scholarly journals Chlorophyll-a growth rates and related environmental variables in global temperate and cold-temperate lakes

2021 ◽  
Author(s):  
Hannah Adams ◽  
Jane Ye ◽  
Bhaleka Persaud ◽  
Stephanie Slowinski ◽  
Homa Kheyrollah Pour ◽  
...  

Abstract. Lakes are key ecosystems within the global biogeosphere. However, the bottom-up controls on the biological productivity of lakes, including surface temperature, ice phenology, nutrient loads and mixing regime, are increasingly altered by climate warming and land-use changes. To better understand the environmental drivers of lake productivity, we assembled a dataset on chlorophyll-a concentrations, as well as associated water quality parameters and surface solar irradiance, for temperate and cold-temperate lakes experiencing seasonal ice cover. We developed a method to identify periods of rapid algal growth from in situ chlorophyll-a time series data and applied it to measurements performed between 1964 and 2019 across 357 lakes, predominantly located north of 40°. Long-term trends show that the algal growth windows have been occurring earlier in the year, thus potentially extending the growing season and increasing the annual productivity of northern lakes. The dataset is also used to analyze the relationship between chlorophyll-a growth rates and solar irradiance. Lakes of higher trophic status exhibit a higher sensitivity to solar radiation, especially at moderate irradiance values during spring. The lower sensitivity of chlorophyll-a growth rates to solar irradiance in oligotrophic lakes likely reflects the dominant role of nutrient limitation. Chlorophyll-a growth rates are significantly influenced by light availability in spring but not in summer and fall, consistent with a switch to top-down control of summer and fall algal communities. The growth window dataset can be used to analyze trends in lake productivity across the northern hemisphere or at smaller, regional scales. We present some general trends in the data and encourage other researchers to use the open dataset for their own research questions.

2013 ◽  
Vol 70 (5) ◽  
pp. 815-823 ◽  
Author(s):  
Jennifer M. Blair ◽  
Ilia Ostrovsky ◽  
Brendan J. Hicks ◽  
Robert J. Pitkethley ◽  
Paul Scholes

To predict potential effects of climate and anthropogenic impacts on fish growth, we compared growth rates of rainbow trout (Oncorhynchus mykiss) in nine closely located warm-temperate lakes of contrasting morphometry, stratification and mixing regime, and trophic state. Analyses of long-term mark–recapture data showed that in deep oligotrophic and mesotrophic lakes, trout growth rates increased with increasing indices of lake productivity. In contrast, in shallow eutrophic lakes, where fish habitat volume is constrained by temperature and dissolved oxygen, trout growth rates declined with increasing productivity. Growth rates were higher in lakes with greater volumes of favourable habitat (i.e., dissolved oxygen > 6.0 mg·L−1 and temperature < 21 °C) and lower in lakes with increased turbidity, chlorophyll a, and nitrogen concentrations. Our findings suggest that increases in lake productivity and temperatures as a result of global climatic change are likely to be more detrimental to salmonid habitat quality in shallower, productive lakes, while salmonids will better endure such changes in deeper, oligotrophic lakes. Fishery managers can use this information to aid future stocking decisions for salmonid fisheries in warm-temperate climates.


Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 31 ◽  
Author(s):  
Maria N. Metsoviti ◽  
George Papapolymerou ◽  
Ioannis T. Karapanagiotidis ◽  
Nikolaos Katsoulas

In this research, the effect of solar irradiance on Chlorella vulgaris cultivated in open bioreactors under greenhouse conditions was investigated, as well as of ratio of light intensity in the 420–520 nm range to light in the 580–680 nm range (I420–520/I580–680) and of artificial irradiation provided by red and white LED lamps in a closed flat plate laboratory bioreactor on the growth rate and composition. The increase in solar irradiance led to faster growth rates (μexp) of C. vulgaris under both environmental conditions studied in the greenhouse (in June up to 0.33 d−1 and in September up to 0.29 d−1) and higher lipid content in microalgal biomass (in June up to 25.6% and in September up to 24.7%). In the experiments conducted in the closed bioreactor, as the ratio I420–520/I580–680 increased, the specific growth rate and the biomass, protein and lipid productivities increased as well. Additionally, the increase in light intensity with red and white LED lamps resulted in faster growth rates (the μexp increased up to 0.36 d−1) and higher lipid content (up to 22.2%), while the protein, fiber, ash and moisture content remained relatively constant. Overall, the trend in biomass, lipid, and protein productivities as a function of light intensity was similar in the two systems (greenhouse and bioreactor).


