Recruitment is set early during life (<2 years of age) for many fish populations (Hjort 1914, Houde 1987). From fertilization to juvenile stages, fishes are susceptible to abiotic and biotic factors that directly or indirectly influence growth, condition, and survival (Ludsin et al. 2014, Pritt et al. 2014). The mechanistic processes influencing recruitment, their interactions,and the timing at which they are most influential remains unclear for many fishes. By improving understanding of early life history (ELH) ecology and recruitment constraints, we can improve monitoring and support more informed management decisions. Long-term ELH monitoring programs that inform management are limited for cisco (Coregonus artedi) across the Great Lakes.
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Lake Superior
Use of multi-gear sampling to improve abundance estimates of demersal Coregonines in the Great Lakes
Acoustic and mid-water trawl surveys have been used to estimate abundance and biomass of Great Lakes coregonines for decades. Acoustic sampling has potential to be an important tool in the assessment of future coregonine restoration efforts because new populations...
Enhancing Kiyi (Coregonus kiyi) research to support the conservation and restoration of deep-water coregonine diversity in the Laurentian Great Lakes
The deep-water coregonines of the Coregonus species complex (including C. hoyi, C. kiyi, C. nigripinnis, C. zenithicus, C. johannae, and C. reighardi) in the Laurentian Great Lakes were among the fishes most impacted by overfishing, invasive species, and habitat...
Inventorying Great Lakes survey and life history information to facilitate coregonine science, conservation, and restoration
Population models are a critical tool for informing native fish conservation and the types of models that can be developed are determined by data availability. In the Great Lakes, the size of the ecosystems and the multi-organizational management approach means...
Developing a Great Lakes-wide database of coregonine stocking
A database of information associated with the release of hatchery-raised Coregonine fishes of Great Lakes origin was constructed and populated with all available records (>4,700) of stocking events. The information includes species, quantities, life stages, source...
Susceptibility and clearance of Aeromonas salmonicida (furunculosis) in Coregonus artedi (lake herring)
Aquaflor® (florfenicol) and Terramycin®200 for Fish (oxytetracycline) are approved medications in the United States for delivery with feed to control mortality in salmonids due to furunculosis associated with Aeromonas salmonicida. The purpose of this study was to...
How many cisco should be stocked, and at what life stage?
Historically, members of the coregonine complex (Coregonus spp.) were the most abundant and ecologically important fish species in the Great Lakes (especially the cisco C. artedi), but anthropogenic influences caused nearly all populations to collapse by the 1970s....
Lake Superior ciscoe spawning and winter ecology
This proposal expands on our recent work collecting ciscoes in winter near Grand Island, Michigan. This previous Coregonine Restoration Program funded project started the process of gathering data necessary to base Kiyi (Coregonus kiyi) restoration management...
Resolving the cisco complex of Lake Superior using morphological and genetic tools
Here we seek additional funding to follow-up a previous GLRI-funded project, “Morphologic, geographic and genetic variation among Lake Superior ciscoes.” Our goal was to conduct a comprehensive description of the morphological and genetic diversity of the Lake...
Establishing genetic baselines for historic coregonine diversity in Lake Superior
New research surveying morphological and genetic data across contemporary diversity in the cisco species complex has highlighted critical gaps in our understanding of the historic deepwater diversity in Lake Superior. Historic ciscoe diversity in Lake Superior, which...
Implementation of a gap analysis: comparing historical and contemporary coregonine habitat use in the Great Lakes
Understanding and comparing historic and contemporary habitat use and distributions of coregonines (Gap Analysis, Box 2) has been deemed essential to inform all boxes (Planning Phase) of the Great Lakes coregonine restoration framework (CRF). We are requesting support...
Implementation of Coregonine population viability analysis within the Coregonine restoration framework – Year 2
The Coregonine Restoration Framework provides an adaptive management structure to guide restoration of this suite of species in the Great Lakes Region. Initial steps in this effort are underway with the establishment of four science teams [Resolve Taxonomy, GAP...
Resolving taxonomy of the cisco (Coregonus) species complex in the Laurentian Great Lakes and Lake Nipigon
The manager endorsed Coregonine Restoration Framework (CRF) identified a need for reviewing and updating the taxonomy of ciscoes, and this task was assigned to the first of four science teams established in the Planning Phase of the CRF. The ‘Resolve cisco taxonomy’...
Building an adaptive tool for mapping habitat and species to support the Great Lakes coregonine conservation and restoration framework
Coregonines have declined substantially over the past century throughout the Great Lakes. A basin-wide framework, adopted by the Council of Lake Committees, has been developed to conserve and restore these ecologically and economically important native fishes. We are...
Development of a genetic map for cisco and bloater
We constructed a linkage map for cisco (Coregonus artedi), an economically and culturally important fish in the Great Lakes and across North America, which previously lacked a high-density haploid linkage map. We used diploid and haploid cisco from northern Lake Huron...
