Geology topics

Gregg Mackey

Publications and source records attributed to Gregg Mackey.

7 recordsLinked to original sources

USGS2026

Whitefishes—Coregonus spp.

Coregonines represent a diverse group of fishes of the Salmonidae subfamily Coregoninae that have ecological, cultural, and economical importance throughout their range. They are prey for other commercially and recreationally important predatory fish and are harvested for human consumption (Cleland 1982). Coregonines are generally cool- and coldwater species distributed across the northern hemisphere. The Laurentian Great Lakes of North America experienced considerable loss of coregonine biodiversity due to overfishing, the effects of nonnative species, and habitat loss (Bunnell et al. 2023). This resulted in the extinction of several species (Deepwater Cisco, Longjaw Cisco, and Kiyi) and local extirpations of other species (Blackfin Cisco, Shortnose Cisco, Shortjaw Cisco, Bloater, and Cisco) across all lakes (Bunnell et al. 2023). Renewed interest in restoring coregonines as the native prey base in the Laurentian Great Lakes prompted the development of a multi-agency restoration framework (Bunnell et al. 2023, 2024), and stocking of hatchery-produced coregonines is one of the management tools being used in this large restoration effort. This chapter focuses on culture methods for Lake Whitefish, Cisco, and Bloater currently being propagated for restoration and reintroduction in the Great Lakes (Bunnell et al. 2023). The techniques used for these species can serve as a starting point for the culture of other cisco species, such as Kiyi, which fisheries managers may consider for restoration stocking. Lake Whitefish, Cisco, and Bloater (Figure 1) are similar in appearance but have distinctively different life histories. They are silvery-white-colored fish and possess an adipose fin. Lake Whitefish are distinguished from Cisco and Bloater by a snout that overhangs the lower jaw (subterminal), whereas Cisco and Bloater have a lower jaw that extends beyond the snout (terminal). Lake Whitefish can reach lengths up to 79 cm (Phillips et al. 1982). Cisco and Bloater are smaller, reaching lengths of 34 and 30 cm, respectively (Eshenroder et al. 2016; Bunnell et al. 2023). Cisco and Bloater are similar in appearance but can be differentiated by head profiles, number of gill rakers (47 for Cisco and 42 for Bloater; Bunnell et al. 2023), and body morphometry. Lake Whitefish spawn from September through January in water depths of 2–4 m (Phillips et al. 1982). Cisco spawn from November through December in water depths of 1–47 m (Paufve et al. 2022), whereas Bloater spawn later in winter (February through May) at depths of 37–92 m (Koelz 1929; Becker 1983; Eshenroder et al. 2016). After eggs of all three species hatch in the spring, larvae feed on zooplankton and then switch to larger invertebrate prey as they grow; some will begin to feed on other fish species as they reach maturity (Warren and Lehman 1988; Brown and Taylor 1992; Breaker et al. 2020; Gatch et al. 2021). All three species typically mature at ages 4–5, with some maturing beginning at age 2 (Beauchamp 2002; Gorman 2012; DeCosta 2016).

Book chapter↗

USGS2024

U.S. Geological Survey Tunison Laboratory of Aquatic Science research to rehabilitate native prey fish of the Lake Ontario fish community—Coregonine fishes

Restoration of native coregonines to Lake Ontario of the Laurentian Great Lakes will improve the diversity of forage for salmonid predators and ecological function in the lake, but efficacy of experimental releases for native species restoration must be evaluated. The Coregonine Research Program at the U.S. Geological Survey Tunison Laboratory of Aquatic Science encompassed a diverse array of research, with an emphasis on improved culture methods and field assessments of experimentally released juvenile coregonines. This research was carried out to support the Fish Community Objectives of the Lake Ontario Committee, is funded largely by the Great Lakes Restoration Initiative, and was done in collaboration with other laboratories and agencies, particularly, the U.S. Fish and Wildlife Service; New York State Department of Environmental Conservation; Ontario Ministry of Natural Resources and Forestry; and other U.S. Geological Survey laboratories. The Tunison Laboratory of Aquatic Science and partners have developed new and innovative hatchery techniques to raise cisco and bloater to life stages suitable for survival in Lake Ontario; assessed adult bloater survival in Lake Ontario; and evaluated survival, return rate, and reproduction of adult cisco in historic spawning locations in Lake Ontario embayments. Successes, challenges, and research needs are discussed.

Lake Ontario↗

USGS2024

Morphometry, growth, and condition of hatchery-reared Cisco (Coregonus artedi) and Bloater (Coregonus hoyi)

The re-introduction of native species that have been extirpated or in low abundance in the Great Lakes has been a binational initiative between the United States and Canadian governments. Recently, new management programs have been underway that use current hatchery facilities for the restoration of native forage fishes in Lake Ontario. These species include Bloater ( Coregonus hoyi ), which has been extirpated from Lake Ontario for approximately four decades, and Cisco ( C. artedi ), which exists at a fraction of its former abundance. We assessed morphometrics, length-weight relationships, and condition factors during early life development for eight cohorts of Cisco and Bloater reared from 2012-2019. Weekly samples for Cisco and Bloater were measured from hatch until release (29-45 weeks, 133-1,002 samples annually). Head width, gape, mandible length, and mouth height metrics were all larger for Cisco than Bloater at any given size but increased at similar rates for both species. Average condition factors for Cisco and Bloater were 0.54317 and 0.55892, respectively. This information may also improve field identification of these species, helping managers evaluate the relative success of different release strategies for rehabilitation of populations of these native species.

