Great Lakes

Previously determined PCB concentrations in 10 dated sediment cores from Lakes Michigan, Huron, Erie, and Ontario are analyzed by positive matrix factorization in order to find characteristic congener patterns including signs of anaerobic dechlorination. Three or four factors are sufficient to describe the PCB data for each lake. All four lakes are dominated by Aroclors 1248A, 1248G, 1254A, and 1254G. Aroclor 1260 is only a significant factor in Lake Michigan prior to 1975, reflecting in part a usage patterns of heavy chlorinated Aroclors early and less chlorinated Aroclors in the phase-out years in the 1970s. Dated records of factors or sources indicate clear PCB concentration maxima for Lakes Erie (1981) and Ontario(1968), while redistribution of PCBs in the less contaminated Lakes Michigan and Huron has occurred after 1980. Using a single data matrix for all four lakes provides a common basis and possibility to examine low degrees of dechlorination, while individual data matrices for each lake provide more accurate results and better separation of factors. Lakes Ontario, Michigan, and Huron undergo dechlorination via reactions such as 66(24-34) → 25(24-3) and 18(25-2) → 4(2-2) consistent with reactions H' + M, while Lake Erie appears to be dominated by 18(25-2) → 4(2-2) and 53(25-26) → 19(26-2) that are typical for processes M + Q.

Complementary analysis of satellite mission data (altimetry, Moderate Resolution Imaging Spectroradiometers (MODIS)) and climate fields over 2000–2009 was conducted to investigate the variability of the water cover surfaces and the geographical source of water inflowing into the Lake Poopó system. The results suggest that over the time span of 2000–2009 a great part of the variability of the Poopó system originates from geographic sources other than Lake Titicaca. Possible alternative causes include climate change inducing increased temperatures and greater evaporation rates along the Altiplano; increased glacier and snow melting over the Andes Cordillera; and a potential increased anthropogenic water use (such as irrigation, minery, etc.) throughout the path of the Desaguadero River (which connects lakes Titicaca and Poopó). This change in the hydrology of this region could lead to a collapse of water supplies and endanger the already fragile Poopó system as well as the regional socioeconomic system, which closely depends upon it.

Increasing land use pressure has resulted in increasing suspended solids loading to many African lakes in recent decades, causing concern that littoral habitat may be degraded by sedimentation and light limitation. In a companion paper in this issue, we showed that much runoff into Lake Malawi plunges below the euphotic zone and spreads through the lake via the upper metalimnion, thus mitigating nearshore and upper water column impacts. In this study we use data from multiple surveys through two rainy seasons to describe spatio-temporal distributions of suspended solids concentration (SSC) and transparency caused by the flow of runoff through the Linthipe River delta region of Lake Malawi. SSC in interflow at 30-50 m depth was typically an order of magnitude greater than in surface plumes. Seasonal median transparency near the river mouth was inversely proportional to the suspended load in surfacebuoyant inflow, but independent of total loading. This is because storm runoff was more dense (cooler and with higher SSC) than runoff during low-flow periods, so that it was more likely to plunge. The effect was to moderate inter-annual variability in light attenuation near the river mouth because transparency was lower (due to more surface-buoyant inflow of turbid water) in the year when solar irradiance was higher (less cloud cover). The effect was, however, local. Beyond a few kilometers of the river mouth upward mixing of suspended particles carried in interflow reasserted the more intuitive inverse dependence of transparency on total loading.

In large lakes, temporal variability is compounded by strong spatial variability associated with mesoscale physical processes such as upwelling and basin-scale circulation. Here we explore the ability of a three dimensional model (ELCOM-CAEDYM) to capture temporal and spatial variability of phytoplankton and nutrients in Lake Erie. We emphasized the east basin of the lake, where an invasion by dreissenid mussels has given special importance to the question of spatial (particularly nearshore-offshore) variability and many comparative observations were available. We found that the model, which did not include any simulation of the mussels or of smaller diffuse nutrient sources, could capture the major features of the temperature, nutrient and phytoplankton variations. Within basin variability was large compared to among-basin variability, especially but not exclusively in the western regions. Consistent with observations in years prior to, but not after, the mussel invasion the model predicted generally higher phytoplankton concentrations in the nearshore than the offshore zones. The results suggest that the elevated phytoplankton abundance commonly observed in the nearshore of large lakes in the absence of dreissenid mussels does not have to depend on localized nutrient inputs but can be explained by the favourable light, temperature and nutrient environment in the shallower and energetic nearshore zone. The model is currently being extended to allow simulation of the effects of dreissenid mussels.

