Climate change modulates structural and functional lake ecosystem responses to introduced anadromous salmon

2011 ◽  
Vol 68 (4) ◽  
pp. 675-692 ◽  
Author(s):  
Daniel T. Selbie ◽  
Jon N. Sweetman ◽  
Peter Etherton ◽  
Kim D. Hyatt ◽  
D. Paul Rankin ◽  
...  
Keyword(s):  
Climate Warming ◽  
Sockeye Salmon ◽  
Species Turnover ◽  
Late Summer ◽  
Lake Ecosystem ◽  
Ecosystem Structure ◽  
Lake Productivity ◽  
Ecosystem Responses ◽  
Lake Ecology ◽  
Ecosystem Structure And Functioning

We integrated limnological, paleolimnological, and fisheries analyses in Tuya Lake, British Columbia, Canada, to explore the effects and interactions of climate warming and sockeye salmon introductions on northern lake ecology. We tracked millennially unprecedented, climate-correlated changes in inferred lake production, stratification, and trophic structure since the mid-1800s, most likely resulting from declining ice cover and enhanced stratification. Post-1970s algal (diatom) species turnover, coeval across several remote northern Cordilleran lakes, marked an apparent increase in warming and the induction of inferred nitrogen deficiencies in Tuya Lake. Lower post-stocking phosphorus (P) and nitrogen (N) concentrations and a strong P-modeled salmon biomass correlation (r2 = 0.87) indicated salmon production reduced epilimnetic nutrient availability. Post-stocking chlorophyll reductions, late-summer algal dominance by heterocystous cyanobacteria and low-N-tolerant diatoms, and a strong chlorophyll-modeled salmon biomass correlation (r2 = 0.87) indicated that salmon influenced lake productivity, most likely by enhancing climate-induced N-deficiencies. Predicted smolt-biomass nutrient exports were minimal, with post-introduction nutrient reductions likely related to planktivory and enhanced sedimentation losses. Our study highlights how climate warming changes northern lake ecosystem structure and functioning, influencing responses to subsequent stresses.

Coldwater fish oxythermal habitat in Minnesota lakes: influence of total phosphorus, July air temperature, and relative depth

2010 ◽  
Vol 67 (12) ◽  
pp. 2002-2013 ◽  
Author(s):  
Peter C. Jacobson ◽  
Heinz G. Stefan ◽  
Donald L. Pereira
Keyword(s):  
Air Temperature ◽  
Climate Warming ◽  
Lake Trout ◽  
Late Summer ◽  
Relative Depth ◽  
Response Curves ◽  
Lake Productivity ◽  
Species Response ◽  
Minnesota Lakes ◽  
Total P

An empirical model was developed that describes the influence of lake productivity, climate, and morphometry on coldwater fish oxythermal habitat. An oxythermal habitat variable called temperature at 3 mg·L–1 of dissolved oxygen (TDO3) was developed by interpolating the water temperature at a benchmark oxygen concentration (3 mg·L–1) from a temperature–oxygen profile. Coldwater habitat was most available in the least productive lakes (total P < 25 µg·L–1) with the greatest relative depths (geometry ratios < 2 m–0.5) and where mean July air temperatures were less than 17 °C. Species response curves were developed from values of TDO3 measured during the greatest period of oxythermal stress in late summer (maxTDO3). Lake trout was present in lakes with the lowest values of maxTDO3, while cisco was present in lakes with the highest and broadest range of maxTDO3. Projections for a scenario where climate warming (+4 °C in mean July air temperature) was accompanied by eutrophication (doubling of total P) indicated that coldwater fish oxythermal habitat would be devastated in a subset of lakes typical for Minnesota. Protecting deep, unproductive lakes from eutrophication will be a necessary management strategy to ensure that coldwater fish persist in at least some Minnesota lakes after climate warming.

The lake ecosystem simulation program

1995 ◽  
Vol 31 (8) ◽  
pp. 367-370
Author(s):  
J. Heringa ◽  
H. Hylkema ◽  
M. Kroes ◽  
E. Ludden ◽  
P. G. van Schaick Zillesen
Keyword(s):  
Mathematical Model ◽  
Water Resources ◽  
Computer Program ◽  
Water Resources Management ◽  
Lake Ecosystem ◽  
Original Research ◽  
Ecological Processes ◽  
Resources Management ◽  
Lake Ecology ◽  
Ecosystem Simulation

The computer program LAKE simulates a shallow lake ecosystem. The program is based on a mathematical model. In the model the most important aspects of several models for water resources management are integrated (Collins and Wlosinski, 1988; Jørgensen, 1976; Jørgensen et al., 1978; Scheffer, 1988). Furthermore, the model describes several ecological processes that have not yet been described by lake-ecosystem models so far. In the computer program, the mathematical model and an advanced, object oriented, user interface are combined. Following this approach the use of the original research models was extended to a use for the purpose of teaching lake ecology. We suggest that the same approach may be followed to open research models to other groups concerned with water resources management, such as management authorities, industry, agricultural extension, nature conservation and recreation.

