Suresh A. Sethi

• Doctor of Philosophy
• Brooklyn College

Species invasions spur costly and labor-intensive control efforts, yet even local eradication is seldom achieved. When control measures are initially effective, they may drive evolutionary adaptation that prevents full eradication, as has been documented for some chemical and biocontrol approaches. Although the intensity, directionality, and persis...

Wild fish harvests from freshwaters and oceans per person on Earth have been stagnating for decades due to increased food demand from a burgeoning global human population, raising the stakes for maximizing the nutritional benefits from limited fish stocks. Here we adopt an allocation optimization approach using biogeographic and nutrient data for t...

Stocking is an important conservation tool to restore fish populations. Yet, assessing restoration success is often limited by a lack of field-based demographic information at low abundance, particularly for juvenile fish. Using outcomes from cisco (Coregonus artedi) reintroductions to Keuka Lake, New York, USA, we demonstrate a data-driven approac...

Objective The Atlantic Sturgeon Acipenser oxyrinchus is a wide-ranging, long-lived diadromous fish that is endangered in most of its range. Our objective was to develop and apply long-term, detection-corrected indices of relative abundance for juvenile and adult Atlantic Sturgeon in the Hudson River, New York, United States, to support population m...

Aquaculture in the Amazon holds the potential to meet increasing food demands while offering economic opportunities in a region facing deforestation and biodiversity loss. However, expanding aquaculture in this biodiverse region comes with complex environmental and social trade-offs. This Review explores how aquaculture can support sustainable deve...

Understanding how multiple species and populations vary in their recruitment dynamics can elucidate the processes driving recruitment across space and time. Lake Whitefish (Coregonus clupeaformis) and Cisco (C. artedi) are socioecologically important fishes across their range; however, many Laurentian Great Lakes populations have experienced declin...

The survival of animals is impacted by landscapes of spatially varying mortality factors including habitat type, predation risk or harvest risk, among others. Characterization of these spatial mortality processes is important for managing animal populations and their habitats, yet this information has proved challenging to capture. Advances in tele...

Acoustic surveys are important for fish stock assessments, but fish responses to survey vessels can bias acoustic estimates. We leveraged quiet uncrewed surface vessels (USVs) to characterize potential bias in acoustic surveys. Five conventional motorized ships overtook USVs from astern over 2 km transects at night in Lake Superior in 2022. We exam...

Disentangling the suite of ecological drivers that explain recruitment variability for Lake Whitefish Coregonus clupeaformis and Cisco C. artedi is of critical importance for their conservation, management, and stewardship in the Laurentian Great Lakes. However, recruitment is inherently variable and can be regulated by many interacting processes,...

Advances in tagging technologies are expanding opportunities to estimate survival of fish and wildlife populations. Yet, capture and handling effects could impact survival outcomes and bias inference about natural mortality processes. We developed a multistage time-to-event model that can partition the survival process into sequential phases that r...

Stream connectivity restoration through the removal or mitigation of dams and other anthropogenic barriers is critical for aquatic species conservation. Historically, stream connectivity restoration planning has been focused on biophysical criteria; however, aquatic barriers are embedded in social contexts that can constrain restoration decisions....

Acoustic surveys are a foundational component of many fisheries monitoring programs because they allow assessment of spatially extensive stocks. They are widely used to evaluate prey fish throughout the Great Lakes by numerous coordinating vessels. Traditionally, these surveys have been conducted by crewed and motorized vessels, but fish avoidance...

For decades, fish abundance surveys have been performed by large, crewed fisheries vessels using echosounders or trawling. However, the estimates obtained by these traditional methods may be biased due to the propagated noise generated by these vessels. A three-year collaborative effort has been conducted to measure the radiated acoustic signature...

Estimates of juvenile survival are critical for informing population dynamics and the ecology of fish, yet these demographic parameters are difficult to measure. Here, we demonstrate that advances in animal tracking technology provide opportunities to evaluate survival of juvenile tagged fish. We implemented a whole-lake telemetry array in conjunct...

Human changes to freshwater flows affect marine ecosystems, but such impacts are rarely considered in development plans involving dam building and water abstraction from rivers. Now research shows how approaches that integrate flow management and marine fisheries can improve both freshwater and coastal ecosystem sustainability.

