Comparative effects of the large bioturbators, Trypaea australiensis and Heloecius cordiformis, on intertidal sediments of Western Port, Victoria, Australia

2003 ◽  
Vol 54 (6) ◽  
pp. 701 ◽  
Author(s):  
Gitanjali Katrak ◽  
Fiona L. Bird
Keyword(s):  
Surface Sediments ◽  
Feeding Habits ◽  
Benthic Microalgae ◽  
Sediment Surface ◽  
Low Density ◽  
Intertidal Sediments ◽  
Dependent Effect ◽  
Particle Mixing ◽  
Reducing Conditions ◽  
Tracer Particles

The effect of bioturbation by the ghost shrimp Trypaea australiensis and semaphore crab Heloecious cordiformis was compared in sediment-filled tanks in the laboratory. Effect of bioturbator density was also investigated with high- and low-density treatments. It was hypothesised that the two species would influence the sediment profile in different ways owing to their contrasting burrowing and feeding habits. Both species increased porosity of surface sediments relative to control tanks. Crab activity did not alter redox potential, but low densities of shrimp created more oxidising conditions and high densities of shrimp created more reducing conditions than controls. Burial of tracer particles by crabs was restricted to the top 5 cm, whereas shrimp mixed particles to depths of 25 cm. Bioturbator density had little effect on the extent of particle mixing. The presence of both shrimp and crabs increased benthic microalgae in the sediments relative to the controls. Again, crabs had the greatest effect at the sediment surface, whereas shrimp also enhanced concentrations at 25 cm depth. High densities of shrimp had the greatest effect. Overall, shrimp bioturbation influenced deeper sediments than crab bioturbation, but there was no clear density-dependent effect.

Association between the ghost shrimp Trypaea australiensis Dana 1852 (Crustacea : Decapoda) and a small deposit-feeding bivalve Mysella vitrea Laserson 1956 (Mollusca : Leptonidae)

1998 ◽  
Vol 49 (8) ◽  
pp. 801 ◽  
Author(s):  
Geoff Kerr ◽  
Jamie Corfield
Keyword(s):  
Laboratory Experiments ◽  
New South ◽  
Sediment Surface ◽  
Energetic Cost ◽  
Carbon Distribution ◽  
Intertidal Sediments ◽  
Feeding Mode ◽  
South Wales ◽  
Reducing Conditions ◽  
Deposit Feeding

The deep-burrowing species Trypaea australiensis and Mysella vitrea inhabit intertidal sediments of the Richmond River, northern New South Wales. Laboratory experiments indicated that a facultative commensal association may exist between the two organisms, because although the bivalves survived independently, their vertical distribution in sediment was significantly different in the presence of T. australiensis. Field observations indicated that redox potential and bivalve abundance in sediment are weakly correlated. However, the absence of strongly reducing conditions in the first metre of the sediment, due to T. australiensis burrow irrigation, may increase potential niche size for M. vitrea. Tank observations revealed no aggregation of M vitrea around the burrows. Feeding observations suggested that M. vitrea can feed either by collecting particles off the sediment surface or by interstitial pedal feeding; the latter feeding mode would allow use of shrimp burrows for feeding. T. australiensis alters organic carbon distribution in the sediment profile, concentrations being significantly higher in the lowermost regions where T. australiensis was present than in controls. Thus, enrichment resulting from the activities of T. australiensis may provide some reward for the energetic cost to M. vitrea of burrowing deeply.

scholarly journals Influences of Infaunal Burrows on the Community Structure and Activity of Ammonia-Oxidizing Bacteria in Intertidal Sediments

2006 ◽  
Vol 73 (4) ◽  
pp. 1341-1348 ◽  
Author(s):  
Hisashi Satoh ◽  
Yoshiyuki Nakamura ◽  
Satoshi Okabe
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Copy ◽  
Sediment Surface ◽  
Intertidal Sediment ◽  
Rrna Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Intertidal Sediments ◽  
Burrow Wall ◽  
Microelectrode Measurements