2021 ◽  
Vol 324 ◽  
pp. 01007
Author(s):  
Yulius Yulius ◽  
Vaninda Aidina ◽  
Muhammad Ramdhan ◽  
August Daulat

The fishing ground is identical and closely related to chlorophyll-a abundance in the waters, associated with its fisheries potential. This research has been conducted to determine the concentration and distribution of chlorophyll-a in the seas, especially in the Fisheries Management Area (FMA) 712 encompassing the Java Sea. The analysis used monthly time-series data collected from the satellite imagery over the last 11 years, taken through the ERDDAP website. The mean concentration of chlorophyll-a in the study area was 1.13 mg/l in June 2013. Based on 11 years of data processing, it can be concluded that the highest concentration of chlorophyll-a occurred in the west monsoon season from November to April, where increased rainfall caused the nutrient wash from terrestrial to the open waters. The lowest chlorophyll-a concentration happened in the east monsoon season from April to November, where the dry season arrived. The existence of pelagic fishes in FMA 712, such as Sardinella Lemurs and Sardinella Fimbriata, in waters highly influenced by the chlorophyll-a concentration, while Thunnus Sp. and Exocoetidae Sp. not affected significantly to the existence of chlorophyll-a concentration and its distribution.


Author(s):  
Leslie Riley ◽  
Mark Dybdahl ◽  
Robert Hall

We studied positive and negative effects of snail consumers on their resource to determine if positive consumer effects may be facilitating invasion. Consumer- resource interactions often focus on losses to the resource, even though the resource might benefit if consumers recycle nutrients. The New Zealand mudsnail, Potamopyrgus antipodarum, an exotic in western U.S. rivers, attains high densities and dominates macroinvertebrate communities. In one well-studied river, it consumes the majority of primary productivity, cycles most nitrogen and can grow faster at higher densities. In field experiments, we tested the hypothesis that this invasive grazer stimulates algal growth via nitrogen excretion, which might explain its self-facilitation and invasiveness. Using in-stream cages subdivided into "with snails" and "without snails" sections, we examined the response of periphytic algae to snail grazing and excretion and snail excretion alone at various levels of snail biomass. We found that chlorophyll a and GPP (gross primary production) decreased as the biomass of snails increased in the grazed sections. Snail excretion, in the absence of grazing, increased both chlorophyll a and GPP, demonstrating a positive effect of snails on the resource, consistent with the nutrient recycling and enrichment hypothesis. We found no evidence for increased algal growth at intermediate snail densities in grazed treatments, as predicted by the Herbivore Optimization Curve hypothesis. However, the difference in chlorophyll a between "with snails" and "without snails" treatments increased as snail biomass increased. This suggests that snail compensation of the resource, through excretion, decreases at extremely high levels of grazing pressure and the net effect of snail grazing becomes negative. Together, these results suggest that invasiveness in some rivers may be fostered by this self-facilitation and recycling of essential nutrients.


2010 ◽  
Vol 56 (No. 5) ◽  
pp. 209-217 ◽  
Author(s):  
R. Hajiboland ◽  
F. Amirazad

The effect of Zn deficiency was studied in red cabbage (Brassica oleracea L. var. capitata f. rubra) plants grown in nutrient solution under controlled environmental conditions. Zinc starvation affected the number (61%), surface area (72%) and biomass (62%) of leaves more than root biomass (42%). Although chlorophyll fluorescence parameters revealed occurrence of photoinhibition following declined stomatal conductance and reduction of CO2 available at carboxylation sites, photosynthesis apparatus was not damaged seriously under Zn deficiency conditions. Chlorophyll a, chlorophyll a/b ratio, soluble carbohydrates and starch declined but anthocyanins and free phenolics were accumulated under Zn deficiency conditions. Activity of ascorbate peroxidase, catalase and peroxidase enhanced under Zn deficiency conditions, whereas activity of superoxide dismutase declined in leaves but not in roots of Zn-deficient plants. Maintenance of superoxide dismutase activity and malondialdehyde content in roots demonstrated that roots were more protected against reactive oxygen species imbalance under Zn deficiency conditions compared with leaves that was correlated well with the lower sensitivity of roots to low Zn supply.


