Evgeny Pakhomov

Evgeny Pakhomov
University of British Columbia - Vancouver | UBC ·  Department of Earth and Ocean Sciences

PhD

About

423
Publications
70,564
Reads
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Introduction
Evgeny Pakhomov is currently a Professor at the Department of Earth, Ocean and Atmospheric Sciences of the University of British Columbia, Vancouver, Canada as well as a Director of the Institute for the Oceans and Fisheries at UBC. His research focuses on physical-biological interactions and ecosystem response to climate change or global warming, from the Antarctic to coastal British Columbia. Evgeny's research interests span species ecology (from plankton to fish), ecosystem structure and function, and biochemical coupling. His research has also expanded into the poorly studied mesopelagic zone, the deep ocean realm critical in controlling global marine productivity on millennia time scales.
Additional affiliations
July 2003 - present
University of British Columbia - Vancouver
July 2003 - present
University of British Columbia - Vancouver
Position
  • Professor (Full)
January 2001 - August 2003
Fort Hare University

Publications

Publications (423)
Article
Full-text available
The freshwater jellyfish Craspedacusta sowerbii is among the most widespread invasive species, observed across a wide temperature range. The aim of this study is to analyze the polyp and medusa stages response to different temperatures by using (i) an experimental study on the polyp colony growth at 19 and 29 °C, and (ii) prediction of the Thermal...
Article
Full-text available
The shift in strontium (Sr) concentrations in fish otoliths is a commonly used proxy for identification of marine environment entry during diadromous migrations. However, there is still controversy about the appearance of the Sr-based sea entry mark relative to the true point of entry. In this study, the Sr signal lag was assessed in otoliths of ju...
Article
Full-text available
In the Southern Ocean, several zooplankton taxonomic groups, euphausiids, copepods, salps and pteropods, are notable because of their biomass and abundance and their roles in maintaining food webs and ecosystem structure and function, including the provision of globally important ecosystem services. These groups are consumers of microbes, primary a...
Article
Full-text available
Historical samples collected from 1985 to 2020 in coastal and open ocean regions of the Northeast Pacific were utilised to explore salp assemblage composition, morphometrics, and ontogeny of dominant species, as well as spatial, seasonal, and interannual distribution patterns at subarctic latitudes. Species richness was low, however, three of the s...
Article
Full-text available
The pelagic tunicate Salpa thompsoni is recognized as a major metazoan grazer in the Southern Ocean. Long term observations show an increase in this species’ biomass and a southward shift in its distribution both of which are positively correlated with ocean warming and winter sea ice decline around the Antarctic Peninsula. However, our understandi...
Chapter
Full-text available
In the North Pacific, the zooplankton data sets in the western and eastern parts were collected using different sampling gears, most often by Bongo and Juday nets. While preliminary taxonomic zooplankton inter-comparison between nets was performed, the biomass comparison is still unavailable. During winter (February-March) 2019, in the Gulf of Alas...
Chapter
Full-text available
This abstract introduces and presents preliminary results from the Canadian led International Year of the Salmon (IYS) food webs project that is researching the high seas feeding ecology of Pacific salmon and the structure of the food webs that support them. Feeding ecology is a critical factor in salmon growth and survival on the high seas, and th...
Article
Full-text available
Marine ecosystems on continental shelves face multiple challenges due to anthropogenic disturbances, many of which can change the seawater stoichiometry (C:N:P) and consequently elemental ratios of phytoplankton. This change in food quality may not be tolerated by all grazers and predators. Gelatinous and soft-bodied zooplankton (GZ) might be more...
Preprint
Migrating marine taxa encounter diverse habitats that differ environmentally and in foraging conditions over a range of spatial scales. We examined body (RNA/DNA, length-weight residuals) and nutritional condition (fatty acid composition) of juvenile sockeye salmon (Oncorhynchus nerka) in British Columbia, as they migrated through coastal waters th...
Article
Mesopelagic communities are characterized by a large biomass of diverse macrozooplankton and micronekton (MM) performing diel vertical migration (DVM) connecting the surface to the deeper ocean and contributing to biogeochemical fluxes. In the Southern Ocean, a prominent High Nutrient Low Chlorophyll (HNLC) and low carbon export region, the contrib...
Article
