Experimental Marine Ecosystems Research Articles

Periphyton communities in experimental marine ecosystems: scaling the effects of removal from container walls

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 271:27-41 (2004) - doi:10.3354/meps271027 Periphyton communities in experimental marine ecosystems: scaling the effects of removal from container walls Chung-Chi Chen1,2, W. Michael Kemp1,* 1University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, Maryland 21613, USA 2National Taiwan Normal University, Department of Life Sciences, Taipei, Taiwan 116, ROC *Corresponding author. Email: kemp@hpl.umces.edu ABSTRACT: Although it is widely held that growth of periphyton communities on walls of marine mesocosms creates artifacts which bias experimental results, there are surprisingly few studies that directly quantify such Œwall effects¹. To test the hypotheses that the magnitude of wall effects is related to experimental system dimensions and that these effects can be controlled by routine periphyton removal, we conducted a series of studies using cylindrical mesocosms of 5 different sizes and shapes with treatments involving removal of wall periphyton. Results indicate that periphyton biomass and production were consistently and significantly reduced in containers receiving twice-weekly wall-cleaning treatment, but not in systems cleaned at weekly intervals. Whereas partitioning of ecosystem properties (total primary production and algal biomass) among wall, plankton, and sediment habitats revealed large and significant changes with wall-cleaning, treatment effects on the mean values of these and other ecosystem-level properties (e.g. nutrient concentrations) were small to negligible and generally inconsistent. Changes in biomass of wall periphyton and phytoplankton induced by wall-cleaning were significantly related to mesocosm radius. Reductions in wall periphyton with cleaning treatment were generally compensated by parallel increases in algal biomass in other habitats, with enhanced sediment microalgae only present in shallower systems. It appears that wall-cleaning also affected the abundance of benthic macrofauna and bacterioplankton, as well as phytoplankton taxonomic composition. Although periphyton dislodged through wall-cleaning were retained within the mesocosms in this study, we estimate that removal of this material from the experimental systems would have caused a severe nitrogen loss, equivalent to that required for supporting total ecosystem primary production. KEY WORDS: Mesocosms · Experimental ecosystems · Scale · Wall-cleaning · Periphyton · Phytoplankton · Gross primary production · Sediment microalgae · Nutrients Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 271. Online publication date: April 28, 2004 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2004 Inter-Research.

Effects of different N-and P-loading on primary and secondary production in an experimental marine ecosystem

The effects of nutrient loading on phytoplankton, zooplankton and macrozoobenthos in experimental ecosystems was studied in a 7-month experiment. The mesocosms were designed to mimic the major physical characteristics (irradiance, temperature, mixing) of the Dutch coastal zone in the river Rhine plume. Three different nutrient loading scenarios were used, representing present and future conditions. The level of the spring phytoplankton bloom was determined by phosphorus loading, whereas during summer the nitrogen loading determined phytoplankton biomass. The differences in nutrient loading did not result in shifts in phytoplankton species composition. With exception of the early phase of the spring bloom, diatoms dominated phytoplankton biomass in all nutrient treatments. This was ascribed to microzooplankton grazing on smaller algal species. Microzooplankton biomass showed a positive correlation with primary production, and also significant differences between nutrient treatments. Copepod development was limited, probably due to competition with microzooplankton and predation by benthic fauna. Macrobenthos biomass correlated with primary production, and was lower in the lowest nutrient treatment.

Enclosed Experimental Marine Ecosystems: A Review and Recommendations. Based on a Meeting Held at the University of Hamburg, June 1988. C. M. Lalli

<i>Enclosed Experimental Marine Ecosystems: A Review and Recommendations. Based on a Meeting Held at the University of Hamburg, June 1988</i>. C. M. Lalli

Captive Coast Enclosed Experimental Marine Ecosystems: A Review and Recommendations. Coastal and Estuarine Studies 37 C. M. Lalli

Journal Article Captive Coast Get access Enclosed Experimental Marine Ecosystems: A Review and Recommendations. Coastal and Estuarine Studies 37. Lalli C. M., ed. Springer-Verlag, New York, 1990. 218 pp., illus. $49.00 (ISBN 0-387-97341-9 cloth). Candace A. Oviatt, Candace A. Oviatt Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882 Search for other works by this author on: Oxford Academic Google Scholar Barbara K. Sullivan Barbara K. Sullivan Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882 Search for other works by this author on: Oxford Academic Google Scholar BioScience, Volume 41, Issue 6, June 1991, Pages 428–431, https://doi.org/10.2307/1311752 Published: 01 June 1991

