Contemporary spawning of cisco and lake whitefish is not known to occur in southern Green Bay but in recent years a small number (< 10 per year) of cisco adults have been recovered along the Door Peninsula, and lake whitefish larvae have been captured in drift...
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Spatio-statistical modeling and field validation of coregonine spawning and nursery locations for the Great Lakes, including connecting channels and major tributaries
This research builds on the spawning habitat inventory work [GLRI: Inventory and assessment of coregonine spawning locations in lakes Erie and Ontario, including connecting channels] by using data gleaned from the previous study to develop descriptive and predictive...
Historical and contemporary genetic diversity of Coregonus species from Lake Michigan
Advancements in molecular biology methods have allowed researchers to analyze genetic variation in extinct or extirpated species where minuscule amounts of cellular material remain. Here for the first time, we have leveraged one of these methods -...
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...
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...
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...
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...
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...
Movements and habitat use of cisco along a nearshore-offshore gradient in northern Lake Huron
Ciscoes (Coregonus artedi) were an abundant prey fish that linked lower and upper trophic levels in each of the Great Lakes until overexploitation, non-native fish invasions, and environmental degradation resulted in large-scale extirpation and range reduction in the...
Site fidelity, depth-habitat use, and reproductive behavior of ciscoes in Grand Traverse Bay, Lake Michigan
Successful reintroduction of cisco (Coregonus artedi) to the Great Lakes requires that stocked individuals are suitably adapted to environmental conditions at stocking sites. Thus, understanding how cisco ecology, life history, and behavior varies among extant...
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...
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...
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...
Contemporary habitat selection and survival of cisco in Lake Erie
This project addressed impediments to the rehabilitation of Cisco (Coregonus artedi) in Lake Erie through the application of acoustic telemetry to develop novel data on habitat use and survival of experimentally stocked fish. We tagged Cisco at the Tunison Laboratory...
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...
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.