Status and Trends of Saline Lake Research in British Columbia, Canada

Abstract

Saline lakes are distinct, understudied aquatic ecosystems, particularly those that are hydrologically isolated from marine environments. In British Columbia (BC), Canada, the scope and trajectory of scientific research on these systems remain largely undocumented. To address this gap, a meta-analysis was conducted of peer-reviewed scholarly articles focusing on both coastal and inland saline lakes to identify the primary research themes and assess temporal trends in scientific inquiry. The coastal meromictic lakes Sakinaw and Powell were included because of their retention of relict marine waters. Thematic areas of research spanned a diverse array of disciplines, including paleolimnology, neolimnology, halophilic insect and plant ecology, microbial diversity, and functional genomics, as well as astrobiology as analog environments for extraterrestrial life. Temporal analysis revealed variable research intensity across disciplines: the number of paleolimnological training sets has declined, whereas microbial genomics and astrobiological analog investigations have increased. Among inland saline lakes, Mahoney Lake, Pavilion Lake, and various saline lakes within the Cariboo region emerged as key sites of ecological and geochemical interest. This synthesis highlights both the ecological significance and scientific potential of BC’s saline lakes while underscoring the need for more systematic and interdisciplinary research to better understand their roles in broader environmental and evolutionary contexts.

1. Introduction

In Canada, saline lakes—also referred to as alkaline or epsomitic lakes—are predominantly found within the semiarid and arid regions of the Great Plains, where their geochemical and ecological characteristics have been extensively documented [1]. In contrast, the westernmost province of Canada, British Columbia (BC), has received comparatively less attention despite hosting a diverse array of saline lake systems. These lakes occur across various physiographic regions of the province, including the semiarid southern interior, the central and northern interior plateaus, and select coastal areas.

Coastal saline lakes in BC are typically influenced by intermittent groundwater connectivity or episodic marine intrusions. These inputs may result from tidal action, storm surges, tsunamis, or legacy effects of past sea-level fluctuations. In such environments, sodium chloride (NaCl) often dominates the ionic composition, reflecting their marine affinities. In contrast, inland saline lakes within BC tend to exhibit greater geochemical heterogeneity, with diverse assemblages of dissolved ions including calcium (Ca²⁺), sodium (Na⁺), potassium (K⁺), magnesium (Mg²⁺), sulfate (SO₄²⁻), carbonate (CO₃²⁻), chloride (Cl⁻), and bicarbonate (HCO₃⁻) [2]. These ions typically originate from a combination of atmospheric deposition and the chemical weathering of local bedrock, glacial deposits, and surface soils and are transported into lake basins via surface runoff and shallow groundwater flow. In the absence of outflows, evaporative concentration drives salinity increases, often leading to the precipitation of evaporite minerals which can accumulate within the lake sediments. These minerals may also possess commercial value, highlighting the economic importance of saline lakes as potential sources of extractable mineral resources.

Differentiation of saline lakes can be made by dominant anion types, carbonate, chloride, or sulfate, and by concentration of ions, hyposaline (~3–20 mg/L), mesosaline (20–50 mg/L), and hypersaline (>50 mg/L). Salinity may also be quantified by resistance to conducting electricity, known as specific conductance, which is expressed in µSiemens/cm. As salinity can change at annual and decadal time scales, using anion type may be a more reliable lake classification system. Further, meromictic lakes (with stable strata) have multiple salinities, often the lowest layer being hypersaline.

From an ecological perspective, saline lakes are typically characterized by simplified biological communities relative to freshwater systems. The extreme physicochemical conditions—particularly high salinity and associated osmotic stress—pose significant barriers to colonization, with only a limited number of halotolerant and halophilic organisms capable of survival [3]. Early limnological surveys in Saskatchewan led Rawson and Moore [4] to conclude that osmotic regulation is a key physiological constraint shaping faunal composition in these environments. Despite these challenges, saline lakes often support highly specialized and endemic taxa, contributing to regional biodiversity. Moreover, they serve as critical habitats for a number of avian species, offering unique foraging and nesting opportunities. In British Columbia, inland saline lakes support diverse bird species such as the avocet and the pelican [5,6], while coastal saline lakes may provide rearing habitat for anadromous species such as salmon under specific hydrological conditions [7].

In recent years, growing concern has emerged regarding the vulnerability of saline lakes to anthropogenic stressors. These include altered hydrology due to water diversions, nutrient enrichment from agricultural runoff, and broader climate change impacts, which collectively threaten the persistence and ecological integrity of these ecosystems [8]. In response, researchers have called for a more integrative and multidisciplinary approach to the study and conservation of saline lakes globally [9,10]. In particular, these systems may serve not only as ecological refugia but as natural filters or sinks for contaminants, thus playing an underappreciated role in regional biogeochemical cycles and sustainable land use practices [11].

Despite their scientific and ecological significance, saline lakes in British Columbia remain underrepresented in the academic literature. No systematic survey currently exists documenting their number, distribution, or ecological status. Furthermore, a comprehensive synthesis of saline lake research specific to BC has yet to be produced. This study aims to address these gaps by compiling and analyzing existing scholarly research on saline lakes within the province. Through this synthesis, we aim to identify major research themes and historical trends of saline lake research and offer recommendations for future interdisciplinary research that may inform both conservation and sustainable resource management strategies.

2. Methods

This study employed a meta-analytical approach to assess the scope and temporal trends of saline lake research in BC. The analysis focused on academic literature, including peer-reviewed journal articles, university-based master’s and doctoral theses, and select government technical reports. Conference abstracts were generally excluded from the dataset, although a small number of conference proceedings were retained when deemed to offer significant or unique contributions to the subject matter.

