Cryptococcus gattii in wildlife of Vancouver Island, British Columbia, Canada

Although Cryptococcus gattii has emerged as an important pathogen of humans and domestic animals on Vancouver Island, Canada since 1999; its distribution in regional wildlife species is largely unknown. Opportunistic sampling methods were employed to obtain nasal swabs for fungal culture from wild mammal species residing within the coastal Douglas fir biogeoclimatic zone on the southeast coast of the island. Samples were collected from 91 animals representing 14 species. Cryptococcus gattii was isolated from the nasal swabs of two eastern gray squirrels (Sciurus carolinensis) trapped in Duncan, British Columbia. The relative proportion of nasal colonization in wild mammal species is consistent with findings in domestic animals, suggesting that animals may be good indicators of environmental organisms.     

Cretaceous and Eocene poroid hymenophores from Vancouver Island, British Columbia

Two fossil poroid hymenophore fragments, one from the Cretaceous Period and the other from the Eocene Epoch, are described. The permineralized specimens were obtained from marine calcareous concretions on Vancouver Island, British Columbia, Canada, and were studied using the cellulose acetate peel technique. Size and distribution of pores in the hymenophores, as well as the hyphal anatomy of the dissepiments and some hymenial elements, were examined. In the Cretaceous specimen, Quatsinoporites cranhamii sp. nov., pores are round to elliptical, three per mm, and 130-540 μm diam. Dissepiments consist of narrow, simple septate, hyphae. Neither basidia nor basidiospores are present, but acuminate hymenial cystidia, up to 54 μm in length, are common. The Eocene specimen, Appianoporites vancouverensis sp. nov., has a pore density of six per mm and pores are 130-163 μm in diam. Dissepiments consist of narrow, simple septate, thin-walled hyphae. Neither basidia nor basidiospores are present, but acuminate, thick-walled hymenial cystidia, up to 32 μm in length, are common. The poroid hymenophore is a characteristic of a number of extant basidiomycete taxa, including the Boletales, Polyporales and Hymenochaetales. It is unlikely that the fleshy, ephemeral, terrestrial basidiomata of the Boletales would be preserved in a marine environment, and thus the specimens are interpreted as belonging to basidiomycete lineages, with persistent, leathery or corky basidiomata. The simple septate hyphae, the minute pores and presence of cystidia most closely resemble taxa of the Hymenochaetales. These fossils unequivocally push back the minimum age of homobasidiomycetes and extend their paleogeographical range.     

Ultraviolet irradiance and primary production in a Vancouver Island fjord, British Columbia, Canada

The photosynthetic uptake of CO² by phytoplankton enclosed insilica- and quartz-glass bottles suspended at seven depths fromthe sea surface to 7 m was measured in Saanich Inlet, from earlyApril to mid-September, 1976. Rates of uptake were slower inquartz- than in silica-glass bottles at 0 and 1–m depthsduring spring and late summer. Differences were attributed tothe presence of ultraviolet light (315 – 350 nm) in quartz-glassbottles. No differences between bottles were observed in earlysummer months when total irradiances at the sea surface weremaximal. This absence of depression could have been due to thepresence of species resistant to u.v. damage since the taxonomkcomposition of phytoplankton during summer was quite differentthan in spring.     

Diatom (Bacillariophyceae) assemblages in tidal environments of Vancouver Island,British Columbia,Canada

To understand distributions of coastal diatoms along Vancouver Island, British Columbia, Canada, this paper describes diatom assemblages observed in 47 surface sediment samples from intertidal environments. One hundred and eighty-four diatom taxa were identified from five transects crossing tidal flats, salt marshes, and freshwater forests in Tofino, Ucluelet, and Port Alberni. Distributions of the diatom assemblages were consistent with those reported elsewhere in the Pacific Northwest, but a few diatom taxa show different trends in their distributions. For example, one benthic species Denticula subtilis shows widespread distributions along the transect in Tofino. An ordination shown by Detrended Correspondence Analysis (DCA) using a combined dataset indicated overlapped scatter plots of diatom assemblages, suggesting that assemblages with similar species compositions are observed in more than one location. Hierarchical and k-means clustering analyses using Euclidean distance recognized unique small groups along each transect. Rank abundance curves show different trends for richness and evenness of diatom assemblages among the five transects.     

