A centuries-long epidemic of scrapie in British sheep?

The apparent persistence of scrapie in British sheep for more than 250 years is difficult to explain. Susceptibility to scrapie is associated with particular alleles at a single locus, the PrP gene. As the only known effect of these alleles is to confer susceptibility to a fatal disease, natural selection is expected to reduce their frequency, as has been observed in practice during scrapie outbreaks in single sheep flocks. Susceptibility alleles, and hence scrapie itself, are therefore expected to become rare, yet the disease remains widespread. We suggest that the paradox of scrapie's persistence can be explained by the exceptionally long time-scales inherent in the epidemiology of the disease. It is proposed that scrapie should be regarded as epidemic in British sheep but, unlike more familiar epidemics, which have time-scales of months or years, the scrapie epidemic has a time-scale of centuries. This interpretation implies that scrapie should eventually disappear from the sheep population.     

The Collins’ monster,a spinous suspension-feeding lobopodian from the Cambrian Burgess Shale of British Columbia

Lobopodians, a paraphyletic group of rare but morphologically diverse Palaeozoic vermiform animals bearing metameric appendages, are key to the origin of extant panarthropods. First discovered in 1983 on Mount Stephen (Yoho National Park, British Columbia), the Cambrian (Wuliuan) Burgess Shale lobopodian nicknamed ‘Collins’ monster’ is formally described as Collinsovermis monstruosus gen. et sp. nov. A formal systematic treatment of the comparable and poorly known lobopodian Acinocricus stichus from Utah is also provided. The body of Collinsovermis is plump and compact but shows the diagnostic suspension-feeding characters of luolishaniid lobopodians. It possesses 14 contiguous pairs of lobopods, lacking space between them. The 6 anterior pairs are elongate, adorned with about 20 pairs of long and slightly curved ventral spinules arranged in a chevron-like pattern. These appendages terminate in a pair of thin claws and their dorsal surfaces are covered in minute spines or setae. The 8 posterior lobopod pairs, which attach to a truncated body termination, are stout and smooth, each terminated by a single strong recurved claw. Each somite bears a pair of dorsal spines; somites 4 and posteriad bear an additional median spine. The spines on somites 1–3 are much shorter than the spines on the remaining somites. The head is short, bears a terminal mouth and a pair of antenniform outgrowths, and is covered by an oblong sclerite. Collinsovermis, plus Collinsium and Acinocricus, are found to comprise a sub-group of stout luolishaniid lobopodians with remarkably long spinules on the front lobopods, interpreted here as a clade (Teratopodidae fam. nov.) This clade is distinct from both the comparatively slenderer Luolishania and a sub-group composed of Facivermis and Ovatiovermis lacking body sclerites. Luolishaniids were mostly sessile forerunners of arthropods that had coupled efficient suspension-feeding devices and, as in Collinsovermis, strong defensive or deterrent features.     

Test of an environmental flow release in a British Columbia river: does more water mean more fish?

1. Water managers must make difficult decisions about the allocation of streamflows between out‐of‐channel human uses and environmental flows for aquatic resources. However, the effects environmental flows on stream ecosystems are infrequently evaluated. 2. We used a 13‐year experiment in the regulated Bridge River, British Columbia, Canada, to determine whether an environmental flow release designed to increase salmonid productivity was successful. A hierarchical Bayesian model was used to compare juvenile Pacific salmon (Oncorhynchus spp.) abundance before and after the flow release. 3. We found that the total number of salmonids did increase after the release, but most of the gains could be attributed to the rewatering of a previously dry channel located immediately below the dam. In reaches that had flowing water during the baseline period, the response of individual salmon species to the increase in flow was variable, and there was little change in total abundance after the flow release. Our results were inconsistent with both habitat modelling, which predicted a decrease in habitat quality with increasing flow, and holistic instream flow approaches, which imply greater benefits with larger flows. 4. We question whether biotic responses to flow changes can be predicted reliably with currently available methods and suggest that adaptive management or the use of decision tools that account for the uncertainty in the biotic response is required for instream flow decisions when the competing demands for water are great.     