Literature searches were conducted using multiple platforms, including the Okanagan College library database system, Google Scholar, and general web-based search engines (e.g., Google). Search queries incorporated a range of relevant keywords such as ‘saline lake’, ‘alkaline lake’, ‘epsomite’, ‘meromictic’, ‘hypersaline’, and ‘British Columbia’. Despite efforts to develop a comprehensive dataset, the exclusion of documents that lacked relevant keywords in their titles, abstracts, or indexed metadata likely resulted in the omission of some pertinent works.

Following the initial literature compilation, documents were reviewed and categorized according to thematic content. Rather than employing automated keyword analytics or text-mining algorithms, a qualitative and interpretive classification strategy was adopted. Thematic groupings were informed by the principal focus of each study, and research topics were organized into categories such as paleolimnology, neolimnology, microbial and molecular investigations, birds, other biota, geochemical and mineralogical studies, and interdisciplinary or applied research.

In coastal saline lakes, studies involving microbial or genomic-level analysis were grouped under the category ‘molecular’, irrespective of whether they could have also reasonably been classified as ‘microbial’ or ‘other biota’. This classification was based on the methodological focus of the studies, which emphasized laboratory-based or microscopic techniques. Similarly, in the context of inland lakes, interdisciplinary studies that mentioned saline lakes as part of a broader framework were grouped under an ‘other’ category. The classification process considered physical, chemical, and biological components as key differences in themes, while acknowledging the limitations inherent in nonautomated, qualitative categorization.

3. Results and Discussion

A total of 288 scholarly works—including peer-reviewed journal articles, graduate theses, and selected government reports—were identified and included in this meta-analysis of saline lake research in British Columbia. Of these, 49 publications focused on coastal saline lakes, while the remaining 239 addressed inland saline lake systems. Given the distinct hydrogeological origins and environmental conditions associated with each category, coastal and inland lakes were analyzed separately in this study.

3.1. Coastal Lakes

Coastal saline lakes in British Columbia represent rare and ecologically significant environments influenced by saline groundwater discharge or episodic intrusions of seawater. These processes are often modulated by geological or climatic events such as tectonic uplift, tsunamis, storm surges, and sea-level fluctuations. Among the coastal lakes, Sakinaw Lake and Powell Lake emerged as disproportionately studied systems, collectively accounting for a majority of the coastal-focused literature. Both lakes are noted for their meromictic conditions and the presence of relict marine water in their lower strata.

An exception to the seawater-influenced paradigm is found in the natural salt springs of Salt Spring Island, where elevated salinity originates from subsurface geological features rather than marine incursions [12]. These geogenically influenced systems illustrate the diversity of saline lake formation mechanisms along the BC coast.

3.1.1. Temporal Trends in Research Output

A decadal analysis of publication frequency (Figure 1a) reveals marked fluctuations in research activity on coastal saline lakes over time. The earliest identified publications date to the 1960s, followed by a prolonged period of inactivity spanning the 1970s and 1980s. A resurgence in scholarly output began in the 1990s, culminating in a peak during the 2010s. However, there has been a notable decline in the number of publications in the first half of the 2020s, despite accounting for only five years of the decade.

Several explanations may account for this apparent decrease. It is possible that relevant publications were not captured because of search engine limitations, changes in indexing practices, or inconsistent keyword usage. Alternatively, this trend may reflect a genuine shift in research priorities, potentially influenced by broader changes in environmental science funding, interdisciplinary focus, or the increasing urgency of climate-related research [13].

3.1.2. Research Themes

A review of the 49 publications focusing on British Columbia’s coastal saline lakes revealed three predominant research themes: the ecological and management implications for salmonid populations, particularly sockeye salmon; microbial diversity and molecular genetics, particularly of anaerobic and extremophilic bacteria inhabiting meromictic environments; and paleolimnological investigations aimed at reconstructing past environmental and geological disturbances. These thematic areas are not equally represented in the literature. As shown in Figure 1b, studies on salmon dominate the research, followed by molecular and microbial studies, with comparatively fewer publications addressing broader biotic communities.

The prominence of salmon-focused research is consistent with the economic and ecological importance of salmonid fisheries in BC. Sakinaw Lake, in particular, supports a genetically distinct population of sockeye salmon that is part of the Georgia Strait stock complex [14]. As such, it has been the subject of intensive ecological monitoring and fishery management research. These studies have emphasized population dynamics, habitat use, spawning behavior, and conservation strategies in light of declining returns and habitat alteration.

Molecular studies also represent a significant and growing research area, particularly in the 2010s. These investigations often utilize high-resolution genetic, genomic, and microbial community analyses to explore the unique assemblages found in the anoxic bottom waters of meromictic lakes. The use of advanced molecular techniques—such as metagenomics, 16S rRNA gene sequencing, and microbial functional profiling—has enabled researchers to uncover novel bacterial lineages and extremophiles with potentially significant biotechnological and astrobiological relevance [15,16]. These studies are grouped under the thematic category ‘molecular’ in

Table A1. Coastal lakes included in this study, arranged by lake, then year of publication.