ABSTRACT Influences of infaunal burrows constructed by the polychaete (Tylorrhynchus heterochaetus) on O2 concentrations and community structures and abundances of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in intertidal sediments were analyzed by the combined use of a 16S rRNA gene-based molecular approach and microelectrodes. The microelectrode measurements performed in an experimental system developed in an aquarium showed direct evidence of O2 transport down to a depth of 350 mm of the sediment through a burrow. The 16S rRNA gene-cloning analysis revealed that the betaproteobacterial AOB communities in the sediment surface and the burrow walls were dominated by Nitrosomonas sp. strain Nm143-like sequences, and most of the clones in Nitrospira-like NOB clone libraries of the sediment surface and the burrow walls were related to the Nitrospira marina lineage. Furthermore, we investigated vertical distributions of AOB and NOB in the infaunal burrow walls and the bulk sediments by real-time quantitative PCR (Q-PCR) assay. The AOB and Nitrospira-like NOB-specific 16S rRNA gene copy numbers in the burrow walls were comparable with those in the sediment surfaces. These numbers in the burrow wall at a depth of 50 to 55 mm from the surface were, however, higher than those in the bulk sediment at the same depth. The microelectrode measurements showed higher NH4 + consumption activity at the burrow wall than those at the surrounding sediment. This result was consistent with the results of microcosm experiments showing that the consumption rates of NH4 + and total inorganic nitrogen increased with increasing infaunal density in the sediment. These results clearly demonstrated that the infaunal burrows stimulated O2 transport into the sediment in which otherwise reducing conditions prevailed, resulting in development of high NH4 + consumption capacity. Consequently, the infaunal burrow became an important site for NH4 + consumption in the intertidal sediment.

scholarly journals Impact of coastal environmental factors on quinolone distribution in intertidal surface sediments of the Bohai Sea and Yellow Sea, China

2018 ◽  
Vol 19 (2) ◽  
pp. 482-491
Author(s):  
Hang Lang ◽  
Liang Chen ◽  
Guohua Hou ◽  
Wenjuan Wang ◽  
Shengzhang Zou ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Yellow Sea ◽  
Surface Sediments ◽  
Oxolinic Acid ◽  
Intertidal Sediment ◽  
Organic Carbon Content ◽  
Intertidal Sediments ◽  
Intertidal Zones ◽  
Sediment Types ◽  
Intertidal Surface

Abstract Freshwater contaminants tend to precipitate into intertidal surface sediments, particularly in the estuary and intertidal zones during freshwater–seawater mixing. Quinolone-type antibiotics are such contaminants, and their concentrations in the intertidal sediments are important indicators for the whole spectrum of antibiotics used in the estuary and adjacent areas. The impacts of sediment types and environmental factors on the distribution of 16 quinolones were probed based on nine Bohai and 42 Yellow Sea intertidal sediment samples. The samples were collected from locations along the coastal areas in China. Quinolones were detected in all samples, while moxifloxacin, ciprofloxacin, and ofloxacin were detected at a frequency >50%. Sediment types, pH, organic carbon content, K, Na and Fe concentrations had little correlation with quinolone distributions in intertidal sediments. However, combined concentrations of Ca + Mg (46.7 g/kg in Bohai and 13.7 g/kg in Yellow Sea samples) appeared to correlate with oxolinic acid detecting frequencies (88.9% and 4.8%, respectively) and concentrations (2.0–10.1 μg/g and up to 3.09 μg/g, respectively). Different detection frequencies of the quinolones could be attributed to the formation of cation bridges between oxolinic acid and Ca + Mg, which results in dominant sorption of oxolinic acid at different locations and sediment matrices.

scholarly journals Characterization of a receptor for oxidized low-density lipoproteins on rat Kupffer cells: similarity to macrosialin

1997 ◽  
Vol 322 (2) ◽  
pp. 411-415 ◽  
Author(s):  
Agnes G. VAN VELZEN ◽  
Rosângela P. DA SILVA ◽  
Siamon GORDON ◽  
Theo J. C. VAN BERKEL
Keyword(s):  
Molecular Mass ◽  
Kupffer Cells ◽  
Polyclonal Antibody ◽  
Binding Protein ◽  
Low Density Lipoproteins ◽  
Low Density ◽  
Oxidized Low Density Lipoproteins ◽  
Reducing Conditions ◽  
Ldl Catabolism

Rat liver Kupffer cell membranes contain a protein that recognizes specifically oxidized low-density lipoproteins (oxLDL). Visualization after blotting under reducing conditions indicates that the receptor is a monomeric protein, with an estimated molecular mass of 115–120 kDa. N-Glycosidase F and endoglycosidase F treatment resulted in a fall in estimated molecular mass of 24 and 11 kDa respectively, whereas O-glycosidase was ineffective. No effect on the extent of interaction with oxLDL was noticed, suggesting that glycans are not essential for ligand recognition. Using a polyclonal antibody to mouse macrosialin, we visualized macrosialin on blot, and compared this glycoprotein with the oxLDL-binding protein. It appears that the two glycoproteins have a similar molecular mass and are comparably affected by treatment with the different glycosidases. Incubation with trypsin resulted in a reduction in the estimated molecular mass of about 25 kDa for both the oxLDL-binding protein and macrosialin. These results indicate that the oxLDL-binding protein and macrosialin are identical, suggesting a role for macrosialin in modified LDL catabolism.