Investigating the complexities of sustainable fishing at a prehistoric village on western Vancouver Island, British Columbia, Canada

Zooarchaeological data provide direct evidence of long-term human resource utilization relevant to the modern study of sustainability and conservation. On the northwest coast of North America, prehistoric aboriginal communities relied heavily on nearshore marine fish species, many of which have life history characteristics that make them vulnerable to overexploitation. This study examines temporal trends in the abundance and distribution of nearshore fish from skeletal remains recovered from three separate areas of a prehistoric coastal village on the west coast of Vancouver Island (ca. 1800–250 yr BP). Over the course of 1500 years, site inhabitants from these contemporaneously occupied areas regularly utilized Sebastes spp. (rockfish), with varying impacts on abundance and total length. Contrasting temporal trends in Sebastes spp. total length in separate village areas suggest different consequences to prehistoric harvesting practices, differences that can be linked to ethnographic and archaeological evidence of lineage-based territories. These long-term zooarchaeological data provide unique insights into the context and challenges of sustainable resource use in prehistory and can inform contemporary conservation efforts focused on similar species in this modern-day marine protected area.     

Patterns of gametophyte dominance ofIridaea splendens(Rhodophyta) in Vancouver Harbour,Vancouver, British Columbia,Canada

This paper presents results of field and laboratory work on one component of population structure ofIridaea splendens (Setchellet Gardner) Papenfuss (Gigartinaceae, Rhodophyta), the seasonal change in abundance of the gametophyte life-history stage. Investigations of this genus by others (using a variety of sampling and identification techniques) have shown a seasonal gametophyte dominance, sporophyte dominance, or some combination of these two. Gametophyte stages ofIridaea splendens produce kappa carrageenan and tetrasporophyte stages lambda carrageenan; a chemical colorimetric test using resorcinol can be used to identify these stages regardless of the presence of reproductive structures. In this paper we report on the proportion of gametophytes determined both by this chemical test and by the presence of reproductive structures, and on one possible determinant of the seasonal change in dominance. Analysis of field samples using the resorcinol test showed that from June–August the gametophyte stage predominates and from December–February the tetrasporaphyte stage is most common, both in reproductive and non-reproductive thalli (the latter tested as three size classes). Examination of reproductive structures gave similar results. One factor suggested in the literatures as a possible determinant of the haploid/diploid ratio is apomeiosis (in the formation of the tetraspores); our results show this to be unimportant in the Vancouver Harbor populations.Presented at the XIIIth International Seaweed Symposium, University of British Columbia, Vancouver, Canada, August 1989.     

Paralygodium meckertii sp. nov. (Schizaeaceae) from the Upper Cretaceous (Coniacian) of Vancouver Island, British Columbia, Canada

More than 50 specimens of permineralized fertile pinnules with abaxially borne sporangia have been discovered in calcareous marine nodules from the Upper Cretaceous (Coniacian) Comox Formation from the Eden Main localities on Vancouver Island, British Columbia, Canada. Isolated pinnules 1.6–3.0 mm wide × 1.6–2.8 mm long are lobed and abaxially enrolled to form irregular globose structures. Pyriform sporangia 216–300 μm wide × 360–468 μm long occur in two rows on the abaxial surface of pinnule lobes. Sporangia have an apical annulus of 15–18 cells. Spores are tetrahedral and trilete, 33–42 μm in diameter, with straight to concave interradial sides, laesurae extending nearly to the equator, and a psilate exine. Spores are assignable to the sporae dispersae genus Deltoidospora. Fertile pinnules are compared to fossils of Anemia poolensis and two previously described species of Paralygodium, and show closest similarities to P. vancouverensis from the Eocene of British Columbia. The Cretaceous Eden Main specimens differ in number of pinnule lobes and their morphology and are described as a new taxon: P. meckertii sp. nov. This discovery extends the Cretaceous geographic range of Paralygodium from Japan to North America and adds to our knowledge of the diversity of extinct schizaeaceous ferns.     

