North Temperate Lakes Research Articles

Long-term dynamics of lakes in the landscape: long-term ecological research on North Temperate Lakes

This site-synthesis volume presents 20 years of work at the North Temperate Lakes Long-Term Research Site. It provides the definitive information base for the ecology of temperate lakes, and a general assessment of the role of lakes within their landscapes. The Wisconsin temperate lakes LTER site has had a major role in the growth of our modern limonological understanding, and this book also chronicles the history of this work. The book should be of interest to most American limonologists and a significant number of general ecologists.

Characterizing north temperate lake littoral fish assemblages: a comparison between distance sampling and minnow traps

To determine which sampling method may be best employed to monitor changes in fish species composition in littoral areas of small north temperate lakes (≤50 ha), data were collected using distance sampling, based on the line transect method, and a traditional fish sampling method of baited minnow traps. These methods were independently biased in terms of their estimates of species presence and abundance. However, analyses of fish community structure indicated that minnow trap data alone provided a better measure of community structure than did distance sampling data alone. Distance sampling, although a powerful tool in estimating population density, is hindered by a multitude of environmental variables that do not preclude the use of minnow traps. Lakes with clear water containing few species with abundant individuals are best suited for distance sampling. Minnow traps proved to be a fast, efficacious sampling method capable of fairly accurately defining the littoral small-fish community structure in most lakes sampled. These traps are a reliable method for monitoring presence or absence and relative abundance of small-bodied fish species in north temperate lakes. However, the combination of minnow traps and some form of visual sampling will help to ensure that all species are detected in small north temperate lakes.

Rapid food web recovery in response to removal of an introduced apex predator

Non-native species have increased extinction rates, decreased diversity, altered organism distributions, and constrained ecosystem functioning in native aquatic and terrestrial communities. Although widespread fish introductions have dramatically altered fish communities in north temperate lakes, restoration of native fish communities has been rarely accomplished. This study evaluated a native fish community restoration using a stable isotope based metric. Stable isotopes from a native apex predator (lake trout (Salvelinus namaycush)) were used to measure food web changes following removal of a dominant non-native apex predator (smallmouth bass (Micropterus dolomieu)). Prior to bass removal, lake trout consumed primarily invertebrates. Within 2 years of the initiation of an experimental removal effort, lake trout δ13C values(–25.9‰ to –24.9‰) and trophic position (3.5–3.9) increased, reflecting a switch to prey fish consumption that was supported by stomach contents analyses. Here, we show the rapid reestablishment of food web linkages within a native fish community in response to changes in principal energy sources and trophic position of a native apex predator along with the ability to quantify the extent of these changes.

Niche dynamics of largemouth bass (Micropterus salmoides) in a north temperate lake

Niche dynamics of largemouth bass (<i>Micropterus salmoides</i>) in a north temperate lake

Interactions between Stocked Walleyes and Native Yellow Perch in Lake Thirteen, Minnesota: A Case History of Percid Community Dynamics

AbstractStudies of interactions among percids are important for understanding the fish community consequences of using stocking as a management tool and for understanding the ecological role of percids in lakes where they are native species. Percid community responses to discontinuing, then resuming, the stocking of walleye Sander vitreus were monitored in Lake Thirteen, Minnesota, a north temperate lake with a long‐term history of walleye fry stocking. Fish population assessments during 1986–2002 tracked changes in relative abundance, size structure, and growth rates of yellow perch Perca flavescens and walleyes in response to discontinued walleye stocking during 1989–1996. Large changes occurred in the size structure and relative abundance of walleyes. The effect of discontinued stocking was to decrease the abundance of younger age‐classes of walleyes in the lake. Reduced predation on small yellow perch allowed their numbers to increase and led to reduced growth rates while stocking was discontinued. When stocking was resumed, predation by stocked walleyes reversed the trend, reducing yellow perch numbers and improving their growth rates. Density‐dependent growth was evident for both walleyes and yellow perch. Bioenergetics modeling confirmed walleye predation as a plausible explanation for most changes in the yellow perch population. Manipulation of stocking, and the resulting shifts in predator sizes, caused structural changes in the percid populations that altered levels of intraspecific competition for both the predators and prey.

