Although species diversity can be lost through hybridization (Mallet 2005; Seehausen 2006) and hybridization has been common among ciscoes (genus Coregonus, subgenus Leucichthys; Smith 1964; Todd and Stedman 1989; Eshenroder et al. 2016; Ackiss et al. 2020), the...
Bloater/C. hoyi
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...
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...
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...
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...
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...
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 -...
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...
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...