R.J. Beamish

R.J. Beamish
Fisheries and Oceans Canada | DFO · Pacific Biological Station

Doctor of Philosophy

About

391
Publications
60,901
Reads
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13,961
Citations
Additional affiliations
November 1974 - present
Fisheries and Oceans Canada
Position
  • Emeritus Scientist
November 1974 - present
Fisheries and Oceans Canada
Position
  • Scientist Emeritus

Publications

Publications (391)
Article
The commercial and recreational fishery for Coho Salmon Oncorhynchus kisutch in the Strait of Georgia in the 1970s and 1980s that annually averaged 733,800 individuals declined in the 1990s and was closed in 1998. We observed that above a threshold, ocean carrying capacity is regulating production and not the number of juvenile Coho Salmon entering...
Chapter
Pink salmon Oncorhynchus gorbuscha have the smallest body size at maturity, the lowest fecundity, and the shortest life cycle duration among the Pacific salmon. However, it is the most abundant in spawning stocks and widely distributed Pacific salmon. As a biological species, pink salmon emerged about 5 million years ago and is likely the most rece...
Chapter
The historical trends in Canadian Atlantic and Pacific fish stocks and fisheries are reviewed, as is the contribution of fisheries and aquaculture to Canadian coastal economies historically and in the present. Recent trends in oceanographic conditions are reviewed, with a focus on temperature and salinity profiles and currents on both coasts. Ocean...
Article
The Larkin lectures are held every two years at the University of British Columbia in recognition of Dr. Peter Larkin's contributions to fisheries science. The lecture I presented in November 2015 coincided with an announcement that the Institute of Fisheries that Peter Larkin founded in the 1960s would be restructured as the "Institute for Oceans...
Article
Full-text available
The Pacific Lamprey Entosphenus tridentatus, an anadromous fish native to the northern Pacific Ocean and bordering freshwater habitats, has recently experienced steep declines in abundance and range contractions along the West Coast of North America. During the early 1990s, Native American tribes recognized the declining numbers of lamprey and cham...
Article
The variation at 17 microsatellites was analyzed for 5,270 juvenile Coho Salmon Oncorhynchus kisutch obtained from coastal British Columbia and Gulf of Alaska surveys during 1998–2012. A 270-population baseline was used to determine the individual identifications of the fish sampled, with individuals being identified to 22 stocks of origin. Columbi...
Article
Full-text available
Variation at 17 microsatellites was analyzed for 5,270 juvenile Coho Salmon (Oncorhynchus kisutch) obtained from coastal British Columbia and Gulf of Alaska surveys during 1998-2012. A 270-population baseline was used to determine the individual identification of the fish sampled, with individuals identified to 22 stocks of origin. Columbia River a...
Article
Full-text available
During a study of the early marine survival of Chinook Salmon Oncorhynchus tshawytscha and Coho Salmon O. kisutch in the Strait of Georgia from 1998 to 2010, moderate abundances of juvenile Sockeye Salmon O. nerka were observed to remain in the strait much longer than previously thought. In 2008, DNA stock identification showed that these juveniles...
Book
Full-text available
Hagfishes and lampreys, both examples of jawless fishes, are elongated, eel-like animals lacking paired fins, and are the only living representatives of ancient creatures that gave rise to current species of fish and, eventually, humans. This volume provides an overview of the current status of knowledge on a variety of topics related to jawless f...
Book
Full-text available
Hagfishes and lampreys, both examples of jawless fishes, are elongated, eel-like animals lacking paired fins, and are the only living representatives of ancient creatures that gave rise to current species of fish and, eventually, humans. This volume provides an overview of the current status of knowledge on a variety of topics related to jawless f...
Article
It is well known that current equilibrium-based models fall short as predictive descriptions of natural ecosystems, and particularly of fisheries systems that exhibit nonlinear dynamics. For example, model parameters assumed to be fixed constants may actually vary in time, models may fit well to existing data but lack out-of-sample predictive skill...
