Philopatry and vagrancy of white bass (Morone chrysops) spawning in the Sandusky River: Evidence of metapopulation structure in western Lake Erie using otolith chemistry

Although natal homing and philopatry are well studied in anadromous salmon, few studies have investigated philopatric behavior in large, freshwater systems. In western Lake Erie, white bass (Morone chrysops) undergo seasonal spawning migrations from the open-water regions of Lake Erie to nearshore reef complexes and tributaries. The three primary spawning locations in Lake Erie are within 80 km of each other and are not separated by physical barriers. We used naturally occurring differences in otolith strontium concentrations among major spawning locations to address philopatry and vagrancy to the Sandusky River spawning location. Most individuals spawning in the Sandusky River were natal to this river (73%). No statistically significant differences in the extent of homing by sex or age of spawning were found, although a potential pattern of decreased homing with increased age of fish was observed. Given the proportion of vagrant individuals we found spawning in the Sandusky River (27%), it is unlikely that Lake Erie white bass spawning populations are genetically distinct. Furthermore, the white bass population in Lake Erie appears to be structured as a metapopulation, with non-philopatric individuals serving as a link between spawning populations.     

NOTE: First record of natural reproduction by Atlantic salmon (Salmo salar) in the St. Marys River,Michigan

Atlantic salmon (Salmo salar) are native to Lake Ontario; but their populations severely declined by the late 1800s due to human influences. During the early to mid-1900s, Atlantic salmon were stocked throughout the Great Lakes in effort to reestablish them into Lake Ontario and introduce the species into the upper Great Lakes. However, these efforts experienced minimal success. In 1987, Lake Superior State University and the Michigan Department of Natural Resources began stocking Atlantic salmon in the St. Marys River, Michigan, which has resulted in a successful, self-supporting hatchery operation and stable recreational Atlantic salmon fishery. Possibly due to a combination of competition with other salmonid species for spawning habitat, prey selection causing detrimental effects on early life stages and high rates of early mortality syndrome, Atlantic salmon appeared to be severely limited in their ability to naturally reproduce within the upper Great Lakes. In 2012, the first unequivocal documentation of naturally reproduced Atlantic salmon in the St. Marys River was recorded, downstream from the compensation works and parallel to the Soo Locks in Sault Ste. Marie, Michigan.     

Blueback Herring (Alosa aestivalis) in Lake Ontario: First Record,Entry Route,and Colonization Potential

Two juvenile blueback herring (Alosa aestivalis) were caught in Lake Ontario in October 1995, the first record of this anadromous marine clupeid in the Great Lakes. Blueback herring most likely gained entry to Lake Ontario via the Erie Barge Canal, a navigation canal that links the Mohawk-Hudson rivers, which drain to the Atlantic Ocean, to Oneida Lake, which drains to Lake Ontario through the Oneida-Oswego rivers. Blueback herring ascend the Hudson River to spawn and were first reported from the upper Mohawk River in 1978. They currently spawn in several of the upper Mohawk's tributaries, including one about 430 km from the ocean but only 25 km from Oneida Lake. They were first found in Oneida Lake in 1982 and, in fall 1994, large numbers of juvenile blueback herring were found moving down the Oswego River. In the southern United States, blueback herring established self-reproducing populations in several reservoirs, and thus they have the potential to colonize Lake Ontario. If blueback herring become established in Lake Ontario, they could spread to other Great Lakes and impede recovery of depressed populations of indigenous fishes, like lake herring (Coregonus artedi) and lake trout (Salvelinus namaycush), through competition with, or predation on, their larvae.     

Migratory salmonid redd habitat characteristics in the Salmon River,New York

Non-native migratory salmonids ascend tributaries to spawn in all the Great Lakes. In Lake Ontario, these species include Chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), steelhead (O. mykiss), and brown trout (Salmo trutta). Although successful natural reproduction has been documented for many of these species, little research has been conducted on their spawning habitat. We examined the spawning habitat of these four species in the Salmon River, New York. Differences in fish size among the species were significantly correlated with spawning site selection. In the Salmon River, the larger species spawned in deeper areas with larger size substrate and made the largest redds. Discriminant function analysis correctly classified redds by species 64–100% of the time. The size of substrate materials below Lighthouse Hill Dam is within the preferred ranges for spawning for these four species indicating that river armoring has not negatively impacted salmonid production. Intra-specific and inter-specific competition for spawning sites may influence redd site selection for smaller salmonids and could be an impediment for Atlantic salmon (S. salar) restoration.     