Primary Production and Respiration in Pelagic and Benthic Communities at Two Intertidal Sites in the Upper Bay of Fundy

1983 ◽  
Vol 40 (S1) ◽  
pp. s229-s243 ◽  
Author(s):  
B. T. Hargrave ◽  
N. J. Prouse ◽  
G. A. Phillips ◽  
P. A. Neame
Keyword(s):  
Primary Production ◽  
Benthic Communities ◽  
Late Summer ◽  
Benthic Microalgae ◽  
Phytoplankton Production ◽  
Bay Of Fundy ◽  
Intertidal Sediments ◽  
Benthic Primary Production ◽  
Benthic Respiration ◽  
Undisturbed Sediments

Primary production by microalgae on intertidal sediments during ebb tide at two sites in Cumberland and Minas Basin, Bay of Fundy, amounted to 47–83 g C∙m−2∙yr−1 Phytoplankton production measured during flood tide over intertidal sediments in Cumberland Basin varied from 4–10 g C∙m−2∙yr−1 with respiration in the water column between 6 and 12 g∙C∙m−2∙yr−1 depending on concentrations of suspended matter. Respiration by undisturbed sediments (47–62 g C∙m−2∙yr−1) was measured at both locations to estimate aerobic metabolic consumption of organic matter.Maximum rates of benthic primary production occurred during early and late summer at both locations but Values at the Cumberland Basin sites were two to three times greater than those observed in Minas Basin; Chlorophyll a in surface sediments was also lower at the stations in Minas Basin where coarser grained deposits reflect extensive sediment transport. Annual benthic respiration at the two stations in Cumberland Basin, however, was only slightly greater than that at four stations in Minas Basin. Spartina marshes, phytoplankton, and benthic microalgae may provide supplies of organic matter for aerobic consumption in these intertidal sediments which are more similar than are measures of benthic primary production.Key words: benthic microalgae, primary production, intertidal community metabolism, Bay of Fundy

RESPONSES OF THE CLAM MACOMA BALTHICA TO PRUDHOE BAY CRUDE OIL

1977 ◽  
Vol 1977 (1) ◽  
pp. 493-494 ◽  
Author(s):  
D. G. Shaw ◽  
A. J. Paul ◽  
E. R. Smith
Keyword(s):  
Crude Oil ◽  
Oil Pollution ◽  
Macoma Balthica ◽  
Sediment Surface ◽  
Intertidal Sediments ◽  
Tissue Weight ◽  
Indirect Indicator ◽  
Relationship Of ◽  
The Relationship ◽  
Prudhoe Bay

ABSTRACT The responses of the bivalve mollusk Macoma balthica to crude oil have been studied under laboratory conditions designed to simulate the stranding of oil on intertidal sediments in which this animal resides. The relationship of dry tissue weight to shell length, an indirect indicator of general health and fitness, was not significantly altered by exposure to oil at a level which did result in significant mortalities. This suggests that death is caused by a metabolically specific mode of poisoning rather than by a general weakening of the animal. In a second experiment, animals were subjected to two temporarily separated oiling events. Neither in mortalities nor in gas chromatographic analysis of tissues for hydrocarbons were cumulative effects observed. It was also found that a previously-reported tendency of M. balthica to burrow to the sediment surface in the presence of oil increases with decreasing depth of available sediment. We suggest that this behavior may be used as a convenient indicator of oil pollution.

Mercury speciation in the Lower St. Lawrence Estuary

2000 ◽  
Vol 57 (S1) ◽  
pp. 138-147 ◽  
Author(s):  
Daniel Cossa ◽  
Charles Gobeil
Keyword(s):  
Water Column ◽  
Surface Waters ◽  
Feeding Habits ◽  
Mercury Speciation ◽  
Estuarine Sediments ◽  
Sediment Surface ◽  
Pore Waters ◽  
Mass Balance Calculation ◽  
Lawrence Estuary ◽  
St Lawrence Estuary

Mercury speciation was determined in the water column and sediment pore waters of the Lower St. Lawrence Estuary, and total Hg (HgT) was measured in seven biological species, including pelagic and demersal fish and crustaceans. In water, HgT concentrations ranged from 1.8 to 7.8 pM, with the highest levels in surface waters and the lowest in deep waters (1.8-2.9 pM). HgT concentrations in sediment pore waters were 10 times as high, with methyl mercury levels of 5.1-14.4 pM. Reactive Hg (HgR) generally accounted for around 20% of HgT in the water column and <30% in pore waters. The distribution of elemental Hg and HgR suggests that Hg(II) is reduced in surface waters and that inorganic Hg is mobilized during remineralization of organic matter at the sediment surface. In the biota, concentrations ranged between 0.05 and 0.89 nmol·g-1 (wet weight). Feeding habits and habitats account for these observations. Results suggest that the sediment is the main source of Hg contamination for the biota. A mass balance calculation showed that the Hg flux entering the lower estuary from the St. Lawrence River is equivalent to the amount buried in estuarine sediments.