Response of benthic meiofauna to nutrient enrichment of experimental marine ecosystems

Response of benthic meiofauna to nutrient enrichment of experimental marine ecosystems

Dynamics of bacterial communities and qualitative evolution of heterotrophic bacteria during the growth and decomposition processes of phytoplankton in an experimental marine ecosystem

The fluctuations of the bacterial number and the qualitative composition of heterotrophic bacteria were investigated using an experimental marine ecosystem (AME) of 7001, attempting to produce Euterpina acutifrons (Dana) from a monoxenic culture of Phaeodactylum tricorntum Bohlin. During the complete cycle of the system, installation phase, algae growth phase, algae decomposition phase, the bacterial communities homeostasis was tested using aliquots of the AME, severely disturbed via amino acids enrichment. In three identical batches, the bacterial populations showed similar quantitative and qualitative evolutions which all depended on the nature (phytoplanktonic exudates or dead cells) of the carbonaceous compounds from photosynthetic origin. If bacterial communities stayed in a diversified state of organization, considering the physiological and nutritional diversity, quick evolutions were demonstrated.

Physical, chemical and biological responses to simulated wind and tidal mixing in experimental marine ecosystems

Physical, chemical and biological responses to simulated wind and tidal mixing in experimental marine ecosystems

An experimental marine ecosystem response to crude oil and Corexit 9527: Part 2—Biological effects

Three experimental ecosystems were employed to test the effect of Corexit 9527, with and without Prudhoe Bay crude oil, on the ecology of a temperate pelagic ecosystem. The results indicated that Corexit 9527 alone enhanced biological productivity without changing the structure of the ecosystem. The mixture of Corexit and crude oil caused a major change in the ecology of the ecosystem which resulted in large numbers of bacteria and zooflagellates, but a depression of all other zooplankton phyla.

An experimental marine ecosystem response to crude oil and corexit 9527: Part 1—Fate of chemically dispersed crude oil

The fate of Prudhoe Bay crude oil. labelled with n(1− 14 C)-hexadecane and dispersed with Corexit 9527, was studied for 24 days in a polyethylene bag enclosure of sea water by time-series observations of the alkane composition of the crude oil, oil fluorescence, 14C-labelled hexadecane in the particulate phase, bacterial biomass, amounts of sedimented material and parameters of temperature, salinity, particulate organic carbon and nitrogen, and nutrients. By the seventh day, convective and diffusive mixing, important mechanisms for the dispersion of oil, resulted in a fairly homogeneous distribution of oil throughout the enclosed water column. Rapid bacterial biodegradation removed the n-alkane fraction initially, while oil-Corexit dispersion suppressed phytoplankton growth. After 7 days, with the recovery of phytoplankton growth, much of the aged oil sedimented with sinking of diatoms.

Fate and effects of cadmium in an experimental marine ecosystem

Two recirculated marine seawater systems (capacities: 150 and 300 l) were used for the study on cadmium accumulation of biological filter sludge, by the musselMytilus edulis and the plaicePleuronectes platessa for a period of up to 300 days. In the contaminated system Cd concentrations varied from 2.5 to 7.0 μg/l with a mean of 4.6±1.15 μg/l (control: 1.04±0.46 μg/l). Accumulation of Cd by the filter sludge from the control system as well as from the contaminated system was significant. Mean concentrations of control-and contaminated sludge over the experimental period were 2.01±0.86 ng Cd/mg dry wt and 9.98±3.55 ng Cd/mg dry wt respectively. Accumulation of Cd byM. edulis both in the control and in the contaminated system was considerable. After 163 days of exposure the whole body burden of mussels rose from 0.3 ng Cd/mg dry wt to around 10 ng Cd/mg dry wt in the controls and to 70 ng Cd/mg dry wt in the contaminated systems. Accumulation of Cd byP. platessa was analysed in backbone, fins, gills, liver, muscle (fillet), otolith and skin (dorsal and ventral) over a period of 280 days. Elevated Cd contents of livers from control specimens were noticed after 200 days and reached 1.75 ng Cd/mg dry wt in liver. There was considerable accumulation in the liver (maximum values: 3.0 ng Cd/mg dry wt) and gills (6.0 ng Cd/mg dry wt) of specimens from the contaminated system, Cd contents of plaice exposed for identical periods of time were very variable. Growth of plaice living in the contaminated system was at times significantly slower than that of the control group. Of the three biological objects tested-filter sludge,M. edulis, P. platessa—the mussel seemed to be the most sensitive indicator of elevated Cd-concentrations, while the reaction of the plaice was slow and less distinct.

