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1.
The influences of temperature and environmental hypoxia on the growth rates of two California anadromous fishes, white sturgeon (Acipenser transmontanus) and striped bass (Morone saxatilis) were examined. Fish (0.5–0.6 g initial weight) were fedad libitum rations ofArtemia in flow-through aquaria regulated for temperature (15, 20, and 25°C) and oxygen tension (130 and 90 torr Po 2). Growth of sturgeon was significantly greater at 20 °C compared with 15 °C, but there was no difference between 20 and 25 °C. Striped bass growth increased with each 5° increment of temeprature elevation to 3.2% body weight per d at 25 °C, the fastest growth rate measured. The temperature of maximum growth reflected the temperature of the native estuarine rearing area. Environmental hypoxia (90 torr Po 2) reduced growth of sturgeon within each temperature level, whereas striped bass growth was reduced by hypoxia only at the upper two temperatures. Sturgeon were much more active in the growth chambers than striped bass. Sturgeon activity increased with each 5 °C temperature increase under normoxia and hypoxia, except at 25 °C (hypoxia) where activity was insignificantly different from that at 20 °C (hypoxia).  相似文献   

2.
In summer 2009, the effects of 6 years of landscape-level experimental nutrient enrichment on the eastern mudsnail, Nassarius obsoletus (formerly Ilyanassa obsoleta), were examined. The experiment was conducted in five tidal creeks (two nutrient-enriched, three reference creeks) in the Plum Island Estuary, Massachusetts, USA. (42°44′ N, 70°52′ W). After 6 years of enrichment, N. obsoletus size structure differed between treatment creeks with adult snails on average 14 % larger in enriched creeks. N. obsoletus densities (in individuals per square meter) and biomass (in grams dry weight per square meter) were four times higher in nutrient-enriched versus reference creeks. Nutrient enrichment did not significantly affect the biomass of benthic microalgae (a N. obsoletus food resource), but snail density was significantly correlated with benthic microalgal biomass, suggesting bottom–up control of snails. N. obsoletus is abundant on the east and west coast of North America; thus, N. obsoletus density and biomass may be useful variables for monitoring eutrophication effects on North American estuaries.  相似文献   

3.
Feeding habits ofMenidia peninsulae were analyzed monthly over a one year period and compared to planktonic prey available at the capture site. Three feeding stages were found: (1) In early spring, young-of-the-year fed on tychoplankton and detritus. (2) From late spring through winter,M. peninsulae preyed selectively on calanoid copepods and cypris larvae. (3) GravidM. peninsulae fed primarily on amphipods and larval silversides. In the Crystal River area,M. peninsulae reproduce in early spring. Silversides apparently migrate from the higher salinity bays to the lower salinity marshes in the summer, and then move back into the bays in fall.  相似文献   

4.
The impact ofMnemiopsis leidyi as a predator was studied quantitatively to determine their feeding rates on mixed natural zooplankton. These studies showed that feeding rate was independent of food concentration, but a function of both temperature and size of ctenophore. The feeding rate (liters cleared per mg dry weight per day) ranged from about 0.01 for larger ctenophores at lower temperatures (10–15°C) to about 0.1 for smaller ctenophores at higher temperatures (20–25°C). Combining these results with ctenophore biomass estimates from three years of sampling, numerical estimates were made of zooplankton mortality due to ctenophore predation. The maximum summer cropping byM. leidyi was calculated to be an average of 5–10% per day for the bay as a whole. Although substantial, this predation pressure alone does not account for the observed summer decline of zooplankton.  相似文献   