Lake	Author(s)	Year	Theme
Sakinaw Lake	Northcote and Johnson [66]	1964	Neolimnology
	Gustafson and Winans [67]	1999	Salmon
	Perry [68]	1990	Neolimnology
	Perry and Pedersen [17]	1993	Neolimnology
	Murray and Wood [14]	2002	Salmon
	Nelson et al. [69]	2003	Salmon
	Albert and Schluter [70]	2004	Other biota
	McBain [18]	2004	Neolimnology
	Gross et al. [71]	2004	Salmon
	Irvine [72]	2004	Salmon
	Brown and Gaydos [73]	2005	Salmon
	Irvine et al. [74]	2005	Salmon
	Levy [7]	2006	Salmon
	Duchene [75]	2010	Salmon
	Godbout et al. [76]	2010	Salmon
	Vagle et al. [19]	2010	Neolimnology
	Welch et al. [77]	2011	Salmon
	Taylor et al. [78]	2012	Other biota
	Wood et al. [79]	2012	Salmon
	Rinke et al. [80]	2013	Molecular
	Withler et al. [81]	2014	Salmon
	Gies et al. [82]	2014	Molecular
	Farag et al. [83]	2014	Molecular
	Gies [84]	2015	Molecular
	Youssef et al. [85]	2015	Molecular
	Podar et al. [86]	2015	Molecular
	Lin and Pan [87]	2015	Molecular
	Singer et al. [88]	2016	Molecular
	Nobu et al. [89]	2016	Molecular
	Farag et al. [90]	2017	Molecular
	Gibbons et al. [91]	2017	Other biota
	Ramshaw et al. [92]	2019	Salmon
	Walsh et al. [93]	2020	Salmon
	Lüskow and Pakhomov [94]	2024	Other biota
Powell Lake	Williams et al. [95]	1961	Paleolimnology
	Sanderson et al. [96]	1986	Neolimnology
	Perry [68]	1990	Neolimnology
	Wüest et al. [97]	2010	Neolimnology
	Scheifele et al. [20]	2014	Neolimnology
Other lakes	Northcote et al. [98]	1964	Neolimology
	Hutchinson et al. [21]	2000	Paleolimnology
	López and Bobrowski [22]	2001	Paleolimnology
	James et al. [99]	2002	Paleolimnology
	Hutchinson et al. [100]	2004	Paleolimnology
	Nordin et al. [101]	2004	Neolimnology
	Galloway et al. [102]	2007	Paleolimnology
	Roe et al. [103]	2013	Paleolimnology
	Nordin [104]	2013	Neolimnology
	Lemmen [105]	2016	Paleolimnology
	Neil and Lacourse [106]	2019	Neolimnology

.

In contrast, relatively few studies have focused on other aquatic biota. The ‘other biota’ category includes work on less extensively studied taxa such as threespine stickleback and lamprey species. These studies provide insight into ecological interactions and evolutionary processes but remain underrepresented compared with research on salmon and microbes.

Figure 2 presents the temporal distribution of research themes, highlighting the progression of scientific inquiry over time. Research in the 1990s and 2000s included neo- and paleolimnological studies aimed at understanding lake stratification, sedimentation, chemical cycling, and the identification of meromictic conditions in Sakinaw and Powell Lakes. Foundational studies in this domain include work by Perry and Pedersen [17], McBain [18], Vagle et al. [19], and Scheifele et al. [20].

A subset of paleolimnological research has focused on environmental reconstruction and seismic disturbance events rather than strictly limnological parameters. For example, studies by Hutchinson et al. [21] and López and Bobrowski [22] investigated coastal lake sediments as archives of Holocene tectonic and tsunami activity. While these studies are not always limnology-centric, they illustrate the interdisciplinary importance of saline lakes as natural repositories of regional geological history. It should be noted that if estuarine paleosalinity studies—such as the recent work in Serpentine Fen [23]—had been included, the number of relevant papers would have been significantly higher. However, as estuaries fall outside the strict definition of “lakes,” they were excluded from this analysis.

The notable rise in molecular studies in the 2010s coincides with broader advancements in microbial and genomic research methodologies. This surge reflects growing recognition of the unique biochemical and ecological processes occurring in permanently stratified saline lake systems, which may serve as modern analogs for early Earth or extraterrestrial environments.

3.2. Inland Lakes

A total of 239 scholarly publications focused on inland saline lakes in British Columbia was identified and included in this meta-analysis. As with the coastal systems, certain lakes have received disproportionate attention over time, likely because of their unique chemical, biological, or geomorphological characteristics. Among the most frequently studied inland saline lakes are Mahoney Lake, Pavilion Lake, Goodenough Lake, the Basque Lakes complex, and Spotted Lake. These systems have served as focal points for a wide range of limnological, microbial, mineralogical, and ecological research.

3.2.1. Temporal Trends in Research Output

An analysis of publication frequency by decade (Figure 3a) revealed important temporal patterns in the scholarly attention given to inland saline lakes. Only four publications were recorded prior to 1960. From the 1960s onward, research activity steadily increased, peaking in the 1990s with more than 60 publications during that decade. However, this peak was followed by a noticeable decline in the number of studies published during the 2000s and 2010s, a trend that has persisted into the early 2020s.

The reasons for this decline in publication output are likely multifactorial. One potential contributing factor is reduced financial support for environmental and natural science research during the early 21st century. For instance, Statistics Canada reported a decline in federal government expenditures on science and technology—adjusted to 2017 constant dollars—between 1995 and 2000 [24]. Although funding increases were introduced in later years (e.g., the 2018 federal budget [25]), the long lead time required for research design, fieldwork, data analysis, and publication means that these newer investments may not yet be reflected in the publication record.

Another possible explanation relates to the demographic structure of the scientific community in British Columbia. Mackenzie [26] noted that BC had the highest average age of scientists in Canada, which could theoretically lead to decreased research productivity if older researchers are less active in publishing. However, this hypothesis is contested. Gingras [27] presented evidence that academic productivity may actually increase with age, especially among senior researchers who have established research programs, funding networks, and collaborations.

A third potential factor is the pipeline of graduate training and advanced degree holders. During the late 1990s and early 2000s, the number of PhD graduates in Canada remained relatively stagnant or declined, with fewer than 4000 PhDs awarded annually between 1996 and 1999 and a decrease to just 3705 in 2001 [28]. As graduate students often conduct field-based, specialized research such as that required for saline lake studies, a reduction in this cohort may have contributed to the observed decline in scientific output.

In combination, these factors suggest that the downturn in inland saline lake research may reflect systemic issues in research funding, institutional priorities, and academic capacity rather than a loss of scientific relevance or interest in saline ecosystems themselves. Indeed, recent global interest in extreme environments, astrobiological analogs, and ecosystem resilience under climate stress may provide new opportunities to revitalize research on BC’s inland saline lakes.

