Experimental manipulation of sediment organic content and water column aeration reduces Zostera marina (eelgrass) growth and survival

2009 ◽  
Vol 373 (1) ◽  
pp. 26-34 ◽  
Author(s):  
O. Mascaró ◽  
T. Valdemarsen ◽  
M. Holmer ◽  
M. Pérez ◽  
J. Romero
Keyword(s):  
Water Column ◽  
Zostera Marina ◽  
Experimental Manipulation ◽  
Organic Content ◽  
Growth And Survival ◽  
Sediment Organic Content

Tales of lizard tails: effects of tail autotomy on subsequent survival and growth of free-ranging hatchling Uta stansburiana

1997 ◽  
Vol 75 (4) ◽  
pp. 542-548 ◽  
Author(s):  
P. H. Niewiarowski ◽  
J. D. Congdon ◽  
A. E. Dunham ◽  
L. J. Vitt ◽  
D. W. Tinkle
Keyword(s):  
Natural Populations ◽  
Reproductive Investment ◽  
Experimental Manipulation ◽  
Costs And Benefits ◽  
Growth And Survival ◽  
Large Sample ◽  
Uta Stansburiana ◽  
Tail Autotomy ◽  
Trade Offs ◽  
Free Ranging

Potential costs and benefits of tail autotomy in lizards have been inferred almost exclusively from experimental study in semi-natural enclosures and from indirect comparative evidence from natural populations. We present complementary evidence of the costs of tail autotomy to the lizard Uta stansburiana from detailed demographic study of a natural population. On initial capture, we broke the tails of a large sample of free-ranging hatchlings (560) and left the tails of another large sample (455) intact, and then followed subsequent hatchling growth and survival over a 3-year period. Surprisingly, in 1 out of the 3 years of study, survival of female hatchlings with broken tails exceeded that of female hatchlings with intact tails. Furthermore, no effects of tail loss on survivorship were detected for male hatchlings. However, in 2 years when recaptures were very frequent (1961, 1962), growth rates of hatchlings with broken tails were significantly slower than those of their counterparts with intact tails. We discuss our results in the broader context of estimating the relative costs and benefits of tail autotomy in natural populations, and suggest that long-term demographic studies will provide the best opportunity to assess realized fitness costs and benefits with minimum bias. We also describe how experimentally induced tail autotomy can be used as a technique to complement experimental manipulation of reproductive investment in the study of life-history trade-offs.

Sediment pH and Redox Potential Affect the Bioavailability of Al, Cu, Fe, Mn, and Zn to Rooted Aquatic Macrophytes

1993 ◽  
Vol 50 (1) ◽  
pp. 143-148 ◽  
Author(s):  
Leland J. Jackson ◽  
Jacob Kalff ◽  
Joseph B. Rasnnussen
Keyword(s):  
Redox Potential ◽  
Metal Content ◽  
Aquatic Macrophytes ◽  
Organic Content ◽  
Trophic Levels ◽  
Sediment Organic Content ◽  
Sediment Ph ◽  
The Relationship ◽  
Sediment Metal

We have evaluated the role of sediment pH (4.7–7.1) and redox potential (88–305 mV) in determining the bioavailability of five metals to four species of isoetoid macrophytes. The four species (Eleocharis acicularis, Eriocaulon septangulare With., Isoetes sp., and Sagittaria graminae) did not differ significantly in the relationship between the contents of metals in plants and sediment. When data for all species were pooled, 28–80% of the variation in the log of plant metal content was explained by the log of sediment metal (Al, Fe, and Mn) or by the log of sediment organic content (Cu and Zn). Sediment pH explained 45% (Al), 10% (Cu), 20% (Fe), 5% (Mn), and 12% (Zn) variation over and above that explained by the sediment metal content. These results demonstrate that lower sediment pH, in the presence of mildly oxic redox conditions, increases the bioavailability of these five trace metals to rooted aquatic plants. Rooted macrophytes subject to acidification contain higher metal concentrations which may be transferred by grazing to higher trophic levels.

