Lake Tanganyika endemic gastropods also occur in the Lukuga River

Ancient lakes with their endemic species assemblages, like Lake Tanganyika in East Africa, are regarded as hotspots of aquatic biodiversity and as natural laboratories providing insights into evolutionary processes, such as intra-lacustrine speciation. The origin of the gastropod species super flock in Lake Tanganyika has been debated intensively and remains unclear to date. For the fish community, it is generally assumed that it was derived from ancestors occurring in the Congo River Basin. Recently, a central biogeographical role of the Lukuga River system and the connected Lualaba River has been indicated. In an attempt to trace the origin of the enigmatic thalassoid gastropods of Lake Tanganyika, the fauna of the Lukuga-Lualaba systems is currently being studied. A recent expedition allowed collecting mollusc material from the eastern shores of Lake Tanganyika around Kalemie and down the Lukuga River until Niemba. We found gastropods known to be endemic to Lake Tanganyika living in the Lukuga River as far down as 95 km, in populations with reasonable abundances. Based on mitochondrial DNA sequences, these populations are partially genetically distinct from Lake Tanganyika’s populations. However, sister taxa to the species flock have not yet been found in the Lukuga River. Our results are discussed in the context of intra-riverine evolutionary dynamics over shorter time periods. They will also help to understand the biogeographical and evolutionary dynamics within a large spatial and temporal framework, covering Lake Tanganyika and the Congo River system.     

Phytoplankton in Lake Tanganyika: a Comparison of Community Composition and Biomass off Kigoma with Previous Studies 27 Years Ago

The composition and temporal distribution of phytoplankton was studied in the northern basin of Lake Tanganyika and was compared with existing data from 1975 from a nearby locality. Sampling was conducted every 2 weeks from February 2002 to February 2004 at a pelagic station in Lake Tanganyika off Kigoma (Tanzania). Changes in algal community structure were observed: the reported cyanobacteria-chrysophytes-chlorophytes community of 1975 was replaced by a cyanobacteria-chlorophytes-diatom community. Moreover differences in species composition were detected between 1975 and 2002–2003. Besides the rarity of chrysophytes not all the species reported from 1975 were observed and conversely new taxa were found. While taxonomic issues make a direct comparison difficult, our data provide evidence for real floristic changes. These changes may be related to the decreasing productivity of the lake, as was recently reported for Lake Tanganyika and confirmed in the present study.     

A reference inventory for aquatic fauna of the Laurentian Great Lakes

The Laurentian Great Lakes encompass an expansive and diverse set of freshwater ecosystems that contain a concordantly large and diverse vertebrate and invertebrate fauna. Although numerous publications exist concerning the composition and distribution of this fauna, there is at present no single readily available resource that brings all this information together. Here, we present and describe the compilation process for a comprehensive Great Lakes aquatic fauna inventory covering fishes, reptiles, amphibians, zooplankton, mollusks, annelids, insects, mites, and various other aquatic invertebrates. Inventory entries were developed via an extensive search of literature and internet sources and are attributed with detailed nomenclature information, general lake and habitat occurrences, and supporting citations and links to life history and genetic marker information. The inventory scope is the Laurentian Great Lakes proper and their connecting rivers, and their fringing coastal wetlands and lower tributaries. Over 2200 unique taxa are contained in the inventory – 85% resolved to species and 14% to genus. The listing substantially expands previous richness estimates for invertebrates in the Great Lakes, but taxonomic resolution and spatial distribution information for them remains quite uneven. Example pattern analyses for fauna in this inventory show that aquatic vertebrates are generally more widely distributed than invertebrates, and that biodiversity is concentrated in the coastal margins. The inventory is being packaged into a public, searchable database that showcases the biodiversity of the Great Lakes aquatic fauna and can assist the research and management community in their biological investigations.     