3.2.2. Research Themes

Given the greater number of publications and sites of inland saline lakes in British Columbia, it is unsurprising that a wider range of research themes emerged than for coastal systems (Figure 3b). These themes reflect both ecological diversity and varying disciplinary interests in these unique environments.

Although birds do not reside within saline waters themselves, they frequently utilize lake shorelines for nesting, breeding, and foraging, often relying on the aquatic invertebrates that thrive in saline environments. Given their ecological dependence on the lakes, studies focusing on avian populations were deemed relevant and included under the ‘birds’ theme. Two inland lakes—Stum Lake and Alki Lake—were notable for repeated documentation of avian presence (

Table A2. Inland saline lake publications, arranged first by research theme, then by year. The ‘Lake’ column contains one of the following: one or two identified lakes, reference to the fact that more than two lakes were observed, or in the case of training sets, the number of lakes contained.

Research Theme	Author(s)	Year	Lake
birds	Lies and Behle [107]	1999	Stum
	Campbell and Frost [108]	1969	Stum
	Vermeer [109]	1977	Stum
	Bunnell et al. [110]	1981	Stum
	Dunbar [111]	1982	Stum
	Dunbar [112]	1984	Stum
	Breault [113]	1990	various
	Savard [114]	1991	various
	Savard [115]	1994	various
	Cannings [116]	1999	various
	Gebauer [117]	2000	various
	Stewart [118]	2001	Alkali
	VanSpall et al. [6]	2005	Stum
	Campbell [119]	2014	various
	Gyug and Weir [5]	2017	Alki
	Gyug and Weir [120]	2017	Alki
other biota	McKay [121]	1935	Spotted
	Acton [122]	1962	Clinton
	Jarial [29]	1964	various
	Teraguchi [30]	1962	various
	Teraguchi and Northcote [123]	1966	Corbett
	Bassett [124]	1967	various
	Scudder and Mann [125]	1968	various
	Blinn [126]	1969	various
	Broch [127]	1969	various
	Scudder [128]	1969	various
	Scudder [129]	1969	various
	Topping [31]	1969	various
	Blinn [130]	1970	various
	Blinn and Stein [131]	1970	various
	Scudder [132]	1971	various
	Topping [133]	1971	various
	Scudder et al. [134]	1972	various
	Cannings [32]	1973	various
	Anderson [135]	1974	various
	Camm and Stein [136]	1974	Spotted
	Jansson and Scudder [137]	1974	various
	Nordin [138]	1974	various
	Parsons [139]	1974	Slippy Slough
	Cannings [140]	1975	various
	Cannings [141]	1975	various
	Reynolds and Reynolds [142]	1975	various
	Scudder [143]	1975	various
	Scudder et al. [144]	1976	various
	Topping and Acton [145]	1976	various
	Cannings [33]	1977	various
	Cannings and Scudder [146]	1978	various
	Cannings and Scudder [147]	1978	various
	Nimmo and Scudder [148]	1978	various
	Sargent [34]	1978	various
	Scudder [149]	1979	various
	Spence [35]	1979	various
	Cannings et al. [150]	1980	various
	Nordin and Stein [151]	1980	various
	Spence and Scudder [152]	1980	various
	Kangasniemi and Oliver [153]	1983	various
	Lancaster [36]	1985	various
	Mayall [154]	1985	various
	Cannings and Cannings [155]	1987	various
	Cooper et al. [156]	1987	various
	Lancaster and Scudder [157]	1987	various
	Broch [158]	1988	unnamed
	Needham [37]	1990	various
	Chapman et al. [43]	1991	Mahoney
	Ring [12]	1991	Salt Spring
	Hammer and Forró [159]	1992	various
	Patalas et al. [160]	1994	various
	Scudder [161]	1994	various
	Duff et al. [162]	1997	various
	Bennett and Scudder [163]	1998	various
	Overmann et al. [164]	1999	Mahoney
	Fraser [165]	2000	various
	Richardson et al. [166]	2000	various
	Scudder et al. [167]	2001	various
	Derry et al. [168]	2003	various
	Bunbury [169]	2004	various
	Cannings et al. [170]	2005	various
	Scudder and Cannings [171]	2006	Various
	Kenner [172]	2007	Jericho Pond
	Brodersen et al. [173]	2008	various
Kenner and Needham [174]	2008	various
Northcote and Hall [50]	2010	Mahoney
MacLellan and Hume [175]	2011	various
Clark [176]	2015	various
neolimnology	Northcote and Larkin [177]	1956	various
	Northcote and Halsey [178]	1969	various
	Blinn [179]	1971	various
	Topping [180]	1975	various
	Walker and Likens [42]	1975	Mahoney
	Topping and Scudder [181]	1977	various
	Hudec and Sonnenfeld [182]	1980	various
	Sonnenfeld and Hudec [183]	1980	various
	Northcote and Hall [184]	1983	Green, Mahoney
	Shortreed et al. [185]	1984	various
	Hall and Northcote [186]	1986	Mahoney
	Hammer [59]	1986	various
	Northcote and Hall [187]	1990	Mahoney
	Hall and Northcote [188]	1990	Mahoney
	Ward et al. [189]	1990	Mahoney
	Walker [190]	1993	various
	Williams [191]	1996	various
	Barjaktarovic [192]	1999	various
	Bendell-Young [193]	1999	various
	Saros and Fritz [194]	2000	various
	Northcote and Hall [44]	2000	Mahoney
	Barjaktarovic and Bendell-Young [195]	2002	various
	Hall and Northcote [45]	2002	Mahoney
	Michel et al. [196]	2002	various
	James et al. [197]	2004	Quesnell