scholarly journals Ecosystem responses to elevated CO<sub>2</sub> using airborne remote sensing at Mammoth Mountain, California

2018 ◽  
Vol 15 (24) ◽  
pp. 7403-7418 ◽  
Author(s):  
Kerry Cawse-Nicholson ◽  
Joshua B. Fisher ◽  
Caroline A. Famiglietti ◽  
Amy Braverman ◽  
Florian M. Schwandner ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Co2 Emissions ◽  
Elevated Co2 ◽  
Co2 Flux ◽  
Ecosystem Structure ◽  
Soil Co2 ◽  
Ecosystem Responses ◽  
Mammoth Mountain ◽  
And Function ◽  
Canopy Nitrogen

Abstract. We present an exploratory study examining the use of airborne remote-sensing observations to detect ecological responses to elevated CO2 emissions from active volcanic systems. To evaluate these ecosystem responses, existing spectroscopic, thermal, and lidar data acquired over forest ecosystems on Mammoth Mountain volcano, California, were exploited, along with in situ measurements of persistent volcanic soil CO2 fluxes. The elevated CO2 response was used to statistically model ecosystem structure, composition, and function, evaluated via data products including biomass, plant foliar traits and vegetation indices, and evapotranspiration (ET). Using regression ensemble models, we found that soil CO2 flux was a significant predictor for ecological variables, including canopy greenness (normalized vegetation difference index, NDVI), canopy nitrogen, ET, and biomass. With increasing CO2, we found a decrease in ET and an increase in canopy nitrogen, both consistent with theory, suggesting more water- and nutrient-use-efficient canopies. However, we also observed a decrease in NDVI with increasing CO2 (a mean NDVI of 0.27 at 200 g m−2 d−1 CO2 reduced to a mean NDVI of 0.10 at 800 g m−2 d−1 CO2). This is inconsistent with theory though consistent with increased efficiency of fewer leaves. We found a decrease in above-ground biomass with increasing CO2, also inconsistent with theory, but we did also find a decrease in biomass variance, pointing to a long-term homogenization of structure with elevated CO2. Additionally, the relationships between ecological variables changed with elevated CO2, suggesting a shift in coupling/decoupling among ecosystem structure, composition, and function synergies. For example, ET and biomass were significantly correlated for areas without elevated CO2 flux but decoupled with elevated CO2 flux. This study demonstrates that (a) volcanic systems show great potential as a means to study the properties of ecosystems and their responses to elevated CO2 emissions and (b) these ecosystem responses are measurable using a suite of airborne remotely sensed data.

scholarly journals Landscape and biophysical controls of lake productivity to inform evaluation of sockeye salmon ( Oncorhynchus nerka ) populations in data‐limited regions

2020 ◽  
Vol 65 (9) ◽  
pp. 2205-2219 ◽  
Author(s):  
William I. Atlas ◽  
Daniel T. Selbie ◽  
Carrie A. Holt ◽  
Steve Cox‐Rogers ◽  
Charmaine Carr‐Harris ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Lake Productivity ◽  
Biophysical Controls

scholarly journals The MARAS dataset, vegetation and soil characteristics of dryland rangelands across Patagonia

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Gabriel Oliva ◽  
Eder dos Santos ◽  
Osiris Sofía ◽  
Fernando Umaña ◽  
Virginia Massara ◽  
...  
Keyword(s):  
Soil Analysis ◽  
Soil Surface ◽  
Surface Characteristics ◽  
Spatial Pattern Analysis ◽  
Ecosystem Structure ◽  
Species List ◽  
Plant Soil ◽  
Rangeland Monitoring ◽  
Ecosystem Structure And Functioning ◽  
Line Intercept

Abstract We present the MARAS (Environmental Monitoring of Arid and Semiarid Regions) dataset, which stores vegetation and soil data of 426 rangeland monitoring plots installed throughout Patagonia, a 624.500 km2 area of southern Argentina and Chile. Data for each monitoring plot includes basic climatic and landscape features, photographs, 500 point intercepts for vegetation cover, plant species list and biodiversity indexes, 50-m line-intercept transect for vegetation spatial pattern analysis, land function indexes drawn from 11 measures of soil surface characteristics and laboratory soil analysis (pH, conductivity, organic matter, N and texture). Monitoring plots were installed between 2007 and 2019, and are being reassessed at 5-year intervals (247 have been surveyed twice). The MARAS dataset provides a baseline from which to evaluate the impacts of climate change and changes in land use intensity in Patagonian ecosystems, which collectively constitute one of the world´s largest rangeland areas. This dataset will be of interest to scientists exploring key ecological questions such as biodiversity-ecosystem functioning relationships, plant-soil interactions and climatic controls on ecosystem structure and functioning.