Microhabitat use of landlocked juvenile Atlantic salmon (Salmo salar)

Large-scale reintroduction programs for landlocked Atlantic salmon Salmo salar are ongoing in Lakes Ontario and Champlain. Commonly, these programs involve stocking hatchery reared juveniles into streams and thus, quantifying the in situ habitat use of stocked fish can help support these efforts. To examine habitat use, we stocked young-of-the-year (YOY) Atlantic salmon into 14 reaches of the Boquet River in the Lake Champlain Basin. The habitat used by YOY Atlantic salmon, measured from microhabitats that were used versus not used, differed between early and late summer for water depth. In early summer, YOY Atlantic salmon used a more narrow range of habitats compared to late summer. However, in both early and late summer, YOY most often used intermediate values in habitat variables except for water velocity in early summer. In early summer, YOY Atlantic salmon had the highest probability of using a water depth of 26 cm, a water velocity of 1 cm/sec, and a pebble substrate. In late summer, the probability of use was highest at a water depth of 61 cm, a water velocity of 11 cm/sec, and a pebble substrate. Our results show that stocked landlocked YOY Atlantic salmon use similar habitats to anadromous populations and may help managers when determining stocking locations or habitat alterations.     

Majority of age-3 Chinook salmon (Oncorhynchus tshawytscha) in Lake Ontario were wild from 1992 to 2005, based on scale pattern analysis

Stocking of hatchery-raised Chinook salmon has been the principal tool utilized by fishery managers for controlling alewives in Lake Ontario and elsewhere in the Great Lakes. Stocked Chinook salmon are also often viewed by anglers as the principal source of maintaining catch rates. Stocking levels are often controversial and set with limited information about the relative contribution of wild fish to lake-wide populations. Recent research documenting large numbers of age-0 fish in tributaries suggested that wild reproduction was increasing and greater than previously thought. Estimating the contribution of wild Chinook salmon is imperative for successful management of this economically important recreational fishery. To differentiate wild from hatchery-derived Chinook salmon, we developed and validated a classification rule from scale pattern analysis of known-origin fish that was based on the area of the scale focus and the distance between the scale focus and the first circulus. We used this technique to determine the annual proportion of angler-caught, age-3 wild Chinook salmon in Lake Ontario from 1992 to 2005. On average over 14 years, the annual proportion of wild age-3 Chinook salmon was 62% (± 13.6%, 95% CI), but has varied between 24% (± 9.4%) and 82% (± 11.2%). Wild fish have been a high proportion of the Chinook salmon population in Lake Ontario since the late 1980s throughout a period when the lake underwent considerable changes, suggesting that wild and hatchery-origin Chinook salmon are both important components for managing the predator–prey dynamics in Lake Ontario and maintaining angler catch rates.     

Trophic ecology of salmonine predators in northern Lake Huron with emphasis on Atlantic salmon (Salmo salar)

Pacific salmon were introduced to the Great Lakes in the 1960s and now support major recreational fishery. Population declines resulting from invasive species have prompted agencies to consider diversifying sport fisheries through stocking. Atlantic salmon are native to Lake Ontario, but a small fishery has developed in northern Lake Huron since the 1990s that appears suited to the Lake Huron food web leading to requests for increased stocking by anglers and consideration by agencies. However, no study has evaluated the trophic ecology of Atlantic salmon in relation to other salmonine predators in northern Lake Huron. In this study, we used stable isotopes of carbon (δ¹³C) and nitrogen (δ¹⁵N), along with mercury (Hg) concentrations to assess resource use, niche overlap, and contaminant accumulation in Atlantic salmon compared to select Lake Huron predators. Atlantic salmon exhibited considerable niche overlap with Chinook and coho salmon but were strongly differentiated from lake trout. In addition, we observed that Atlantic salmon had similar Hg concentrations as coho but were lower than both Chinook salmon and lake trout. Based upon the relationship between fish size, δ¹⁵N, and Hg, Atlantic salmon bioaccumulate Hg similarly to Pacific salmon but likely have lower consumptive demands than Chinook salmon. Continued attention should be placed on understanding how Atlantic salmon fit into the current Lake Huron food web in order to evaluate the long-term efficacy of the Atlantic salmon stocking program.     