Quantifying Ultraviolet Radiation Mortality Risk In Bluegill Larvae: Effects Of Nest Location

Ultraviolet (UV) radiation (280-400 nm) is an increasing threat to aquatic organisms due to stratospheric ozone depletion and reductions in concentrations of dissolved organic carbon. Because fish are most vulnerable to UV during the egg and larval stages, parental spawning site selection can strongly influence mortality risk. We examined the role of nest location in determining UV-induced mortality risk for bluegill (Lepomis macrochirus) in Lake Giles, Pennsylvania, USA. In a series of five short-term incubation experiments, we found that survival of yolk sac larvae across the range of depths at which bluegill spawn was significantly lower in the presence of ambient-UV levels relative to larvae that were shielded from UV radiation. In addition, survival decreased as a function of cumulative UV exposure, as measured by the number of cyclobutane pyrimidine dimers per megabase DNA in DNA dosimeters. Although UV had the potential to significantly reduce larval survival, DNA dosimeters placed in bluegill nests concurrently with incubation experiments indicated that most nests were exposed to relatively low levels of UV. Only 19% of nests had predicted UV-induced mortality greater than 25%. Consequently, current levels of UV may be an important mortality source at the level of individual nests, but not at the population level. One reason for the weak predicted effect of UV on bluegill survival is that many nests were located at depths by which much of the incident UV had been attenuated. In addition, many of the shallower nests were protected by overhanging trees or other submerged structures. It is important to note that Lake Giles is highly transparent and therefore not representative of all lakes in which bluegill are found. Nevertheless, Lake Giles is a natural system and may be representative of north temperate lakes in the future.

Water color affects the stratification, surface temperature, heat content, and mean epilimnetic irradiance of small lakes

The effects of water color on lake stratification, mean epilimnetic irradiance, and lake temperature dynamics were examined in small, north-temperate lakes that differed widely in water color (1.5–19.8 m–1). Among these lakes, colored lakes differed from clear lakes in the following ways: (i) the epilimnia were shallower and colder, and mean epilimnetic irradiance was reduced; (ii) the diel temperature cycles were more pronounced; (iii) whole-lake heat accumulation during stratification was reduced. The depth of the epilimnion ranged from 2.5 m in the clearest lake to 0.75 m in the most colored lake, and 91% of the variation in epilimnetic depth was explained by water color. Summer mean morning epilimnetic temperature was ~2 °C cooler in the most colored lake compared with the clearest lake. In clear lakes, the diel temperature range (1.4 ± 0.7 °C) was significantly (p = 0.01) less than that in the most colored lake (2.1 ± 1.0 °C). Change in whole-lake heat content was negatively correlated with water color. Increasing water color decreased light penetration more than thermocline depth, leading to reduced mean epilimnetic irradiance in the colored lakes. Thus, in these small lakes, water color significantly affected temperature, thermocline depth, and light climate.

Lack of a unimodal relationship between fish growth and macrophyte cover in 45 north temperate lakes

Macrophytes have several important roles for fish populations in lakes. Theory and experimental evidence support the hypothesis of an optimal intermediate macrophyte cover for fish foraging and growth. However, few multi-lake studies of this relationship have been conducted at the whole-lake scale in north temperate lakes, and results to date have not been consistent. We examined the relationship between macrophyte cover and fish growth for two fish species that are tightly linked to macrophytes, largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus). We conducted our study on 45 thermally stratified north-temperate lakes using nine macrophyte cover metrics at both the whole-lake and littoral-zone scales. We found little evidence to support the hypothesis of an optimal intermediate range of any macrophyte cover metric for fish growth. However, growth for some ages of both species was negatively related to some of the macrophyte metrics at each spatial scale. These results should help direct more holistic management of lakes by informing the management of both macrophytes and fish, and serve as a caution to ecologists and managers attempting to extrapolate theoretical and experimental results to the whole-lake scale.

Branching complexity and morphological characteristics of coarse woody structure as lacustrine fish habitat

The objective of this study was to quantify the physical characteristics of coarse woody structure (CWS) as fish habitat in a north temperate lake. Sixteen species of fish were observed in submerged CWS habitat. Branching complexity, distance above the bole, area below the bole, distance to other CWS, and water depth around CWS were significantly related to abundance of schooling cyprinids (Cyprinidae), rock bass (Ambloplites rupestris), smallmouth bass (Micropterus dolomieu), bluegill (Lepomis macrochirus), yellow perch (Perca flavescens), and walleye (Sander vitreus). Branching complexity was the most common characteristic of CWS related to richness, diversity, and total adult abundance of fish taxa, but was not correlated with the total lengths of fish found in submerged trees. Branching-complexity values ranged from 1 (simple) to 500 (moderately complex) in the littoral zone; for comparison, a living riparian conifer had a branching-complexity value of over 1000. Most CWS in the littoral zone was composed of simple trees without branching, but fish tended to inhabit CWS with branching-complexity values greater than 45. This study shows the importance of CWS with fine branching as littoral-zone fish habitat.

