Dave Preikshot

• PhD
• Researcher at Fisheries and Oceans Canada

The population dynamics of chinook salmon (Oncorhynchus tshawytscha) from the Cowichan River on Vancouver Island, British Columbia, Canada are used by the Pacific Salmon Commission as an index of the general state of chinook salmon coast wide. In recent years the production declined to very low levels despite the use of a hatchery that was intended...

Mortality in the early marine period in a particular habitat is related to the severity of the factors causing mortality and the time that juvenile Pacific salmon Oncorhynchus spp. spend in the habitat. Juvenile sockeye salmon O. nerka produced in the Fraser River rear in the Strait of Georgia immediately upon leaving freshwater. We used catches fr...

In 2007 all juvenile Pacific salmon that entered the Strait of Georgia in the spring had poor growth or poor survival or both. Adult coho salmon that returned the next year had the lowest survival ever recorded. Adult chum salmon from the brood year that returned in 2010 also had extremely poor survival. Juvenile Pacific herring had very poor survi...

The marine survival of juvenile coho salmon Oncorhynchus kisutch from the time they enter the Strait of Georgia in mid-May to the time of our trawl survey in mid-September declined from an average of about 15% in 1998 to approximately 1% in 2007. Early marine survival rates for juvenile coho salmon have been consistently low (<5%) since 2002, and t...

The Model for Assessing Links Between Ecosystems (MALBEC) is a policy gaming tool with potential to explore the impacts of climate change, harvest policies, hatchery policies, and freshwater habitat capacity changes on salmon at the North Pacific scale. This article provides background information on the MALBEC project, methods, input data, and pre...

For the overwhelming majority of species, we lack long‐term information on the dynamics of populations. As a consequence, we face considerable uncertainty about how to discriminate among competing hypotheses of population decline and design conservation plans. The marbled murrelet Brachyramphus marmoratus is a small seabird that nests in coastal ol...

Although ecosystem-based management can lead to sustainable resource use, its successful implementation depends on stakeholders’ acceptance. A framework to integrate scientific knowledge about the ecosystems with stakeholders’ preferences is therefore needed. We propose here a ‘Public Sentiment Index,’ or PSI, as an integration framework that combi...

Data from biological, economic, sociological, and technological attribute lists for 32 African lake fisheries were analysed with multivariate statistics. Multidimensional scaling (MDS) was used to create two-dimensional graphic ordinations of the fisheries for each of these four attributes lists. An overall MDS ordination was also generated, based...

rapfish is a new multi-disciplinary rapid appraisal technique for evaluating the comparative sustainability of fisheries. For the purpose of this analysis, fisheries may be defined flexibly as entities with a broad scope, such as all the fisheries in a lake, or with narrower scope, such as those in a single jurisdiction, target species, gear type o...

The mean trophic level (TL) of fish landed in fisheries on the east and west coasts of Canada is declining by 0.03-0.10·decade-1, similar to global trends. This finding is based on data from United Nations Food and Agriculture Organization and the Canadian Department of Fisheries and Oceans and other Canadian sources for the period 1873-1997. Signi...

A better understanding of the whole Prince William Sound (PWS) food web and its dynamics was achieved by constructing a balanced trophic model using the Ecopath approach. The PWS model was a cohesive synthesis of the overall biotic community with a focus on energy flow structure, and response to perturbations, both natural and anthropogenic. Forty-...

This paper presents a multidisciplinary approach for the comparative eval- uation of small-scale tropical fisheries. Previously, these most often have been studied within single disciplines of the social or natural sciences, rarely leading to broad comparisons. Here, multidimensional scaling, ca- nonical correlation, and cluster analysis were used...

This chapter describes a new multivariate, multidisciplinary and interdisciplinary rapid appraisal technique that can be used to classify world fisheries and diagnose their problems. For ecological, technological, economic and social categories, we chose 15–25 attributes that (a) are easily and objectively scored on a ranked scale using readily ava...