Profundal Sediment Organic Content and Physical Character Do Not Reflect Lake Trophic Status, but Rather Reflect Inorganic Sedimentation and Exposure

1992 ◽  
Vol 49 (7) ◽  
pp. 1431-1438 ◽  
Author(s):  
D. J. Rowan ◽  
J. Kalff ◽  
J. B. Rasmussen
Keyword(s):  
Organic Matter ◽  
Water Content ◽  
Bulk Density ◽  
Trophic Status ◽  
Organic Content ◽  
Sedimentation Rates ◽  
Lake Surface ◽  
Lake Trophic Status ◽  
Sediment Organic Content ◽  
Lake Surface Area

An analysis of profundal sediment data from 83 north-temperate lakes shows that increasing inorganic sedimentation and exposure (or lake surface area) results in lower organic content and water content, and greater bulk density. Because sedimentation rates are unavailable for most lakes, we estimate sedimentation rates from readily available catchment sediment loads using a mass-balance model. The mass-balance estimate of sediment retention (per square metre of depositional zone) is an excellent predictor of measured inorganic sedimentation rates for a data set covering 19 lakes (R2 = 0.92). Multiple regressions are used to predict organic content, water content, and bulk density of profundal sediment from inorganic sedimentation rates and either exposure or lake surface area, which are surrogates for the energy of the depositional environment. These analyses explain 76, 74, and 66% of the between-lake variation in the three sediment parameters, respectively. Sediment organic content is not related to lake trophic status (chlorophyll a) and is negatively correlated with net organic matter sedimentation rates. The common occurrence of organic-rich sediments in oligotrophic shield lakes is, therefore, not a reflection of high organic matter inputs, but rather the extremely low inputs of mineral sediments to these lakes.

The Distribution of Nucula Turgida (Bivalvia: Protobranchia) From Dublin Bay, Ireland, and the Effect of Sediment Organic Content

1986 ◽  
Vol 66 (1) ◽  
pp. 119-130 ◽  
Author(s):  
James G. Wilson ◽  
Colin Shelley
Keyword(s):  
Organic Matter ◽  
Clay Fraction ◽  
Fine Sand ◽  
Organic Content ◽  
Muddy Sand ◽  
Sediment Organic Content

Recent investigations (Walker & Rees, 1980; Davis & Wilson, 1983b) have shown that the protobranch bivalve Nucula turgida (Leckenby and Marshall) occupies an important niche in the ecology of Dublin Bay, where it is the dominant organism over much of the southern part of the outer bay. This is an area of moderately sorted fine sand (Harris, 1980) with a pelite (silt and clay) fraction of less than 10% and a consequently low percentage of organic matter of around 1% (Davis & Wilson, 1983 b). Trevallion (1965) described the N. turgida habitat as one of firm muddy sand, adding that the animals avoided mud due to their inability to maintain position or feeding and respiratory currents and also avoided gravel due to their inability to burrow in coarse substrates.

NUTRIENT DYNAMICS IN EELGRASS (ZOSTERA MARINA) MEADOW AND THE VARIATION OF NUTRIENT CONTENTS OF EELGRASS

2017 ◽  
Author(s):  
Toshimasa Asahi ◽  
Toshimasa Asahi ◽  
Kazuhiko Ichimi ◽  
Kazuhiko Ichimi ◽  
Kuninao Tada ◽  
...  
Keyword(s):  
Water Column ◽  
Pore Water ◽  
Sediment Core ◽  
Zostera Marina ◽  
Nutrient Dynamics ◽  
Similar Rate ◽  
Nutrient Concentrations ◽  
Nutrient Source ◽  
Nutrient Contents ◽  
Seagrass Biomass

Nutrient dynamics in seagrass beds and nutrient demands of seagrass biomass are not clear, although nutrient uptake of seagrass has been experimentally studied in the laboratory. We conducted the field observations and the bottom sediment core incubations to estimate nutrient fluxes in the seagrass, Zostera marina meadow. DIN (nitrate, nitrite and ammonium) concentrations were always low particularly during the Z. marina growing season (from spring to summer), and water exchanges caused by tidal currents hardly supplied nutrient demand for Z. marina. Sediment pore water also supplied insufficient nutrients to Z. marina, because pore water had less volume than the water column, although DIN concentrations of pore water were 10-100 fold higher than those of the water column. Nutrient flux from sediment to water column estimated by the sediment core incubation experiments showed a similar rate with tidal water exchange. Thus, our results suggested that Z. marina adapted for low nutrient concentrations and each nutrient source in the Z. marina meadow slightly contributed but could not support Z. marina growth. We found that another nutrient source, for example, precipitation, supplied high DIN to the Z. marina meadow. After rainfall, the DIN concentration of seawater in the Z. marina meadow increased 2-5 times higher. Moreover, nitrogen content of eelgrass also increased 2-3 times higher during several days. Those results suggested that Z. marina was usually exposed to a low nutrient concentration but could uptake abundant nutrients from temporary nutrient supplies such as precipitation.