Is pelagic top-down control in lakes augmented by benthic energy pathways?

Modern food web studies are typically conducted from a trophic dynamic perspective that focuses on combined roles of top-down and bottom-up forces in regulating food web structure. Recognition of spatial food web subsidies in diverse ecosystems highlights the importance of energy flow as a foundation for understanding trophic dynamics. Here, we consider how different energy flow configurations might affect trophic dynamics in north-temperate lakes. A literature review revealed that littoral piscivores exert top-down control on prey fishes. In contrast, analysis of littoral predator diets indicated extensive omnivory and heavy reliance on zoobenthic prey. We explored this uncoupling between trophic dynamics (piscivores regulate prey fish) and energy flow (zoobenthos in piscivore diets) using a biomass dynamic model. This model compared top-down impacts of a piscivore on prey fishes under two scenarios: consumption of prey fish only and consumption of prey fish plus zoobenthos. The model predicted that elimination of zoobenthivory leads to a 50% reduction in piscivore standing stock and concomitant 2.5-fold increase in prey fish abundance (i.e., zoobenthivory plays a key role in mediating pelagic top-down control). These results highlight the role of benthic–pelagic linkages in regulating trophic dynamics and underscore the value of whole-ecosystem approaches to the study of food webs.

Spatial heterogeneity of daphniid parasitism within lakes

Spatially explicit models show that local interactions of hosts and parasites can strongly influence invasion and persistence of parasites and can create lasting spatial patchiness of parasite distributions. These predictions have been supported by experiments conducted in two-dimensional landscapes. Yet, three-dimensional systems, such as lakes, ponds, and oceans, have received comparatively little attention from epidemiologists. Freshwater zooplankton hosts often aggregate horizontally and vertically in lakes, potentially leading to local host-parasite interactions in one-, two-, or three-dimensions. To evaluate the potential spatial component of daphniid parasitism driven by these local interactions (patchiness), we surveyed vertical and horizontal heterogeneity of pelagic Daphnia infected with multiple microparasites in several north temperate lakes. These surveys uncovered little evidence for persistent vertical patchiness of parasitism, since the prevalence of two parasites showed little consistent trend with depth in four lakes (but more heterogeneity during day than at night). On a horizontal scale of tens of meters, we found little systematic evidence of strong aggregation and spatial patterning of daphniid hosts and parasites. Yet, we observed broad-scale, basin-wide patterns of parasite prevalence. These patterns suggest that nearshore offshore gradients, rather than local-scale interactions, could play a role in governing epidemiology of this open water host-parasite system.

The effects of nutrients and zooplankton community structure on phytoplankton growth in a subtropical Australian reservoir: An enclosure study

Patterns of zooplankton–phytoplankton interactions in subtropical lakes of the Southern Hemisphere may deviate from those established for north-temperate lakes. We tested the responses of phytoplankton growth to different community structures of zooplankton and nutrient enrichment in a subtropical Australian reservoir for the prediction of potential outcomes of lake biomanipulation. Two zooplankton communities were created in lake enclosures over 4 weeks: a rotifer-dominated community developed in the presence of planktivorous fish ( Hypseleotris spp.) and a Ceriodaphnia-dominated community developed in the absence of fish. Biomass gradients of both communities were established in 20 L containers and several separate containers received no additions (controls) or were enriched with nitrogen and/or phosphorus. The growth rate of total phytoplankton significantly increased in response to nutrient enrichment, indicating nutrient limitation. Most phytoplankton taxa were not markedly affected by grazing of either zooplankton community. However, both communities had significant stimulatory effects on the growth of inedible chlorophytes. The ability of zooplankton grazing to negatively affect phytoplankton growth during the summer was counteracted regardless of zooplankton community structure, possibly by nutrients regenerated by zooplankton. We hypothesise that in the subtropical system studied, changes in food web nutrient recycling may be more important for the outcome of biomanipulation than grazing impacts.