Coregonines fishes, including lake whitefish (Coregonus clupeaformis) and cisco (C. artedi), are socioecologically important in the Laurentian Great Lakes and of conservation concern, but the processes driving recruitment variability are unclear. In Lake Ontario, cisco and lake whitefish exhibit similar spawning behaviors and early life-histories,...

Diet analysis is a vital tool for understanding trophic interactions and is frequently used to inform conservation and management. Molecular approaches can identify diet items that are impossible to distinguish using more traditional visual‐based methods. Yet, our understanding of how different variables, such as predator species or prey ration siz...

Molecular methods including metabarcoding and quantitative polymerase chain reaction have shown promise for estimating species abundance by quantifying the concentration of genetic material in field samples. However, the relationship between specimen abundance and detectable concentrations of genetic material is often variable in practice. DNA mixt...

Advancements in environmental DNA (eDNA) approaches have allowed for rapid and efficient species detections in diverse environments. Although most eDNA research is focused on leveraging genetic diversity to identify taxa, some recent studies have explored the potential for these approaches to detect within‐species genetic variation, allowing for po...

The introduction of hippos into the wild in Colombia has been marked by their rapid population growth and widespread dispersal on the landscape, high financial costs of management, and conflicting social perspectives on their management and fate. Here we use population projection models to investigate the effectiveness and cost of management option...

Prey fish abundances in the Great Lakes are a driver for several agencies’ commitments to the Council of Lake Committees to support fisheries management. These management decisions have profound economic and social impacts within the Great Lakes region. Fisheries estimates done by echosounders or trawling may be biased due to the propagated noise f...

Acoustic surveys of fish are a foundational component of many fisheries monitoring programs, including surveys in the Great Lakes. These surveys are conducted with traditional crewed and motorized vessels, but fish avoidance of these types of platforms has been reported in multiple studies, potentially biasing estimates. A quiet uncrewed surface ve...

Bottom-towed fishing gears produce significant amounts of seafood globally but can result in seafloor habitat damage. Spatial closures provide an important option for mitigating benthic impacts, but their performance as a fisheries management policy depends on numerous factors, including how fish respond to habitat quality changes. Spatial fisherie...

Invasive species introductions in high latitudes are accelerating and elevating the need to address questions of their effects on Subarctic and Arctic ecosystems. As a driver of ecosystem function, submerged aquatic vegetation is one of the most deleterious biological invasions to aquatic food webs. The aquatic plant Elodea spp. has potential to be...

Hatchery programmes are frequently used to supplement inland fisheries, yet achieving successful management outcomes often requires information on stocked versus naturally reproduced fish abundance. Parentage‐based tagging – genetically assigning offspring to their parents – has potential to be an effective approach for distinguishing stocked and n...

Arctic marine ecosystems are undergoing rapid physical and biological change associated with climate warming and loss of sea ice. Sea ice loss will impact many species through altered spatial and temporal availability of resources. In the Bering and Chukchi Seas, the Pacific walrus Odobenus rosmarus divergens is one species that could be impacted b...

Widespread stream network fragmentation from dams and culverts has altered habitat connectivity in river ecosystems and presents an acute threat to migratory fish. To support watershed management for an iconic migratory fish group, we assessed juvenile salmon growth outcomes across habitat use strategies and characterized how these life histories m...

Inland fisheries feed greater than 150 million people globally, yet their status is rarely assessed due to their socio-ecological complexity and pervasive lack of data. Here, we leverage an unprecedented landings time series from the Amazon, Earth's largest river basin, together with theoretical food web models to examine (i) taxonomic and trait-ba...

Round Goby Neogobius melanostomus , a non-native fish species to North America, has been rapidly expanding through the connected waterways of the Laurentian Great Lakes. Here, we document the eastward and southern expansion of Round Goby into the Hudson River, an iconic coastal estuary that drains to Long Island Sound and the Atlantic seaboard. In...

Coregonine fishes are important to Laurentian Great Lakes food webs and fisheries and are central to basin-wide conservation initiatives. In Lake Ontario, binational management objectives include conserving and restoring spawning stocks of cisco (Coregonus artedi) and lake whitefish (C. clupeaformis), but the spatial extent of contemporary coregoni...