Biomass size spectra (i.e., the distribution of biomass by body size) are increasingly being used to describe energy flows through pelagic communities. We relate spatial and temporal variability in mesozooplankton normalized biomass size spectra (NBSS) to environmental drivers to understand how climatic variability impacts these energy flows. Seaso...
Preprint
Full-text available
The weight-specific metabolic rates of the Antarctic pelagic tunicate Salpa thompsoni Foxton, 1961 were studied during March-April of 1998 and March 2002. The study revealed large variability in metabolic rates and attempted to explain the observed variability. The main factors driving variability, which were previously overlooked, included density...
Preprint
For over 50 years, the conceptualisation of low-nutrient oligotrophic systems having longer food chains and thus lower energy transfer to fish than their high-nutrient eutrophic counterparts ¹ has achieved the status of an ecological paradigm. However, recent global assessments indicate global fish biomass could be much higher than previously thoug...
Article
Full-text available
Poleward range shifts are a global-scale response to warming, but these vary greatly among taxa and are hard to predict for individual species, localized regions or over shorter (years to decadal) timescales. Moving poleward might be easier in the Arctic than in the Southern Ocean, where evidence for range shifts is sparse and contradictory. Here,...
Article
Full-text available
Krill and salps are important for carbon flux in the Southern Ocean, but the extent of their contribution and the consequences of shifts in dominance from krill to salps remain unclear. We present a direct comparison of the contribution of krill and salp faecal pellets (FP) to vertical carbon flux at the Antarctic Peninsula using a combination of s...
Article
Full-text available
The freshwater jellyfish Craspedacusta sowerbii is one of the most widespread invasive species, but its global distribution remains uncertain due to ephemeral appearances and general lack of information in various aquatic environments. The aim of this study was to map current and future distributions (2050 and 2100) using Species Distribution Model...
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
Full-text available
The temporal dynamics of five copepod species common to coastal waters of the Pacific Northwest were examined in relation to variability in spring temperature and phytoplankton dynamics in 2008, 2009, and 2010 in Rivers Inlet, British Columbia, Canada. The five species were differentiated by life history strategies. Acartia longiremis , Metridia pa...
Article
Full-text available
Globally important services are supported by Southern Ocean ecosystems, underpinned by the structure, function, and dynamics of complex interconnected and regionally distinctive food webs. These food webs vary in response to a combination of physical and chemical processes that alter productivity, species composition and the relative abundance and...
Article
Full-text available
Stable isotope analysis was used to determine the relative dietary importance of kelp-derived detritus to plankton and benthic organisms along a gradient of kelp abundance driven by recovering sea otter populations along the west coast of Vancouver Island (WCVI), Canada. The study used region-specific kelp isotope values (δ 13 C and δ 15 N) and sea...
Article
Full-text available
The strontium (Sr) and barium (Ba) profiles in otoliths of juvenile sockeye salmon Oncorhynchus nerka from British Columbia are measured using a Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) system and analyzed. The highest possible measurement resolution (near-daily) was used to assess variability and repeatability of the...
Poster
Full-text available
Abstract: Microplastics (MP, <5mm) have emerged as significant, ubiquitous marine contaminants; due to their size and persistent nature, MP are ingested by a variety of marine species. Studies have revealed MP transfer between low trophic levels, but few have (1) modelled the bioaccumulation potential of MP across foodwebs, and (2) investigated m...
Article
The recruitment of many fish species is thought to be dependent on a match with the timing of spring phytoplankton biomass. This process is mediated by zooplankton dynamics. However, it remains unclear how phenological changes are coupled across trophic levels, and what mechanisms link variation in spring phytoplankton timing to changes in the phen...
Article
Full-text available
Following a brief review of their biology, this contribution is an attempt to provide a global overview of the catches of mesopelagic fishes (of which 2.68 million tonnes were officially reported to the FAO) throughout the world ocean from 1950 to 2018, to serve as a baseline to a future development of these fisheries. The overview is based on a th...
Article
Full-text available
Over the past decades, two key grazers in the Southern Ocean (SO), krill and salps, have experienced drastic changes in their distribution and abundance, leading to increasing overlap of their habitats. Both species occupy different ecological niches and long-term shifts in their distributions are expected to have cascading effects on the SO ecosys...