A long-term rusty crayfish (Orconectes rusticus) invasion: dispersal patterns and community change in a north temperate lake

Rusty crayfish (Orconectes rusticus) were first observed in Trout Lake, Wisconsin, in 1979 and took 19 years to completely disperse around the littoral zone, advancing at an average rate of 0.68 km·year–1. With the invasion of rusty crayfish, we found that fishes that share prey taxa with crayfish declined in numbers over time, but piscivorous fish species did not change in abundance. Snails declined from &gt;10 000 to &lt;5 snails·m–2 in one of the first invaded areas. Mean abundance of Odonata, Amphipoda, and Trichoptera decreased significantly lake-wide. Resident crayfish species nearly disappeared, although total crayfish abundance, driven by high abundances of rusty crayfish, continued to rise. Submerged macrophyte species richness declined by as much as 80% at some locations. Together these responses demonstrate dramatic long-term changes in the littoral zone biota of Trout Lake. Continued invasions of similar lakes in the region suggest that these impacts are occurring on a region-wide basis with potentially irreversible effects on communities and ecosystems. Only through long-term natural experiments such as this study can researchers ascertain the full extent of invasions and their impacts on community and ecosystem process that respond at spatial and temporal scales not captured in mesocosm studies.

The influence of residential and cottage development on littoral zone fish communities in a mesotrophic north temperate lake

We used the rapid visual technique (RVT), an underwater visual assessment method developed in marine environments, to assess the influence of residential and cottage development on littoral zone fish communities in Pigeon Lake, a shallow, mesotrophic Canadian lake with extensive shoreline disturbance. We used RVT to assess 135 sites, stratified by degree of residential and cottage development (undeveloped, moderately developed, highly developed) and habitat type (three substrate/vegetation categories). Sites with different degrees of residential and cottage development did not differ significantly in species richness. When the RVT site scores of each species life stage (young-of-year, juveniles and adults) were compared among development categories, only 11% of species life stages showed significant differences; all were most abundant in moderately developed sites. Habitat had a greater influence than development on within-taxon abundance, as 46% of species life stages showed significant among-habitat differences in RVT score. The absence of significant fish community differences between developed and undeveloped sites may be due to the shallowness, extensive macrophyte cover and raised shorelines from the construction of the Trent-Severn Waterway. However, there do appear to be changes in the fish community over the last 35 years, as six cyprinids and one cyprinodont species that were present in Pigeon Lake in the 1970s were not detected by our sampling. RVT provided comparable data to that obtained by straight line transects on the relative abundance of species in the lake, but RVT was more effective at detecting species and life stages present at individual sites.

Seasonal Dynamics of Phytoplankton and Planktonic Protozoan Communities in a Northern Temperate Humic Lake: Diversity in a Dinoflagellate Dominated System

Species diversity and richness, and seasonal population dynamics of phytoplankton, planktonic protozoa, and bacterioplankton sampled from the epilimnion of Crystal Bog in 2000, were examined in order to test the hypothesis that these groups' diversity and abundance patterns might be linked. Crystal Bog, a humic lake in Vilas County, Wisconsin, is part of the North Temperate Lakes Long-Term Ecological Research Site. Phytoplankton and planktonic protozoa were identified and enumerated in a settling chamber with an inverted microscope. Bacterial cells were enumerated with the use of fluorescence 4', 6'-diamidino-2-phenylindole (DAPI)-staining procedures, and automated ribosomal intergenic spacer analysis (ARISA) was used to assess bacterioplankton diversity. Bacterial cell counts showed little seasonal variation and averaged 2.6 x 10(6) cells/mL over the ice-free season. Phytoplankton and planktonic protozoan numbers varied by up to two orders of magnitude and were most numerous in late spring and summer. Dinoflagellates largely dominated Crystal Bog throughout the ice-free period, specifically Peridiniopsis quadridens in the spring, Peridinium limbatum in summer, and Gymnodinium fuscum and P. quadridens in fall. Brief blooms of Cryptomonas, Dinobryon, and Synura occurred between periods of dinoflagellate domination. The dominant dinoflagellate, Peridinium limbatum, was calculated to have a growth rate of 0.065 day(-1) and a doubling time of 10.7 days. Heterotrophic nanoflagellates (HNFs) were a consistent component of the planktonic protozoa; seasonal patterns were determined for three genera of HNFs (Monosiga, Bicosoeca, and Desmarella moniliformis). Three genera of ciliates (Coleps, Strobilidium, and Strombidium) comprised the greater part of the planktonic protozoa in Crystal Bog. The number of species of planktonic protozoa was too low to calculate a diversity index. Shannon-Weaver diversity indices for phytoplankton and bacterioplankton in the epilimnion followed very similar seasonal patterns in this lake, supporting the hypothesis that in freshwaters, diversity patterns of these groups are linked.