Predicted short-term radial-growth changes of trees based on past climate on Vancouver Island,British Columbia

Tree-ring radial expansion estimator (TREE) is an integrated radial growth model that allows users to define short-term climate change scenarios to anticipate the impact upon mature trees found growing at high elevation on Vancouver Island, British Columbia. Five individualistic models were built to represent the radial growth behaviour of mountain hemlock (Tsuga mertensiana (Bong.) Carr), yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach), western red-cedar (Thuja plicata Donn), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees. The models were developed on climate-radial growth relationships incorporating Nanaimo climate station data, and were able to explain from 55 to 68 per cent of the variance in radial growth. The models can be run with modifications to yearly precipitation and temperature variables, giving the user the ability to investigate the radial-growth impacts of a wide range of possible climate change scenarios. Results from eight such scenarios show that species growing within their ecological limits illustrate a limited change in radial growth to forecasted climate, while species growing at an ecotonal boundary are usually very sensitive to a specific climate variables (e.g., July temperature). A forecasted alteration to this key variable will then radically alter the radial-growth rate of the species.     

The consumption of euphausiids by the pelagic fish community off southwestern Vancouver Island, British Columbia

The consumption of adult euphausiids was estimated for the sevenmost abundant fish species found on the continental shelf offsouthwestern Vancouver Island, British Columbia, Canada. Empiricaldata on fish feeding rates, diets and biomass were used to estimateeuphausiid consumption in August for each year from 1985 to1997. The fish community in August was estimated to consumean average 297 kt of euphausiids (124 t km^–2). Pacifichake (Merluccius productus) and Pacific herring (Clupea harengus)accounted for 60% and 30%, respectively, of the total euphausiidsconsumed by fish. The total estimated consumption of euphausiidsper tonne of fish averaged 0.93, and there was no significanttrend in the time series. In addition, there was no significantrelationship between the total fish community consumption oreuphausiids consumed per tonne of fish and euphausiid biomass,and there was no change in the fraction of euphausiids in thediet of small or large Pacific hake. Thus, it appears that predationpressure from the pelagic fish community was relatively constantand not responsible for the apparent fivefold decline in adulteuphausiid biomass observed in the 1990s.     

Predicted short-term radial-growth changes of trees based on past climate on Vancouver Island, British Columbia

Tree-ring radial expansion estimator (TREE) is an integrated radial growth model that allows users to define short-term climate change scenarios to anticipate the impact upon mature trees found growing at high elevation on Vancouver Island, British Columbia. Five individualistic models were built to represent the radial growth behaviour of mountain hemlock (Tsuga mertensiana (Bong.) Carr), yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach), western red-cedar (Thuja plicata Donn), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees. The models were developed on climate-radial growth relationships incorporating Nanaimo climate station data, and were able to explain from 55 to 68 per cent of the variance in radial growth. The models can be run with modifications to yearly precipitation and temperature variables, giving the user the ability to investigate the radial-growth impacts of a wide range of possible climate change scenarios. Results from eight such scenarios show that species growing within their ecological limits illustrate a limited change in radial growth to forecasted climate, while species growing at an ecotonal boundary are usually very sensitive to a specific climate variables (e.g., July temperature). A forecasted alteration to this key variable will then radically alter the radial-growth rate of the species.     

Putative neoplastic disorders in mussels (Mytilus edulis) from Southern Vancouver Island waters,British Columbia

Histologic examination of wild populations of Mytilus edulis in Saanich Inlet, British Columbia, Canada, revealed the presence of a highly invasive neoplasm. Two types of neoplasms were recognized; most were of hematopoietic origin, except in one mussel which had a presumptive gonadal neoplasm. Both types were apparently malignant neoplasms, based on their anaplastic appearance, invasiveness, mitotic activity, and associated tissue necrosis. This condition was observed from what is believed to be the earliest stage of the disease to the terminal stage, in which the connective tissue was almost completely replaced.     