Ecology and Evolutionary Biology↗

USGS2024

Cisco (Coregonus artedi) and bloater (Coregonus hoyi) culture manual

The primary objective of the Coregonine Research Program established at the U.S. Geological Survey, Great Lakes Science Center, Tunison Laboratory of Aquatic Science as mandated by the Great Lakes Restoration Initiative is to restore native coregonines, specifically Coregonus artedi (Lesueur, 1818; ciscoes) and Coregonus hoyi (Milner, 1874; bloaters) into Lake Ontario. This objective focuses on providing an alternative food source for top predators and improving the ecological function of Lake Ontario as it relates to native versus invasive species control. To complete this goal, hatchery techniques were developed to grow ciscoes and bloaters; these techniques are described in this standard operating manual.

Techniques and Methods↗

USGS2023

Field and laboratory validation of new sampling gear to quantify coregonine egg deposition and larval emergence across spawning habitat gradients

The influence of habitat and environmental conditions on Great Lakes coregonine reproduction is not well described, in part, because we lack sampling gears for early life stages that are effective across habitats. We designed new egg and larval emergence traps to quantify coregonine reproductive success across variable depths and substrates and tested them in laboratory and field settings. In the laboratory, our new metal ring egg traps had greater egg retention (94–100%) and faster post-catch processing (5–7 min) relative to a commonly employed fiber mat trap (30–67% and 30–60 min). In Lake Ontario’s Chaumont Bay, egg densities for lake whitefish Coregonus clupeaformis (0–5,832 eggs m −2 ) and cisco Coregonus artedi (0–426,501 eggs m −2 ) measured with metal ring traps (n = 112) varied across habitats but were greatest between 2–5 m on rock and dreissenid mussel substrates. Emergence traps used an inverted cone, fine mesh, and a clear collection chamber to capture positively phototactic emerging larvae. In the laboratory, traps captured 69–80% of emerged larvae. In Chaumont Bay, emergence traps deployed for 21 days after ice out caught only cisco larvae. Emergence rates varied across habitats (0–118 larvae m −2 day −1 , n = 85) but were highest on dreissenid mussel reef substrate. Our samplers improved processing efficiency and facilitated large sample sizes to quantify variability in egg deposition densities and emergence rates across habitats. These methods can advance coregonine conservation by determining how anthropogenic changes to habitat and environmental conditions influence incubation success.

Journal of Great Lakes Research↗

USGS2022

Results of the collaborative Lake Ontario bloater restoration stocking and assessment, 2012–2020

Bloater, Coregonus hoyi , are deepwater planktivores native to the Laurentian Great Lakes and Lake Nipigon. Interpretations of commercial fishery time series suggest they were common in Lake Ontario through the early 1900s but by the 1950s were no longer captured by commercial fishers. Annual bottom trawl surveys that began in 1978 and sampled extensively across putative bloater habitat only yielded one individual (1983), suggesting that the species had been locally extirpated. In 2012, a multiagency restoration program stocked bloater into Lake Ontario from gametes collected in Lake Michigan. From 2012 to 2020, 1,028,191 bloater were stocked into Lake Ontario. Bottom trawl surveys first detected stocked fish in 2015, and through 2020 ten bloater have been caught (total length mean = 129 mm, s.d. = 44 mm, range: 96–240 mm). Hatchery applied marks and genetic analyses confirmed the species identification and identified stocking location for some individuals. Trawl capture locations and acoustic telemetry suggested that stocked fish dispersed throughout the main lake within months or sooner, and the depth distribution of recaptured bloater was similar to historic distributions in Lake Ontario and other Great Lakes. Predicted bloater trawl catches, based on modeled population abundance and trawl survey efficiency, were similar to observed catches, suggesting that post-stocking survival is less than 20% and contemporary bottom trawl surveys can quantify bloater abundance at low densities and track restoration.

Lake Ontario↗

USGS2016

Mark retention of calcein in Cisco and Bloater

Since 2012, a multi-agency initiative to restore these native forage species has been under way. Evaluating the restoration success of Cisco Coregonus artedi and Bloater C. hoyi in Lake Ontario waters requires methods to identify stocked fish. However, juvenile Cisco and Bloater are fragile; thus, mass marking techniques that reduce the handling of individual fish are required and have not previously been evaluated. In 2014–2015 we evaluated the usefulness of calcein (SE-MARK) as a marker on bony structures, including the otolith. Juvenile Bloater and Cisco (14, 100, 128 d old) were immersed in a calcein bath at 5,000 mg/L of water for 4 min to apply the chemical marker. Observations of the marking retention were evaluated 8 d following the treatment. All fish immersed in calcein had strong brilliant marks (rating scale 3) on all bony structures including scales, fin rays, jaw bones, and vertebrate. The otolith was the only hard structure that did not show a brilliant marking due to the opaque nature of the structure. Our results suggest that calcein produces a strong discernable mark on hard bony structures of Cisco and Bloater; however, long-term retention needs further study.

Lake Ontario↗