Patterns and Rates of Nitrogen Release by Benthic Chironomidae and Oligochaeta

1983 ◽  
Vol 40 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Wayne S. Gardner ◽  
Thomas F. Nalepa ◽  
David R. Slavens ◽  
Gwenyth A. Laird
Keyword(s):  
Benthic Invertebrates ◽  
Lake Michigan ◽  
Dry Weight ◽  
Phosphorus Release ◽  
Primary Amines ◽  
Ammonium Excretion ◽  
Nitrogen Release ◽  
Release Rates ◽  
Amine Nitrogen ◽  
Metabolic Pool

Metabolic mineralization of ammonium by tubificid worms and chironomid larvae appears to be an important mechanism contributing to nitrogen regeneration from aerobic lake sediments. Mean weight [ash free dry weight (AFDW)] – specific ammonium release rates ranged from 3 to 15 nmol NH4 (mg AFDW)]−1∙h−1 for chironomid and tubificid species collected at different times and temperatures from nearshore Lake Michigan sediments. Although mean rates of nitrogen release were similar for the two groups of benthic invertebrates, the patterns of release were different. Tubificids released nitrogen (ammonium plus primary amines) continuously, whereas chironomids released it in spurts several times per hour. Mean ammonium-release rates were generally constant with time after the animals were removed from food for both species. This implies that ammonium regeneration for these benthic animals is primarily an endogenous process. Conversely, primary amine nitrogen release often decreased with time after food removal and may reflect either egestion of partially digested materials from the animals' guts or a decrease in the metabolic pool size of free amino acids. Based on previous measurements of phosphorus release, mean molar NH4:PO4 ratios in excreted materials were calculated to be 15:1 for chironomids and 35:1 for tubificids.Key words: nitrogen release, benthic invertebrates, chironomids, tubificids, ammonium excretion, amino acid release

Release of Phosphorus by Certain Benthic Invertebrates

1981 ◽  
Vol 38 (8) ◽  
pp. 978-981 ◽  
Author(s):  
Wayne S. Gardner ◽  
Thomas F. Nalepa ◽  
Michael A. Quigley ◽  
John M. Malczyk
Keyword(s):  
Benthic Invertebrates ◽  
Lake Michigan ◽  
Nutrient Release ◽  
Dry Weight ◽  
Inorganic Phosphorus ◽  
Benthic Invertebrate ◽  
Phosphorus Release ◽  
Release Rates ◽  
Temperature Regimes ◽  
Two Temperature

Phosphate release rates by Stylodrilus heringianus, tubificids, and Chironomus spp. were quantified in laboratory experiments by incubating the animals in wet sand under two temperature regimes (5 and 20 °C) and under two nutritional states (full and empty guts). Inorganic phosphorus release rates (± SE) for animals incubated 24 h ranged from 0.12 ± 0.02 (n = 5) nmol phosphorus (P)∙(mg ash-free dry weight)−1∙h−1 for S. heringianus beginning with cleared guts at 5 °C to 0.81 ± 0.09 (n = 5) nmol P∙(mg ash-free dry weight)−1∙h−1 for chironomids beginning with full guts at 20 °C. Calculations based on total invertebrate bio-mass and mean basal release rate suggest that benthic invertebrate excretion could account for most P released from aerobic Lake Michigan sediments.Key words: phosphorus, benthic invertebrates, macroinvertebrates, excretion, nutrients, sediments, nutrient release

Phosphorus Release Processes in Nearshore Southern Lake Michigan

1986 ◽  
Vol 43 (6) ◽  
pp. 1201-1207 ◽  
Author(s):  
Michael A. Quigley ◽  
John A. Robbins
Keyword(s):  
Pore Water ◽  
Lake Michigan ◽  
Sampling Site ◽  
Soluble Reactive Phosphorus ◽  
Fine Sand ◽  
Phosphorus Release ◽  
Fickian Diffusion ◽  
Phosphorus Cycle ◽  
Release Rates ◽  
Overlying Water

We determined soluble reactive phosphorus (SRP) release rates from intact, medium-fine sand cores obtained from an 11-m-deep sampling site in nearshore Lake Michigan during July–October 1980. Mean SRP release ranged from 0.17 ± 0.03 (SE) to 0.57 ± 0.04 mg PO4-P∙m−2∙d−1. Pore water analysis indicated that, despite high dissolved oxygen concentrations in the uppermost 6 cm of sediment, SRP concentrations increased rapidly with depth throughout this zone. Moreover, a Fickian diffusion equation based on the SRP pore water gradient and physical sediment features predicted a release rate (1.12 mg PO4-P∙m−1∙d−1) that was 2–7 times higher than release rates measured from intact cores. Results suggest that nearshore sediments provide a ready pathway for the return of SRP to overlying water, and this process warrants inclusion in future conceptual models of Lake Michigan's phosphorus cycle.