Fisheries management is a complex task made even more challenging by rapid and unprecedented socioecological transformations associated with climate change. The Resist‐Accept‐Direct (RAD) framework can be a useful tool to support fisheries management in facing the high uncertainty and variability associated with aquatic ecosystem transformations. H...

Trophic interactions are drivers of ecosystem change and stability, yet are often excluded from fishery assessment models, despite their potential capacity to improve estimates of species dynamics and future fishery sustainability. In Lake Ontario, recreational salmonine fisheries, including Chinook salmon (Oncorhynchus tshawytscha) and lake trout...

Proposed hydropower dams at more than 350 sites throughout the Amazon require strategic evaluation of trade-offs between the numerous ecosystem services provided by Earth’s largest and most biodiverse river basin. These services are spatially variable, hence collective impacts of newly built dams depend strongly on their configuration. We use multi...

Restoring stream ecosystem integrity by removing unused or derelict dams has become a priority for watershed conservation globally. However, efforts to restore connectivity are constrained by the availability of accurate dam inventories which often overlook smaller unmapped riverine dams. Here we develop and test a machine learning approach to iden...

Intensifying global change is propelling many ecosystems toward irreversible transformations. Natural resource managers face the complex task of conserving these important resources under unprecedented conditions and expanding uncertainty. As once familiar ecological conditions disappear, traditional management approaches that assume the future wil...

Numerous hydropower facilities are under construction or planned in tropical and subtropical rivers worldwide. While dams are typically designed considering historic river discharge regimes, climate change is likely to induce large-scale alterations in river hydrology. Here we analyze how future climate change will affect river hydrology, electrici...

Cisco (Coregonus artedi) once dominated fish communities in the Laurentian Great Lakes. Restoring the abundance and distribution of this species has emerged as a management priority, yet our understanding of Cisco spawning habitat use is insufficient to characterise habitat needs for these populations and assess whether availability of suitable spa...

Widespread overharvest has led to marine ecosystem degradation and declining fishery catches in many tropical communities. To allow stocks to recover and provide increased flows of food and income, reductions in fishing effort are necessary. The development of Alternative Income Generating Activities can help to reduce the economic reliance of coas...

Ecosystem transformation involves the emergence of persistent ecological or social–ecological systems that diverge, dramatically and irreversibly, from prior ecosystem structure and function. Such transformations are occurring at increasing rates across the planet in response to changes in climate, land use, and other factors. Consequently, a dynam...

Although biodiversity loss adversely influences a variety of ecosystem functions, how declining wild food diversity affects nutrient supplies for people is poorly understood. Here, we analyze the impact of declining biodiversity on nutrients supplied by fish using detailed information from the Peruvian Amazon, where inland fisheries provide a criti...

Release of hatchery-reared juvenile cisco (Coregonus artedi) is an important tool for recovering Great Lakes populations, but post-release survival is unknown. Telemetry using small acoustic tags provides opportunities to assess the efficacy of hatchery-reared fish releases. However, better understanding of the tolerance of juvenile cisco to acoust...

With declining capture fisheries production, maintaining nutrient supplies largely hinges on substituting wild fish with economically comparable farmed animals. Although such transitions are increasingly commonplace across global inland and coastal communities, their nutritional consequences are unknown. Here, using human demographic and health inf...

• Juvenile Pacific salmon exhibit diverse habitat use and migration strategies to navigate high environmental variability and predation risk during freshwater residency. Increasingly, urbanization and climate‐driven hydrological alterations are affecting the availability and quality of aquatic habitats in salmon catchments. Thus, conservation of fr...

Advances in environmental DNA (eDNA) methodologies have led to improvements in the ability to detect species and communities in aquatic environments, yet the majority of studies emphasize biological diversity at the species level by targeting variable sites within the mitochondrial genome. Here, we demonstrate that eDNA approaches also have the cap...

The ability to monitor water temperature is important for assessing changes in riverine ecosystems resulting from climate warming. Direct in situ water temperature collection efforts provide point-samples but are cost-prohibitive for characterizing stream temperatures across large spatial scales, especially for small, remote streams. In contrast, s...

