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Your search for Ecological processes returned 67 records. Showing Records 26 to 55. Please Select a Record to View.

 

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Title: The Effects of Variable Removal Levels of the Sea Urchin, Strongylocentrotus faciscanus, on near-shore rocky communities in the traditional territory of the Hesquiat First Nation

Year: 2001

Author(s): Robert C. Mooney, California State Polytechnic University

Type: Academic Thesis

Description:
The shallow subtidal regions near Hot Springs Cove, Vancouver Isalnd, British Columbia are characterized by large rocky areas dominated by the red sea urchin, Strongylocentrotus franciscanus. S. franciscanus were removed at three sites with four levels of urchin removal per site. Manipulations of urchin density were maintained throughout the experiment and monitored seasonally for two seasons pre-treatment and seven seasons post-treatment. The manipulations resulted in increased gonad indices of remaining red sea urchins and caused the conversion of urchin dominated subtidal regions into kelp dominated communities with greater fish abundance. As well, a feeding experiment illustrated that the depressed gonad indices of field-collected urchins resulted from limited food resources in areas of high urchin density. The removal of sea urchins at all levels results in a rapid increase in the presence of laminarialean algal species (kelps). Study plots where all urchins were removed developed a dense understory and seasonal canopy of kelps with little bare rock remaining. Intermediate levels of removal resulted in a mosaic of smaller urchin-dominated and kelp-dominated patches. Control plots tended to maintain the urchin-dominated barrens-state throughout the study period. Sea urchins that were fed M. intergrifolia during the feeding experiment showed 2.9 and 2.4 times greater gonadal development by weight than urchins collected from the field before and after the feeding trial, respectively. These results suggest that food limitation is an important factor in the gonadal development of this urchin population. Findings suggest that with supplemental feeding, the resource base of sea urchins could be expanded to include barren habitats. The removal of S. franciscanus at all levels results in an increase in the fecundity (measured as gonad index) for the sea urchins that remained, as well as for the urchins that reinvaded the total removal plots. All study plots showed an increase in gonad index over time, but the increase in gonad index was statistically greater for urchins in removal plots versus the control plots. The results indicate that small isolated urchin removals can have measurable effects on the fishery value of nearby urchins. Of the seven fish species monitored, pile perch, striped seaperch, kelp perch and black rockfish were most associated with kelp forest habitat. Kelp greenling, lingcod and copper rockfish showed no association with kelp forest habitat. The experimental approach taken indicates that sea urchin removal, and subsequent kelp growth, determined relative fish abundance. High densities of S. franciscanus appear to be responsible for the absence of kelp forest habitat in the region, the depressed fecundity (gonad index) of S. franciscanus, and the abundance of some fish species. The effect of urchin removal is discussed in regards to the implications for ecological theory as well as sea urchin fisheries management.

 

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Title: Foraging patterns of gray whales in central Clayoquot Sound, British Columbia, Canada

Year: 2001

Author(s): Jason S. Dunham, Whale Research Laboratory, UVic; David A. Duffus, Whale Research Laboratory, UVic

Type: Journal Article

Description:
Gray whales, Eschrichtius robustus, forage in parts of Clayoquot Sound on several prey species in different habitats. Between June and September in 1996 and 1997 we carried out analyses of the density, biomass and other measures of their primary prey species, and of whales' movement patterns in response to prey characteristics. The prey base consists of hyper-benthic mysids (family Mysidae), pelagic porcelain crab larvae (4 spp. of family Porcellanidae), benthic amphids (family Ampeliscidae) and benthic ghost shrimp, Callianassa californiensis. Whales foraged primarily for mysids, switch to porcelain crab larvae in August, and then to amphipods even later in teh season when these organisms increased in body size. In 1997, whales rapidly switched from feeding on planktonic to benthic prey during mid-August. Sampling indicated low numbers of mysids and crab larvae at that time. Selection of amphipod prey was based on high biomass and a high proportion of individuals less than 6 mm in length. In parts of the study area gray whales did not return to forage on benthic amphipods when this size criteria was not met. A single whale departed from a ghost shrimp feeding ground because its search time for food was long, it achieved only a low biomass removal rate, and it was not able to find sufficient food each day. We show that gray whales are dynamic and selective foragers that switch prey and foraging tactics rapidly to take advantage of short-term availability of energy.

 

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Title: Variations in gray whale feeding behaviour in the presence of whale-watching vessels in Clayoquot Sound.

Year: 2000

Author(s): Joanna Bass

Type: Academic Thesis

Description:
The growing industry of whale-watching is allowing increasing numbers of people access to whales in their natural environment, and constitutes a non-consumptive use of the whales compared to whaling. At the same time, questions are often raised about the hidden effects of whale-watching on the whales. Ph.D. Thesis, University of Victoria

 

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Title: Cypre Hydrometric and Climate Inventory Project: 2000 Inventory Report

Year: 2000

Author(s): Long Beach Model Forest Society

Type: Report (unpublished)

Description:
"This document is the 2000 inventory report for the Cype hydrometric and climate station. The report provides the site description, data collection methodology, summarized precipitation, air temperature, discharge, turbidity and water temperature data for the Cypre station for the year 2000 (p1)

 

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Title: Gray whale prey and whale distributions in Clayoquot Sound, British Columbia.