Mysis relicta was sampled in Lake Ontario biweekly with vertical tows from May through November 1984. Two sites were studied off Hamlin Beach State Park, one station at 35 m and the other at 100 m. At the 35-m station, total abundance ranged from near zero in late September to 207 m-2 in mid-August, with a mean abundance of 48 organisms m-2 for the study period. Average biomass and production values at the 35-m station were 0.08 g dry weight m-2 and 0.13 g dry weight m-2 per 7 months, respectively. At the 100-m station, total abundance ranged from 110 m-2 in late September to 860 m-2 in mid-July, with a mean abundance of 378 m-2 for the study period. Average biomass and total production at the 100-m station was 0.68 g dry weight m-2 and 1.23 g dry weight m-2 per 7 months, respectively. Mysis relicta abundance increased from 1971 to 1984 in the offshore and nearshore ofLake Ontario.

Rapid assessments are used as qualitative approaches to evaluate wetland quality in the absence of quantitative data and adequate time to assess wetland structure and function. To examine how rapid assessment methods assess bird assemblages in wetlands, we compared bird communities with both the Ohio Rapid Assessment Method (ORAM) and detailed data gathered from 51 coastal riverine wetlands in the western Great Lakes region. We found that birds did not choose wetlands at random but responded to vegetative structure and the degree of anthropogenic disturbance within and surrounding the wetland. ORAM scores adequately reflected the degree of anthropogenic disturbance affecting the wetlands but were insufficient to explain bird species richness or the abundance of several bird species that were obligates of these wetlands. Bird assemblages in the western Great Lakes region spanned a wider range of wetland conditions than were reflected in the ORAM scores. Modification of ORAM scores with a focus on submetrics related to anthropogenic disturbance and vegetative structure improved the ability of ORAM to reflect conditions important to wetland birds. ORAM could be improved for use in the western Great Lakes with a greater emphasis on the landscape context and anthropogenic disturbance of the wetland.

We investigated the seasonal occurrence of Hemimysis anomala in the diets of fish that prey on macroinvertebrates at two sites with established Hemimysis populations east of Oswego, NY, during 2009-2010. In 2009, we examined 320 stomachs from 10 species and found Hemimysis only in alewife (Alosa pseudoharengus), rockbass (Ambloplites rupestris), and yellow perch (Perca flavescens). Of those species, alewife consumed Hemimysis most frequently and it represented a greater proportion of their diets. During 2009, the dry weight composition of Hemimysis in alewife diets varied seasonally between b 1% in June, 5% in July, 98.5% in August, and 18.8% in September. In contrast, we examined 667 stomachs from 15 species in 2010 and observed Hemimysis in only one alewife and two rockbass stomachs. For alewife from September 2009, we found no relationship between predator size and the number of Hemimysis consumed, or between the presence of Hemimysis in fish diets and the presence of other diet taxa or diet diversity. Fish diets collected as bycatch from other assessments revealed large numbers of Hemimysis in fishes that had not previously been observed consuming Hemimysis in Lake Ontario, including cisco (Coregonus artedi) and white perch (Morone americana).

A detailed review of historical literature and museum data revealed that flathead catfish were not historically native in the Great Lakes Basin, with the possible exception of a relict population in Lake Erie. The species has invaded Lake Erie, Lake St. Clair, Lake Huron, nearly all drainages in Michigan, and the Fox/Wolf and Milwaukee drainages in Wisconsin. They have not been collected from Lake Superior yet, and the temperature suitability of that lake is questionable. Flathead catfish have been stocked sparingly in the Great Lakes and is not the mechanism responsible for their spread. A stocking in 1968 in Ohio may be one exception to this. Dispersal resulted from both natural range expansions and unauthorized introductions. The invasion is ongoing, with the species invading both from the east and the west to meet in northern Lake Michigan. Much of this invasion has likely taken place since the 1990s. This species has been documented to have significant impacts on native fishes in other areas where it has been introduced; therefore, educating the public not to release them into new waters is important. Frequent monitoring of rivers and lakes for the presence of this species would detect new populations early so that management actions could be utilized on new populations if desired.