Dominance of the noxious cyanobacterium Microcystis aeruginosa in low‐nutrient lakes is associated with exotic zebra mussels

To examine the hypothesis that invasion by zebra mussels (Dreissena polymorpha) promotes phytoplankton dominance by the noxious cyanobacterium Microcystis aeruginosa, 61 Michigan lakes of varying nutrient levels that contain or lack zebra mussels were surveyed during late summer. After accounting for variation in total phosphorus (TP) concentrations, lakes with Dreissena had lower total phytoplankton biomass, as measured by chlorophyll a and algal cell biovolume. Phytoplankton biomass increased with TP in both sets of lakes, although the elevations of the relationship differed. The percentage of the total phytoplankton comprised by cyanobacteria increased with TP in lakes without Dreissena (R2 = 0.21, P = 0.025) but not in lakes with Dreissena (P = 0.79). Surprisingly, there was a positive influence of Dreissena invasion on Microcystis dominance in lakes with TP ≪ 25 µg L−1 (P 5 0.0018) but not in lakes with TP ≫ 25 µg L−1 (P = 0.86). The finding that Microcystis, a relatively grazing‐resistant component of the phytoplankton, was favored by Dreissena in low‐ but not in high‐nutrient lakes is somewhat counterintuitive, but predator‐prey models make this prediction in certain cases when the cost for the prey of being consumption resistant is a low maximum population growth rate. This Dreissena‐cyanobacteria interaction contradicts well‐established patterns of increasing cyanobacteria with nutrient enrichment in north‐temperate lakes and suggests that the monitoring and abatement of nutrient inputs to lakes may not be sufficient to predict and control cyanobacterial dominance of Dreissena‐invaded lakes.

PREDICTING OCCURRENCES AND IMPACTS OF SMALLMOUTH BASS INTRODUCTIONS IN NORTH TEMPERATE LAKES

Smallmouth bass and other warmwater littoral piscivores are presently expanding their geographic range northward into lakes across southern Canada. Smallmouth bass introduction can dramatically reduce minnow abundances, causing native lake trout to shift to low quality, invertebrate-based diets. Here we develop models to predict future occurrences and impacts of smallmouth bass in central Ontario, with the goal of identifying “vulnerable” lakes in order to better guide prevention efforts. Using local and regional environmental variables for 3046 central Ontario lakes, an artificial neural network was used to predict lakes that are likely to be invaded by bass. Smallmouth bass can significantly influence the occurrence and abundance of small-bodied fishes (mainly minnows), and stable isotope analysis of food webs in 18 lakes revealed that lake trout are buffered from impacts of bass on minnows in lakes containing pelagic prey fishes. In the absence of pelagic prey fishes, the trophic niche of lake trout depends on the presence of bass; lake trout feed primarily on zooplankton in the presence of bass, and minnows in the absence of bass. Of the 3046 lakes, the 788 lake trout lakes in central Ontario were classified according to their vulnerability to bass invasion based on the predictability of bass occurrence and their subsequent impacts, and mapped in a Geographic Information System (GIS). Only 48 lake trout lakes (6%) were classified as “high vulnerability”—predicted to be invaded and impacted by bass. Another 301 lakes had a sensitive food web structure but were not predicted to support a bass population. Based on this information, efforts to prevent further impacts can be optimized by focusing on this vulnerable subset of lakes.