Chinook and Coho salmon hybrids linked to habitat and climatic changes on Vancouver Island,British Columbia

Between 2013 and 2019, 63 presumed Chinook salmon Oncorhynchus tshawytscha sampled primarily in the Strait of Georgia (0.63% of total sample) were identified as potential Chinook–Coho (Oncorhynchus kisutch) hybrids by the presence of anomalous microsatellite genotypes. Their hybrid origin was confirmed by single nucleotide polymorphism amplification of two species‐specific amplicons. Mitochondrial DNA indicated that most of these fish resulted from the hybridization of Coho salmon females and Chinook salmon males. Although no diagnostic external features were identified, several individuals displayed an abnormal scale arrangement on the caudal peduncle. One hybrid juvenile examined for meristics exhibited a pyloric caeca count intermediate between published values for Chinook and Coho salmon. Most hybrids originated in the Cowichan River during the 2014 brood year. Their prevalence in the watershed is a naturally occurring event, likely exacerbated by prolonged low water levels which limit habitat and delay Chinook salmon spawning, in addition to the differential abundance of the parental species. This research is the first to document ongoing natural hybridization (Chinook–Coho salmon crosses) and link it to habitat and climatic changes, and includes the identification of eight F1 adults and two juvenile backcross or F2 hybrids. The potential negative impacts of hybridization, particularly in Coho salmon through potential introgression, warrant hybrid identification as an ecosystem monitoring tool within a survey program.     

New insights into the northward migration route of gray whales between Vancouver Island,British Columbia,and southeastern Alaska

The route taken by northward migrating gray whales during spring between Vancouver Island and southeastern Alaska, a distance of about 575 km, has long been uncertain. It is generally believed that the whales closely follow the western, outer coastline of Haida Gwaii (formerly the Queen Charlotte Islands), an archipelago lying between Vancouver Island and southeastern Alaska, consistent with their pattern of migrating close to shore over the majority of their northward migratory corridor. By tracking satellite‐tagged individuals and surveying whales from shore bases, we provide evidence that this is not the primary migratory corridor, but instead that most whales migrate through Hecate Strait and Dixon Entrance, broad waterways that lie to the east and north of Haida Gwaii. By using this route, northbound gray whales potentially face a wider range of industrial activities and developments than they would by migrating along the outer coast.     

Diversity of the understory vascular vegetation in 40 year-old and old-growth forest stands on Vancouver Island,British Columbia

Abstract. We studied plant diversity of the understory vascular vegetation in 40 yr-old plantations (immature stands) and old-growth forest stands on southwestern Vancouver Island, British Columbia, Canada. Site-specific comparisons using several indices of species diversity were made between: (1) immature stands segregated according to the canopy cover and dominant canopy tree species; and (2) immature and old-growth stands. There were no significant differences (P < 0.05) among immature stands in species richness (S) and the Shannon-Wiener index (H′), in relation to the canopy cover or in S, H′ and evenness (E) in relation to the dominant canopy tree species. Using the same indices, the plant diversity varied with edaphic conditions (represented by five site associations) and time (represented by two developmental stages). At both stand- and site levels, plant diversity increased with increasing soil moisture, from slightly dry to moist sites, and with increasing plant-available soil nitrogen in both immature and old-growth stands; and the plant diversity of immature stands across the sites studied was considerably lower than in old-growth stands, regardless of site association. The indices of plant diversity, floristic similarity indices, and species turnover rates indicated that the immature stands had their plant diversity at a minimum, but a drastic loss of diversity expected in the stem exclusion stage had not materialized. We attributed decline in plant diversity to the absence of old-growth structural features in immature stands. Several measures to foster the stand-level diversity were proposed.     