Management issues in the Lake Victoria watershed

Lake Victoria is the largest lake in Africa (68 800 km²) and is the eighth largest lake in the world by volume. The three East African countries of Tanzania, Uganda and Kenya share Lake Victoria and its resources. The total annual catch of fish from the lake ranges between 400 × 10⁶ kg and 500 × 10⁶ kg, bringing these riparian countries a combined annual income of approximately US$250 000–500 000 from exports alone. Approximately 30 million people live in the riparian region and the catchment, with about 2 million of these depending directly or indirectly on fishing activities. Tragically, Lake Victoria’s extremely diverse fauna was decimated in only 30 years following the introduction of non‐native Nile perch in the early 1960s. An estimated 200 endemic cichlid species became extinct. Dramatic increases in overfishing, pollution from various sources, effects of noxious water weeds and other associated problems threaten the sustainability of the lake’s resources and the economies of the riparian governments and peoples. Regulations governing Lake Victoria’s resources are different in each country. The laws concerning treatment of effluents from point sources in the three countries are not harmonized, neither are implementation or enforcement provisions. The governments of Kenya, Uganda and Tanzania have begun to put in place regional mechanisms to address the lake’s many problems including the creation of a permanent regional international institution through the establishment of the Lake Victoria Fisheries Organization (LVFO). A strategic vision document and action plans have been developed. Efforts are being made at local, national and regional levels to control the water hyacinth, including manual pulling, mechanical harvesting and introduction of weevils that weaken hyacinth root systems. To address the problem of overfishing, fishermen committees at landing beaches have been put in place. Each country has committed to take all necessary measures including legislation to implement the decisions of the LVFO governing bodies. All three countries have agreed to adopt and enforce legislation and regulations prohibiting the introduction of non‐indigenous species to the lake and to enforce existing regulations regarding fisheries. A Global Environment Facility project which provides funding to the Lake Victoria Fisheries Organization addresses land use management, catchment forestation, fisheries research and management, water hyacinth control, industrial effluent treatment and municipal waste treatment.     

The lobed-lipped species of Haplochromis (Teleostei,Cichlidae) from Lake Edward,two instead of one

Thickened lips have evolved several times within the cichlid flocks of the East African Great Lakes. This distinct and easily recognisable phenotype is a model trait to study convergent evolution. Lake Edward (Eastern Africa) contains a unique cichlid assemblage, which has remained largely understudied. Hitherto, only one cichlid species with lobed lips, Haplochromis labiatus, was known from this lake. This species has a blunt snout and rounded and mostly retrognathous jaws. However, we found specimens with lobed lips, but with acute snouts and slender and mostly prognathous jaws. These belong to a species, hitherto unknown to science: H. lobatus sp. nov. Both species occur sympatrically. We evaluated the morphological diversity within these species by investigating a total of 112 specimens using traditional and geometric morphometric approaches. Both species are formally (re)described and show a relatively large variation in their trophic morphologies, which complicates identification. Both have a small gape, stout outer teeth that strongly decrease in size laterad, and a lower jaw set anteriorly with procumbently-implanted outer teeth. Haplochromis labiatus differs from H. lobatus sp. nov. by a straight to convex vs. straight to concave head, a slightly shorter and broader lower jaw (27.7–34.3 vs. 31.2–40.7% HL; 71.4–92.4 vs. 48.5–70.5% LJL), and lobed lips that are thickened uniformly over their whole lengths vs. medially enlarged. Gut content observations revealed that both species have an insectivorous diet. While both exploit similar food sources, their morphological differences presumably prevent them from entering into direct ecological competition.     

A review on the status of some major fish species in Lake Victoria and possible conservation strategies

Lake Victoria, the second largest freshwater lake in the world, supports an enormous flora and fauna biomass, with a large human population around the Lake. The lake is a source of food (fish), water for domestic use and crop and livestock production, transportation and tourism, among other uses. As a result of these varied uses, human intervention within the lake and its catchment has resulted in several ecological changes in the lake in recent years, with profound effects on its fish resources. One of the most notable changes is the reduction and risk of extinction of some fish species, including the endemic tilapiine species (Oreochromis esculentus and Oreochromis variabilis), catfishes (Xenoclarias eupogon), haplochromines and cyprinids (Labeo victorianus and Barbus altinialis) in the lake. The reduced biodiversity, as well as extinctions within the lake, has been attributed to the introduction of alien fish species (e.g. Nile perch (Lates niloticus) and Nile tilapia (Oreochromis niloticus) into the lake, habitat loss and cultural eutrophication. If left unchecked, these changes will have devastating effects on the lake's resources, as well as to people living around the lake and beyond who depend on the lake fisheries for their livelihood. Thus, there is an urgent need for management measures based on sound scientific research to be implemented in order to curb the loss of ichthyodiversity within the lake, as well as to save the livelihoods of those stakeholders who are either directly or indirectly dependent on the lake.     