The linkage between land use in a catchment basin and downstream aquatic ecosystems, especially effects on algae attached to substrata or loosely aggregated in the littoral zone, represents a void in our understanding of lake systems. The occurrence of beds of metaphyton at some stream mouths and not others in Conesus Lake, NY (USA) provided an opportunity to consider the relationship between land use and phosphorus and nitrogen losses on the development of shoreline metaphyton blooms. Experiments were performed in the littoral zone of a large temperate lake to test the hypothesis that effluent high in phosphorus and nitrate from tributaries draining agricultural watersheds had a stimulatory effect on the growth of littoral metaphyton, while effluent from a forested watershed did not. The study encompassed six watersheds of varying agricultural use (60-80%) and a forested watershed (12% agriculture). For each experiment, two quadruplicate sets of plexiglass incubation chambers (height = 50 cm, interior diameter = 9.5 cm) containing native assemblages of metaphyton received lake or tributary water continuously over a 3-day lake incubation period. Growth of metaphyton incubated in lake water and in tributary water was compared and differences appeared to be related to nutrient concentrations. A statistically significant stimulatory effect was measured for the six tributaries draining agricultural watersheds but not for the forested watershed. Tributary loadings appear to stimulate metaphyton at sites where the hydrology and hydrodynamincs are suitable. A significant positive linear relationship existed between percent metaphyton cover in the littoral zone and the percent of land use in agriculture. Metaphyton abundance is impacted by land use practices and subsequent loss of nutrients from the catchment.

Efforts to restore lake trout (Salvelinus namaycush) in Lake Huron after their collapse in the 1940s were underway in the early 1970s with completion of the first round oflampricide applications in tributary streams and the stocking of several genotypes. We assess results of rehabilitation and establish a historical basis for comparison by quantifying the catch of spawning lake trout from Michigan waters in 1929-1932. Sixty-eight percent of this catch occurred in northern waters (MH-1) and most of the rest (15%) was from remote reefs in the middle of the main basin. Sea lampreys (Petromyzon mari-nus) increased in the early 1980s in the main basin and depressed spawning populations of lake trout. This increase was especially severe in northern waters and appeared to be associated with untreated populations in the St. Marys River. Excessive commercial fishing stemming from unresolved treaty rights also contributed to loss of spawning fish in northern Michigan waters. Seneca-strain lake trout did not appear to be attacked by sea lampreys until they reached a size > 532 mm. At sizes > 632 mm, Seneca trout were 40-fold more abundant than the Marquette strain in matched-planting experiments. Natural reproduction past the fry stage has occurred in Thunder Bay and South Bay, but prospects for self-sustaining populations of lake trout in the main basin are poor because sea lampreys are too abundant, only one side of the basin is stocked, and stocking is deferred to allow commercial gillnetting in areas where most of the spawning occurred historically. Backcross lake trout, a lake trout x splake (S. fontinalis x S. namaycush) hybrid, did not reproduce in Georgian Bay, but this genotype is being replaced with pure-strain lake trout, whose early performance appears promising.

I've uploaded the final manuscript of this article, which was published in Mathilde Lévêque and Déborah Lévy-Bertherat, dir., Enfants sauvages : Représentations et savoirs.  Hermann, 2017, pp.49-62.
It is based on the paper I presented at the conference on Feral Children (Enfants sauvages) at the École Normale Supérieure in December 2015. Takes a post-colonial approach to the life and times of Marie-Angélique Leblanc (Fox territory 1712?--Paris, 1775), the so-called "wild girl of Champagne" (jeune fille sauvage de Champagne) discovered in 1731.  With thanks to the many readers on academia.com who helped make it better!

This report provides an assessment of the potential costs of a worst-case hydrocarbon spill from Enbridge Energy Limited Partners’ Line 5 pipeline system (Line 5) in the Straits of Mackinac. The assessment was conducted over the first half of 2018 by Michigan Technological University and its subcontractors, and was performed for the Michigan Departments of Environmental Quality and Natural Resources, the Michigan Agency for Energy, and the Michigan Office of Attorney General (collectively the State) as recommended in the Michigan Petroleum Task Force Report of July 2015.