Abstract Close‐kin mark–recapture (CKMR) is a powerful new method for the assessment of fish and wildlife population dynamics. Unlike traditional mark–recapture techniques, the use of kinship as an identifying mark is robust to many forms of capture heterogeneity including variation in gear efficiency and tagging‐based effects such as loss and diff...

This report makes the case for valuing nature in our economies, examines current biodiversity financing and the future funding needs to protect our most important biodiversity, thus calculating the "biodiversity financing gap" between now and 2030. It then outlines nine policies and mechanisms that have the potential to close that gap.

Ecosystem transformation can be defined as the emergence of a self‐organizing, self‐sustaining, ecological or social–ecological system that deviates from prior ecosystem structure and function. These transformations are occurring across the globe; consequently, a static view of ecosystem processes is likely no longer sufficient for managing fish, w...

We developed single nucleotide polymorphism (SNP) markers to support a genetics-based capture-mark-recapture (CMR) project implemented for the management of Pacific walrus (Odobenus rosmarus divergens). Using a combination of Restriction-site Associated DNA sequencing (RADSeq) and genome resequencing, 57,504 single nucleotide variants were identifi...

The kin structure of a species at relatively fine spatial scales impacts broad-scale patterns in genetic structure at the population level. However, kin structure rarely has been elucidated for migratory marine mammals. The Pacific walrus (Odobenus rosmarus divergens) exhibits migratory behavior linked to seasonal patterns in sea ice dynamics. Cons...

• The round goby (Neogobius melanostomus) is among the fastest‐spreading introduced aquatic species in North America and is radiating inland from the Great Lakes into freshwater ecosystems across the landscape. Predicting and managing the impacts of round gobies requires information on the factors influencing their distribution in habitats along th...

Cisco (Coregonus artedi) and lake whitefish (Coregonus clupeaformis) are native fish species of management concern in the Laurentian Great Lakes that often overlap in spawning locations and timing. Thus, species-level inference from in situ sampling requires methods to differentiate their eggs. Genetic barcoding and hatching eggs to visually identi...

Ecosystem-scale examination of fish communities typically involves creating spatio-temporally explicit relative abundance distribution maps using data from multiple fishery-independent surveys. However, sampling performance varies by vessel and sampling gear, which may influence estimated species distribution patterns. Using GAMMs, the effect of di...

Wild‐caught fish account for approximately one‐half of all seafood consumed globally, yet there is strong evidence that improved science and management are needed to ensure the biological, economic, and social sustainability of this critical food source. Presently, insufficient resources are allocated to achieve such sustainability, but conservatio...

Recent research in city planning has measured “walkability” and multi-modalism through quantification of the built environment. Results have shown correlations with increased property values and neighbourhood stabilisation as well as a lack of spatial distribution of accessible resources based on socio-economic class. Some studies suggest that impr...

Explains the relationship between ecological disturbance and biological diversity, in greater depth and breadth.

Hundreds of dams have been proposed throughout the Amazon basin, one of the world's largest untapped hydropower frontiers. While hydropower is a potentially clean source of renewable energy, some projects produce high greenhouse gas (GHG) emissions per unit electricity generated (carbon intensity). Here we show how carbon intensities of proposed Am...

In situ observations of incubating fish eggs can identify spawning sites and spawning habitat preferences, informing the ecology of fishes with benthic eggs. Suction pumps have been used to sample benthic-incubating, non-adhesive fish eggs, yet their sampling efficiency is not well known. Imperfect or systematically variable egg detection could bia...

Bycatch of Pacific halibut (Hippoglossus stenolepis) limits many trawl fisheries in Alaska and greatly concerns stakeholders from local communities and fisheries that rely on Pacific halibut. To reduce Pacific halibut mortality, trawlers in the Bering Sea that target flatfish have been developing expedited release procedures to sort Pacific halibut...

Minimizing fishing impacts on seafloor ecosystems is a growing focus of ocean management; however, few quantitative tools exist to guide seascape-scale habitat management. To meet these needs, we developed a model to assess benthic ecosystem impacts from fishing gear contact. The habitat impacts model is cast in discrete time and can accommodate ov...