Indications of the effects of climate change on the pelagic fishery of Lake Kariba,Zambia–Zimbabwe

The pelagic fishery of Lake Kariba comprises the introduced clupeid, Limnothrissa miodon, from Lake Tanganyika. The annual fishery catches grew logistically from 1974, when commercial fishing began. It peaked at 37 000 tonnes (estimated mean sustainable yield = 40 000 tonnes) around 1990 and declined steadily thereafter. A piecewise regression of Limnothrissa catches against time gives a breakpoint around 1987–1988. Regressions of Limnothrissa against air temperature and lake temperature gave breakpoints of 34.8 and 28.7 °C, respectively. Other studies indicate that Lake Kariba has warmed by close to 2 °C, with accompanying changes in thermal stratification. The lake phytoplankton is now dominated by Cyanophyceae, particularly Cylindrospermum raciborskii. The lake zooplankton population has greatly diminished. These data are similar to the results obtained for Lake Tanganyika (Nature 2003; 424 , 766–8). In the Lake Tanganyika study, the declining pelagic fishery has been attributed to reduced food availability resulting from a reduced phototrophic zone depth, as well as epilimnion nutrient recharge from reduced mixing. The warming observed in Lake Kariba and its environs is consistent with the IPCC Fourth Assessment Report (AR4). While the effects of global warming have been observed in large natural lakes, this is the first study in which global warming has affected the ecosystem of a large impoundment.     

Changes in the Biodiversity of Freshwater Mussels in the Canadian Waters of the Lower Great Lakes Drainage Basin Over the Past 140 Years

Severe declines in the diversity and abundance of freshwater mussels have been documented over the past century in the United States. Although similar trends might be expected in Canada, mussels have received little attention to date. The Committee On the Status of Endangered Wildlife In Canada (COSEWIC) expanded its mandate in 1994 to include invertebrates, thus providing the impetus for assessing the health of Canada's freshwater mussel fauna. The purpose of this study was to determine if there have been changes over time in the richness and composition of freshwater mussel communities in the lower Great Lakes drainage basin, which historically supported the most diverse and unique mussel fauna in Canada. Over 4,100 occurrence records for 40 species of mussels collected from approximately 1,500 sites between 1860 and 1996 were compiled and examined together for the first time. Comparisons of historical and recent data revealed a pattern of species losses and changing community composition throughout the basin, particularly in the species-rich Lake Erie and Lake St. Clair drainages. River systems that once supported numerous species characteristic of a wide variety of habitats are now dominated by fewer siltation- and pollution-tolerant species of the Subfamily Anodontinae. A detailed examination of the data for the Grand, Thames, and Moira rivers confirmed that the same trends are occurring in widely-separated systems throughout the basin. The results of this study provide compelling evidence that the steady decline in freshwater mussel diversity that has been documented for the United States is also occurring in Canada.     

Hydrothermal vents in Lake Tanganyika harbor spore-forming thermophiles with extremely rapid growth

A thermophilic anaerobic bacterium was isolated from a sublacustrine hydrothermal vent site in Lake Tanganyika (East Africa) with recorded fluid temperatures of 66-103 °C and pH values of 7.7-8.9. The bacterium (strain TR10) was rod-shaped, about 1 by 5 μm in size, and readily formed distal endospores. Based on the 16 S rDNA sequence the novel strain was homologous to Thermobrachium celere and Caloramator indicus, which are closely related. The novel strain was strictly anaerobic, fermentative and had a doubling time as short as 10 min during growth on complex substrates, such as yeast extract and peptone. The optimum temperature for growth was 60 °C, while minimum and maximum temperatures were 40 and 75 °C. The pH response was alkalitolerant with optimum pH at 7.4 and 8.5 depending on the growth medium. The distinct feature of rapid proliferation and endospore formation may allow the novel organism to exploit the temporarily fluctuating growth conditions in the hydrothermal vent environments of Lake Tanganyika.     