5.
Oyster reefs provide structural habitat for resident crabs and fishes, most of which have planktonic larvae that are dependent upon transport/retention processes for successful settlement. High rates of freshwater inflow have the potential to disrupt these processes, creating spatial gaps between larval distribution and settlement habitat. To investigate whether inflow can impact subsequent recruitment to oyster reefs, densities of crab larvae and post-settlement juveniles and adults were compared in Estero Bay, Florida, over 22 months (2005–2006). Three species were selected for comparison: Petrolisthes armatus, Eurypanopeus depressus, and Rhithropanopeus harrisii. All are important members of oyster reef communities in Southwest Florida; all exhibit protracted spawning, with larvae present throughout the year; and each is distributed unevenly on reefs in different salinity regimes. Recruitment to oyster reefs was positively correlated with bay-wide larval supply at all five reefs examined. Species-specific larval connectivity to settlement sites was altered by inflow: where connectivity was enhanced by increased inflow, stock–recruitment curves were linear; where connectivity was reduced by high inflows, stock–recruitment curves were asymptotic at higher larval densities. Maximum recruit density varied by an order of magnitude among reefs. Although live oyster density was a good indicator of habitat quality in regard to crab density, it did not account for the high variability in recruit densities. Variation in recruit density at higher levels of larval supply may primarily be caused by inflow-induced variation in larval connectivity, creating an abiotic simulation of what has widely been regarded as density dependence in stock–recruitment curves.  相似文献   

6.
Plankton samples of the MECCAS- (Microbial Exchanges and Coupling in Coastal Atlantic Systems) Project, taken in February, June, and August 1985 and April 1986, were analyzed to study the spatio-temporal distribution of sand shrimp, Crangon septemspinosa, larvae of Chesapeake Bay. With up to 250.9 larvae m?3, results confirm C. septemspinosa as a very abundant decapod larval form in early spring in the study area. The overwhelming majority (94.5%) of the larvae occurred in April 1986; a second minor peak of larval production was observed in February 1985. The first two larval stages comprised 81.1% of the collected larvae, and complete series of all developmental stages including juveniles were obtained in June 1985 and April 1986. Newly hatched larvae occurred over a wide range of salinities (22.00–33.60‰), while more advanced forms were found mainly at higher salinities (>30‰). High larval abundances (>50 larvae m?3) were obtained between 10°C; another considerably smaller peak in abundance occurred at temperatures ranging from 2.7°C to 4.5°C. Compared to other developmental stages, high abundances of the first two larval stages were collected at the highest chlorophyll concentrations. The significance of phytoplankton as a possible energy source for early stages of planktonic larvae and the role of phytoplankton as a possible chemical stimulus for larval release is discussed in terms of stomach and mouthpart structure and larval sensitivity to their chemical environment. *** DIRECT SUPPORT *** A01BY066 00016  相似文献   

7.
Average summer densities of the xanthid crab,Eurytium limosum, in an intertidal salt marsh on Sapelo Island, Georgia were in the range of 7.5 to 80.0 individuals m?2. Crab densities were lowest in wet, lowlying marsh and highest in well-drained creekbank and mussel mound habitats. An analysis of crab stomach contents indicated that feeding occurred mostly around high tide, especially at night. Although the diet included some plant material,Eurytium limosum is primarily predatory and consumed crabs, polychaetes, ostracods, bivalves, and snails. In the laboratory, under simulated low-tide field conditions, both small (11–15 mm carapace width) and large (20–37 mm CW)Eurytium could capture and consume young killifish (Fundulus heteroclitus). Large crabs consumed the entire size range (7–19 mm total length) of larval/juvenile fish offered, but small crabs did not prey upon fish >11.5 mm TL. The potential importance ofE. limosum as a predator on young killifish may not be realized in the field because alternative prey are available and the crabs feed primarily at high tide, when young killifish are dispersed in the water column and are less vulnerable to benthic predators.  相似文献   

