Linking plastic ingestion research with marine wildlife conservation

Plastic is an increasingly pervasive marine pollutant. Concomitantly, the number of studies documenting plastic ingestion in wildlife is accelerating. Many of these studies aim to provide a baseline against which future levels of plastic ingestion can be compared, and are motivated by an underlying interest in the conservation of their study species and ecosystems. Although this research has helped to raise the profile of plastic as a pollutant of emerging concern, there is a disconnect between research examining plastic pollution and wildlife conservation. We present ideas to further discussion about how plastic ingestion research could benefit wildlife conservation by prioritising studies that elucidates the significance of plastic pollution as a population-level threat, identifies vulnerable populations, and evaluates strategies for mitigating impacts. The benefit of plastic ingestion research to marine wildlife can be improved by establishing a clearer understanding of how discoveries will be integrated into conservation and policy actions

Recommended best practices for plastic and litter ingestion studies in marine birds: Collection, processing, and reporting

doi: 10.1139/facets-2018-0043Marine plastic pollution is an environmental contaminant of significant concern. There is a lack of consistency in sample collection and processing that continues to impede meta-analyses and largescale comparisons across time and space. This is true for most taxa, including seabirds, which are the most studied megafauna group with regards to plastic ingestion research. Consequently, it is difficult to evaluate the impacts and extent of plastic contamination in seabirds fully and accurately, and to make inferences about species for which we have little or no data. We provide a synthesized set of recommendations specific for seabirds and plastic ingestion studies that include best practices in relation to sample collection, processing, and reporting, as well as highlighting some “cross-cutting” methods. We include guidance for how carcasses, regurgitations, and pellets should be handled and treated to prevent cross-contamination, and a discussion of what size class of microplastics can be assessed in each sample type. Although we focus on marine bird samples, we also include standardized techniques to remove sediment and biological material that are generalizable to other taxa. Lastly, metrics and data presentation of ingested plastics are briefly reviewed in the context of seabird studies.Copyright: © 2019 Provencher et al. This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The attached file is the published pdf

Employing Predictive Spatial Models to Inform Conservation Planning for Seabirds in the Labrador Sea

Seabirds are vulnerable to incidental harm from human activities in the ocean, and knowledge of their seasonal distribution is required to assess risk and effectively inform marine conservation planning. Significant hydrocarbon discoveries and exploration licenses in the Labrador Sea underscore the need for quantitative information on seabird seasonal distribution and abundance, as this region is known to provide important habitat for seabirds year-round. We explore the utility of density surface modeling (DSM) to improve seabird information available for regional conservation and management decision making. We, (1) develop seasonal density surface models for seabirds in the Labrador Sea using data from vessel-based surveys (2006–2014; 13,783 linear km of surveys), (2) present measures of uncertainty in model predictions, (3) discuss how density surface models can inform conservation and management decision making, and 4) explore challenges and potential pitfalls associated with using these modeling procedures. Models predicted large areas of high seabird density in fall over continental shelf waters (max. ~80 birds·km−2) driven largely by the southward migration of murres (Uria spp.) and dovekies (Alle alle) from Arctic breeding colonies. The continental shelf break was also highlighted as an important habitat feature, with predictions of high seabird densities particularly during summer (max. ~70 birds·km−2). Notable concentrations of seabirds overlapped with several significant hydrocarbon discoveries on the continental shelf and large areas in the vicinity of the southern shelf break, which are in the early stages of exploration. Some, but not all, areas of high seabird density were within current Ecologically and Biologically Significant Area (EBSA) boundaries. Building predictive spatial models required knowledge of Distance Sampling and GAMs, and significant investments of time and computational power—resource needs that are becoming more common in ecological modeling. Visualization of predictions and their uncertainty needed to be considered for appropriate interpretation by end users. Model uncertainty tended to be greater where survey effort was limited or where predictor covariates exceeded the range of those observed. Predictive spatial models proved useful in generating defensible estimates of seabird densities in many areas of interest to the oil and gas industry in the Labrador Sea, and will have continued use in marine risk assessments and spatial planning activities in the region and beyond

Determining the impacts of hydrological drought on endangered Nooksack dace (Rhinichthys cataractae) at the population and individual level : Implications for minimum environmental flow requirements

Understanding the impacts of hydrological drought is crucial to the conservation of freshwater fishes. In British Columbia, Nooksack dace (Cyprinidae: Rhinichthys cataractae) are an endangered riffle specialist and are threatened by extremely low summer flows. The purpose of this thesis was to explore the impacts of drought on Nooksack dace, whether pool habitats may act as refugia to mitigate these impacts, and to define minimum environmental flow requirements. The first two objectives were addressed using a combination of field survey and experimental manipulations. A reduction in Nooksack dace population size with declining summer flow in Bertrand Creek, and a marked decrease in growth at low discharge in experimental riffles, indicated that low discharge has negative impacts on dace at both population and individual levels. Pool habitats were found to play a minor role in mitigating the negative impacts of hydrological drought (e.g., decreased growth rate), save as a refuge from stranding when riffles dewater. The third objective was addressed using the Instream Flow Incremental Methodology (IFIM). Because this study involved an endangered species an emphasis was placed on evaluating two fundamental assumptions of the methodology. Experimental results for Nooksack dace growth at different depths and velocities provided support for the first assumption, that density-based Habitat Suitability Curves (HSCs) accurately reflect habitat quality, but only for the lower limits of the HSCs. Next, a significant positive relationship between Weighted Usable Area (WUA) and dace biomass was found, supporting the assumption that such a relationship exists. However, this relationship was weak indicating a high degree of uncertainty in how Nooksack dace biomass will respond at high discharges. The IFIM model predicted that habitat availability for Nooksack dace begins to decline most rapidly at discharges of 0.12 m³.s-¹. As there is low confidence in upper ranges of the HSCs this low flow threshold may underestimate declines with discharge, and therefore protection of at least 0.12 m³.s-¹ is considered necessary for the persistence of Nooksack dace individuals and populations. Compared to conventional instream flow criteria, 0.12 m³.s-¹ represents ~10% mean annual discharge which is the threshold for severely degraded habitat.Science, Faculty ofZoology, Department ofGraduat

Differential declines among nesting habitats of breeding Herring gulls (Larus argentatus) and Great Black-backed gulls (Larus marinus) in Witless Bay, Newfoundland and Labrador, Canada

Environmental conditions in eastern Newfoundland have changed considerably since the 1970s, as both bottom-up oceanographic and anthropogenic influences on seabird populations have fluctuated considerably. The diet, reproductive success, and presumably survival of gulls are intrinsically linked to these processes, and breeding populations have declined considerably through the 1980s and 1990s. To assess the populations of breeding large gulls in the Witless Bay Ecological Reserve in eastern Newfoundland and Labrador, Canada, nests were surveyed and clutch size determined for Herring Gulls (Larus argentatus) and Great Black-backed Gulls (L. marinus) breeding on Great, Gull, and Pee Pee Islands in 2011-2012. The total number of breeding gulls of these two species combined decreased by 41% on Gull Island, 78% on Great Island and 51% on Pee Pee Island since 2000. However, the declines differed among habitat type, with modest declines on puffin slopes (-15% to -52%) and the steepest declines in meadows (-70% to -88%), suggesting that large-scale causative factors are not solely responsible for changes in population size. Clutch size did not differ from that in 2000. Differential recruitment among highly philopatric gulls stemming from bottom-up diet-related variation in breeding success may be responsible for different changes in populations among different habitats