The effects of harmful algal species and food concentration on zooplankton grazer production of dissolved organic matter and inorganic nutrients

Harmful Algae ◽  
2011 ◽  
Vol 10 (3) ◽  
pp. 291-303 ◽  
Author(s):  
Grace K. Saba ◽  
Deborah K. Steinberg ◽  
Deborah A. Bronk ◽  
Allen R. Place
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Algal Species ◽  
Food Concentration ◽  
Inorganic Nutrients

Dissolved organic matter as P source for biofilms in two contrasting low-order streams

2019 ◽  
Vol 193 (2) ◽  
pp. 131-142
Author(s):  
Verónica Díaz-Villanueva
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Deciduous Forest ◽  
Spatial Scales ◽  
Algal Species ◽  
Community Level ◽  
Nutrient Concentrations ◽  
Organic Substrates ◽  
One Year ◽  
Forest Streams

Forest streams receive large amounts of leaves whose leachates are an important source of dissolved organic matter (DOM), providing not only carbon but also organic nutrients to the microbial communities in streams. I carried out a field study to evaluate the effect of different DOM concentrations on the biofilm structure and functional traits in two similar forest streams belonging to the same catchment. I compared biofilm biomass and nutri- ent content throughout one year, algal species composition, and biofilm community-level physiological profiles in two streams with different DOM concentration and aromaticity. Dissolved nutrient concentrations were higher in the stream with higher DOM concentration, with a concomitant higher biofilm biomass, and there was also a temporal pattern, with higher values during the autumn. Phosphorus content in biofilms was also higher in the high DOM stream, coincidently with a higher capacity of the community to utilize organic P source (glucose-1-P) as a substrate. In contrast, the biofilms from the stream with lower DOM concentrations preferentially used N-organic substrates (amino acids and amines). These results reveal that the biofilms of forest streams make use of organic matter nutrients, so that streams with different DOM loads may differ in biofilm biomass due to changes in both bacterial and autotrophic biomass. In addition, biofilm dynamics may be related to forest phenology, as the highest OM input in this deciduous forest is represented by tree leaves, which supply DOM through leachates, and in particular, with P-rich leachates. In conclusion, different DOM concentrations in two nearby streams led to differences in the community-level physiological profile, as has been previously demonstrated at larger spatial scales in oceans, lakes and along larger rivers.

Processing of humic-rich riverine dissolved organic matter by estuarine bacteria: effects of predegradation and inorganic nutrients

2014 ◽  
Vol 76 (3) ◽  
pp. 451-463 ◽  
Author(s):  
E. Asmala ◽  
R. Autio ◽  
H. Kaartokallio ◽  
C. A. Stedmon ◽  
D. N. Thomas
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Inorganic Nutrients

scholarly journals Effects of food concentration and diet on chromophoric dissolved organic matter accumulation and fluorescent composition during grazing experiments with the copepod Calanus finmarchicus

2004 ◽  
Vol 61 (4) ◽  
pp. 542-551 ◽  
Author(s):  
Juanita Urban-Rich ◽  
James T McCarty ◽  
Mark Shailer
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Exponential Growth ◽  
Life Stage ◽  
Food Concentration ◽  
Prorocentrum Minimum ◽  
Calanus Finmarchicus ◽  
Food Type ◽  
Chromophoric Dissolved Organic Matter ◽  
Effects Of Food Concentration

AbstractLaboratory experiments were conducted with Calanus finmarchicus copepodites IV–V to examine the effects of food concentration, food type, and life stage on chromophoric dissolved organic matter (CDOM) release from copepods. Changes in CDOM absorption and fluorescence were monitored by incubating copepods in rotating bottles for 24 h in the dark with controlled diets. Copepods were fed a range of food concentrations from 800 to 15 000 cells l−1 of either Thalassiosira weissflogii and Skeletonema costatum or Prorocentrum minimum in stationary and exponential growth phases. Results from these studies indicate that diet does have an effect on the amount and type of CDOM released by C. finmarchicus. A diet of either diatoms or dinoflagellates in exponential growth will result in a release of humic-like material, while feeding on senescent cells leads to a net input of protein-like material. Only at very high senescent cell concentrations (>5000 cells l−1) can humic-like material accumulate. This could lead to seasonal cycles in the amount and type of CDOM released by copepods, such that humic-like material will be released in the spring and at the height of phytoplankton blooms, while protein-like material will be added to the water as the bloom dies. The humic-like material found in these studies is blue-shifted compared to the standard humic material (Peaks A, M, and C) measured in seawater. The role of this humic-like material in the environment is currently unknown, but it could be important in absorbing UV radiation.