Among the important physical characteristics of a lake are whether it stratifies seasonally, and if so, the depth to which wind-mixing is limited by the stratification. It is generally known that sufficiently shallow lakes tend to remain isothermal throughout the year and that the depth of the thermocline in stratified lakes correlates positively with the surface area of the lake. Observations from lakes in several different regions of the temperate zone of the northern hemisphere show that whether a lake stratifies depends on both the maximum depth and the surface area of the lake, whereas the depth of the thermocline depends primarily on the surface area. A modification of previously published scaling arguments provides a plausible theoretical basis for some of this behavior. These arguments account for additional shear-induced mixing associated with the fundamental internal seiche in small lakes and with near-inertial motion in big lakes. For lakes of crossbasin diameter less than 5,000 m (surface area less than 25 km1, an estimate of the depth of the thermocline, h, at the time of maximum heat content is given by: h :::: 2.0 (-'-) 112 L 112 7 g..:lp where t is the wind stress associated with late summer storms, .dp is the density contrast between epilimnion and hypolimnion typical for lakes in that region near the time of maximum heat content, g is the gravitational acceleration, and L is the square root of the surface area of the lake. A consistent set of units must be employed. ADDITIONAL INDEX WORDS: Dimensional analysis, wind-induced mixing, buoyancy, Coriolis force.

The vast, well-oxygenated hypolimnia of Lake Baikal and the Great Lakes were both dominated by endemic planktivorous fishes. These dominants, two species of sculpins (Comephorus, Comephoridae) in Lake Baikal and six species of deepwater ciscoes (Coregonus, Salmonidae) in the Great Lakes, although distant taxonomically, have morphologies suggesting a surprising degree of functional convergence. Here it is proposed that the same two buoyancy-regulation strategies observed in Baikal sculpins also arose in the deepwater ciscoes of the Great Lakes. One strategy favors hydrostatic lift (generated by low specific gravity) and is characterized by fatter, larger-bodied fish with smaller paired fins; the second strategy favors hydrodynamic lift (generated by swimming) and is characterized by leaner, smaller-bodied fish with larger paired fins. Both types likely evolved to feed on a single species of ecologically analogous, vertically migrating macrozooplankter: Macrohectopus branickii in Lake Baikal and Mysis relicta in the Great Lakes. It is suggested that Coregonus did not diversify and proliferate in Lake Baikal as they did in the Great Lakes because by the time Coregonus colonized Lake Baikal, pelagic sculpins were already dominant.

The surface energy balance of Lake Superior was measured using the eddy covariance method at a remote, offshore site at 0.5-h intervals from June 2008 through November 2010. Pronounced seasonal patterns in the surface energy balance were observed, with a five-month delay between maximum summer net radiation and maximum winter latent and sensible heat fluxes. Late season (winter) evaporation and sensible heat losses from the lake typically occurred in two- to three-day-long events, and were associated with significant release of stored heat from the lake. The majority of the evaporative heat loss (70–88%) and sensible heat loss (97–99%) occurred between October and March, with 464mm (2008–2009) and 645mm (2009–2010) of evaporative water loss occurring over the water year starting October 1. Evaporation was proportional to the horizontal wind speed, inversely proportional to the ambient vapor pressure, and was well described by the ratio of wind speed to vapor pressure. This ratio remained relatively constant between the two water years, so the differences in evaporative water loss between years were largely associated with differences in lake surface conditions (e.g. water temperature, ice cover, and ice duration). Since late-season water temperature decline is driven by evaporative and sensible heat loss, the potential for a negative feedback mechanism between evaporation and ice cover is discussed.