scholarly journals Relationships between shallow-water cumacean assemblages and sediment characteristics facing the Iranian coast of the Persian Gulf

2009 ◽  
Vol 90 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Daniel Martin ◽  
Ulla Fernadez-Arcaya ◽  
Paula Tirado ◽  
Éric Dutrieux ◽  
Jordi Corbera
Keyword(s):  
Shallow Water ◽  
Persian Gulf ◽  
Organic Content ◽  
Sediment Characteristics ◽  
Ecological Data ◽  
Sediment Organic Content ◽  
Mean Grain Size ◽  
Iranian Coast ◽  
The Mean ◽  
The Persian Gulf

During two sampling campaigns carried out in August 1998 and November 2002, 232 cumaeans from eight species belonging to the families Bodotriidae and Nannastacidae were collected. This paper presents the first ecological data on a shallow water tropical cumacean assemblage from the Persian Gulf, where 50% of the existing species were recently described as new for the science. Neither the environmental conditions (except for the sediment organic content) nor the cumacean assemblage descriptors differed between the two sampling periods. However, two different species dominated in each period (i.e. Eocuma travancoricum and Heterocuma inerme in 1998 and 2002, respectively) and the MDS analysis revealed differences in the assemblage composition between periods, particularly for the deepest sampling stations. An increasing density together with the increase in gravel content, and a decreasing density together with the increasing silt content characterized the distribution pattern of both the whole cumacean assemblages and the two dominant species, the latter being also positively correlated with the mean grain size and negatively correlated with depth and organic matter (E. travancoricum) and with depth (H. inerme).

scholarly journals Historical development of three man-made reservoirs in a mining region: A story told by subfossil chironomids

2018 ◽  
Author(s):  
Tímea Chamutiová ◽  
Ladislav Hamerlík ◽  
Katarzyna Szarlowicz ◽  
Radovan Pipík ◽  
Dušan Starek ◽  
...  
Keyword(s):  
18Th Century ◽  
Sediment Cores ◽  
Oxygen Depletion ◽  
Organic Content ◽  
Water Level Fluctuations ◽  
Subfossil Chironomids ◽  
Reservoir Development ◽  
Sediment Organic Content ◽  
Dramatic Shift ◽  
Second Period

Chironomid stratigraphic changes were studied in three man-made reservoirs situated in a region intensely used for mining in the past (Banska Stiavnica, Central Europe) The reservoirs were built in the first half of the 18th century and are remnants of a former hydro-energetic system that provided water for operating mining and smelting facilities until the 1920s. The dated sequence of sediment cores span the last 170–200 years, however the oldest sediments were not identified. A total of 58 taxa were recorded with the most common taxa being Cladotanytarsus mancus-type, Polypedilum nubeculosum-type, Procladius spp. and Tanytarsus spp. Changes in the subfossil assemblages suggest that all reservoirs followed similar developmental trends. The low number of chironomid remains and the prevalence of littoral and rheophilic taxa characterize the initial phase of reservoirs connected with severe water level fluctuations and unproductive conditions. A dramatic shift in both qualitative and quantitative structure of the chironomid assemblages correspond to the documented decline of mining activities in the region. The second period of the reservoir development is also connected to changes in sediment composition and an increase of sediment organic content. In this phase, chironomids indicate nutrient enrichment, developed profundal zone with oxygen depletion and a complexity of littoral habitats. Since the 1970s, changes in the assemblage structure indicate the reduction of the profundal fauna and increasing importance of littoral taxa. Despite the significantly different usage of the reservoirs after the mining phase (recreation and angling vs drinking water supply) the chironomid succession trajectories were fairly similar.

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