Positive and negative effects of allochthonous dissolved organic matter and inorganic nutrients on phytoplankton growth

2002 ◽  
Vol 59 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Jennifer L Klug
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Phytoplankton Community ◽  
Phytoplankton Growth ◽  
Inorganic Nutrients ◽  
Physiological Status ◽  
Negative Effects ◽  
Positive Effects ◽  
Negative Effect ◽  
Positive Effect

Dissolved organic matter (DOM) can have both positive and negative effects on phytoplankton growth. The magnitude of these effects may vary depending on the source of DOM and the composition of the phytoplankton community. Here, I address the relative importance of the positive and negative effects of DOM extracts on phytoplankton growth. In short-term experiments with phytoplankton from West Long Lake, a small, moderately coloured lake in northern Michigan, U.S.A., the net effect of doubling ambient DOM on phytoplankton growth was positive. Increasing DOM concentrations from ~10 mg C·L–1 to ~20 mg C·L–1 had a negative effect on total phytoplankton growth by reducing irradiance and thus reducing the depth to which growth was positive. However, inorganic nutrients in the DOM extracts increased growth at each irradiance level. The positive effect on phytoplankton growth owing to the nutrients associated with DOM was greater than the negative effect caused by shading. Although the positive effects of allochthonous DOM inputs outweighed the negative effects for the nutrient-limited phytoplankton in these experiments, the net effect depends on the concentration and availability of nutrients associated with allochthonous DOM as well as the physiological status of the phytoplankton community.

Dissolved organic matter utilization and oxygen uptake in algal–bacterial microcosms

1979 ◽  
Vol 25 (11) ◽  
pp. 1315-1320 ◽  
Author(s):  
David L. Tison ◽  
A. J. Lingg
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Algal Biomass ◽  
Algal Species ◽  
Chlorella Pyrenoidosa ◽  
Individual Species ◽  
Bacterial Respiration ◽  
Bacterial Microbiota ◽  
Limiting Nutrient ◽  
Algal Photosynthesis

Under closed laboratory conditions, at non-limiting nutrient levels, the biomass of Anabaena variabilis. Anacystis nidnlans, Chlorella pyrenoidosa. and Selanastrum capricornutum increased with increasing levels of dissolved organic matter (DOM) as a result of bacterially produced carbon dioxide (CO2) and (or) cofactors. Oxygen (O2) produced as a result of algal photosynthesis was sufficient to supply the majority of O2 required by the bacterial community. The percentage of DOM utilized by bacteria which was subsequently incorporated into algal biomass varied with individual species indicating that the association between individual algal species and the bacterial microbiota varied.Under natural conditions bacteria could provide CO2 and (or) cofactors for algal photosynthesis which in turn supplies O2 for bacterial respiration. This mutualistic association in aquatic environments could result in an increase in planktonic and epiphytic algal biomass if other nutrients are available.

scholarly journals Behaviour of dissolved organic matter and inorganic nutrients during experimental sea-ice formation

2001 ◽  
Vol 33 ◽  
pp. 317-321 ◽  
Author(s):  
Virginia Giannelli ◽  
David N. Thomas ◽  
Christian Haas ◽  
Gerhard Kattner ◽  
Hilary Kennedy ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Sea Ice ◽  
Organic Compounds ◽  
Sea Water ◽  
Ice Cores ◽  
Inorganic Nutrients ◽  
Ice Formation ◽  
Solid Matrix ◽  
Dissolved Organic Compounds