Previous work indicated that the abundance of yellow perch (Perca flavescens) in the eastern basin of Lake Ontario declined from 1976 to 1999 despite production of moderate to strong year classes each year during 1991 through 1995. Adult perch stock size failed to increase because of accelerated mortality after the first fall of life. Increases in mortality coincided with a number of ecosystem changes including increased abundance of double-crested cormorants (Phalacrocorax auritus). Otoliths obtained from cormorant pellets collected on Little Galloo Island were used to examine the size and age of perch consumed by cormorants during 1993 to 1994 and 1996 to 1999. Size and age specific diet composition, combined with existing estimates of yellow perch consumed annually by cormorants were compared to perch population projections to evaluate the potential for this new form of predation to induce observed population trends. Perch stock abundance was projected using a range of standing stock estimates from the literature partitioned with age composition data from the eastern basin population. The total length of perch consumed by cormorants ranged from 59 to 236 mm, the majority of which were age-1 (48%), age-2 (20%), and age-3 (20%). Comparisons of age structured predation by cormorants and perch population projections indicated that cormorant predation reduced age-3 perch abundance most. At a high estimate of 65 kg/ha, cormorants were capable of consuming 29% of the age-3 perch stock. This analysis indicated that cormorant predation had the potential to play an important role in regulating perch population levels in the eastern basin during the 1990s.

Little is known about the ecology of round goby (Neogobius melanostomus), an invasive benthic fish, in the profundal zone of the Great Lakes. In April 2002April -2005 we caught increasing numbers of round gobies with a bottom trawl in the 45-150 m depth range of southwestern Lake Ontario. In 2005, we examined gut contents of 30 round gobies from each of three depths, 55, 95, and 130 m, and qualitatively compared gut contents with density of benthic invertebrates determined by Ponar grabs. Round goby guts contained mostly Dreissena spp. and opposum shrimp, Mysis relicta (Mysis); the frequency of occurrence of dreissenids in guts decreased with depth, whereas the frequency of occurrence of Mysis in guts increased with depth. Abundance of these invertebrates in the environment followed the same pattern, although dreissenids of optimum edible size (3-12 mm) were still abundant (1,373/m 2 ) at 130 m, where round gobies primarily consumed Mysis, suggesting that round gobies may switch from dreissenids to more profitable prey when it is available. Other food items were ostracods and fish, with ostracods generally eaten by smaller round gobies and fish eaten by larger round gobies. Occurrence and increasing abundance of round gobies in the profundal zone and predation on Mysis by round goby could have far-reaching consequences for the Lake Ontario fish community.

We reviewed the published literature to provide an inventory of Laurentian Great Lakes artificial reef projects and their purposes. We also sought to characterize physical and biological monitoring for artificial reef projects in the Great Lakes and determine the success of artificial reefs in meeting project objectives. We found records of 6 artificial reefs in Lake Erie, 8 in Lake Michigan, 3 in Lakes Huron and Ontario, and 2 in Lake Superior. We found 9 reefs in Great Lakes connecting channels and 6 reefs in Great Lakes tributaries. Objectives of artificial reef creation have included reducing impacts of currents and waves, providing safe harbors, improving sport-fishing opportunities, and enhancing/restoring fish spawning habitats. Most reefs in the lakes themselves were incidental (not created purposely for fish habitat) or built to improve local sport fishing, whereas reefs in tributaries and connecting channels were more frequently built to benefit fish spawning. Levels of assessment of reef performance varied; but long-term monitoring was uncommon as was assessment of physical attributes. Artificial reefs were often successful at attracting recreational species and spawning fish; however, population-level benefits of artificial reefs are unclear. Stressors such as sedimentation and bio-fouling can limit the effectiveness of artificial reefs as spawning enhancement tools. Our investigation underscores the need to develop standard protocols for monitoring the biological and physical attributes of artificial structures. Further, long-term monitoring is needed to assess the benefits of artificial reefs to fish populations and inform future artificial reef projects.

We examined the stomach contents of 1,045 lake trout (Salvelinus namaycush) caught on Six Fathom Bank and Yankee Reef, two offshore reef complexes in Lake Huron, during late spring and early summer [1998][1999][2000][2001][2002][2003]. Lake trout ranged in total length from 213 to 858 mm, and in age from 2 to 14 years. In total, 742 stomachs contained food. On a wet-weight basis, alewife (Alosa pseudoharengus) dominated the spring-summer diet of lake trout on both of these offshore reef complexes. Alewives accounted for 75 to 90% of lake trout diet, depending on the lake trout size category. Size of alewives found in lake trout stomachs increased with increasing lake trout size. Faster growth of juvenile lake trout on Six Fathom Bank and Yankee Reef than on Sheboygan Reef in Lake Michigan was attributed to greater availability of small alewives on the offshore reefs in Lake Huron. Our findings indicated that alewives inhabited Six Fathom Bank and Yankee Reef during spring and summer months. Thus, our study provided support for the contention that alewives may have interfered with natural reproduction by lake trout on these offshore reef complexes in Lake Huron.