8.
Oxygen consumption rates were measured individually for mixed groups of male, female, and immature striped bass,Morone saxatilis, in filtered Patuxent River, Maryland, water and in filtered water containing suspensions of either fuller’s earth or Patuxent River sediment. Oxygen consumption was determined at fixed swimming speeds at two temperatures, 15 and 22.5°C. Oxygen consumption of striped bass in filtered 15°C water increased as swimming speed increased. At 22.5°C, the same range of swimming speeds had no effect on rates of oxygen consumption. Similar data were obtained with fish swimming at the same speeds in water containing 0.79 g per liter fuller’s earth particles (15°C), and among those swimming at 31.7 and 49.0 cm per s in water containing 1.32 g per 1 Patuxent River sediment (22.5°C). Male and female striped bass respiration rates were similar under all test conditions. At 15°C, striped bass oxygen consumption rates during exposure to fuller’s earth while swimming at 8.6 and 31.7 cm per s did not differ from rates of fish swimming at the same speeds in filtered water. At 49.0 cm per s, rates were significantly depressed. Respiration rates of fish exposed to Patuxent River sediment at 22.5°C while swimming at 31.7 and 49.0 cm per s were significantly lower than those of fish in filtered water. Respiratory response of striped bass to suspended particle stress was manifested by depressed oxygen consumption. This is considered a short-term response to an acute stress. This response and the potential for hematological response to chronic suspended particle stress are discussed.  相似文献   

9.
Replicate groups of larvae from each of three female grass shrimp,Palaemonetes pugio, collected at each of six sites within Chesapeake Bay were reared in the laboratory to metamorphosis at 25°C, 25 ppt salinity. They were provided with approximately 300Artemia nauplii/larva/day. Sites were selected to provide both suspected Kepone® contaminated and non-contamined shrimp populations. A sample of eggs, adult females with and without eggs, and newly hatched larvae from each site were analyzed by Virginia Institute of Marine Science for Kepone as were postlarvae obtained through laboratory rearings. Females and eggs from the James River had highest concentrations of Kepone (0.63 and 0.47 ppm, respectively) with samples from the Lafayette River at the mouth of the James River having the second highest levels (0.04 and 0.4 ppm). Concentrations in ovigerous females and eggs in the populations most distant from the James (mouth of Potomac and upper Potomac River) were at or below the limits of detectability (0.001 to 0.015 ppm). In laboratory reared postlarvae from each site, concentrations of Kepone were undetectable. Despite these apparent differences in Kepone concentrations in the various populations we found no significant differences in larval survival, larval duration, or length of post-larvae attributable to site of origin. Highly significant differences in larval duration and size of post-larvae were attributable to parental variation.  相似文献   

10.
The temperature tolerance and resistance times of postlarval (<25 mm SL) and small juvenile spot,Leiostomus xanthurus, from the Cape Fear Estuary, North Carolina were tested in the laboratory. Critical thermal maximum techniques were used to determine first equilibrium loss (FEL) and critical thermal maximum (CTM) end points and thermal shock methods were used to determine 96-h upper incipient lethal temperatures (LT50). Acclimation temperatures ranged from 10 to 35°C and acclimation salinities were 10, 20 and 30‰. A quadratics model was fit to the CTM and FEL data; r2 values were 0.924 and 0.928 respectively. Acclimation salinity, estimated weight, acclimation salinity by acclimation temperature interaction and acclimation temperature by estimated weight interaction were the significant components of the CTM model. Predicted CTM values ranged from 30°C at 10 °C and 30‰ acclimation to just over 40°C at 30 °C and 30‰ acclimation. Acclimation temperature, acclimation temperature squared, estimated weight and acclimation temperatures by estimated weight interaction were the significant components of the FEL model. Predicted FEL values ranged from around 28°C at 10°C and 10‰ acclimation to about 39°C at 30°C and 30‰ acclimation. The 96-h LT50 values of spot acclimated to 20‰ increased linearly with acclimation temperature to 25°C. From about 25 to 35°C, LT50 values increased very little with acclimation temperature. The ultimate upper incipient lethal temperature of postlarval and small juvenile spot was estimated at 35.2°C. Increased salinity increased resistance time but decreased LT50 estimates. Thermal shock tests were better for predicting the effects of thermal addition than were CTM tests.  相似文献   