	Stasiuk et al. [198]	2005	Kilpoola
	Bluteau [199]	2006	theoretical
	Northcote and Hall [49]	2006	Mahoney, Blue
	Renaut et al. [200]	2006	various
	Northcote and Hall [201]	2008	Mahoney
	Lim et al. [55]	2009	Pavilion
	Wassenaar et al. [202]	2011	Spotted
	Hall and Northcote [46]	2012	Mahoney
	Laval et al. [203]	2012	Quesnell
	Gilhooly III et al. [204]	2016	Mahoney
	Bieber [205]	2022	Salt, Clinton
paleolimnology	Mathewes and King [206]	1989	various
	Overmann et al. [207]	1993	Mahoney
	Heinrichs [208]	1995	various
	Hall et al. [209]	1997	Williams
	Heinrichs et al. [210]	1997	Mahoney
	Lowe et al. [211]	1997	Mahoney
	von Westarp [212]	1997	Kilpoola
	Coolen and Overmann [213]	1998	Mahoney
	Laird and Cumming [214]	1998	Big
	Heinrichs et al. [215]	1999	Kilpoola
	Hall and Northcote [216]	2000	Mahoney
	Reavie et al. [217]	2000	various
	Walker and Pellatt [218]	2001	various
	Bennett et al. [219]	2001	Big
	Laird and Cumming [220]	2001	various
	Cumming et al. [221]	2002	Big
	Laird et al. [222]	2003	various
	Heinrichs and Walker [223]	2006	various
	Enache and Cumming [224]	2009	Opatcho
	Galloway et al. [225]	2011	Felker
	Mihindukulasooriya [226]	2014	Cleland
	Parekh et al. [227]	2014	various
	Parducci et al. [228]	2017	Mahoney, various
	Heinrichs et al. [41]	2020	Mahoney
	Mushet et al. [229]	2022	Roche
	Shea et al. [230]	2022	Turquoise
	Mushet [231]	2023	Roche
training sets	Hall and Smol [232]	1992	46
	Blinn [233]	1993	63
	Cumming et al. [234]	1993	102
	Cumming and Smol [235]	1993	65
	Wilson et al. [236]	1994	111
	Duff and Smol [237]	1995	60
	Reavie et al. [238]	1995	64
	Walker et al. [239]	1995	86
	Zeeb and Smol [240]	1995	60
	Wilson et al. [241]	1996	219
	Vinebrooke et al. [242]	1998	111
	Bos et al. [243]	1999	33
	Heinrichs et al. [244]	2001	87
	Wilson and Gajewski [245]	2002	42
	Wilson and Gajewski [246]	2004	39
	Cumming et al. [247]	2015	251
microbial	Bauld [248]	1981	unnamed
	Overmann et al. [249]	1991	Mahoney
	Overmann et al. [250]	1992	Mahoney
	Overmann and Pfennig [251]	1992	Mahoney
	Renaut [252]	1993	various
	Ferris et al. [253]	1994	various
	Overmann et al. [254]	1994	Mahoney
	Ferris et al. [255]	1995	various
	Overmann et al. [256]	1996	Mahoney
	Overmann et al. [257]	1996	Mahoney
	Schulz-Lam et al. [258]	1996	Goodenough
	Ferris et al. [259]	1997	Kelly
	Overmann [260]	1997	Mahoney
	Slater [261]	1997	various
	Overmann et al. [262]	1999	Mahoney
	Overmann [263]	2001	Mahoney
	Yurkova et al. [264]	2002	Mahoney
	Rathgeber et al. [265]	2005	Mahoney
	Rathgeber [48]	2006	Mahoney
	Power et al. [266]	2007	unnamed
	Overmann [47]	2008	Mahoney
	Foster [267]	2009	various
	Power et al. [268]	2009	various
	Klepac-Ceraj et al. [269]	2012	Mahoney
	Wilson et al. [270]	2012	Spotted
	Bovee [271]	2013	Mahoney
	Bovee and Pearson [272]	2014	Mahoney
	Hamilton et al. [273]	2014	Mahoney
	Russell et al. [274]	2014	Pavilion
	Hamilton et al. [275]	2016	Mahoney
	Hamilton et al. [276]	2016b	various
	O’Beirne [52]	2018	Mahoney
	Fox-Powell and Cockell [277]	2018	Basque
	Crisler et al. [278]	2019	Basque
	Jiao et al. [279]	2021	various
	Kuzyk et al. [51]	2022	Mahoney, Blue
	Kuzyk et al. [51]	2022b	Mahoney, Blue
	O’Beirne et al. [53]	2022	Mahoney
	Haas et al. [280]	2024	Last Chance, Goodenough
	Varona et al. [54]	2025	Mahoney
astrobiology	Peterson et al. [57]	2007	Basque
	Pike et al. [281]	2008	Kelly
	Foster et al. [282]	2010	Basque
	Lim et al. [56]	2011	Pavillion
	Cannon [283]	2012	Spotted
	Pontrefract et al. [284]	2017	Spotted
	Olsson-Francis [58]	2018	Spotted
	White et al. [285]	2020	Kelly, Pavilion
	Buffo et al. [286]	2022	various
	Nichols et a.l [287]	2023	various
	Bonacolta et al. [288]	2024	Kelly, Pavilion
(geo)chemistry	Jenkins [289]	1918	Spotted
	Cummings [290]	1940	various
	Nesbitt [291]	1973	Basque
	Hoffman [292]	1976	various
	Eugster and Jones [293]	1979	Basque
	Murphy et al. [294]	1983	Black
	Goudie and Cooke [295]	1984	needed
	Renaut and Long [296]	1987	various
	Renault and Long [297]	1989	various
	Renaut [298]	1990	various
	Renaut and Stead [299]	1990	various
	Cook [300]	1992	various
	Cook and Jackaman [301]	1993	various
	Cook and Luscombe [302]	1994	various
	Renaut [303]	1994	Clinton
	Hirst [304]	1995	Goodenough, Last Chance
	Simandl et al. [305]	2000	various
	Power et al. [306]	2014	various
	Raudsepp et al. [307]	2023	various
	Raudsepp et al. [308]	2024	various
wastewater	Pedersen and Losher [309]	1988	Buttle
	Fisher [310]	2002	Copper Mine Pit
	Zadereev et al. [311]	2017	Copper Mine Pit
other	Neave [312]	1972	Lac du Bois
	Olmstead [313]	1984	various

). Stum Lake, in particular, supports a breeding population of pelicans. Alki Lake’s proximity to Kelowna and Okanagan College likely contributed to its prominence, as researchers affiliated with the institution frequently conducted fieldwork there.