Article
Full-text available
The collapse of the commercial fishery and the major decline in catches in the recreational fishery for Chinook Salmon Oncorhynchus tshawytscha in the Strait of Georgia since the mid-1990s represents a major economic loss to British Columbia. Early marine residence is critical for survival of Chinook Salmon, but measuring the amount of mortality ha...
Article
Full-text available
We outlined the route and relative timing of juvenile Sockeye Salmon Oncorhynchus nerka migration by analyzing stock composition and relative CPUE in marine sampling conducted in coastal British Columbia and the Gulf of Alaska. Variation at 14 microsatellites was analyzed for 10,500 juvenile Sockeye Salmon obtained from surveys conducted during 199...
Conference Paper
Morrison Creek lamprey (Lampetra richardsoni variety marifuga) is found in Morrison Creek, Vancouver Island. It is the only known representation of an intermediate phase between parasitic and non-parasitic lamprey. It is listed as endangered and requiring protection, but studies have shown a possible decrease in abundance of >90% over the past 25 y...
Conference Paper
Pacific lamprey and river lamprey are caught incidentally in trawls used to catch juvenile Pacific salmon in the Strait of Georgia. Both species could escape through the meshes in most of the net except for the small mesh at the cod end. Thus, we propose that the catches of lamprey probably are a relative index of abundance among years. From 1998 t...
Article
Full-text available
The variation at 14 microsatellites was analyzed for 10,500 juvenile Sockeye Salmon Oncorhynchus nerka obtained from coastal British Columbia and Gulf of Alaska surveys during 1996–2011. A 404-population baseline was used to determine the individual identifications of the fish sampled, with individuals being identified to 47 populations or stocks o...
Conference Paper
The Fraser River is 1,375 km in length, with the 3rd greatest mean annual flow in Canada, and is one of the major salmon producing rivers of the world. It drains an area of 234,000 km2, the 5th largest drainage in Canada, ¼ of the area of the Province of British Columbia, flowing into the ocean through the City of Vancouver. The dominant organism i...
Article
Full-text available
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...
Article
Full-text available
Record low returns of sockeye salmon Oncorhynchus nerka to the Fraser River in 2009 were followed by record high returns to the river in 2010, providing an unprecedented opportunity to examine links between oceanic factors and the survival of Pacific salmon stocks. The low returns in 2009 indicated poor early marine survival of juvenile sockeye sal...
Article
Full-text available
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...
Article
Full-text available
Trawl studies from 1998 to 2009 indicated that juvenile Pacific salmon Oncorhynchus spp. and Pacific herring Clupea pallasii represented 98% of the fish in the surface waters of the Strait of Georgia during the day in the spring and early summer. Standardized catches of all juvenile Pacific salmon in the trawl surveys were lowest in 2007. Catches o...
Book
The salmon louse Lepeophtheirus salmonis is adapted to survive in hostile marine environments of the northern hemisphere, including an ability to parasitize several species of salmon. Salmonids are some of the most economically important and sought after fish for human consumption, and louse parasitism has a significant impact both on cultured and...
Conference Paper
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...
Conference Paper
Investigations of climate effects on fisheries are typically focused on unidirectional changes in productivity (e.g., decreased recruitment, geographic shifts), but many fishery resources are exhibiting recent increases in variability associated with climate, making forecasts more difficult. Life history strategy is naturally adapted to respond to...
Article
The pH of Lumsden Lake was closely related to the measured amount of acid entering the lake from bulk precipitation. In 1972 it was estimated that an excess of 2135 kg of H2SO4 was added to the lake from the atmosphere. The predicted annual change in lake pH was from 5.2 to 4.8 and the actual measured change was from 5.2 to 4.7. In 1973 an estimate...
Article
Full-text available
High concentrations of zinc and other heavy metals were found in lakes in the immediate vicinity of the Flin Flon smelters. In a study of 31 lakes, 7 had Zn levels above 100 μg/ℓ, 6 had levels between 50 and 100 μg/ℓ, and the remainder had concentrations < 50 μg/ℓ. The accuracy and precision of the heavy metal chemical analyses were evaluated using...