At the interface of the Great Lakes and their tributary rivers lies the rivermouths, a class of aquatic ecosystem where lake and lotic processes mix and distinct features emerge. Many rivermouths are the focal point of both human interaction with the Great Lakes and human impacts to the lakes; many cities, ports, and beaches are located in rivermouth ecosystems, and these human pressures often degrade key ecological functions that rivermouths provide. Despite their ecological uniqueness and apparent economic importance, there has been relatively little research on these ecosystems as a class relative to studies on upstream rivers or the open-lake waters. Here we present a synthesis of current knowledge about ecosystem structure and function in Great Lakes rivermouths based on studies in both Laurentian rivermouths, coastal wetlands, and marine estuarine systems. A conceptual model is presented that establishes a common semantic framework for discussing the characteristic spatial features of rivermouths. This model then is used to conceptually link ecosystem structure and function to ecological services provided by rivermouths. This synthesis helps identify the critical gaps in understanding rivermouth ecology. Specifically, additional information is needed on how rivermouths collectively influence the Great Lakes ecosystem, how human alterations influence rivermouth functions, and how ecosystem services provided by rivermouths can be managed to benefit the surrounding socioeconomic networks.

Water quality monitoring in lakes is often done by regularly sampling water quality variables of interest at fixed stations. Station location is a critical component of monitoring network design. Geostatistical methods were used to quantify redundancy in an intentionally dense network of lake stations on Lake Winnipeg, Canada. Water isotope samples (δ 2 H, δ 18 O) were collected approximately every 1-2 km during research cruises in September-October 2009, for a total of 240 lakewide stations. Two statistical approaches were used to assess redundancy: 1) kriging, a spatial interpolation technique, was performed in a reduced multivariate space and kriging variance was used to assess the suitability of the sampled network configuration; and 2) Local Moran's I values were calculated. Moran's I identified clusters of stations that were similar or different. Good kriging models were developed for both δ 2 H and δ 18 O. When assessed individually, a large number of stations were identified as redundant but redundancy was based on the premise that all other stations remained in the network. When the analysis was performed on clusters of stations, within each cluster, up to four stations could be removed without significant loss of information. Relationships of redundancy were confirmed by Local Moran's I values. In combination, these techniques identified stations that were statistically important or redundant. This study emphasizes the importance of completing the evaluation of information provided by an individual station with information from clusters of stations within a network.

After near extirpation earlier this century in the Great Lakes, double-crested cormorant (Phalacrocorax auritus) populations reached all-time highs, raising concerns among sport anglers and fisheries managers, who see cormorants as a significant source of mortality for yellow perch (Perca flavescens), whose populations are perceived to have declined in concert with cormorant increases. We partitioned age-specific perch mortality for 1995 into that caused by

Smallmouth bass Micropterus dolomieu and largemouth bass M. salmoides in southwestern Lake Michigan use shallow, warm harbors for spawning during spring. After the reproductive period ends in early summer, catch rates from standardized sampling of smallmouth bass in harbors decrease. Fishes are presumed to use the main lake during summer but little is known about how black basses use main-lake habitat in Lake Michigan or mechanisms driving this transition. We tracked smallmouth bass (N = 26) and largemouth bass (N = 8) using radio and acoustic telemetry during 2005-2006 near North Point Marina, IL. A temperature difference persisted between inside and outside the harbor for much of May-October where harbor temperatures were generally warmer than those outside the harbor. Smallmouth bass responded to water temperature changes, inhabiting the harbor until temperatures outside the harbor approached 18.5°C, at which time they left the harbor. Frequent temperature fluctuations of > 3°C occurred outside the harbor within 24-hour periods. Sudden reductions in water temperature were associated with smallmouth bass temporarily returning to the harbor until the temperature outside the harbor again approached 18.5°C. As water cooled during fall, smallmouth bass again returned to the harbor. Largemouth bass exhibited comparatively restricted movements during this time and rarely ranged outside the harbor. Thus, home range estimates for smallmouth bass (142.6 ha) were an order of magnitude greater than those of largemouth bass (12.9 ha). Both water temperature and species played a role in determining the degree of movement outside the harbor but both black basses used the harbor as a thermal refuge.