2013 ◽  
Vol 42 (1) ◽  
Author(s):  
Krystyna Kalinowska

AbstractCiliate abundance and species composition were studied in the sandy beaches of six lakes of different trophic status (Poland). Samples of wet sand were taken in June 2007 from the euarenal (emergent sand), hygroarenal (sand wetted by lake waves) and hydroarenal (submerged sand) zones. The numbers of ciliates ranged from 105 to 2933 ind. cm−3 of sand and did not show any visible trend with lake productivity. In all the studied lakes, ciliates were much more numerous in the euarenal than in the hydroarenal. Small bacterivorous scuticociliates dominated in the euarenal, while Hymenostomatida, Cyrtophorida, Hypotrichida as well as Scuticociliatida comprised a significant part of the ciliate community in the hygro- and hydroarenal zones. There were positive correlations between ciliates and the concentrations of chlorophyll a and total nitrogen.


2013 ◽  
Vol 16 (3) ◽  
pp. 572-587 ◽  
Author(s):  
Dongfang Liang ◽  
Rebecca W. Zeckoski ◽  
Xiaolin Wang

Before railroad and lorry traffic became common, many canals were built for transportation purposes. Water quality in canals has become a major concern as maintenance of these historically active canals has declined. A generic canal model has been developed to simulate the hydro-environmental processes specifically relevant to inland navigational canals, namely lockage, weir overflow, boat traffic, and algal growth. Apart from the movement of water, three types of particulate matter are tracked: algae (chlorophyll-a), inorganic non-cohesive sediment, and inorganic cohesive sediment. The newly developed model was applied to the Kennet and Avon Canal in southern England. The method of determining the input parameters for the model was documented herein, including setting up a Hydrological Simulation Program – Fortran model to obtain the landscape flow and sediment runoff to the canal. The model predictions were compared with the observed hydrological, sediment, and chlorophyll-a data at monitoring locations along the canal, and favourable agreements were achieved.


2019 ◽  
Vol 99 (7) ◽  
pp. 1467-1479
Author(s):  
Elizabeth Talbot ◽  
Jorn Bruggeman ◽  
Chris Hauton ◽  
Stephen Widdicombe

AbstractBenthic communities, critical to the health and function of marine ecosystems, are under increasing pressure from anthropogenic impacts such as pollution, eutrophication and climate change. In order to refine predictions of likely future changes in benthic communities resulting from these impacts, we must first better constrain their responses to natural seasonality in environmental conditions. Epibenthic time series data (July 2008–May 2014) have been collected from Station L4, situated 7.25 nautical miles south of Plymouth in the Western English Channel. These data were analysed to establish patterns in community abundance, wet biomass and composition, and to link any observed patterns to environmental variables. A clear response to the input of organic material from phytoplankton blooms was detected, with sediment surface living deposit feeders showing an immediate increase in abundance, while predators and scavengers responded later, with an increase in biomass. We suggest that this response is a result of two factors. The low organic content of the L4 sediment results in food limitation of the community, and the mild winter/early spring bottom water temperatures allow the benthos to take immediate advantage of bloom sedimentation. An inter-annual change in community composition was also detected, as the community shifted from one dominated by the anomuran Anapagurus laevis to one dominated by the gastropod Turitella communis. This appeared to be related to a period of high larval recruitment for T. communis in 2013/2014, suggesting that changes in the recruitment success of one species can affect the structure of an entire community.


Sign in / Sign up

Export Citation Format

Share Document