Year: 1999

Author(s): Jason Scott Dunham

Type: Academic Thesis

Description:
Planktonic and benthic gray whale prey species were studied in Clayoquot Sound,Vancouver Island, British Columbia, Canada (1996-97). M.Sc. Thesis, University of Victoria

 

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Title: The Canadian system of Soil Classification

Year: 1998

Type: Book

Description:
none

 

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Title: Natural Cd and Pb variations in Mytilus californianus during the upwelling seasons

Year: 1997

Author(s): M. Lucila Lares; Kristin J. Orians

Type: Journal Article

Description:
The short term variability of Cd and Pb in Mytilus californianus in relation to upwelling events was studied. Sea water and mussel samples were taken daily for 4 weeks during the upwelling season (late summer) on the west coast of Vancouver Island. Upwelling indicators were measured and related to the variations in dissolved Cd and Pb in sea water. High variability in Cd and Pb mussel concentrations were detected, with significant differences found from one day to another. After normalizing, to account for the variability due to the condition of the mussel, significant differences among samples were still detected. The differeneces in mussel Cd were associated with the variations in dissolved Cd due to upwelling. Mussel Pb, however, was not related to variations in dissolved Pb. Principal component analysis was used to unravel patterns of variation among all variables measured. Parallel to the sampling of natural mussel beds, a transplant experiment was performed to compare the variability of intertidal vs. subtidal mussels. The trasnplnated mussels exhibited a less variable condition index and revealed more clearly the relation of dissolved Cd with the concentrations in the mussels. Lead in mussels, again, did not show a relationship with dissolved Pb. In addition, the mantle edge (from 3 days with highest and lowest Cd concentrations) was analyzed as an alternative indicator which could exhibit less variability. The Cd variability in the mantle edge was compared with that of the gills and the remainder. The mantle edge, even though it showed less variability that the gills and the remainder, still exhibited significant differences between days.

 

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Title: British Columbia: A Natural History

Year: 1996

Author(s): Richard Cannings; Sydney Cannings

Type: Book

Description:
none

 

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Title: Managing Forest Ecosystems to conserve Fungus Diversity and Sustain Wild Mushroom Harvests

Year: 1994

Type: Book

Description:
none

 

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Title: Natural Disturbances in Clayoquot Valley and Characterization of Wind Disturbance in Clayoquot Sound

Year: 1994

Author(s): Audrey Pearson

Type: Report (unpublished)

Description:
none

 

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Title: Hesquiaht Nation Herring Survey 1992

Year: 1992

Author(s): Phillip Rhem

Type: Report (published)

Description:
From the introduction:"As a preliminary step in understanding the ecosystem of the Hesquiat territory, we collected information on the migration and spawning of pacific herring..."

 

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Title: The ecology, status, and conservation of marine and shoreline birds on the west coast of Vancouver Island.

Year: 1992

Author(s): Kees Vermeer

Type: Proceedings

Description:
"This book presents the proceedings of a symposium on the ecology, status and conservation of marine and shoreline birds on the west coast of Vancouver Island. The symposium was held on 8 April 1991 at the Institute of Ocean Sciences, Sidney, BC. The objective of the symposium was to combine various discipline to provide a review of what is currently known about the marine biology of the west coast of Vancouver Island, with a particular emphasis on birds.

 

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Title: Coastal Temperate Rain Forests: Ecological Characteristics, Status and Distribution Worldwide

Year: 1992

Author(s): Jim Weigand; Andy Mitchell; Dennis Morgan

Type: Report (unpublished)

Description:
Ecotrust and Conservational International have prepared this document for the explicit purpose of soliciting comments from researchers and managers working in coastal temperate rain forests around the world. We have developed a global GIS database to assess the distribution and status of coastal temperate rain forests, and so that new information can be incorporated in the database as it becomes available. This report presents conflicting estimates of the areal extent of coastal temperate rain forests as a result of different methods and information sources. We hope that readers will inform us of any errors or additional data that would help us refine and update the global database, and to build future regional databases. This report includes preliminary maps illustrating the "original" extent of coastal temperate rain forests. We define original as post-glaciation, pre-human settlement. In many regions, this admittedly translates to pre-colonial settlement.

 

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Title: The physical oceanography of the west coast of Vancouver Island

Year: 1991

Author(s): Howard Freeland

Type: Proceedings

Description:
Abstract: The physical oceanography of the west coast of Vancouver Island is reviewed, with emphasisi on those aspects that might affect the behaviour of marine birds. pp10-14.