The most extensively studied biological theme was ‘other biota’, with a predominant focus on halotolerant insects and other invertebrates. These studies have greatly expanded our understanding of species adaptations to hypersaline environments. A significant contributor to this body of research was entomologist G.G.E. Scudder, who authored or coauthored 20 publications included in this analysis. Scudder also mentored numerous graduate students whose theses and subsequent publications further enriched the field. Notable among these are Jarial [29], Taraguchi [30], Topping [31], Cannings [32], Cannings [33], Sargent [34], Spence [35], Lancaster [36], and Needham [37]. The academic lineage stemming from Scudder’s mentorship had a demonstrable influence on the volume and depth of saline lake research in the province.

The term ‘neolimnology’ was used here to refer broadly to modern limnological studies examining contemporary ecological, chemical, and physical processes within saline lakes. To allow for more precise thematic analysis, separated from neolimnology were ‘microbial’, ‘chemical’, and ‘paleolimnology’ themes. Furthermore, training sets were separated from paleolimnology, given the high numbers of publications in this theme. This left more than 30 publications within neolimnology, providing critical insights into how modern saline lakes function; their states of mixis (the timing and degree of turnover of the water column), productivity, and nutrient cycling; their water balance under varying climatic and hydrological conditions; and how they may respond to future environmental changes.

Microbial investigations constituted the second-largest research theme overall. The majority of these studies were published after 1990, coinciding with the advent and refinement of molecular and genomic techniques that enabled the exploration of microbial diversity and function in extreme environments (Figure 4). These studies often focused on microbial mats, benthic biofilms, and water-column communities, which exhibit remarkable metabolic versatility and environmental resilience. Inland saline lakes such as Pavilion, Goodenough, Last Chance, and the Basque Lakes are known to host microbialites and stratified microbial ecosystems, which are of growing interest in microbial ecology and geobiology. A particularly novel subtheme that emerged from the microbial literature is that of astrobiology. Several inland saline lakes in British Columbia have been studied as terrestrial analogs for extraterrestrial environments, particularly in relation to Mars and icy moons such as Europa. The presence of microbialites, stromatolite-like structures, and hypersaline, anoxic conditions make these lakes ideal natural laboratories for understanding life in extreme environments. These studies often intersect with planetary science and exoplanet habitability modeling, underscoring the interdisciplinary value of inland saline lake ecosystems.

Chemical studies represent the earliest category of published saline lake research in British Columbia. The first known paper on the subject, published in 1918, focused on the ionic composition of Spotted Lake. From the 1970s to the 1990s, a number of publications addressed sediment origin, mineralogical processes, and salt precipitation. These studies provided foundational data on lake chemistry and depositional environments.

Unlike the more uniform geological context of the saline lakes in Saskatchewan [1], British Columbia’s inland saline lakes occur within a geologically complex landscape composed of numerous distinct terranes [38]. As a result, the ionic composition of these lakes varies substantially by region. Additionally, BC’s topographically diverse terrain, including multiple mountain ranges such as the Coast and Cascade Mountains, creates pronounced rain shadow patterns [39] that have a direct influence on lake hydrology and salinity concentration. While general temperature patterns follow latitudinal trends, local topographic and maritime influences introduce additional complexity that must be considered when interpreting spatial differences among lake systems (see Figure 5).

Paleolimnological research on inland saline lakes in British Columbia emerged as a prominent theme in the late 1980s, coinciding with the growing availability of sediment core analysis and bioindicator-based reconstruction techniques. From the early 1990s through approximately 2005, there was a notable increase in studies that developed and applied modern calibration (training) sets, primarily based on diatom, chironomid, and chrysophyte (e.g., cyst or pigment) assemblages. These microfossil groups serve as reliable proxies for past environmental conditions, including salinity, pH, nutrient status, and lake level fluctuations.

A significant proportion of these studies focused on Mahoney Lake and nearby Kilpoola Lake in the southern interior of the province. These lakes, characterized by high sulfate concentrations and seasonal anoxia, provide ideal conditions for preserving biogenic remains in sediment. Several quantitative reconstructions of historical limnological conditions were produced from these sites, contributing to regional paleoclimate models and long-term ecological assessments.

Since approximately 2005, there has been a marked decline in paleolimnological publications. This decrease may reflect shifting research priorities or reduced funding for long-term environmental reconstruction projects. Despite this decline, the foundational work in this field remains critical for understanding baseline ecological conditions and informing predictions about future changes under anthropogenic and climatic pressures.

An additional, atypical theme that emerged from the literature pertains to anthropogenically created saline lakes, most notably the case of the Copper Pit Lake on Vancouver Island. This site, formed by the intentional flooding of a former open-pit copper mine approximately 400 m deep, represents a rare example of a managed meromictic system engineered to contain acid rock drainage [40]. The resulting stratified water body developed distinct saline and anoxic layers, mimicking certain natural saline lake conditions. Although artificial, this site has been studied in the context of mine reclamation, geochemical stability, and limnological evolution, offering unique insights into how human-engineered aquatic systems can parallel naturally occurring saline lake environments.

3.2.3. Inland Lakes of Special Interest

Several inland saline lakes in British Columbia have emerged as focal points for multidisciplinary research because of their unique geochemical profiles, microbial communities, and potential applications in astrobiology and environmental monitoring. These systems provide valuable insights into limnological processes operating under extreme conditions, and some serve as natural laboratories for broader scientific inquiries, including analog studies for early Earth and extraterrestrial life.

Mahoney Lake (location indicated in

Table A3. Location coordinates for the lakes shown in Figure 5a.

