Tony J. Pitcher

Tony J. Pitcher
University of British Columbia - Vancouver | UBC · Institute for the Oceans ad Fisheries

Doctor of Philosophy

About

387
Publications
116,997
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22,646
Citations
Additional affiliations
January 1993 - present
University of British Columbia - Vancouver
Position
  • Professor
January 1993 - July 2017
University of British Columbia - Vancouver
Position
  • Professor

Publications

Publications (387)
Article
Pacific herring (Clupea pallasii) is a schooling planktivorous fish consumed by numerous fish, seabirds, and marine mammals. This paper aimed to determine whether Pacific herring serves as a key forage fish (i.e. strongly supports predator populations) in the southeastern Gulf of Alaska. All analyses were conducted using mass- and energy-balanced e...
Article
Pacific herring (Clupea pallasii) plays an important and multifaceted role in the Northeast Pacific as a forage fish in coastal ecosystems, target species for commercial fisheries, and culturally significant subsistence resource for coastal communities. This study comparatively evaluated herring fisheries management strategy performance relative to...
Article
Full-text available
This paper examines the structure and dynamics of the marine ecosystem surrounding Haida Gwaii (an archipelago in the southeastern Gulf of Alaska). Based on previous research, a set of improved mass-balanced models was constructed in Ecopath with Ecosim (EwE) to represent ecosystem states existing circa 1900, 1950, and currently. These models featu...
Article
We respond in detail to the criticisms that our paper employed unreliable data and that our methods are not credible. Our necessarily confidential sources (over 120 interviews) describe the procedures being used in laundering 27 IUU fish products, including US pollock and Russian crab, destined for the Japanese seafood market. We describe serious s...
Article
Full-text available
Bycatch in fisheries can have profound effects on the abundance of species with relatively low resilience to increased mortality, can alter the evolutionary characteristics and concomitant fitness of affected populations through heritable trait-based selective removals, and can alter ecosystem functions, structure and services through food web trop...
Article
An investigation of illegal and unreported fishing in source countries, including product mixing during movement through intermediary countries and reprocessing in the product supply chain, indicates that 24–36% of 2.15 million tonnes of wild-seafood imports to Japan in 2015 contained material of illegal and unreported origin, valued at $1.6 to $2....
Article
Full-text available
This paper analyzes the trophic role of Pacific herring, the potential consequences of its depletion, and the impacts of alternative herring fishing strategies on a Northeast Pacific food web in relation to precautionary, ecosystem-based management. We used an Ecopath with Ecosim ecosystem model parameterized for northern British Columbia (Canada),...
Data
Basic Ecopath parameters. (XLSX)
Data
Basic Ecosim parameters. (XLSX)
Data
Ecosim time series matrix. (XLSX)
Data
Sensitivity analyses, supplementary references and figures. (DOCX)
Article
Full-text available
The ecological importance of Pacific herring (Clupea pallasii) in the Northeast Pacific was re-evaluated by accounting for its high average energy content. An existing mass-balanced Ecopath food web model focusing on northern British Columbia waters was converted into a set of energy-balanced models using published energy content values for all fun...
Article
An investigation of illegal and unreported fishing in source countries indicates that 24–36% of 2.15 million tonnes of wild-seafood imports to Japan in 2015 were of illegal and unreported origin, valued at $1.6 to $2.4 billion, out of a total import of US$ 13 billion. A supply chain case study of crab imported from Russia illustrates the intricacie...
Article
Full-text available
We present a comprehensive analysis of estimation of fisheries Maximum Sustainable Yield (MSY) reference points using an ecosystem model built for Mille Lacs Lake, the second largest lake within Minnesota, USA. Data from single-species modelling output, extensive annual sampling for species abundances, annual catch-survey, stomach-content analysis...
Data
Parameterization of Mille Lacs Lake ecosystem model. (PDF)
Data
Ecosim model fitting from 1985 to 2006. The dots are the observations and the lines are the Ecosim predictions. Prediction lines that exactly follow the dots are forced biomasses. (TIF)
Chapter
Full-text available
OVER THE PAST 150 years, herring—an iconic small, silvery fish—has had a profound influence on the ecology, economy, and culture of Can-ada's Pacific coast. British Columbia Coastal First Nations celebrate the crucial ecosystem role of these " silver darlings, " which provide sustenance for many marine mammals, predatory fish, and seabirds, and—thr...
Article
Full-text available
The Marine Strategy Framework Directive intends to adopt ecosystem-based management for resources, biodiversity and habitats that puts emphasis on maintaining the health of the ecosystem alongside appropriate human use of the marine environment, for the benefit of current and future generations. Within the overall framework of ecosystem-based manag...
Technical Report
Full-text available
We here present a fitted and partly validated Ecopath with Ecosim model for the Norwegian Sea and Barents Sea. Ecopath mass-balance model parameters were obtained from the literature on Norwegian and Barents Sea organisms and from approximations. Predator-prey vulnerability parameters for Ecosim were fitted by driving a past state model balanced fo...
Article
Full-text available
This report describes the structure and workings of an Ecopath with Ecosim (EwE) ecosystem model for the waters surrounding Haida Gwaii, British Columbia. The model area lies in the southernmost part of the Gulf of Alaska Large Marine Ecosystem, and hence is predominantly boreal in species composition, although with more commonalities with the Cali...
Article
Full-text available
