Post Archive:

Lake Erie

Development of conceptual early life history models and evaluation of sampling techniques in support of long-term monitoring for cisco and lake whitefish

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.

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...

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....

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.  

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...

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...