Discovery of a “Living Dinosaur”: Globally unique modern hexactinellid sponge reefs off British Columbia, Canada

Summary Globally unique hexactinellid sponge reefs occur on the continental shelf off British Columbia, Canada. They cover about 425 km² of seafloor on the continental shelf off British Columbia (Canada) in water depths between 165 and 240 metres and occur on a low-angle deep shelf, iceberg scoured seafloor, characterized by very low sedimentation rates and very stable environmental conditions. The sponge bioherms are up to 19 metres high with steep flanks, whereas the biostromes are 2–10 metres thick and many kilometres wide. They all consist of dense populations of only seven hexactinellid species. Three of them, all hexactinosan species (Aphrocallistes vastus, Heterochone calyx, Farrea occa) are the main frambuilders, composing a true rigid framework of sponge skeletons encased in a organic rich matrix of modern clay baffled by the sponges. Growth rates of hexactinosan sponges range in the order of 0–7 centimetres per year. The base of the oldest sponge reefs date from approximately 9000 years b.p. Different invertebrate and fish faunas occupy the reefs than occur on adjacent seafloor areas and some species appear to use the sponge reef complex structures as refugia where they can hide. Sidescan sonar data and direct observation by manned submersible clearly show that large areas of sponge reefs have been heavily damaged by seafloor trawling in the past decade. These unique extant siliceous sponge reefs can be used as a modern analogue for a better understanding and interpretation of fossil siliceous sponge reefs, known from many ages and many locations world wide.     

“Markings” of a Class: The Statistical Trail Left by the First Graduating Class in Medicine,University of British Columbia

In 1954 the first class in medicine graduated from the University of British Columbia. This class of 57 men and three women left a statistical trail behind them which began before they entered medical school, and which now has extended 10 years into their professional postgraduate careers. This first class was made up largely of British Columbians of older age than subsequent classes. The overall achievement and aptitude of the class was high, as measured by premedical grades, intelligence tests and Medical College Admission Test scores. Interest tests at the time of admission indicated that the members of the class had major interest levels in the fields of science and social service or humanitarianism. The subsequent medical school performance of the class was exceptional. Of the class, 63.4% interned in teaching hospitals. By 1964 only 53.4% of the graduates were engaged in general practice. Most of the graduates are now practising in British Columbia.     

Tests of the annual hypothesis and temporal calibration of a 6375‐varve fish‐bearing interval,Eocene horsefly beds,British Columbia,Canada

Eocene lake sediments from Horsefly, British Columbia are rich in fossils of the catostomid fish Amyzon aggregatum. Previous studies of this fish in a 700‐year sequence of varves have demonstrated their potential use in studies of fine‐scale temporal variation in taphonomy and morphology. Tests of the annual (varve) hypothesis for the layers, together with reliable temporal calibration, are necessary prerequisites to any such application. In the present study, a longer continuous sequence from this deposit is subjected to additional tests of the annual hypothesis and is temporally calibrated. Tests include spectral analysis of varve thicknesses, scanning electron microscopy and elemental analysis of dark and light laminae, and analysis of within‐couplet distribution of seasonal fossils. Results support the hypothesis that the couplets are true varves.

Some 6375 varves occur in the studied interval. Each varve is composed of a diatom‐dominated summer lamina and a winter lamina richer in clays, pyrite, and gypsum. Occasional turbidites and thin layers of volcanic ash allow counting and identification of individual varves under low‐power magnification. Fish are rare in the upper 2000 varves but abundant and extensively distributed in the lower 4000 varves of the sequence, making these a potentially valuable interval for studies of microstratigraphic variation in morphology and taphonomy.     