Lake	Coordinates
Sakinaw	52°16′60″ N	123°01′30″ W
Powell	51°46′30″ N	122°16′40″ W
Stum	49°57′30″ N	119°25′20″ W
Alkalai	49°04′40″ N	119°34′00″ W
Alki	51°04′40″ N	121°35′40″ W
Spotted	50°01′20″ N	120°37′20″ W
Pavilion	50°11′30″ N	119°22′40″ W
Clinton	49°17′20″ N	119°34′40″ W
Corbett	48°55′20″ N	123°33′20″ W
Slippy Slough	49°16′20″ N	123°11′40″ W
Mahoney	49°18′10″ N	119°34′20″ W
Salt Spring	52°32′40″ N	121°02′50″ W
Jericho Pond	49°01′40″ N	119°33′50″ W
Green	49°02′20″ N	119°33′40″ W
Quesnell	49°20′50″ N	119°43′00″ W
Kilpoola	50°52′00″ N	121°44′20″ W
Blue	51°04′30″ N	121°35′00″ W
Salt	52°07′10″ N	122°04′10″ W
Williams	51°40′00″ N	121°27′00″ W
Big	53°44′50″ N	122°17′20″ W
Opatcho	51°56′50″ N	121°59′50″ W
Felker	50°49′50″ N	116°23′40″ W
Cleland	50°28′30″ N	120°09′00″ W
Roche	50°49′50″ N	121°41′20″ W
Turquioise	51°19′50″ N	121°38′30″ W
Goodenough	51°01′00″ N	121°46′00″ W
Kelly	50°36′00″ N	121°21′30″ W
Basque	51°19′40″ N	121°38′00″ W
Last Chance	49°41′30″ N	125°33′05″ W
Black (Trout)	50°36′00″ N	127°28′40″ W
Buttle	50°47′50″ N	120°27′30″ W
Copper Mine Pit	49°40′50″ N	124°00′20″ W

) is arguably the most extensively studied saline lake in British Columbia. A comprehensive review of over five decades of research was recently published by Heinrichs et al. [41], summarizing studies across a wide range of limnological themes. However, additional significant contributions to the understanding of Mahoney Lake were not included in that review and merit acknowledgment here. These include early and foundational works such as Walker and Likens [42] and later studies examining microbial dynamics, sulfur cycling, and limnological structure, e.g., Chapman et al. [43], Northcote and Hall [44], Hall and Northcote [45,46], Overmann [47], Rathegeber [48], and Northcote and Hall [49,50].

Recent additions to the literature further expand this knowledge base. Kuzyk et al. [51] investigated contemporary sedimentation and water chemistry, while O’Beirne [52] and O’Beirne et al. [53] applied high-resolution techniques to reconstruct past biogeochemical changes. A recent publication by Varona et al. [54] extends this work using advanced geochemical modeling. Mahoney Lake is particularly noteworthy for its bimeromictic stratification, dominance of sulfur-utilizing bacteria, and unusually high sulfate and sodium concentrations. Its status as a biogeochemically extreme and microbially rich environment continues to make it an ideal site for microbial ecology and limnological research.

Although Pavilion Lake is not highly saline by strict geochemical standards [55], it holds exceptional scientific value due to its subaqueous microbialite structures. Situated in the Thompson–Nicola region, this lake hosts one of the few known occurrences of large microbialite formations in relatively clear and cool hyposaline water. These carbonate structures, found from shallow margins to deeper basins, have been the focus of extensive study through international collaboration, including projects under the Canadian Space Agency’s Canadian Analogue Research Network (CARN), NASA’s Ames Research Center, and the National Geographic Society [56]. Pavilion Lake serves as a planetary analog for studying biosignatures and microbialite formation in extraterrestrial settings, especially in the context of Mars and ancient Earth environments. While not categorized as a hypersaline lake, its inclusion in this discussion is justified by its relevance to microbial ecology and astrobiological modeling.

A cluster of highly saline to alkaline lakes located on the Cariboo Plateau—including Last Chance Lake, Kelly Lake, Clinton Lake, Goodenough Lake, Salt Lake, and the Basque Lakes—also stands out for its scientific importance. These systems have been investigated extensively for both sedimentary records and microbial assemblages (Table A2). Their geochemical heterogeneity, ranging from carbonate-dominated to sulfate-rich systems, provides ideal conditions for studying microbial mats, halotolerant invertebrates, and biogeochemical cycling under extreme ionic regimes. Like Pavilion Lake, several of these Cariboo Plateau lakes have been referenced in the context of astrobiology. Peterson et al. [57] and subsequent studies have emphasized their relevance to the search for biosignatures and the understanding of microbial survival strategies in hypersaline environments, strengthening their status as analogs for life on Mars.

Spotted Lake, known as kɬlil̕xʷ in nsyilxcən—the language of the Syilx (Okanagan) First Nation—is one of the most iconic saline lakes in British Columbia and holds both scientific and cultural significance. It was the subject of the earliest documented study of a saline lake in the province (circa 1918) and continues to captivate researchers due to its seasonal salt precipitates, circular mineral “spots,” and extraordinary mineral content. Recent studies, such as Olsson-Francis et al. [58], have proposed that Spotted Lake serves as an effective terrestrial analog for extraterrestrial environments that could harbor microbial life. Its seasonal hypersalinity, dominance of magnesium sulfate (epsomite), and visual similarities to evaporite terrains on Mars make it an ideal candidate for planetary analog studies. Furthermore, the cultural stewardship of the site by the Syilx people underscores the need for research to be conducted with respect to Indigenous values and knowledge systems.

3.3. Distribution of Saline Lakes

Hammer [59] posited that the formation and persistence of saline lakes are largely governed by climatic controls—particularly the balance between evaporation and precipitation. According to this framework, regions characterized by high potential evaporation and low annual precipitation are most likely to support the development of closed-basin saline or alkaline lakes (Figure 5a). In British Columbia, this climatic pattern is most pronounced in the central interior, particularly within rain-shadowed zones east of the Coast and Cascade Mountain ranges.