Excess Unsupported 210Pb in Lake Sediment from Rocky Mountain Lakes: A Groundwater Effect

1985 ◽  
Vol 42 (7) ◽  
pp. 1249-1254 ◽  
Author(s):  
Stephen A. Norton ◽  
Charles T. Hess ◽  
Geneva M. Blake ◽  
Marilyn L. Morrison ◽  
Jill Baron
Keyword(s):  
Water Column ◽  
National Park ◽  
Surface Sediments ◽  
Sediment Cores ◽  
Rocky Mountain ◽  
Dry Weight ◽  
Mountain Lakes ◽  
Rocky Mountain National Park ◽  
Sediment Surface ◽  
Unsupported 210Pb

Sediment cores from four high-altitude (approximately 3200 m) lakes in Rocky Mountain National Park, Colorado, were dated by 210Pb chronology. Background (supported) 210Pb activities for the four cores range from 0.26 to 0.93 Beq/g dry weight, high for typical oligotrophic lakes, integrated unsupported 210Pb ranges from 0.81 (a typical value for most lakes) to 11.0 Beq/cm2. The 210Pb activity in the surface sediments ranges from 1.48 to 22.2 Beq/g dry weight. Sediment from Lake Louise, the most unusual of the four, has 22.2 Beq/g dry weight at the sediment surface, an integrated unsupported 210Pb = 11.0 Beq/cm2, and supported 210Pb = 0.74 Beq/g dry weight. 226Ra content of the sediment is insufficient to explain either the high unsupported 210Pb or the Rn content of the water column of Lake Louise, which averaged 96.2 Beq/L. We concluded that 222Rn-rich groundwater entering the lake is the source of the high 222Rn in the water column. This, in turn, is capable of supporting the unusually high 210Pb flux to the sediment surface. Groundwater with high 222Rn may control the 210Pb budget of lakes where sediment cores have integrated unsupported 210Pb greater than 2 Beq/cm2.

scholarly journals Not the mature 56 kDa lipoprotein lipase protein but a 37 kDa protein co-purifying with the lipase mediates the binding of low density lipoproteins to J774 macrophages

1998 ◽  
Vol 330 (2) ◽  
pp. 765-769 ◽  
Author(s):  
L. Wendy HENDRIKS ◽  
C. Leonie Van VARK ◽  
Kees SCHOONDERWOERD ◽  
Hans JANSEN ◽  
M. Louis HAVEKES
Keyword(s):  
Lipoprotein Lipase ◽  
Low Density Lipoprotein ◽  
Bovine Milk ◽  
Density Lipoprotein ◽  
Low Density ◽  
Terminal Domain ◽  
Reducing Conditions ◽  
Stimulatory Capacity ◽  
J774 Cells ◽  
Carboxy Terminal

Lipoprotein lipase (LPL) purified from bovine milk showed variable abilities to stimulate the binding of low density lipoprotein (LDL) to J774 macrophages. The presence of a 37 kDa protein in the LPL sample seemed to be of importance for its stimulatory capacity. In order to investigate this, we isolated LPL from bovine milk via heparin Sepharose chromatography using a continuous salt gradient. Fractions containing the 37 kDa protein (as shown by SDS/PAGE under reducing conditions) eluted first from the column, followed by the 56 kDa LPL protein. The LPL enzymatic activity co-eluted with the 56 kDa protein, whereas the amount of 37 kDa protein fully paralleled the stimulatory effect on the binding of LDL to J774 cells. Samples not containing the 37 kDa protein were far less effective in stimulating the binding. Western blotting using a monoclonal antibody 5D2 against amino acids 396-405 in the carboxy-terminal domain of LPL, showed that the 37 kDa protein may be the C-terminal domain of LPL, presumably generated by proteolytic degradation of the mature LPL protein by milk proteases during its isolation. Furthermore, the functional mass of LPL for stimulation of the binding of LDL, as determined by radiation inactivation, was shown to be 30.9±1.8 kDa. We therefore suggest that cleavage of LPL at protease-sensitive sites causes a conformational change, generating an LPL protein which is more effective in mediating the binding and uptake of lipoproteins by cells.

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