 

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Title: Zooplankton on the west coast of Vancouver Island: distribution and availability to marine birds

Year: 1991

Author(s): David Mackas, Canadian Wildlife Service; Moira Galbraith, Canadian Wildlife Service

Type: Proceedings

Description:
Abstract: The outer coast of Vancouver Island is biologically highly productive because of large summer inputs of upwelled nutrients and resulting dense phytoplankton blooms. The resident zooplankton populations are well fed from spring through autumn; their seasonal cycle and spatial distribution are set largely by advective patterns and bathymetry. pp15-21.

 

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Title: Distribution, abundance, and habitat of prey fish on the west coast of Vancouver Island

Year: 1991

Author(s): Douglas Hay; Michael Healey; Daniel Ware; Norman Wilimovsky

Type: Proceedings

Description:
Abstract: The distribution, abundance and habitat of the major fish species on the west coast of Vancouver Island are reviewed in the context of availability to seabirds. pp22-29.

 

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Title: Invertebrate fisheries and their possible conflicts with marine birds

Year: 1991

Author(s): Neil Bourne

Type: Proceedings

Description:
abstract: Marine invertebrate resources in British Columbia support valuable commercial fisheries and are also used in the recreational fishery...A brief description of the habitat of marine invertebrates in commercial fisheries along the west coast of Vancouver Island is presented, along with a summary of the fisheries. Possible conflicts with marine birds are also identified. pp30-36.

 

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Title: Factors affecting the distribution of kelp and its importance as a food source.

Year: 1991

Author(s): Robert DeWreede

Type: Proceedings

Description:
abstract: Kelp beds form a major habitat in many near-shore marine sites in British Columbia. The abundance and distribution of kelps are determined in part by such factors as salinity, light and temperature and by herbivores, such as sea urchins and limpets. Sea otters Enhydra lutris influence kelp distribution by consuming urchins. Together these factors determine the age (and hence size and stage) and structure of kelp stands. Birds are predators of organisms that live in kelp beds, but almost nothing is known of kelp-bird interactions in British Columbia. pp37-40.

 

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Title: The diet of birds as a tool for monitoring the biological environment.

Year: 1991

Author(s): Kees Vermeer, Canadian Wildlife Service

Type: Proceedings

Description:
abstract: A review of the diet of marine birds in nesting colonies, in estuaries, in inlets and over offshore banks along the west coast of Vancouver Island indicates that little is known of the diet of most nesting seabirds, except for the major nexting species. pp41-50.

 

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Title: Population trends of Pelagic Cormorants and Glaucous-winged Gulls nesting on the west coast of Vancouver Island.

Year: 1991

Author(s): Kees Vermeer; Ken Morgan; Peter Ewins

Type: Proceedings

Description:
abstract: In 1989, the numbers of nesting Pelagic Cormorants Phalacrocorax pelagicus and Glaucous-winged Gulls Larus glaucescens on the west coast of Vancouver Island were censused, and the reproductive success of 16 gull colonies was investigated. pp60-64

 

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Title: Population, nesting habitat, and reproductive success of American Black Oystercatchers on the west coast of Vancouver Island.

Year: 1991

Author(s): Kees Vermeer; Ken Morgan; Peter Ewins; G.E. John Smith

Type: Proceedings

Description:
abstract: The nesting population of American Black Oyster-catchers Haematopus bachmani was censused and their island and nest site habitat were investigated in Barkley Sound and in the Flores Island-Cape Beale region of the west coast of Vancouver Island in 1989. pp65-70.

 

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Title: Marbled Murrelet activity patterns in the Carmanah Valley on the southwest coast of Vancouver Island.

Year: 1991

Author(s): Irene Manley; Robyn Shortt; Alan Burger

Type: Proceedings

Description:
abstract: Inland observations of Marbled Murrelets Brachyramphus marmoratus were made in the Caramanah Valley on the southwest coast of Vancouver Island during the summer of 1990.pp71-75.

 

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Title: Habitat analysis and co-occurrence of seabirds on the west coast of Vancouver Island.

Year: 1991

Author(s): Kees Vermeer; Ken Morgan; G.E. John Smith

Type: Proceedings

Description:
abstract: The distribution of pelagic birds on the west coast of Vancouver Island was related to physical and biological parameters and co-occurrence of bird species during spring, summer and fall. Twenty-six significant correlations of pelagive birds with water depth 31 with distance from land, 18 with surface salinity, and 20 with surface temperature were observed. pp.78-85.

 

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Title: Marine bird populations and habitat use in a fjord on the west coast of Vancouver Island.

Year: 1991

Author(s): Kees Vermeer; Ken Morgan

Type: Proceedings

Description:
abstract: Marine bird populations in Alberni Channel were surveyed monthly from September 1987 through August 1988. pp86-96.

 

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Title: Bird populations of estuaries on the southwest coast of Vancouver Island.

Year: 1991

Author(s): Kees Vermeer; Ken Morgan; Adrian Dorst; Bruce Whittington

Type: Proceedings

Description:
abstract: The species composition and population of water birds were investigated in eight estuaries on the southwest coast of Vancouver Island: Sooke Harbour, Sarita River, Somass River, Barkley Sound estuarine area, and four small estuaries in Clayoquot Sound. pp97-108.