Post‐Spawning Survival and Downstream Passage of Landlocked Atlantic Salmon (Salmo salar) in a Regulated River: Is There Potential for Repeat Spawning?

Repeat salmonid spawners may make large contributions to total recruitment and long term population stability. Despite their potential importance, relatively little is known about this phase of the life history for anadromous populations, and nothing has been reported for landlocked populations. Here, we studied post‐spawning behaviour and survival of landlocked Atlantic salmon in relation to downstream dam passage in the River Klarälven, Sweden. Eight hydropower stations separate the feeding grounds in Lake Vänern from the spawning grounds in the River Klarälven, and no measures to facilitate downstream migration are present in the river. Forty‐nine percent of the salmon survived spawning and initiated downstream migration. Females and small fish had higher post‐spawning survival than males and large fish. The post‐spawners migrated downstream in autumn and spring and remained relatively inactive in the river during winter. Downstream migration speed in the free flowing part of the river was highly variable with a median of 9.30 km/day. Most fish passed the first hydropower station via upward‐opening spill gates after a median residence time in the forebay of 25 min. However, no tagged fish survived passage of all eight hydropower stations to reach Lake Vänern. This result underscores the need for remedial measures to increase the survival of downstream migrating kelts. Copyright © 2015 John Wiley & Sons, Ltd.     

Diel variation in summer habitat use,feeding periodicity,and diet of subyearling Atlantic salmon in the Salmon River Basin,New York

The habitat use, diet composition, and feeding periodicity of subyearling Atlantic salmon (Salmo salar) was examined during both day and night periods during summer in tributaries of Lake Ontario. The amount of cover used was the major habitat variable that differed between day and night periods in both streams. At night subyearling Atlantic salmon were associated with significantly less cover than during the day. Principal Component Analysis showed that habitat selection of subyearling Atlantic salmon was more pronounced during the day in both streams and that salmon in Orwell Brook exhibited more diel variability in habitat use than salmon in Trout Brook. Subyearling salmon fed primarily from the benthic substrate on baetids, chironomids, and leptocerids. There was a substantial amount of diel variation in diet composition with peak feeding occurring from 0400 h to 0800 h on July 21–22, 2008.     

Population Characteristics and Spawning Migration Dynamics of Pink Salmon in U.S. Waters of the St. Marys River

Population attributes and migratory dynamics of spawning pink salmon Oncorhynchus gorbuscha were examined in U.S. waters of the St. Marys River from 1998 through 2002. Spawning migrations were monitored twice each week from late August through early October of each sampling year using a single gill net set immediately below their spawning grounds. Pink salmon were captured between 23 August and 11 October, with the peak migration event in all years occurring between 10 and 22 September. Catch-per-unit-effort was greater in even years (57 fish/night) than in odd years (30 fish/night). Water temperature during spawning migrations ranged from 11.4 to 21.4°C, with nearly 90% of fish captured between 15.0 and 19.7°C. The proportion of females captured (mean = 0.25; range, 0.09 to 0.35) declined after the peak-migration event, with few females caught during October. Total length and wet weight of male and female fish displayed much variability within and among years. Relative condition of male pink salmon declined over the spawning migration, with a sharp decline observed after peak migration events. Pink salmon representing ages 2 through 4 were captured during the study period, with a large percentage (range, 14.6 to 50.6%) of these fish deviating from their usual two-year life cycle. These are the first reported age-3 pink salmon from a Lake Huron tributary and first age-4 fish observed in any freshwater or marine system. Our results suggest that the naturalization of pink salmon to the upper Great Lakes has resulted in system-specific modifications to their potamodromous life history.     