As illustrated in Figure 5b, estimates of precipitation and actual evaporation across the province reveal several areas where the gap between these variables narrows considerably, particularly around the 400 mm evaporation isoline. Notable among these are the Kamloops–Clinton corridor and the southern Okanagan Valley, both of which exhibit a high concentration of saline lakes. These regions experience pronounced moisture deficits, contributing to the progressive concentration of dissolved salts in endorheic basins.

Further refinement using climate moisture deficit (CMD) data from Wang et al. [60] identifies additional regions within BC that may be conducive to saline lake development. These include valley bottoms near Vanderhoof, Houston, and Telegraph Creek, where arid conditions driven by local topography and continental positioning result in substantial CMD values. These areas may harbor saline or hyposaline aquatic systems that have yet to be fully characterized or documented in the published literature.

The importance of broader climatic mechanisms in modulating effective moisture availability has also been highlighted in studies beyond BC. Pienitz et al. [61,62] and Veres et al. [63] documented saline lake systems in the Yukon Territory, north of BC, indicating that latitude control of temperature does not determine salinity trends. Instead, regional climatic dynamics—such as oceanic moisture transport, orographic precipitation gradients, and continental high-pressure anomalies (e.g., “heat domes”)—play a significant role. Such conditions can dramatically amplify evapotranspiration and reduce surface water inputs, thereby promoting salinization even at higher latitudes.

Whitfield [64] further emphasized the linkage between hydroclimatic variability and climate change across BC, noting evidence of prolonged dry seasons and declining snowpack in northern and interior regions. These trends suggest that currently freshwater, closed-basin lakes in the province may face increasing salinization in the future as hydrological balance shifts toward greater evaporative loss relative to inflow. As a result, changes in climate may act synergistically with topographic and geologic factors to alter lake chemistry over decadal to centennial timescales. Thus, the spatial distribution and salinity of BC’s inland lakes are influenced by a complex interplay of regional climate patterns, topographic variability, and long-term hydrological change. Understanding these factors is essential for predicting how current freshwater systems may transition toward salinity under ongoing climate change and for identifying previously undocumented saline systems in climatically marginal regions.

Figure 5. Sketch maps of British Columbia. (a) Approximate locations (indicated by stars) of saline lakes named in Appendix A, (accurate locations are provided in Table A3); (b) water balance, adapted from the 1978 Hydrological Atlas of Canada [65] using data from the 1941–1970 Climate Normals.

Figure 5. Sketch maps of British Columbia. (a) Approximate locations (indicated by stars) of saline lakes named in Appendix A, (accurate locations are provided in Table A3); (b) water balance, adapted from the 1978 Hydrological Atlas of Canada [65] using data from the 1941–1970 Climate Normals.

4. Conclusions

Saline lake research in British Columbia spans more than a century, beginning with early geochemical investigations in 1918 and continuing into the present day with advanced microbial and genomic studies. These aquatic systems encompass a wide range of limnological diversity, from deep meromictic coastal lakes—formed in glacially carved fjords and influenced by relict seawater intrusions—to inland closed-basin saline and alkaline lakes. Coastal systems such as Sakinaw and Powell Lakes are notable for their permanent stratification and ancient marine chemistry. Inland lakes, including Mahoney, Pavilion, and several across the Cariboo Plateau, have supported research spanning sediment geochemistry, paleolimnology, microbial ecology, and astrobiology.

Analysis of publication trends over time revealed a shift in research emphasis. While paleo- and neolimnological investigations peaked in the late 20th century, their frequency has declined since the early 2000s. In contrast, microbial and genomic studies have gained momentum, driven by technological advances and growing interest in extreme environments as analogs for early Earth or extraterrestrial ecosystems. This transition highlights the evolving scientific value of these lakes, but draws attention to gaps in our current understanding—particularly in the geographic distribution, ecological status, and future vulnerability of saline lakes in British Columbia.

Given their ecological uniqueness and sensitivity to hydrological and climatic variability, saline lakes in BC constitute a significant yet underrecognized natural resource. A more comprehensive understanding of their distribution, environmental drivers, and long-term ecological trajectories is essential in light of projected climate change and increasing anthropogenic pressures.

Future research efforts should prioritize the following:

• Systematic inventory and mapping of saline and potentially saline lakes across BC, with particular attention to climatically marginal regions identified via climate moisture deficit (CMD) modeling. This should integrate remote sensing tools and geochemical validation, and the data be made available for public access;
• Long-term monitoring programs of these identified saline lakes to assess chemical, biological, and physical trends under changing climate and land-use regimes, essential for tracking lake stability and resilience;
• Development of science-based environmental protection policies particular to saline lakes, including the expansion of protected status;
• Expansion of microbial and genomic investigations beyond well-characterized sites such as Mahoney and Pavilion Lakes, applying high-throughput sequencing and metagenomic techniques to underexplored systems;
• Strengthened collaboration with space and planetary sciences, particularly in lakes exhibiting microbialites or other biosignature-rich features of astrobiological interest;
• Inclusion of Indigenous ecological knowledge (IEK) in future research design and interpretation, particularly for culturally significant lakes such as kɬlil̕xʷ (Spotted Lake), to ensure ethical, community-driven research practices;
• Renewed funding and graduate training initiatives to reverse the post-2000 decline in academic output and cultivate the next generation of saline lake researchers.

By addressing these priorities, research on saline lakes in British Columbia can continue to yield insights of ecological, geochemical, and planetary importance while supporting conservation and sustainable management of these exceptional ecosystems. Implementation of improved, science-based management policies and practices around saline lakes would serve to prevent future degradation. These steps may include refining buffer zone size for agricultural, development, and other human activities, or enhanced protection status as parks or ecological reserves.