Ecological health assessment of the Ousteri wetland in India through synthesizing remote sensing and inventory data

Ousteri Lake is one of the important wetlands in India, harbouring many different types of flora and providing a suitable habitat for many different fauna, being declared as a sanctuary in October 2008. The National Wetland Conservation Program of Ministry of Environment and Forests identified Ousteri Lake as a nationally important wetland, and the Bombay Natural History Society (BNHS) named it an Important Bird Area (IBA). The International Union for Conservation of Nature and Natural Resources (IUCN) also has identified this lake as a heritage site. The present study examined the state of environment in and around the Ousteri wetland, assessing the probable threats to the lake and its ecological environs. Ousteri Lake supports diverse rich and rare flora and fauna. Because of its extreme hydrological fluctuations over the annual cycle, the lake exhibits interesting patterns of flora and fauna. The north‐east monsoons leave the lake flooded during the winter months, while the scorching summers leave it totally dry. Ousteri Lake had been primarily used as a tank for irrigation purposes, with ~2,000 acres being cultivated. The main crop is paddy, and the only subsidiary is sugar cane. The natural vegetation, significantly altered by human activities, consists of over 220 species belonging to 63 families. The vegetation study conducted earlier have reported a total of 472 plant species, with the herbs being 40% of this total, followed by trees (21%). Other life forms in the lake are represented by less than 100 species. Ousteri Lake and its environs also provide a wide variety of habitat for many floral species, with 190 species being listed as least concern, 23 species as near threatened and 24 species as vulnerable, according to the IUCN Red List. About 14 floral species are being categorized as endemic. Further, about 202 fauna are listed as least concern, 13 species as near threatened, two species as vulnerable, three species as endangered and one as critically endangered. Moreover, five species are in an endemic category.     

Inorganic Nitrogen Uptake and River Inputs in Northern Lake Tanganyika

Northern Lake Tanganyika is characterized by an almost permanently stratified water column which causes severe nutrient depletion in surface waters. Any external N source to surface waters, therefore, is of importance in sustaining primary production. This study attempted to quantify riverine input of dissolved inorganic nitrogen (DIN) to the extreme northern end of Lake Tanganyika (surface = 900 km²) as well as the DIN uptake by surface phytoplankton. Results showed that riverine DIN inputs (1,930 tons of N/year) were of similar importance to atmospheric deposition (1,520 to 1,720 tons of N/year) and were maximal during the dry season. Moreover, seasonal DIN variations in river and lake waters showed maximum concentrations during part of the dry season (May to July 1999) probably due to high atmospheric inputs. Phytoplanktonic nitrate and ammonium uptake rates were measured during nine cruises and varied from 0.01 to 19.3 nM/h. These values suggest that uptake by phytoplankton in the surface waters could represent a DIN sink of about 14,400 tons of N/year, thereby utilizing all available DIN coming in from external sources. External DIN sources represent approximately 25% of the annual phytoplankton N requirements, showing the major importance of unquantified N sources in sustaining primary production in the northern basin of Lake Tanganyika. These sources could include organic N present in the external sources, and internal N supply.     

Variable niche breadth in benthic diatoms: Implications of ecological specialization and generalization for community structure

The mechanisms that regulate the composition and structure of biological communities remain poorly understood. Diatom communities have traditionally been assumed to be a collection of r-selected, ecologically redundant generalist taxa with distributions constrained largely by dispersal limitation. Here, we challenge this notion by presenting a novel model that uses distributional data to estimate ecological specialization for groups of diatom taxa. We further develop this model to evaluate relationships among ecological specialization, taxonomic richness, and species’ abundance using field data collected from ancient Lake Matano and the broader Malili Lakes system (Sulawesi, Indonesia), as well as Mazinaw Lake (Ontario, Canada). We demonstrated that diatom niche breadth is highly variable both at the assemblage scale and among genera within assemblages. Ecologically-specialized genera exhibited higher taxonomic richness than their generalist counterparts, suggesting that ecological specialization serves to support the sympatric coexistence of multiple species by limiting competitive interactions among congeneric taxa. This assertion is further supported by species’ abundance patterns, which suggested that resources are evenly partitioned among taxa within specialist genera, while less-specialized genera are composed of taxa with either exceptionally high or exceptionally low abundances reflective of their relative success in competitive interactions with one another. Our findings indicate that the often-overlooked complement of rare taxa within diatom assemblages are in fact the entities that respond most sensitively to environmental conditions and are worthy of far greater consideration in environmental assessment and paleolimnological studies.     