Multivariate analysis of experimental marine ecosystems

Twelve replicate 150-l laboratory microcosms were developed using whole water samples and natural benthic communities from Narragansett Bay, Rhode Island (USA). The microcosms were scaled to the bay in terms of salinity, temperature, light input, volume pelagic community to area of benthic community, density of macrofauna, turbulent mixing, and flushing time. The microcosms were self maintaining during a six month study period with over 35 species of phytoplankton and 30 species of macro-invertebrates. Some 25 species of meroplankton entered the microcosms and sucessfully colonized the benthic communities. Zooplankton were present in all life stages. After an initial study of replication among the 12 tanks, the microcosms were perturbed with 3 levels of treated urban sewage for a three month period. Three microcosms were maintained at each level with 3 tanks remaining as controls. At the end of 3 months, the sewage input was terminated and the response of the systems was followed for an additional 2 months. Both time series data and multivariate statistical analysis of over 10 different parameters indicated that the replication of the microcosms was adequate to show the effects of experimental treatments. Control microcosms were generally within the range of variation expected in Narragansett Bay. Moreover, the results suggested that the microcosms responded to the gradient of sewage input in a manner similar to that of the bay. During the two month period after the sewage was discontinued, all of the microcosms became increasingly similar, though the tanks that had been subjected to higher levels of sewage remained distinct. It was apparent throughout the study that comparisons of microcosms and natural systems must account for the large variation characteristic of each. For this, and other reasons, multivariate statistical techniques appear to provide a powerful tool for experimental ecosystem analysis.

Ecotoxicology of crude oils and the use of experimental marine ecosystems

Ecotoxicological investigations are generally undertaken in the laboratory on some constituents of ecosystems. The complementary synthetic aspect, comprising the analysis of the overall effect of a pollutant on an ecosystem, also falls within the framework of the science of pollution. The present study deals with the effects of a crude Kuwait oil on the primary production of experimental ecosystems

Distribution of Radioactive and Stable Zinc in an Experimental Marine Ecosystem

The distribution of radioactive and stable Zn in an experimental marine ecosystem is described. We added 1 mCi of 65Zn to 2000 liters of sea water and a mixed community of planktonic and benthic algae in a fiberglass tank, after which the ecosystem was left undisturbed for 9 months. We then measured the 65Zn specific activities for (1) particulate Zn (0.45 μ filterable), (2) extractable Zn (from water passed through a 0.45-μ filter and then treated with dithizone), (3) total dissolved Zn (from samples passed through a 0.45-μ filter and treated with acid prior to extraction with dithizone), and (4) dialyzable Zn. Zinc-65 specific activities were not significantly different among the extractable, dialyzable, or acid-treated samples of the water. Further, absolute concentrations of 65Zn and total Zn were no higher in the acid-treated samples than in the extracted or dialyzed samples, which indicates that nearly all of the soluble Zn in the water was dithizone-extractable and dialyzable. Zinc-65 specific activities were significantly less, however, in the particulate material than in the water. This difference indicates that equilibrium of Zn between particulate material and water had not been reached after 9 months. Three months later (December 1969) 65Zn specific activities were determined again for particulate material and total dissolved Zn. The mean specific activity of 65Zn in the particulate samples showed a small but significant increase, but it was still less than in the water. Concentration factors in the particulate matter were 980 for 65Zn and 1400 for total Zn. Samples of benthic algae taken in March 1970 had a mean specific activity of 65Zn similar to the mean 65Zn specific activity of water samples taken 3 months earlier.