Purpose We assessed the effect of elective extended field radiation (EFRT) and nodal dose escalation on locoregional control and survival in patients with node-positive cervical cancer treated with definitive chemoradiation at 2 academic institutions. Methods and Materials Patients with cervical cancer with pelvic and/or paraortic lymph node (PALN...

Management options to mitigate potential effects from the overlap of anthropogenic and marine mammal activities require understanding of species’ habitat use and movement patterns. We analyzed high temporal frequency industrial marine mammal monitoring program aerial surveys conducted over a protracted period from April to October of 2013 and 2014...

Species distribution models (SDMs) are commonly used to model the spatial structure of species in the marine environment, however, most fail to account for detectability of the target species. This can result in underestimates of occupancy, where nondetection is conflated with absence. The site occupancy model (SOM) overcomes this failure by treati...

A history of overexploitation and industrialization of riverine habitats has impacted Shortnose Sturgeon Acipenser brevirostrum, leading this species to be one of the earliest listed under the U.S. Endangered Species Act. Presently, understanding spatial ecology of Shortnose Sturgeon is based on observations from a limited number of Atlantic coasta...

Mixtures of DNA from multiple contributors present a novel opportunity to count individuals to inform fish and wildlife ecology. We apply a likelihood‐based framework to estimate the number of contributors to a DNA mixture for ecological applications. We then assess the performance of DNA mixture estimation through a combination of simulation analy...

We provide an exact and approximation algorithm based on Dynamic Programming and an approximation algorithm based on Mixed Integer Programming for optimizing for the so-called dendritic connectivity on tree-structured networks in a multi-objective setting. Dendritic connectivity describes the degree of connectedness of a network. We consider differ...

The spawning migration travel times of chum salmon, Oncorhynchus keta (Walbaum), fitted with gastrically implanted radio tags vs external spaghetti tags were tested for a short [≈60 river km (rkm)] and long migration route (≈730 rkm) on the Koyukuk River, Alaska, USA. Using a novel application of statistical arrival curve models to infer travel tim...

Real-world problems are often not fully characterized by a single optimal solution, as they frequently involve multiple competing objectives; it is therefore important to identify the so-called Pareto frontier, which captures solution trade-offs. We propose a fully polynomial-time approximation scheme based on Dynamic Programming (DP) for computing...

Context Efficient restoration of longitudinal river connectivity relies on barrier mitigation prioritization tools that incorporate stream network spatial structure to maximize ecological benefits given limited resources. Typically, ecological benefits of barrier mitigation are measured using proxies such as the amount of accessible riverine habita...

The remoteness of subarctic and arctic ecosystems no longer protects against invasive species introductions. Rather, the mix of urban hubs surrounded by undeveloped expanses creates a ratchet process whereby anthropogenic activity is sufficient to introduce and spread invaders, but for which the costs of monitoring and managing remote ecosystems is...

Juvenile salmon life history strategies, survival, and habitat interactions may vary by age cohort. However, aging individual juvenile fish using scale reading is time consuming and can be error prone. Fork length data are routinely measured while sampling juvenile salmonids. We explore the performance of aging juvenile fish based solely on fork le...

Error-tolerant likelihood-based match calling presents a promising technique to accurately identify recapture events in genetic mark–recapture studies by combining probabilities of latent genotypes and probabilities of observed genotypes, which may contain genotyping errors. Combined with clustering algorithms to group samples into sets of recaptur...

Supplementary Materials are combined into a single .pdf document, with the following contents: Supplement 1: Detail of the error-tolerant likelihood-based match calling and sample clustering approach Supplement 2: R script to implement the error-tolerant likelihood-based match calling model and sample clustering algorithms: MSATs Supplement 3: R sc...

We used Global Positioning System (GPS) radiotelemetry data from 7 breeding female wolves (Canis lupus; n = 14 dennings) in 3 regions across Alaska, USA, during 2008–2011 to develop and compare methods for estimating the onset of denning, and thus infer timing of parturition. We developed and tested 2 estimators based on a combination of GPS radioc...