Patterns in spatial use of land-locked Atlantic salmon (Salmo salar) in a large lake

Understanding the spatial use of reintroduced fish is useful for fisheries management and evaluating restoration success. Atlantic salmon (Salmo salar) were reintroduced into Lake Ontario in the 1990s; however, the movement ecology of these land-locked fish is unknown. Using acoustic telemetry and Floy tag mark-recaptures, we examined seasonal home range and space use of Atlantic salmon in Lake Ontario. Hatchery-raised adult Atlantic salmon were tagged with acoustic transmitters (n = 14; 8 with depth sensors) or Floy tags (n = 1915) and released. Both acoustic telemetry and Floy tag recaptures (n = 90) indicated cross lake movements, and home ranges encompassed nearly the entire lake in summer but was smaller in winter. Movements were nearshore (<2 km from shore) from spring to summer at ～20 m bathymetric depths, with movements closer to shore in the fall, and further offshore (～5.5 km from shore and 45 m bathymetric depths) in winter. Depth use was relatively shallow (<4 m) with occasional deeper dives (max = 28.5 m), and small diel vertical movements (1–5 m), moving deeper during daytime, consistent with ocean movements of Atlantic salmon. There appears to be spatial segregation among Atlantic salmon and other Lake Ontario salmonids, however, overlap likely occurs in nearshore waters during the spring. Wide-ranging movements of Atlantic salmon in binational (Canada/USA) waters reflects the importance of government agencies collaborating to ensure sustainable fisheries and the coordination of species restoration activities. This is the first study to provide detailed spatial use of Lake Ontario Atlantic salmon to assist in the management of this reintroduced species.     

Habitat use by subyearling Chinook and coho salmon in Lake Ontario tributaries

The habitat use of subyearling Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) was examined in three tributaries of Lake Ontario. A total of 1781 habitat observations were made on Chinook salmon (698) and coho salmon (1083). During both spring and fall, subyearling coho salmon used pool habitat with abundant cover. During spring, principal component analysis revealed that water depth was the most important variable governing subyearling Chinook salmon habitat use. Substrate materials used by Chinook salmon in the spring and coho salmon in the fall were significantly smaller than were present on average within the study reaches. When the two species occurred sympatrically during spring they exhibited similar habitat selection. Although the habitat used by coho salmon in Lake Ontario tributaries was consistent with observations of habitat use in their native range, higher water velocities were less important to Chinook salmon than has previously been reported.     

The Impacts of Atlantic Salmon Stocking on Rainbow Trout in Barnum House Creek,Lake Ontario

We compared the impacts of stocking age-0 Atlantic salmon (Salmo salar) at high and low densities, and no stocking on abundance and growth of age-0 rainbow trout (Oncorhyncus mykiss) in Barnum House Creek, Ontario during 1993 to 2005. A similar stream, Shelter Valley Creek, was chosen as an appropriate reference stream where age-0 Atlantic salmon were not stocked. The catches of age-0 rainbow trout in Barnum House and the reference stream were highly correlated (r = 0.96) during years when no stocking occurred; however, this relationship did not persist in years when Atlantic salmon were stocked. The catch of age-0 rainbow trout in Barnum House Creek was significantly lower under both high (P = 0.00026) and low (P = 0.011) density Atlantic salmon stocking treatments compared with the no stocking treatment. The catches of age-0 rainbow trout and age-0 Atlantic salmon were negatively correlated in Barnum House Creek (r = −0.63). The length of age-0 rainbow trout in Barnum House Creek was depressed significantly (P = 0.004), under the high intensity Atlantic salmon stocking treatment, but not under the low intensity treatment (P = 0.20). In contrast, the length of age-0 rainbow trout in Shelter Valley Creek was unchanged over the same period. Restoration stocking of Atlantic salmon in Lake Ontario tributaries may impact rainbow trout abundance and growth.     