Dietary differences among commercially important fishes in Lake Tanganyika assessed using stable isotope analysis

The pelagic fishery of Lake Tanganyika, which is largely made up of the three species Lates stappersii, Limnothrissa miodon, and Stolothrissa tanganicae, has been in decline, and there is no clear understanding of the primary underlying causes. It has been suggested that climate change has altered the primary productivity of the system, but detailed knowledge of the system's food web is required to elucidate the effect on higher trophic levels. The aim of this study is to determine the diet of the three commercially important fish species. Muscle tissue samples for stable isotope analysis were taken from February through April 2017, supplemented with stomach samples from L. stappersii for use in stomach content analysis. The stomach analysis showed an ontogenetic change in the diet composition of L. stappersii, shifting from copepods to fish larvae, supplemented with shrimp, to whole fish prey as the fish grew larger. Stable carbon and nitrogen isotope values from fish muscle were consistent with this observation, and also seemed to indicate that fish of similar sizes had similar diets, irrespective of species. This suggests that the diet of the pelagic fish species might be better explained by size, rather than species. The isotope data revealed a short range of δ¹⁵N values from primary consumers to fish, which may help explain the high fisheries productivity of Lake Tanganyika, and the strong impact of primary productivity changes on fisheries yield.     

Tonle Sap Lake: Current status and important research directions for environmental management

Tonle Sap Lake (TSL) in Cambodia is the largest freshwater body in South‐East Asia and one of the most productive ecosystems in the world. The lake and its ecosystems are widely under threat, however, due to anthropogenic activities occurring inside and outside its basin (e.g., water infrastructure development; land use change), being poorly understood in most aspects. This study provides an updated review of the state of knowledge of the TSL ecosystem, as well as important research directions for sustainable lake environmental management of Tonle Sap Lake by focusing on four major topics, including climate change and hydrology, sediment dynamics, nutrient dynamics and primary and secondary production. The findings of this study suggest anthropogenic activities in the TSL basin, as well as the Mekong, in combination together with climate changes, are key contributing factors in the degradation of the TSL ecosystem. Insufficient accurate data, however, precludes quantitative assessment of such impacts, making it difficult to quantitatively assess and accurately understand the ecosystem process in the lake ecosystem. More efforts are recommended in regard to environmental monitoring in all sub‐basins around TSL, assessing seasonal changes in nutrient and sediment inputs corresponding to water level and flow changes, assessing cumulative impacts of water infrastructure and climate change on the ecosystem dynamics, and elucidation of ecosystem processes within the lake's internal system.     

Phytoplankton trends in the Great Lakes, 2001–2011

We describe recent trends in phytoplankton composition and abundance in the Laurentian Great Lakes using synoptic spring (April) and summer (August) sampling events from 2001 through 2011, a period of rapid shifts in pelagic food webs and water quality. Data analysis identified qualitative and quantitative changes in algal densities, biovolume, and taxonomic composition of assemblages. Since 2001, Lake Superior has changed subtly with an increase in small-celled blue-green algae in spring and a recent decline in summer centric diatoms, possibly a result of lake warming and changes in water quality. Spring phytoplankton declines mainly attributed to diatoms occurred in Lakes Huron and Michigan, a probable result of invasions by non-native dreissenids that have reduced pelagic nutrients and selectively consumed certain taxa. The decline in Lake Huron's spring phytoplankton biovolume was earlier and more severe than that in Lake Michigan, despite a faster and more abundant dreissenid invasion in Lake Michigan. Lake Erie's central basin had a notable increase in spring centric diatoms (largely Aulacoseira), while the whole of Lake Erie shows a summer increase in cyanobacteria, complementing that found in coastal regions. The composition of Lake Ontario's species assemblage shifted, but little overall change in algal abundance was observed with the exception of higher summer densities of cyanophytes. Additional mechanisms for shifts in the pelagic primary producers are described or hypothesized in the context of concurrent shifts in water quality and invertebrate populations. Tracking these trends and explaining driving factors will be critical to the management of lake conditions.     

