant influence of year and harvest location on condition. Male belugas harvested from the western area of the TN MPA had smaller mean blubber thickness and girth compared to the other TN MPA areas, whereas there was no significant difference in female condition across the TN MPA. There was a significant difference inside and outside the TN MPA for all four indicators, with larger mean blubber thickness inside the TN MPA, females exhibiting larger mean girth and males exhibiting smaller mean girth inside the TN MPA. Indicators confirm that belugas from entrapment events had significantly lower body condition than belugas harvested during the summer and can serve as thresholds for condition indicators. This study provides guidance on the selection and use of condition indicators for their application in monitoring the TN MPA and demonstrates that careful consideration is required for indicator development and selection. [ABSTRACT FROM AUTHOR]

Climate change is expected to impact Arctic marine mammals, as they may be particularly vulnerable to large annual variability in the environment. Beluga whales ( Delphinapterus leucas) occupy the circumpolar Arctic year-round, and seasonal movement patterns in this landscape are closely linked to sea ice and changing conditions. Here, we examine the association between beluga spring locations along the Mackenzie Shelf and three relevant habitat variables: sea ice (total concentration, floe size, and distance to ice edge), bathymetry and turbidity. Beluga locations in 2012 and 2013 were analyzed across the study area, as well as in three discrete subareas of the Mackenzie Shelf: Shallow Bay, Kugmallit Bay and Tuktoyaktuk Peninsula. In both years, beluga were found more than expected by chance in locations of open water/light ice concentrations and medium ice floes, and displayed a significant association with turbid water (i.e., increased freshwater flow). Largely ice-free conditions in 2012 led to a wide variation in habitat use in all three subareas. Beluga whales in 2012 preferred the ice edge and were found in heavier ice concentrations, larger floes and high turbidity water in the Shallow Bay subarea. Open water environments were preferred by beluga found in the Kugmallit Bay subarea. In contrast, heavy ice conditions in 2013 resulted in restricted habitat use and selection of shallow depth (<50 m) and low levels of turbidity. These results provide knowledge on spring habitat selection as well as insight into the adaptability of beluga under expected changes associated with climate and human activity in the Beaufort Sea. [ABSTRACT FROM AUTHOR]

The immense challenges associated with realizing ocean and coastal sustainability require highly skilled interdisciplinary marine scientists. However, the barriers experienced by early career researchers (ECRs) seeking to address these challenges, and the support required to overcome those barriers, are not well understood. This study examines the perspectives of ECRs on opportunities to build interdisciplinary research capacity in marine science. We engaged 23 current and former graduate students and postdoctoral fellows in a policy Delphi method with three rounds of surveying that included semi-structured questionnaires and q-methodology. We identified the following five barriers that limit ECRs' capacity for interdisciplinary research: (i) demanding workloads; (ii) stress linked to funding, publishing, and employment uncertainty; (iii) limited support for balancing personal and professional commitments; (iv) ineffective supervisory support; and (v) the steep learning curve associated with interdisciplinary research. Our analysis highlights three main types of responses to these barriers adopted by ECRs, including "taking on too much", "coping effectively", and "maintaining material wellbeing at any cost". To overcome these barriers, we propose the following three institutional actions to build early career interdisciplinary researcher capacity: formalize mentorship, create interdisciplinary research groups, and mainstream mental health support. [ABSTRACT FROM AUTHOR]

Oceanic ecosystem services support a range of human benefits, and Canada has extensive research networks producing growing data sets. We present a first effort to compile, link, and harmonize available information to provide new perspectives on the status of Canadian ocean ecosystems and corresponding research. The metadata database currently includes 1094 individual assessments and data sets from government ( n = 716), nongovernment ( n = 320), and academic sources ( n = 58), comprising research on marine species, natural drivers and resources, human activities, ecosystem services, and governance, with data sets spanning 1979-2012 on average. Overall, research shows a strong prevalence towards single-species fishery studies, with an underrepresentation of economic and social aspects, and of the Arctic region in general. Nevertheless, the number of studies that are multispecies or ecosystem-based have increased since the 1960s. We present and discuss two illustrative case studies - marine protected area establishment in Canada and herring resource use by the Heiltsuk First Nation - highlighting the potential use of multidisciplinary data sets drawn from metadata records. Identifying knowledge gaps is key to achieving the comprehensive, accessible and interdisciplinary data sets and subsequent analyses necessary for new sustainability policies that meet both ecological and socioeconomic needs. [ABSTRACT FROM AUTHOR]