Article
Full-text available
Gila trout, Salmo gilae, has a diploid chromosome complement of 2n = 56 consisting of 49 metacentric and submetacentric chromosomes and 7 acrocentric or telocentric chromosomes. Karyotypes of this and other species of western North American trouts of the genus Salmo suggest that chromosomal modifications are correlated to speciation in this genus....
Article
Full-text available
Cross sections of the 4th–8th fin rays from the second dorsal fin provided reliable ages of lingcod (Ophiodon elongatus), although there was some difficulty interpreting the ages of 1- and 2-yr-old fish. Length was an acceptable indicator of age 1- and 2-yr-old fish. After a scale age of 5 or 6 yr, the scale annulus became difficult to identify. Af...
Article
Full-text available
White (Catostomus commersoni) and longnose (C. catostomus) suckers possess diploid complements of 98 chromosomes, including metacentrics, submetacentrics, and acrocentrics. White sucker karyotypes differ consistently from longnose karyotypes by the presence of an additional four metacentrics. The karyotypes of the size and age at maturity of varian...
Article
Full-text available
A simple, inexpensive fish tag that allows for growth of the fish is described. Growth rates of smallmouth bass were not significantly affected by tagging. The rate of retention on smallmouth bass was much higher than that for a tag described by Fraser but rates of retention of the two tags on largemouth bass were not significantly different. Estim...
Article
Full-text available
The loss of populations of lake trout (Salvelinus namaycush), lake herring (Coregonus artedii), white suckers (Catostomus commersoni), and other fishes in Lumsden Lake was attributed to increasing levels of acidity within the lake. An absence of fishes was also observed in nearby lakes. In some lakes, acid levels have increased more than one hundre...
Article
Full-text available
The use of new materials and a modification of the basic trapnet design produced nets that fished successfully for large and small fishes in areas where conventional collecting techniques were difficult to apply. Parts of the trap can be interchanged to fish at depths of 1–5 m.
Article
Full-text available
The use of the scale method to determine age of mature white suckers should be avoided. Sections of pectoral fin rays can provide accurate age determinations for most populations once the position of the first annulus has been identified. The age of immature white suckers can be estimated by both methods. It is suggested that, for identification of...
Article
Full-text available
White suckers (Catostomus commersoni) in the acidic Lumsden Lake in 1967 and 1968 exhibited reduced annual growth followed by death. The reduced growth and death appeared directly related to the low pH and not to a shortage of food caused by the decreasing pH.
Article
Full-text available
An age-structure model that incorporates recent information regarding growth and reproduction has been developed to investigate the dynamics of spiny dogfish (Squalus acanthias) populations in British Columbia waters. Mechanisms for density-dependent regulation of abundance were evaluated on the basis of theoretical effectiveness and ability to pre...
Article
Full-text available
A comparison of ages determined from surfaces of otoliths and from sections of otoliths showed that ages were similar up to a section age of 22–24 yr. The growth pattern observed on thin sections of otoliths and from broken and burned otoliths from the region of the nucleus was interpreted to indicate that Pacific ocean perch probably live much lon...
Article
Full-text available
We identified years of anomalously high and low discharge from the Fraser River and compared these years with indices of anomalously high and low production of Pacific salmon (Oncorhynchus spp.) and Pacific herring (Clupea pallasi). For chinook (O. tshawytscha) and coho salmon (O. kisutch), we found that brood years that went to sea in a year when...
Article
Full-text available
Otolith microstructure exhibited some characteristic differences between hatchery-reared and wild chinook salmon (Oncorhynchus tshawytscha) from the Cowichan River. Daily growth increments that formed in the otoliths of the hatchery-reared chinook salmon after exogenous feeding were more regular in width and contrast than those in the otoliths of w...
Article
Full-text available
River lamprey (Lampetra ayresi) enter the Strait of Georgia from the Fraser River and feed almost exclusively on Pacific herring (Clupea harengus) and salmon (Oncorhynchus spp.). Although the major prey of river lamprey is Pacific herring, the greater effect of lamprey predation was on the populations of chinook (O. tshawytscha) and coho (O. kisutc...