Zoning of marine space is increasingly used to reconcile conflicting socio-economic and conservation goals for marine resources: marine spatial planning entails appraisal of the outcomes of ecosystem-based trade-offs by stakeholders. This report gives the results of a pilot study using state-of-the-art, spatial ecosystem modelling of potential mari...
Technical Report
Full-text available
Chapter
This chapter surveys the principal assessment frameworks and associated modelling used in freshwater fisheries. Although modelling and assessment techniques are similar, the average freshwater fishery has about one tenth of the catches, value, food production and livelihoods of the average marine fishery. Significant exceptions are major fisheries...
Chapter
This chapter analyses synoptically biological indicators (relation between the growth parameters K and L∞ and growth performance index φ(symbol)'), fishery indicators (annual catches from 1960 to 2012) of the species of Merluccius and Macruronus included in previous chapters of this book, as well as economic indicators (prices of the main products)...
Article
Knowing where and how seafood is caught or farmed is central to empowering consumers, and the importers that supply them, with informed choices. Given the wide-ranging, complex and at times commercially sensitive nature of global seafood trade, it can prove very challenging to link imported seafood with information about its provenance. The databas...
Article
Only in the last century did humans overwhelmingly accept that fisheries resources are finite. Consequently, ‘there are more fish still in the sea than ever came out of it’ served as a popular metaphor for unbounded expectations for half a millennium, expectations that also extended to use of the planet in general. By reconstructing historical fish...
Article
Full-text available
The recovery of whale populations from historical depletion may have the potential to noticeably affect Northeast Pacific ecosystems and fisheries. Surplus production models based on whaling catch records were used to reconstruct the historical abundances of five large whale species in the waters surrounding Haida Gwaii, British Columbia. The resul...
Article
Full-text available
The aim of this study was to examine the ecological plausibility of the "krill surplus" hypothesis and the effects of whaling on the Southern Ocean food web using mass-balance ecosystem modelling. The depletion trajectory and unexploited biomass of each rorqual population in the Antarctic was reconstructed using yearly catch records and a set of sp...
Article
Full-text available
Humanity’s relationship with fish dates back to prehistory, when ancestral hominins evolved the capacity to exploit aquatic resources. The impacts of early fishing on aquatic ecosystems were likely minimal, as primitive technology was used to harvest fish primarily for food. As fishing technology became more sophisticated and human populations disp...
Article
Full-text available
Illegal and unreported catches represented 20–32% by weight of wild-caught seafood imported to the USA in 2011, as determined from robust estimates, including uncertainty, of illegal and unreported fishing activities in the source countries. These illegal imports are valued at between $1.3 and $2.1 billion, out of a total of $16.5 billion for the 2...
Article
The data requirements for most quantitative fishery assessment models are extensive, and most of the fisheries in the world lack time series of the required biological and socioeconomic data. Many innovative approaches have been developed to improve data collection for fisheries. We explored the use of data from fishers' interviews to estimate time...
Article
Full-text available
This paper reports recent developments in Rapfish, a normative, scalable and flexible rapid appraisal technique that integrates both ecological and human dimensions to evaluate the status of fisheries in reference to a norm or goal. Appraisal status targets may be sustainability, compliance with a standard (such as the UN code of conduct for respon...
Conference Paper
Background/Question/Methods The dismal state of world fisheries today reflects humanity's moral failure to maintain ecosystem health and productivity, while benefitting from nature's goods and services. Accelerating depletion of fishery resources jeopardizes not only ecological integrity, but also social justice. This raises ecological ethics iss...
Conference Paper
Background/Question/Methods Cisco, Coregonus artedi, is a coregonid forage fish widely distributed in central and northern Minnesota. Since the 1980s, the large 537km2 Mille Lacs Lake, Minnesota, has experienced a decline in its cisco population. As cisco is a cold water stenotherm, the population decline has been attributed to an increase in the...
Conference Paper
Background/Question/Methods Mille Lacs is a large 537km2, shallow glacial lake in northern Minnesota that supports important native (Ojibwe) and recreational fisheries. As part of an initiative in ecosystem-based management, the Minnesota Department of Natural Resources provided extensive field data that allowed the construction of a whole-ecosys...
Article
Mille Lacs Lake, Minnesota, has experienced a decline in the population of Cisco Coregonus artedi since the 1980s. Cisco is a coldwater stenotherm, and the population decline is often attributed to a general increase in the lake temperature. However, there also has been a fishery for this species during the last 20 years. To investigate the influen...
Article
Full-text available
This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (north-east Atlantic Ocean) and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in situ research, iden...
Article
Proposals for marine conservation measures have proliferated in the last 2 decades due to increased reports of fishery declines and interest in conservation. Fishers and fisheries managers have often disagreed strongly when discussing controls on fisheries. In such situations, ecosystem-based models and fisheries-stock assessment models can help re...
Article
Full-text available
This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (northeast Atlantic Ocean) and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in situ research , iden...