Origins of Rainbow Smelt in Lake Ontario

The first rainbow smelt (Osmerus mordax) to enter Lake Ontario were probably migrants from an anadromous strain introduced into New York's Finger Lakes. Since the upper Great Lakes were originally stocked with a landlocked strain from Green Lake, Maine, subsequent migration to Lake Ontario from Lake Erie makes Lake Ontario unique among the Great Lakes in probably having received introductions from two distinct populations.     

Examination of the influence of juvenile Atlantic salmon on the feeding mode of juvenile steelhead in Lake Ontario tributaries

We examined diets of 1204 allopatric and sympatric juvenile Atlantic salmon (Salmo salar) and steelhead (Oncorhynchus mykiss) in three tributaries of Lake Ontario. The diet composition of both species consisted primarily of ephemeropterans, trichopterans, and chironomids, although juvenile steelhead consumed more terrestrial invertebrates, especially at the sympatric sites. Subyearlings of both species consumed small prey (i.e. chironomids) whereas large prey (i.e. perlids) made up a higher percentage of the diet of yearlings. The diet of juvenile steelhead at the allopatric sites was more closely associated with the composition of the benthos than with the drift, but was about equally associated with the benthos and drift at the sympatric sites. The diet of both subyearling and yearling Atlantic salmon was more closely associated with the benthos than the drift at the sympatric sites. The evidence suggests that juvenile steelhead may subtly alter their feeding behavior in sympatry with Atlantic salmon. This behavioral adaptation may reduce competitive interactions between these species.     

Evidence of successful river spawning by lake trout (Salvelinus namaycush) in the Lower Niagara River,Lake Ontario

Restoration of a wild-produced lake trout Salvelinus namaycush population in Lake Ontario has not been successful despite the adult population often meeting or exceeding restoration targets. Lack of high-quality spawning habitat in Lake Ontario is suggested as one impediment to recruitment of wild lake trout, although the quantity and location of spawning habitat is poorly understood. If high-quality spawning habitat is limited in Lake Ontario, lake trout may be using uncommon spawning locations such as rivers. Anecdotal angler accounts point to the Niagara River as a lake trout spawning location. To better understand the potential of the Niagara River as a spawning location, egg and juvenile fish collections were conducted 12–14 river kilometers from the mouth of the Niagara River from 2010 to 2012; and mature female lake trout with surgically implanted acoustic tags were monitored from 2015 to 2019. Genetic analyses confirmed 60% of collected eggs and 93% of collected post-hatch juvenile fish in the Niagara River were lake trout. Tagged female lake trout returned to the Niagara River over consecutive years during the spawning season. The short duration of lake trout presence in the river (mean = 56 days/year) suggests female lake trout use the Niagara River primarily for spawning. Diversity in spawning locations may provide lake trout population’s resilience against environmental variability through a portfolio effect. Improved identification of riverine spawning locations, including their overall contribution to wild recruitment, may be a useful tool for managers to restore a wild-produced population of lake trout in Lake Ontario.     

Lake Sturgeon Waters and Fisheries in New York State

Historic and contemporary records of lake sturgeon (Acipenser fulvescens) occurrences in new York State have been assembled in this report to assist in planning and prioritizing the areas for restoration. This has become important because information about this threatened species is not easily assembled nor easily retrieved from the few remaining fishermen. Lake sturgeon were identified in 17 waters of New York State in the Great Lakes drainage including Lakes Erie, Ontario, Champlain, and the Niagara and St. Lawrence rivers. Two other rivers in the Laurentain Great Lakes drainage had self-sustaining populations, five others historically supported spawning runs, and five other waters had historical records of use or relict populations. Lake Erie provided the largest historic fishery for lake sturgeon in New York State (1,678 tonne reported in 1885) followed by Lake Ontario (292 tonne reported in 1890). All the major waters (the first five identified above) had large harvests, and two tributaries to the St. Lawrence River, the Grasse and Oswegatchie rivers, also provided commercial harvests. The Great Lakes fisheries were reduced to abandonment by the 1940s and the remaining ones were discontinued by the 1960s. Currently, lake sturgeon are self-sustaining at very low levels in the upper Niagara, St. Lawrence, and the Grasse rivers. The fish is protected from harvest in all areas but one.     