scholarly journals Balanced harvesting is the bioeconomic equilibrium of a size-structured Beverton-Holt model

2016 ◽  
Vol 74 (1) ◽  
pp. 112-120 ◽  
Author(s):  
Michael J. Plank
Keyword(s):  
Single Species ◽  
Size Spectrum ◽  
Ecosystem Structure ◽  
Fishing Mortality ◽  
Biomass Transfer ◽  
Body Sizes ◽  
Relative Production ◽  
Ecosystem Structure And Functioning ◽  
Classical Size ◽  
Spectrum Model

Balanced harvesting (BH) was introduced as an alternative strategy to size-at-entry fishing with the aim of maintaining ecosystem structure and functioning. BH has been criticized on a number of grounds, including that it would require an infeasible level of micromanagement and enforcement. Recent results from a size-spectrum model show that the distribution of fishing mortality across body sizes that emerges from the behaviour of a large number of fishing agents corresponds to BH in a single species. Size-spectrum models differ from classical size-structured models used in fisheries as they are based on a bookkeeping of biomass transfer from prey to predator rather than a von Bertalanffy growth model. Here we investigate a classical Beverton-Holt model coupled with the Gordon-Schaefer harvesting model extended to allow for differential fishing pressure at different body sizes. This models an open-access fishery in which individual fishing agents act to maximize their own economic return. We show that the equilibrium of the harvesting model produces an aggregate fishing mortality that is closely matched to the production at different body sizes, in other words BH of a single species. These results have significant implications because they show that the robustness of BH does not depend on arguments about the relative production levels of small versus large fish.

Productivity of Owikeno Lake, British Columbia

1969 ◽  
Vol 26 (5) ◽  
pp. 1363-1368 ◽  
Author(s):  
David W. Narver
Keyword(s):  
British Columbia ◽  
North America ◽  
Primary Productivity ◽  
Sockeye Salmon ◽  
Nursery Area ◽  
The Other ◽  
Lake Productivity ◽  
The Third ◽  
Annual Total

Although Owikeno Lake is the third highest producer of adult sockeye salmon in North America in terms of mean annual total return (catch plus escapement) per unit of lake nursery area, limited measurements of other indices of lake productivity suggest that its primary productivity is much lower than that of the other four highest sockeye-producing lakes. The implications of these results to sockeye production are discussed.

scholarly journals Fisheries impacts on lake ecosystem structure in the context of a changing climate and trophic state

2017 ◽  
Author(s):  
Tiina Nõges ◽  
Orlane Anneville ◽  
Jean Guillard ◽  
Juta Haberman ◽  
Ain Järvalt ◽  
...  
Keyword(s):  
Water Quality ◽  
Trophic State ◽  
Scale Effects ◽  
Trophic Levels ◽  
Interactive Effects ◽  
Phosphorus Loading ◽  
Lake Ecosystem ◽  
Ecosystem Structure ◽  
Top Down ◽  
Lake Basins

<p>Through cascading effects within lake food webs, commercial and recreational fisheries may indirectly affect the abundances of organisms at lower trophic levels, such as phytoplankton, even if they are not directly consumed. So far, interactive effects of fisheries, changing trophic state and climate upon lake ecosystems have been largely overlooked. Here we analyse case studies from five European lake basins of differing trophic states (Lake Võrtsjärv, two basins of Windermere, Lake Geneva and Lake Maggiore) with long-term limnological and fisheries data. Decreasing phosphorus concentrations (re-oligotrophication) and increasing water temperatures have been reported in all five lake basins, while phytoplankton concentration has decreased only slightly or even increased in some cases. To examine possible ecosystem-scale effects of fisheries, we analysed correlations between fish and fisheries data, and other food web components and environmental factors. Re-oligotrophication over different ranges of the trophic scale induced different fish responsesIn the deeper lakes Geneva and Maggiore, we found a stronger link between phytoplankton and planktivorous fish and thus a more important cascading top-down effect than in other lakes. This connection makes careful ecosystem-based fisheries management extremely important for maintaining high water quality in such systems. We also demonstrated that increasing water temperature might favour piscivores at low phosphorus loading, but suppresses them at high phosphorus loading and might thus either enhance or diminish the cascading top-down control over phytoplankton with strong implications for water quality.</p>

scholarly journals A feeding guild indicator to assess environmental change impacts on marine ecosystem structure and functioning

2020 ◽  
Vol 57 (9) ◽  
pp. 1769-1781 ◽  
Author(s):  
Murray S. A. Thompson ◽  
Hugo Pontalier ◽  
Michael A. Spence ◽  
John K. Pinnegar ◽  
Simon P. R. Greenstreet ◽  
...  
Keyword(s):  
Environmental Change ◽  
Marine Ecosystem ◽  
Ecosystem Structure ◽  
Feeding Guild ◽  
Ecosystem Structure And Functioning
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