AbstractIt is well established that during sea-ice formation, crystals aggregate into a solid matrix, and dissolved sea-water constituents, including inorganic nutrients, are rejected from the ice matrix. However, the behaviour of dissolved organic matter (DOM) during ice formation and growth has not been studied to date. DOM is the primary energetic substrate for microbial heterotrophic activity in sea water and sea ice, and therefore it is at the base of the trophic fluxes within the microbial food web. The aim of our study was to compare the behaviour of DOM and inorganic nutrients during formation and growth of sea ice. Experiments were conducted in a large indoor ice-tank facility (Hamburg Ship Model Basin, Germany) at −15°C. Three 1 m3 tanks, to which synthetic sea water, nutrients and dissolved organic compounds (diatom-extracted DOM) had been added, were sampled over a period of 5 days during sea-ice formation. Samples were collected throughout the experiment from water underlying the ice, and at the end from the ice as well. Brine was obtained from the ice by centrifuging ice cores. Inorganic nutrients (nitrate and phosphate) were substantially enriched in brine in comparison to water and ice phases, consistent with the processes of ice formation and brine rejection. Dissolved organic carbon (DOC) was also enriched in brine but was more variable and enriched in comparison to a dilution line. No difference in bacteria numbers was observed between water, ice and brine. No bacteria growth was measured, and this therefore had no influence on the measurable DOC levels. We conclude that the incorporation of dissolved organic compounds in newly forming ice is conservative. However, since the proportions of DOC in the brine were partially higher than those of the inorganic nutrients, concentrating effects of DOC in brine might be different compared to salts.

scholarly journals Sensitivity of the N. AEGEAN SEA ecosystem to Black Sea Water inputs

2014 ◽  
Vol 15 (4) ◽  
pp. 790 ◽  
Author(s):  
G. PETIHAKIS ◽  
K. TSIARAS ◽  
G. TRIANTAFYLLOU ◽  
S. KALARONI ◽  
A. POLLANI
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Black Sea ◽  
Sea Water ◽  
Aegean Sea ◽  
Microbial Loop ◽  
Inorganic Nutrients ◽  
The North ◽  
North Aegean Sea ◽  
The Impact

The effect of Black Sea Water (BSW) inputs on the North Aegean Sea productivity and food web dynamics was investigated, by means of sensitivity simulations, investigating the effect of the inflowing BSW, in terms of inorganic nutrients and dissolved organic matter. The model used has been successfully applied in the area in the past and extensively presented. Considering the importance of the microbial loop in the ecosystem functioning, the role of the dissolved organics and in order to achieve a more realistic representation of the Dissolved Organic Matter pool, the bacteria sub-model was appropriately revised. The importance of the microbial loop is highlighted by the carbon fluxes where almost 50% of carbon is channelled within it. The impact of dissolved organic matter (DOM) (in the inflowing to the Aegean Sea, BSW) appears to be stronger than the impact of dissolved inorganic nutrients, showing a more extended effect over the N Aegean. Bacterial production and biomass is more strongly affected in the simulations by modified DOM, unlike phytoplankton biomass and production, which are more dependent on the inflowing nutrients and particularly phosphorus (inorganic and dissolved organic). In the phytoplankton composition, the dinoflagellates appear to be mostly affected, being favoured by higher nutrient availability at the expense of all other groups, particularly picoplankton, indicating a shift to a more classical food chain.

Influence of dissolved organic matter and inorganic nutrients on the biofilm bacterial community on artificial substrates in a northeastern Ohio, USA, stream

2006 ◽  
Vol 52 (6) ◽  
pp. 540-549 ◽  
Author(s):  
Ola A Olapade ◽  
Laura G Leff
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Nutrient Dynamics ◽  
Inorganic Nutrients ◽  
Artificial Substrates ◽  
Response Patterns ◽  
Ceramic Tiles ◽  
Phylogenetic Groups ◽  
Leaf Leachate ◽  
The Individual

Stream bacteria may be influenced by the composition and availability of dissolved organic matter (DOM) and inorganic nutrients, but knowledge about how individual phylogenetic groups in biofilm are affected is still limited. In this study, the influence of DOM and inorganic nutrients on stream biofilm bacteria was examined. Biofilms were developed on artificial substrates (unglazed ceramic tiles) for 21 days in a northeastern Ohio (USA) stream for five consecutive seasons. Then, the developed biofilm assemblages were exposed, in the laboratory, to DOM (glucose, leaf leachate, and algal exudates) and inorganic nutrients (nitrate, phosphate, and nitrate and phosphate in combination) amendments for 6 days. Bacterial numbers in the biofilms were generally higher in response to the DOM treatments than to the inorganic nutrient treatments. There were also apparent seasonal variations in the response patterns of the individual bacterial taxa to the nutrient treatments; an indication that limiting resources to bacteria in stream biofilms may change over time. Overall, in contrast to the other treatments, bacterial abundance was generally highest in response to the low-molecular-weight DOM (i.e., glucose) treatment. These results further suggest that there are interactions among the different bacterial groups in biofilms that are impacted by the associated nutrient dynamics among seasons in stream ecosystems.Key words: biofilms, nutrients, DOM, bacteria, in situ hybridization.

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