Article
Full-text available
Anadromous Pacific lamprey, Lampetra tridentata, typically construct nests and reproduce in lotic environments. In the summer of 1984, Pacific lamprey were observed spawning in shallow lentic water in two regions of the Babine Lake system, British Columbia. Nests were subject to wave action but an obvious unidirectional flow was not observed.
Article
Full-text available
Metamorphosis in Lampetra ayresi begins in July but is not completed until approximately April of the following year when the oesophagus opens. The prolonged period of metamorphosis differs from that of other lamprey species and may have evolved in response to the pattern of discharge of the Fraser River. Prior to the opening of the oesophagus, som...
Article
Full-text available
A population of lamprey in a small stream on Vancouver Island, British Columbia, Canada, was shown to contain the nonparasitic Lampetra richardsoni and a parasitic variety.
Article
A total of 72 735 adult sablefish (Anaplopoma fimbria) were tagged and released off the west coast of Canada from 1977 to 1982. As of December 31, 1985, 11 212 (15%) have been recaptured or 16 539 (23%) when recaptures were standardized for differences in recovery effort and unreported recaptures. Off Vancouver Island, relatively few sablefish move...
Article
Full-text available
The construction of dams on the outlet of Elsie Lake, in British Columbia, prevented young adult Pacific lamprey (Lampetra tridentata) from going to sea and adult lamprey from spawning above the dams. This resulted in a high incidence of lamprey attacks on resident trout that was initially interpreted as indicating that the lamprey population was l...
Article
Full-text available
The migration of young adult Lampetra tridentata out of the Nicola River during 1984–85 through 1987–88 was estimated to be approximately 176 000,19 000,90 000, and 102 000; at the same time, approximately 749 000, 909 000, 920 000, and 605 000 large ammocoetes, age 4 and 5 yr, left the river. Migration of young adults started in September, with th...
Article
We present statistical models for estimating the true age distribution of a population, based on multiple readings from individual fish. There are two steps to this process. The first involves estimating a classification matrix that defines the probability of assigning an age a to a fish when its true age is b. Since true age is unknown, we require...
Article
Full-text available
Model simulations revealed that wind mixing was the dominant physical mechanism that added nitrate to the surface layer and subsequently enhanced primary productivity in the Strait of Georgia. Simulations of high Fraser River runoff showed that the enhanced stability of the water column in the vicinity of the riverine plume made wind mixing of nutr...
Article
Full-text available
A reexamination of white sucker populations originally used to document the subspecies validity and biology of a dwarf white sucker, Catostomus commersoni utawana, provided no evidence of two separate populations of different-sized individuals. Small mature white suckers and larger or normal-sized white suckers still were present, but there was a c...
Article
Full-text available
Ripening ovaries of Pacific hake from the Strait of Georgia contained several size-classes of oocytes. Only those from the group of the largest yolked oocytes became hydrated and were eventually released to be fertilized. Examination of ovaries from recently spawned fish showed that smaller, residual yolked oocytes were being resorbed. Yolked oocyt...
Article
Full-text available
Fifteen populations of lake whitefish (Coregonus clupeaformis) were sampled to compare the fin-ray and scale aging techniques. There was good agreement between aging methods in fast growing populations, but usually fin-ray ages were larger than scale ages in slow-growing populations. The validity of each aging method was tested by comparing fin-ray...
Article
Full-text available
River lamprey (Lampetra ayresi) metamorphose in late July with downstream migration occurring in the following year from May to July. Once adults enter salt water they begin to feed immediately by consuming chunks of flesh primarily from herring and young salmon. From June until September they increase in size by an estimated 11–14 cm and 12–18 g....
Article
Age of sablefish (Anoplopoma fimbria) was estimated using broken and burnt otoliths. A partial validation of the method was achieved using fish of known age, oxytetracycline-injected fish, and results of tagging studies. Estimated ages indicated that most sablefish stocks contain a large number of fish that are much older than previously determined...