Recent invasion theory has hypothesized that newly established exotic species may initially
be free of their native parasites, augmenting their population success. Others have hypothesized
that invaders may introduce exotic parasites to native species and/or may become hosts to native parasites
in their new habitats. Our study analyzed the parasites of two exotic Eurasian gobies that were
detected in the Great Lakes in 1990: the round goby Apollonia melanostoma and the tubenose goby Proterorhinus
semilunaris. We compared our results from the central region of their introduced ranges in
Lakes Huron, St. Clair, and Erie with other studies in the Great Lakes over the past decade, as well as
Eurasian native and nonindigenous habitats. Results showed that goby-specific metazoan parasites were
absent in the Great Lakes, and all but one species were represented only as larvae, suggesting that adult
parasites presently are poorly-adapted to the new gobies as hosts. Seven parasitic species are known to
infest the tubenose goby in the Great Lakes, including our new finding of the acanthocephalan Southwellina
hispida, and all are rare. We provide the first findings of four parasite species in the round goby and
clarified two others, totaling 22 in the Great Lakes—with most being rare. In contrast, 72 round goby
parasites occur in the Black Sea region. Trematodes are the most common parasitic group of the round
goby in the Great Lakes, as in their native Black Sea range and Baltic Sea introduction. Holarctic trematode
Diplostomum spathaceum larvae, which are one of two widely distributed species shared with Eurasia,
were found in round goby eyes from all Great Lakes localities except Lake Huron proper. Our study
and others reveal no overall increases in parasitism of the invasive gobies over the past decade after
their establishment in the Great Lakes. In conclusion, the parasite “load” on the invasive gobies appears
relatively low in comparison with their native habitats, lending support to the “enemy release
hypothesis.”

Mysis diluviana and Hemimysis anomala are the only two species of mysid shrimps in the order Mysidacea that are present in the Laurentian Great Lakes of North America. M. diluviana has inhabited the deep, cold waters of this region since Pleistocene-era glacial retreat and is widely considered to have a central role in the functioning of offshore food webs in systems they inhabit. More recently, the Great Lakes were invaded by
the Ponto-Caspian native Hemimysis, a species that inhabits warmer water and shallower depths relative to M. diluviana. Hemimysis has rapidly expanded throughout the Great Lakes region and has become integrated into nearshore food webs as both food for planktivorous fish and predators and competitors of zooplankton.
This special issue is composed of 14 papers that represent the most recent advances in our understanding of the ecological importance of both species of mysids to lake and river ecosystems in the Great Lakes region of North America. Topics discussed in this special issue will inform future research in all systems influenced by mysid ecology.

The history of the War of 1812 has been dominated by scrutiny of the duelling frigates, squadron actions, and the British blockade of American ports. Yet, during the conflict from 1812 to 1815, sailors and marines were just as likely to be involved in maritime raiding operations and other irregular missions as they were to work the 'great guns' in ship versus ship combat. This paper reexamines operations on the Great Lakes, and particularly Lake Ontario, in order to illuminate the role of irregular operations and small unit and small craft actions. These types of operations were common throughout the age of sail, but receive little attention from scholars. In order to broaden the scope of operational naval history, and the understanding of the roles and missions of naval forces, a wider investigation of naval irregular warfare is warranted both in the War of 1812 and across naval history more generally.

Le projet de dérivation de la ville de Waukesha s’inscrit dans une longue expérience en ce qui a trait aux transferts des eaux. Le présent essai présentera tout d’abord le régime transfrontalier du bassin des Grands Lacs. Ensuite, un lien sera fait entre les normes nord-américaines et le droit international de l’eau pour identifier où se situent les deux pays dans le débat sur les normes coutumières internationales. L’analyse du cas de Waukesha sera ensuite présentée en débutant par le Traité de 1909 et la Commission mixte internationale (CMI), suivis de l’Entente et du Pacte. Cette dernière partie se terminera avec une analyse critique de la gouvernance des Grands Lacs.