Niche partitioning and photosynthetic response of alectorioid lichens from subalpine spruce–fir forest in north-central British Columbia,Canada: the role of canopy microclimate gradients

The distribution of alectorioid lichens in subalpine spruce–fir forests of north-central British Columbia is strongly influenced by vertical position within the canopy; Bryoria dominates upper canopy exposures, while Alectoria dominates lower canopy positions. The hypothesis that this height-related niche partitioning reflects differential growth responses to gradients in canopy microclimate is examined. Field measurements of canopy microclimate, taken over a 2-year period, were used in conjunction with laboratory-based measurements of net photosynthesis (NP) and dark respiration to model net assimilation (NA) response of Alectoria sarmentosa and Bryoria spp. (mixed collections of Bryoria fremontii and B. pseudofuscescens) at two different heights (15 and 4 m) within the canopy. Microclimate measurements indicate that lichen thalli are regularly hydrated from snowmelt events during the winter period (October–April), totalling 26 and 29% of the time, respectively, for Alectoria and Bryoria, though most winter hydration exposure (c. 75%) occurred in the dark. In the summer (May–September), rainfall was the major hydration source, with Alectoria and Bryoria each hydrated c. 16% of the time (45% of this in the dark). The NP temperature optimum (T_opt) in light saturated thalli of Alectoria was 18·1 and 22·9°C, for winter and summer measurements, respectively. In Bryoria the corresponding seasonal rise in T_optwas smaller, from 15·9 to 16·3°C. Both species showed an increase in maximum rates of NP during the summer period, from 1·52 to 1·92 mg CO₂ g⁻¹ h⁻¹for Alectoria, and from 1·79 to 2·33 mg CO₂ g⁻¹ h⁻¹for Bryoria. Although lichen hydration events peaked in early winter (October and November), NA modelling predicts that maximum growth should occur during the summer period. In Alectoria, higher rates of NA were predicted for thalli in lower canopy positions, especially during the summer months. In Bryoria, no clear trends of NA uptake with canopy position were observed. Thus, while NP response to gradients of canopy microclimate may provide a basis for niche partitioning in Alectoria, other factors (perhaps exclusionary) may be more important for Bryoria. One such factor is documented, namely the greater sensitivity of Bryoria to extended hydration exposure and we speculate that greater rates of fragmentation in upper canopy exposures may limit upper canopy biomass accumulation in Alectoria. Niche partitioning in these alectorioid lichens may therefore reflect both positive (growth responses) and negative (physical and physiological limitations) responses to gradients in canopy microclimate.     

A Plethora of ‘suitable enemies’: British racism at the dawn of the twenty-first century1

In this article, I begin by looking at older forms of British racism before addressing myself to some newer forms – anti-asylum-seeker racism, xeno-racism and Islamophobia. I argue that in contemporary Britain there are a plethora of ‘suitable enemies’. Given that contemporary British racism is multifaceted, and in order to set the scene for newer forms of racism, I begin by contextualizing them alongside older forms of racism, while also demonstrating that these older forms continue to flourish. For conceptual clarity, I deal separately with colour-coded racism, non-colour-coded racism, and what I will call hybridist racism.     

British Columbia’s Fish Health Regulatory Framework’s Contribution to Sustainability Goals Related to Salmon Aquaculture

Salmon farming is a significant contribution to the global seafood market to which the goal of sustainability is often applied. Diseases related to farms are perhaps the most contentious issues associated with sustainable salmon farming. We reviewed literature and policies in British Columbia, Canada, as well as interviewed key informants to examine how fish health regulations do or could support sustainability goals. We found four main obstacles to the development and application of a sustainability-based health management system. First, salmon farming faced the same challenges as other industries when trying to establish an operational definition of sustainability that captures all stakeholders’ interests. Second, there was no program responsible for integrating the various regulations, responsible departments, and monitoring efforts to develop a comprehensive view of sustainability. Third, there was inadequate research base and social consensus on the criteria that should be used to track health outcomes for sustainability purposes. Fourth, the regulatory and management paradigm for salmon farming has been focused on diseases and pathogens as opposed to embracing a more inclusive health promotion model that includes biotic, abiotic, and social determinants of health. A transparent and inclusive participatory process that effectively links expert views with community and industry concerns should serve as the foundation for the next generation of health management regulations for salmon farming.     

Charles McLean Fraser (1872–1946) – his contributions to hydroid research and to the development of fisheries biology and academia in British Columbia

Hydrobiologia - Charles McLean Fraser (1872–1946) is best remembered for his work on hydroids, but he was also involved in a much broader range of activities during the development of marine...