Transformations of residual 15N in a coniferous forest soil humus layer in northern Vancouver Island,British Columbia

We studied the effect of ¹⁵N labelling duration on the mineralisation and immobilisation of native and applied (residual) N in the humus layer of a Humo-Ferric Podzol. Ammonium sulphate, labelled with ¹⁵N, was applied to 1 m² plots at a rate of 200 kg N ha^–1. Fertiliser application was timed so that when samples were collected they had been labelled with ¹⁵N for 24 hours, 7 months and 31 months. In a 42-day aerobic incubation of the samples, net mineralisation of total and applied N was greatest in the 24-hr treatment followed by those from the 31-month treatment (p<0.05), indicating that immobilised ¹⁵N was more remineralisable in the samples with ¹⁵N labelled for 24 hours. The percentage of applied N found in the total N mineralised (net) ranged from 76.6 to 87.4%, 13.1 to 42.0% and 10.6 to 14.0% in samples from the 24-hr and 7- and 31-month treatments, respectively, showing reduced relative availability of residual N with increased labelling duration. The carbon mineralisation rate had the following order: 7-month > 24-hr > 31-month treatment. Net mineralisation of C and N was poorly correlated with each other (r=-0.02, p=0.89). Anaerobic incubation showed net mineralisation for the 7- and 31-month treatments but net immobilisation for the 24-hr treatment for both total and applied N, suggesting that immobilisation of inorganic N was encouraged when there was a large pool of mineral N in the soil. Both total and applied N in the extractable organic N fraction and in the N flushed after fumigation with chloroform had the following order: 24-hr > 7-month > 31-month treatment. The results confirmed that N fertiliser was being immobilised within hours after application by the humus material through the microbial population and that the immobilised N had a low mineralisation potential after one growing season.     

Ectoparasitic insects of bats in British Columbia, Canada

One species of parasitic bug (Hemiptera : Cimicidae), 3 species of fleas (Siphonaptera: Ischnopsyllidae), and 2 species of parasitic flies (Diptera : Nycteribiidae) were collected from 9 species of bats (Chiroptera : Vespertilionidae) in southern interior and northeastern British Columbia, Canada. Female bats that return daily to maternity roosts were more frequently infested with both cimicids and ischnopsyllids than were male bats. Some differences in ectoparasite infestation can be attributed to differences in roosting behavior of the host. New national records for 2 parasite species, and 8 new host records are established for Canada.     

Oribatid mite communities in the canopy of montane Abies amabilis and Tsuga heterophylla trees on Vancouver Island, British Columbia

To study the oribatid mite community inhabiting microhabitats in the canopy of montane Abies amabilis [(Douglas ex D. Don) Lindl.] and Tsuga heterophylla [(Raf.) Sarg] tree species across five elevational sites, we collected 180 branch tips and 180 foliose/crustose lichen samples over three time periods. Thirty-three species of oribatid mites were identified from the study area. Mite species richness and abundance was significantly affected by microhabitat, and this association was independent of sampling time. At the microhabitat scale, distinct species assemblages were associated with lichen and branch tip habitats, and to a lesser degree, tree species. Conifer specificity was most apparent in the closely related species of Jugatala, where Jugatala tuberosa Ewing was only found on branch tips from A. amabilis and Jugatala sp. was primarily found on branch tips from T. heterophylla. Microhabitat specificity was most pronounced in Dendrozetes sp. where most individuals were found on branch tips and Anachiperia geminus Lindo et al. that occurred primarily on lichens. Principal components analysis of oribatid mite community composition further showed a high degree of association with microhabitat and tree species. Habitat profiles are difficult to discern for many species because tree, microhabitat, and elevation preferences confound distribution patterns. Given the significant tree-microhabitat associations in species composition in this montane canopy study, we suggest that sampling multiple microhabitats across elevations to look for patterns in community structure offers opportunities to explicitly test organizing principles in community ecology.     

Margaretbarromyces dictyosporus gen. sp. nov.: a permineralized corticolous ascomycete from the Eocene of Vancouver Island, British Columbia

A single, permineralized ascoma resembling a pseudothecium assignable to the Pleosporales is described from the Eocene Appian Way fossil locality on Vancouver Island, British Columbia. The ascoma is globose, ostiolate, and erumpent on a fragment of the bark from an unidentified seed plant. Basally arranged asci contain large, multicelled, obovate ascospores within a single cavity or locule enclosed by a two-layered pseudoparenchymatous tissue that ostensibly represents ascostroma. Given this interpretation of the specimen's morphological features, Margaretbarromyces dictyosporus gen. sp. nov. represents the first report of a corticolous pleosporalean ascoma in the fossil record.