Redesigning nearshore and offshore fish community protocols to incorporate new species identification approaches and determine optimal sampling strategies
The objective of this work was to begin the process of describing Lake Superior larval ciscoe population dynamics at the species level, something which was not possible prior to 2019 (Ackiss et al. 2020) and use this information to develop standard collection protocols. From 2014-2023, larval fish were sampled at 163 and collected at 159 locations across Lake Superior. Due to COVID restrictions, no sampling occurred in 2020 and sampling in 2021 was limited to USA waters. Across all years, this sampling yielded 90,618 ciscoe larvae of which 11,751 individuals were identified based on genomics. The 4,369 larval ciscoes collected in 2023 have not yet but will be genomically identified. Genomic identifications yielded 78 Bloater, 8,671 Cisco, 75 Lake Whitefish, 1,969 Kiyi, and 958 putative hybrids. Principal findings include the widespread distribution of all species across the lake by July; high annual variation in hatching dates, sequential species hatch dates that match chronological spawning periods; Cisco first, Kiyi second, and Bloater third, and the occurrence of a genetically unique stock of Cisco along the north shore of the lake.
In 2022, unprecedented larval ciscoe survival past July provided an opportunity to collect young age-0 ciscoes in August, September, and October and evaluate their population dynamics. This effort resulted in the collection and genomic identification of 79 Bloater, 456 Cisco, 1,086 Kiyi, and 77 putative hybrids. A principal finding to date was documenting the late-summer movement of these fish from the surface, their preferred habitat in May-July, to 10-15 m below the surface in early August at around 25 mm in total length. This discovery has implications for when and how these fish can be collected.
A third outgrowth of this study was the opportunity to compare morphological-based species identifications to genomic-based species identifications for age-0 and near age-1 fish. This work could lead to a better understanding of which species, and at which size they can be reliably identified aboard the ship based on morphological characteristics. Dual identifications to date include 503 Bloater, 81 Cisco, 75 Kiyi, 3 Shortnose Cisco, 4 Pygmy Whitefish, and 89 putative hybrids, with an additional 2,292 age-1 ciscoes collected in 2023 remaining to be genomically identified. Preliminary analyses show rates of accurate morphological identification as compared to genomics to be highest for Cisco and lowest for Bloater, with the overall identification accuracy exceeding 90% for all three ciscoes when total length exceeds 140 mm.
Morphologic, geographic and genetic variation among Lake Superior ciscoes
The Laurentian Great Lakes once contained a diverse endemic cisco complex, but a series of factors resulted in declines in diversity and now Lake Superior is the only Great Lake with a relatively intact cisco complex. Although the large, pelagic cisco, Coregonus...
Comparing genetic population structure of Great Lakes cisco and lake whitefish to help determine restoration targets
Species diversity is necessary for the maintenance of sustainable fisheries because differential use of habitats can help buffer against unpredictable conditions. Therefore, an important first step to maintaining or restoring species diversity is describing extant...
Quantifying a potential mechanism between ice cover and cisco recruitment success: what role does light play in cisco embryonic development and larval survival?
Over the past several decades, Coregonus recruitment has dwindled to unprecedented levels for unknown reasons. Coregonus species are fall spawners whose embryos incubate under ice throughout the winter and hatch in spring. Recent changes in ice cover coupled with poor...
Kiyi reproductive phenology in Lake Superior
Kiyi historically occurred in Lakes Huron, Michigan, Ontario, and Superior. Today they occur in Lake Superior. Reestablishing Kiyi into lakes where it went extinct is a topic of discussion among Laurentian Great Lakes fishery managers. An impediment to re-introducing...
How does ecological function correspond to morphology in coregonines from Lakes Superior, Michigan, and Huron?
Fish managers recognize the value of diversity, within species and within communities, but most are focused on how diversity translates to function within the food web. For example, how does the diet of lake whitefish (Coregonus clupeaformis) differ from that of cisco...
Genetic diversity among Great Lakes cisco species: exploring taxonomic and population boundaries
Ciscoes (Coregonus artedi, hoyi, kiyi, zenithicus, and nigripinnis) once formed a diverse species flock in the Great Lakes. While several taxa appear to have been extirpated, those that remain are an important part of the Great Lakes food web. Deepwater forms (C....
Are there differences in larval and juvenile gene expression between hatchery and wild coregonids?
Management agencies are investigating best practices for coregonid (C. artedi and C. hoyi) culture, stocking, and broodstock development. However, before large scale production can begin, decisions about the sources of broodstock, culture practices, and stocking rates...
Building molecular tools for coregonine species identification
The larval phase of Coregonus spp. represent a bottleneck in year class strength that is not well understood in extant populations and could present an impediment for coregonine restoration efforts in the Great Lakes. The use of species-specific DNA sequences to...
Historical habitat use by Coregonus artedi in the upper Great Lakes and critical embayments
The restoration of the once abundant cisco (Coregonus artedi) is a management interest across the Laurentian Great Lakes. To inform restoration, we describe historical distributions of cisco in the upper Great Lakes (i.e., Lakes Superior, Michigan, and Huron) by...