Phosphorus Release Patterns and the Effects of Reproductive Stage and Ecdysis in Daphnia magna

1982 ◽  
Vol 39 (9) ◽  
pp. 1310-1314 ◽  
Author(s):  
Donald Scavia ◽  
Margaret J. McFarland
Keyword(s):  
Daphnia Magna ◽  
Reproductive Cycle ◽  
High Performance ◽  
Dry Weight ◽  
Flow Cell ◽  
Phosphorus Release ◽  
Reproductive Stage ◽  
Release Rates ◽  
Phosphorus Excretion ◽  
Mature Embryos

Rates of continuous phosphorus release by individual Daphnia magna (0.3 – 0.9 mg dry weight) were measured using high performance liquid chromatography components in conjunction with a specially designed incubation flow cell. Within the temporal resolution of the technique (3 min), phosphorus release often appeared pulsed rather than only steady. We found significant variation in release rates among the different stages of an individual's parthenogenetic reproductive cycle. Rates observed for animals carrying more mature embryos were lower than those earlier in the reproductive cycle. Rates of phosphorus release observed at and after ecdysis averaged 6.7 times higher than rates observed at other times.Key words: phosphorus, excretion, reproductive stage, ecdysis, Daphnia magna

scholarly journals Maternal effects as a recruitment mechanism in Lake Michigan yellow perch (Perca flavescens)

2001 ◽  
Vol 58 (7) ◽  
pp. 1477-1487 ◽  
Author(s):  
Christopher J Heyer ◽  
Thomas J Miller ◽  
Fred P Binkowski ◽  
Elaine M Caldarone ◽  
James A Rice
Keyword(s):  
Maternal Effects ◽  
Null Hypothesis ◽  
Yellow Perch ◽  
Lake Michigan ◽  
Gonadosomatic Index ◽  
Perca Flavescens ◽  
Dry Weight ◽  
Phenotypic Traits ◽  
High Fecundity ◽  
Larval Traits

Changes that occurred in the distribution of adult Lake Michigan yellow perch (Perca flavescens) phenotypic traits suggest that maternal effects on larval traits may be substantially influencing the recruitment of this heavily exploited species. We investigated maternal effects on yellow perch larvae at hatching in 10 maternal lines to test the null hypothesis of no effect of maternal phenotype on offspring phenotype and condition. Analyses lead to a rejection of the null hypothesis and indicated that the observed maternal effects likely resulted from differences among females in size, age, gonadosomatic index, and egg production. The observed maternal effects were expressed in the offspring by differences in larval total length, yolk volume, dry weight, and DNA quantity. Older, larger females were found to have high fecundity, yet low gonadosomatic index. Furthermore, older, larger females produced offspring that were, on average, short with large yolk sacs and high quantities of body reserves, as measured by dry weight and total DNA content. We conclude that the distribution of Lake Michigan yellow perch larval traits at hatching is linked to maternal influences and that this linkage may provide a mechanism through which managers can help rebuild the population.

scholarly journals Occurrence of Escherichia coli and Enterococci in Cladophora (Chlorophyta) in Nearshore Water and Beach Sand of Lake Michigan

2003 ◽  
Vol 69 (8) ◽  
pp. 4714-4719 ◽  
Author(s):  
Richard L. Whitman ◽  
Dawn A. Shively ◽  
Heather Pawlik ◽  
Meredith B. Nevers ◽  
Muruleedhara N. Byappanahalli
Keyword(s):  
Escherichia Coli ◽  
Lake Michigan ◽  
Dry Weight ◽  
Point Sources ◽  
Indicator Bacteria ◽  
Beach Sand ◽  
Cladophora Glomerata ◽  
Strongly Correlated ◽  
Fecal Indicator ◽  
E Coli