Invasive species introductions in Arctic and Subarctic ecosystems are growing as climate change manifests and human activity increases in high latitudes. The aquatic plants of the genus Elodea are potential invaders to Arctic and Subarctic ecosystems circumpolar and at least one species is already established in Alaska, USA. To illustrate the probl...

In this study, we examined summer and fall freshwater rearing habitat use by juvenile coho salmon (Oncorhynchus kisutch) in the quickly urbanising Big Lake drainage in south-central Alaska. Habitat use was assessed by regressing fish count data against habitat survey information across thirty study sites using generalised linear mixed models. Habit...

Missed counts are commonplace when enumerating fish passing a weir. Typically “connect-the-dots” linear interpolation is used to impute missed passage; however, this method fails to characterize uncertainty about estimates and cannot be implemented when the tails of a run are missed. Here, we present a statistical approach to imputing missing passa...

Conceptual ecological models synthesize information about complex systems into simplified visual maps and can be used to prioritize system components for research or management attention. In this article, we introduce conceptual modeling methods that incorporate expert ratings about a suite of properties of system components, including assessment o...

Management and technical approaches that achieve a sustainable level of fish production while at the same time minimizing or limiting the wider ecological effects caused through fishing gear contact with the seabed might be considered to be ‘best practice’. To identify future knowledge-needs that would help to support a transition towards the adopt...

Variation in the timing of migration to freshwaters to spawn is one important dimension of the life history variation within individual salmon stocks. That variable has important implications for developing sustainable fisheries that simultaneously exploit multiple populations within the same geographic area. We examined the variation in migration...

The efficacy of fish habitat conservation in land planning processes in Alaska is often constrained by the extent of current knowledge of fish distributions and habitat use. In response to requests for information from land and salmon resource management stakeholders regarding Auke Lake sockeye salmon (Oncorhynchus nerka) status and life history, w...

Fishing communities are subject to economic risk as the commercial fisheries they rely on are intrinsically volatile. The degree to which a community is exposed to economic risk depends on a community׳s ability to confront and/or alter its exposure to volatile fishery conditions through risk-reduction mechanisms. In this article, economic risk – as...

Chinook salmon, Oncorhynchus tshawytscha (Walbaum), is an important biological and cultural resource in Alaska, but knowledge about Chinook salmon ecology is limited in many regions. From 2009 to 2012, spawning distribution and abundance of a northern Chinook salmon population on the Togiak River in south-west Alaska were assessed. Chinook salmon p...

Molecular markers with inadequate power to discriminate among individuals can lead to false recaptures (shadows), and inaccurate genotyping can lead to missed recaptures (ghosts), potentially biasing genetic mark–recapture estimates. We used simulations to examine the impact of microsatellite (MSAT) and single nucleotide polymorphism (SNP) marker-s...

Objective: Dose-response relationships for meningioma radiosurgery are poorly characterized. We evaluated determinants of local recurrence for meningiomas treated with Gamma Knife radiosurgery (GKRS), to guide future treatment approaches to optimize tumor control. Materials and Methods: A total of 101 consecutive patients (108 tumors) who underwent...

Time stratified Lincoln–Petersen mark–recapture models can generate estimates of salmon abundance that are robust to capture heterogeneity. Bayesian implementation of these estimators provides a flexible framework to formulate different model structures, including random effects structures and models with functional relationships between parameters...

Imperfect detection associated with sampling gear presents challenges for wildlife inventory and monitoring efforts. We examined occupancy dynamics and habitat use of juvenile coho salmon, Oncorhynchus kisutch, in shallow lake environments over a summer and early fall season in the Knik River area of south central Alaska using models which control...

Sethi, S. A., Dalton, M., and Hilborn, R. 2012. Managing harvest risk with catch-pooling cooperatives – ICES Journal of Marine Science, 69: 1038–1044. Catch-pooling cooperatives are a strategy for fishers to manage variability which can be organized independently of a central management agency. We examined the statistical properties of equal-share...

Traditional measures that quantify variation in natural resource systems include both upside and downside deviations as contributing to variability, such as standard deviation or the coefficient of variation. Here we introduce three risk measures from investment theory, which quantify variability in natural resource systems by analyzing either upsi...