Stay cool: habitat selection of a cyclopoid copepod in a north temperate oligotrophic lake

Summary1. We studied the vertical distributions of Cyclops cf. sibiricus in Lake Toya, a north temperate oligotrophic lake. During the winter circulation period, their distribution was vertically homogeneous both day and night. During the summer stratification period, C. cf. sibiricus stayed below the thermocline. Diel vertical migration (DVM) was pronounced in advanced developmental stages, although the upper limit of the migration became deeper as the thermocline gradually descended. This seasonal change was observed throughout the 4‐year study period, implying that thermal structure is the primary determinant of C. cf. sibiricus distribution.2. In a field experiment, C. cf. sibiricus incubated in the summer epilimnion, which most of the population never experience, developed faster and grew better than in their original habitat. We consider that trans‐thermocline DVM would not have evolved because of possible disadvantages such as the cost of migration offset the benefit observed in the field experiment. The rapid temperature change at the thermocline may act as a swimming‐cost estimator for the copepod.3. Low food availability in deep water during the summer stratification period seemed to determine the lower limit of C. cf. sibiricus distribution, and the copepod minimised the risks of predation by fish via DVM. These results suggest that C. cf. sibiricus modified their distribution seasonally to obtain maximum benefit in terms of individual fitness.

Diet Overlap and Predation between Smallmouth Bass and Walleye in a North Temperate Lake

ABSTRACT Walleye (Stizostedion vitreum vitreum) and smallmouth bass (Micropterus dolomieu) diets from Big Crooked Lake, Wisconsin were examined to assess the degree of diet overlap and predation occurring between these species in an attempt to determine whether walleye influence smallmouth bass recruitment, which is consistently low compared to proximal lakes that do not have walleye. Of 389 adult walleye stomachs examined from June 1999 through March 2000, a total of 879 prey fish was found, but only one was identified as a smallmouth bass. In 303 smallmouth bass stomachs examined, 55 prey fish were found and no cannibalism was evident, nor were walleye preyed upon. Dietary overlap using the Schoener resource overlap index was 0.416, 0.293 and 0.205 for the months June, July and August 1999, respectively, indicating that there was not a significant dietary overlap during summer months. Because neither diet overlap nor predation appeared substantial in Big Crooked Lake, additional research on interactions among younger age classes of walleye, interactions at other times of the year, and interactions with other species are needed to elucidate limitations to smallmouth bass recruitment in this system.

Restoration of the eutrophic Lake Eymir, Turkey, by biomanipulation after a major external nutrient control I

Nutrient loading in lakes is recognized as a serious threat to water quality. Over 25 years of raw sewage effluent discharge shifted Lake Eymir from a state dominated by submerged plants to a turbid water state. Successful effluent diversion undertaken in 1995 achieved 88% and 95% reductions in the areal loading of total phosphorus (TP) and dissolved inorganic nitrogen (DIN), respectively. Furthermore, the reduced load of TP was very close to the suggested threshold areal load (0.6 g m−2 yr−1) to attain recovery. Even though diversion also reduced the in-lake TP level by half, the poor water clarity and low submerged plant coverage (112 ± 43 cm and 2.5% coverage of the lake total surface area, respectively) persisted. Domination of the fish stock by planktivorous tench (Tinca tinca L.) and the benthivorous common carp (Cyprinus carpio L.) (66 ± 0.7 and 31 ± 1 kg CPUE, respectively) appeared to perpetuate the poor water condition. A substantial fish removal effort over 1 year achieved a 57% reduction in the fish stock which led to a 2.5-fold increase in Secchi disk transparency. This increase occurred largely because of a 4.5-fold decrease in the inorganic suspended solid concentration, and to some extent, a decrease in chlorophyll-a concentration. A strong top-down effect of fish on the large-sized grazers was evident as density and the body size of Daphnia pulexde Geer increased significantly after the fish removal. Even though the spring and annual euphotic depths occurred well above the maximum and mean depths of the lake, respectively, re-development of submerged plants was poor (6.2% coverage). A weak re-establishment of submerged plants might be attributed to an insufficiently viable seed bank, inappropriate chemical conditions of the sediment (severe oxygen deficiency), or to the high coot (Fulica atra L.) density. However, the top-down effect of fish appeared to be of great importance in determining water clarity, and in turn, conditions for submerged plant development in a warm temperate lake as recorded in the north temperate lakes. Furthermore, this study provides evidence for the importance of top-down control of fish, which, in turn, can be effectively utilised as a restoration strategy in warm-temperate lakes as well. More applications, along with long monitoring programs, are needed to develop a better understanding about requirements for biomanipulation success in this climate.