ABSTRACT Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density of Escherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (± standard errors) of 5.3 (± 4.8) and 4.8 (± 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P < 0.001, R 2 = 0.73, n = 17) but not in northern beaches (P = 0.892, n = 16). Both E. coli and enterococci survived for over 6 months in sun-dried Cladophora mats stored at 4°C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches.

scholarly journals Plant Growth and Leachate Electrical Conductivity and pH as Influenced by Controlled-release Fertilizer Blends and Coating Technologies

2017 ◽  
Vol 27 (5) ◽  
pp. 639-643 ◽  
Author(s):  
Carey Grable ◽  
Joshua Knight ◽  
Dewayne L. Ingram
Keyword(s):  
Trace Elements ◽  
Controlled Release ◽  
Polymer Coating ◽  
Ornamental Plants ◽  
Nutrient Release ◽  
Dry Weight ◽  
Polymer Coatings ◽  
Release Rates ◽  
Shoot Dry Weight ◽  
Controlled Release Fertilizers

Although controlled-release fertilizers (CRFs) have been used in container-grown ornamental plants for decades, new coating technologies and blends of fertilizers coated for specific release rates are being employed to customize fertility for specific environments and crops. A study was conducted in the transitional climate of Kentucky to determine the nutrient release rates of three controlled-release blends of 8- to 9-month release and growth response of ‘Double Play Pink’ japanese spirea (Spiraea japonica) and ‘Smaragd’ arbovitae (Thuja occidentalis). Fertilizer 1 (16N–3.5P–8.3K–1.8Mg + trace elements) and Fertilizer 2 (18N–3.1P–8.3K–1.8Mg + trace elements) were prototype blends with different experimental polymer coatings. Fertilizer 3 was a blend of 18N–2.2P–6.6K–1.1Ca–1.4Mg–5.8S + trace elements, which combined 100% resin-coated prills with a polymer coating. Fertilizer 4 was commercially available 15N–3.9P–10K–1.3Mg–6S + trace elements. Fertilizer 3 released its nutrients earlier in the 12-week study than the other three fertilizers and resulted in lower shoot dry weight in both species. The new polymer coating technologies show promise for delivering a predicted release rate and are appropriate for container production of these woody shrubs in Kentucky. An interesting side note of this experiment was that leachate pH measurements across treatments averaged 1.2 units lower for arbovitae (6.3) than for japanese spirea (7.5) at week 12. It was assumed that chemical and/or biological reactions at the root/substrate interface in arbovitae moderated pH increases over the study.

Mass Flux and "Nutritional Composition" of settling Epilimnetic Particles in Lake Michigan

1989 ◽  
Vol 46 (7) ◽  
pp. 1118-1124 ◽  
Author(s):  
Wayne S. Gardner ◽  
Brian J. Eadie ◽  
Joann F. Chandler ◽  
Christopher C. Parrish ◽  
John M. Malczyk
Keyword(s):  
Fatty Acids ◽  
Biogenic Silica ◽  
Nutritional Value ◽  
Lake Michigan ◽  
Algal Bloom ◽  
Dry Weight ◽  
Organic Content ◽  
Nutritional Composition ◽  
Benthic Organisms ◽  
Potential Food

A series of sediment-trap samples, collected at a 30-m depth in southeastern Lake Michigan, was analyzed to evaluate the seasonal flux and nutritional value of settling epilimnetic particles as potential food for benthic organisms. Flux was highest in the spring (due in part to resuspension), lowest in the summer during stratification, and intermediate during autumn months. Organic content of the particles ranged from 10% ash free dry weight (AFDW) in March through May samples to 17–19% in July–August samples. During the summer, microbial degradation of organic materials occurred in the trap bottles without added preservative, as evidenced by less AFDW in nonpreserved trap bottles than in similar chloroform-preserved bottles. The percentage of AFDW occuring as lipid ranged from 3.5% in April–May up to 14% during May through August. Dominant lipid classes were hydrocarbons, polar lipids including phospholipids and chlorophyll a, and free fatty acids. The ratio of n-alkane C-17 (algal indicator) to n-alkane C-29 (terrestrial or resuspension indicator) and the ratio of biogenic silica to AFDW in preserved samples both reached a maximum in May, shortly before lipid content peaked in the benthic amphipod, Pontoporeia hoyi. This observation agrees with the hypothesis that P. hoyi receives much of its nutrition from the spring algal bloom.

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