Article
Full-text available
Polar marine ecosystems are particularly vulnerable to the effects of climate change. Warming temperatures, freshening seawater, and disruption to sea‐ice formation potentially all have cascading effects on food webs. New approaches are needed to better understand spatiotemporal interactions among biogeochemical processes at the base of Southern Oc...
Article
The Kerguelen Plateau is a region of natural iron fertilization in the Southern Ocean, within the typically iron limited High Nutrient Low Chlorophyll (HNLC) waters of the eastward flowing Antarctic Circumpolar Current. Between 26 February and 19 March 2018, the MOBYDICK expedition investigated pelagic ecosystem dynamics in the Kerguelen Island reg...
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...
Technical Report
Full-text available
The Antarctic has long been seen as an untouchable wilderness where few venture beyond scientists at remote research bases, scattered fishing vessels, and a limited number of well-heeled tourists. Yet shifts in Antarctic processes, driven by human-caused climate change, are impacting wider earth systems, with profound implications for human and eco...
Article
Full-text available
Survival of larval Antarctic krill ( Euphausia superba ) during winter is largely dependent upon the presence of sea ice as it provides an important source of food and shelter. We hypothesized that sea ice provides additional benefits because it hosts fewer competitors and provides reduced predation risk for krill larvae than the water column. To t...
Article
Vast regions of the Central Pacific, inhabited by low-lying Micronesian nations, have been poorly studied for zooplankton. Atolls of the Republic of the Marshall Islands (RMI) have been surveyed before, during, and after the US nuclear weapons tests between 1946–1958, and gelatinous taxa were sporadically mentioned. Gelatinous zooplankton (GZ) were...
Article
Vertical distribution and size-dependent migrations of the pelagic tunicate Salpa thompsoni were studied during late summer to early autumn (26th February – 15th March 2018) at contrasting hydrological stations over the Kerguelen Plateau (Southern Indian Ocean). Vertical migrators, such as S. thompsoni, have potentially significant impacts on the b...
Article
Normalized biomass size spectra (NBSS) are frequently used to describe pelagic communities. However, the underlying structure of NBSS may lead to varying intercepts and slopes when only a portion of the biomass range is sampled. This may be further perpetuated by the sampling efficiency of different gears/mesh sizes. Spatial and seasonal effects of...
Article
Full-text available
The freshwater jellyfish species of the genus Craspedacusta purportedly originated from the Yangtze River catchment area, China, and has now been observed on all continents, except Antarctica. Sightings of C. sowerbii in the Pacific regions of Canada were compiled to document some of the northernmost records of this species in the Americas. Species...
Article
Gelatinous and soft-bodied zooplankton (GZ) have long been considered to have low energetic value (‘trophic dead end hypothesis’) and are insufficient to sustain higher trophic levels. However, the nutritional composition and energy content of GZ are often poorly known for entire groups, ignoring species-, size- and stage-specific differences. In t...
Article
Full-text available
We examined spatial patterns in diet, trophic niche width and niche overlap for chum, pink and sockeye salmon across the North Pacific during 1959–1969. This is a baseline period before major hatchery enhancement occurred coinciding with a negative phase of the Pacific Decadal Oscillation. Large-scale (between regions) and fine-scale (within region...
Article
Temperate coastal marine environments are typified by strong seasonality and highly productive annual spring phytoplankton blooms. However, in areas of strong tidal activity, coastal waters may remain in a state of low productivity year-round due to light limitation induced by deep mixing. Such high-nutrient low-chlorophyll (HNLC) environments can...
Article
This study aimed to obtain the first estimates of S. thompsoni population dynamics and growth rates over the Kerguelen Plateau (Southern Indian Ocean). Micronekton, including salps, were repeatedly sampled during late summer to early autumn (26th February – 15th March 2018) at contrasting hydrological stations on the Kerguelen Plateau in the southe...
Conference Paper
Full-text available
Pacific salmon (Oncorhynchus spp.) are renowned for their high mobility, complex population structure, and homing to natal spawning grounds. Following a year or more in freshwater and estuarine habitats, sockeye salmon (O. nerka) in British Columbia, for example, are thought to move north and northwest along the coast during their first summer and...