东太湖不同人为干扰程度区域植物多样性研究

水产养殖等人为活动会影响水生植被群落结构、群落动态和生物多样性。为具体分析人为活动对水生植被群落的影响,2013~2014年,在东太湖人工干扰严重的网围养殖区和人工干扰较轻的非养殖区选取11个样点进行了8次实地采样分析。分析结果表明,东太湖现有双子叶植物16科21属23种,主要有3种植物群落类;在人为干扰严重的围栏养殖区域,植物多样性较轻度人为干扰的湖区有明显下降;但植物多样性在2010年退渔还湖后较2002~2008年有较为明显的提高。     

Discontinuities in the distribution of invertebrates in impounded south island rivers,New Zealand

The invertebrate fauna of 10 river systems, five with impoundments and five without, were sampled. No significant difference was found either in taxonomic richness or invertebrate densities between impounded and unimpounded sites at similar positions along river continua. However, plecopteran species richness was significantly lower and plecopteran density reduced in post-impoundment sites. Densities of Deleatidium spp. (Ephemeroptera: Leptephlebiidae) were significantly lower at lake outlets compared with other sites. Two species of Zelandobius (Plecoptera: Gripopterygidae) and Eriopterini (Diptera: Tipulidae) snowed distributions apparently curtailed by impoundments, whereas Potamopyrgus antipodarum (Mollusca: Hydrobiidae) had an extended distribution. Margalef's, Menhinick's, Berger-Parker and Shannon indices, total taxa present and plecopteran taxa were plotted against stream order, stream width and distance from the source. Menhinick's and Shannon-Weaver indices produced statistically significant but weak regressions, and discontinuity distances and intensity could not be accurately calculated. The usefulness of diversity indices as a measure of the magnitude of impoundment effects in the South Island seems to be limited.     

The ecological history of Lake Erie as recorded by the phytoplankton community

Lake Erie's water quality has fluctuated since European settlement due to cultural eutrophication and the effects of invasive species. Our attempts to understand the cause-and-effect linkages between observed ecosystem changes and various stressors are evolving. Non-indigenous species, pollutants, land-use and climate change that can alter a lake's physical and chemical environment can manifest rapid changes in community composition and abundance of phytoplankton. As such, for many decades researchers have used phytoplankton data from Lake Erie to track environmental changes. We provide a chronological account of previous and ongoing assessments of pelagic algae to summarize past and present environmental conditions of Lake Erie. This review necessarily focuses on diatom-based assessments as their preserved remains in sediments have been used to hind-cast human-induced impacts and recovery. Because of their uniqueness, this review summarizes where possible the long-term trends according to the western, central and eastern lake basins. Overall, this historical assessment summarizes a period of significant eutrophication throughout most of the 20th century, followed by water quality improvement due to nutrient reductions and establishment of filter-feeding dreissenids. Recent data suggest new issues associated with blooms of diatoms and blue-green algae. The challenges facing Lake Erie underline the need for continued monitoring and evaluation of historical records that will help us distinguish natural from anthropogenic changes, and to reveal the causes and extent of environmental insults in order to make management decisions.     

Population Characteristics of the Invading White Perch (Morone Americana) in Western Lake Erie

The white perch (Morone americana) is an East Coast estuarine species that invaded Lake Erie in the 1950s, but did not increase in abundance until the mid 1970s. We studied its distribution and population dynamics in western Lake Erie during this period of rapid increase in population size. White perch spawned in riffle areas of tributary streams of western Lake Erie during late April, and then moved downstream into the lake. They were abundant in nearshore and reef habitats throughout most of the year, although a few were collected in deep offshore areas. Increasingly strong year classes were produced each year in 1980–1984. The age structure of the population reflected a surge in recruitment in the 1980s; fish of age–1 and age–2 were abundant, but older fish were still rare. White perch in western Lake Erie grew faster and matured earlier than those in most other populations, but growth rates appeared to be declining as the population expanded. White perch can be expected eventually to colonize suitable habitats throughout the Great Lakes.     

Annotated Checklist of the Free-Living Copepods of the Great Lakes

An annotated checklist of the free-living copepods of the Laurentian Great Lakes is developed on the basis of published records. Synonymies are included for each species, relating, wherever possible, invalid names in the literature with currently recognized taxonomy. Twelve species of calanoids, six species of planktonic cyclopoids, nine species of benthic/ littoral cyclopoids, and fourteen species of harpacticoids have been reported from the Great Lakes. Ten of the calanoids and four of the cyclopoids are characteristic of limnetic waters. Three calanoids and two planktonic cyclopoids have been reported infrequently and are perhaps accidental occurrences. The composition of the planktonic copepod fauna in most subregions of the Great Lakes is well-known. In contrast, the sampling of benthic/littoral cyclopoids and harpacticoids has been so infrequent that their kinds, areas of occurrence, and relative abundances are still poorly understood.