CHUM SALMON SPAWNING ACTIVITY IN TRIBUTARIES BELOW BONNEVILLE DAM: THE RELATIONSHIP WITH TAILWATER ELEVATION AND SEASONAL PRECIPITATION

Chum salmon (Oncorhynchus keta) below Bonneville Dam migrate through as well as hold and spawn in both tributaries and mainstem areas of the Columbia River, USA. Whether fluctuations in tailwater elevation influence spawning in tributaries is unclear. We examined the relationship between Bonneville Dam tailwater elevation, seasonal precipitation and chum salmon spawning activities in three tributary spawning areas. In these tributaries, we assessed initial date of entry, time required to enter and length of spawning season, as well as the proportion of the total population that spawned in tributaries and the distribution of spawners among tributaries. Using linear regression, these variables were compared to cumulative hours of tailwater elevation ≥ 3.5 m and cumulative precipitation. Increased Bonneville Dam tailwater elevation was associated with later and longer lasting chum salmon spawning activities, but was not associated with the distribution of chum salmon spawners in tributaries. Increased seasonal precipitation was associated with a more prolonged spawning season and relatively even distribution of adult chum salmon, but was unrelated to the timing of chum salmon spawning in tributaries. The regulation of tailwater elevation downstream from Bonneville Dam can influence the spawning process for chum salmon in tributaries that enter the regulated area. How important this influence is to the decline of chum salmon in the Columbia River is unclear. Published in 2011 by John Wiley & Sons, Ltd.     

Spatial Distribution and Habitat Use of Spawning American Shad in the St. Johns River,Florida

American shad Alosa sapidissima populations along the Atlantic Coast of North America are near historic lows despite management actions designed to rebuild stocks. Florida's St. Johns River supports the southernmost population of this anadromous species, and as water use in the St. Johns basin increases, there is concern that their spawning may be affected. We assessed American Shad movement and habitat use in the St. Johns River during three spawning migrations (2009–2011) using acoustic telemetry. Spatial distribution patterns of telemetered shad during each year were largely similar; most shad were located within reaches from Lake Monroe (rkm 276) to just downstream of Lake Harney (rkm 308); some individuals made excursions as far upstream as Lake Poinsett (rkm 386+). Water levels varied among years (low‐water level: 2009 and 2011; higher water level: 2010), and lower water levels may have contributed to an apparent constriction of spawning grounds in 2009 and 2011. Telemetered shad selected deeper sections of river with faster currents. Our results verified that the primary spawning grounds for American shad in the St. Johns have not changed substantially in the past 50 years; thus, these areas should rank high for habitat protection. We also demonstrated linkages between American Shad distribution and habitat use and river flow that should be further developed and considered in future water withdrawal, regulation, or conservation efforts. Copyright © 2015 John Wiley & Sons, Ltd.     

Assessment of Asian carp spawning potential in tributaries to the Canadian Lake Ontario basin

Urgent action is needed to prevent the successful establishment of four invasive fish species, collectively known as Asian carps, within the Great Lakes basin. Preliminary assessments of spawning potential of Great Lakes tributaries are needed to effectively allocate resources to early-detection programs and more detailed hydrodynamic modelling. Previous preliminary assessments determining the Asian carp spawning potential of tributaries potentially masked temporal variations in stream temperature and velocity. A preliminary assessment was developed that incorporates both the spawning biology of Asian carps and the hydrodynamics of tributaries, based on data at a higher temporal resolution than used previously, to determine the spawning potential of a tributary. The assessment was conducted on eight Lake Ontario tributaries, based on in-situ temperature and velocity data from 2009 to 2014. Two tributaries were found to be suitable using mean data across the assessed time frame; however, inter-annual suitability varied greatly and six tributaries were found to be suitable in at least one of six years over the study period. The assessment highlights previously unexplored inter-annual variation in suitability and provides a method using existing data to identify suitable tributaries for more detailed analyses involving hydrodynamic modelling. This approach can be used as a heuristic first step to inform management actions, such as early-detection and rapid-response programs, to prevent Asian carp spawning in the Canadian Great Lakes basin.