11.
The solubility of amorphous silica in aqueous salt solutions at 25° to 300°C can be calculated using information on its solubility in pure water and a model in which the activity of water in the salt solution is defined to equal the effective density. pe, of “free” water in that solution. At temperatures of 100°C and above, pe closely equals the product of the density of the solution times the weight fraction of water in the solution. At 25°C, a correction parameter must be applied to pe that incorporates a term called the apparent cation hydration number, h. Because of the many assumptions and other uncertainties involved in determining values of h, by the model used here, the reported numbers are not necessarily real hydration numbers even though they do agree with some published values determined by activity and diffusion methods. Whether or not h is a real hydration number, it would appear to be useful in its inclusion within a more extensive activity coefficient term that describes the departure of silica solubilities in concentrated salt solutions from expected behavior according to the model presented here. Values of h can be calculated from measured amorphous silica solubilities in salt solutions at 25°C provided there is no complexing of dissolved silica with the dissolved salt, or if the degree of complexing is known. The previously postulated aqueous silica-sulfate complexing in aqueous Na2SO4 solutions is supported by results of the present effective density of water model.  相似文献   

12.
The thermal response of the natural ferroan phlogopite-1M, K2(Mg4.46Fe0.83Al0. 34Ti0.22)(Si5.51Al2. 49)O20[OH3.59F0.41] from Quebec, Canada, was studied with an in situ neutron powder diffraction. The in situ temperature conditions were set up at ?263, 25, 100°C and thereafter at a 100°C intervals up to 900°C. The crystal structure was refined by the Rietveld method (R p=2.35–2.78%, R wp=3.01–3.52%). The orientation of the O–H vector of the sample was determined by the refinement of the diffraction pattern. With increasing temperature, the angle of the OH bond to the (001) plane decreased from 87.3 to 72.5°. At room temperature, a = 5.13 Å, b = 9.20 Å, c = 10.21 Å, β = 100.06° and V(volume) = 491.69 Å3. The expansion rate of the unit cell dimensions varied discontinuously with a break at 500°C. The shape of the M-octahedron underwent some significant changes such as flattening at 500°C. At temperatures above 500°C, the octahedral thickness and mean distance was decreased, while the octahedral flattening angle increased. Those results were attributed to the Fe oxidation and dehydroxylation processes. The dehydroxylation mechanism of the ferroan phlogopite was studied by the Fourier transform infrared spectroscopy (FTIR) after heated at temperatures ranging from 25 to 800°C with an electric furnace in a vacuum. In the OH stretching region, the intensity of the OH band associated with Fe2+(N B-band) begun to decrease outstandingly at 500°C. The changes of the IR spectra confirmed that dehydroxylation was closely related to the oxidation in the vacuum of the ferrous iron in the M-octahedron. The decrease in the angle of the OH bond to the (001) plane, with increasing temperature, might be related to the imbalance of charge in the M-octahedra due to Fe oxidation.  相似文献   

13.
Seasonality and abundance of ichthyoplankton in great South Bay,New York   总被引：1，自引：0，他引：1  
The seasonality and abundance patterns of ichthyoplankton were investigated during 1985–1986 in Great South Bay, New York, USA. Eggs representing 17 species and larvae representing 23 species of fish were identified. Bay anchovy, Anchoa mitchilli, was the most abundant ichthyoplankter, comprising >96% of the eggs and >69% of the larvae collected. Bay anchovy spawned throughout the bay from late May through August, with peak baywide densities of >200 eggs and 6 larvae m?3. Eggs of windowpane flounder (Scophthalmus aquosus) ranked second in abundance and were present in both spring and fall. Other dominant larvae were winter flounder (Pleuronectes americanus) and American sand lance (Ammodytes americanus). Their combined density reached 8 m?3 and accounted for the winter peak in larvae. The seasonality of abundance of larval fish was strongly correlated with reported densities of copepod nauplii prey.  相似文献   

14.
Stromatolites forming today on a small scale in hydrothermal environments are chemical and biological analogues of much larger Precambrian formations. Carbon isotopic composition varied as a function of CO2 concentration, pH, and species composition. Stratiform, layered stromatolites grew in silica-depositing springs at 55° to 70°C; they consisted mainly of a unicellular alga, Synechococcus, and a filamentous, photosynthetic bacterium, Chloroflexus. These thermophiles become enriched in 12C as the concentration of carbon dioxide in the effluent waters increases. At a concentration of 40 ppm total inorganic C, and δ13C of organic carbon was ～ ?12%., whereas at 900 ppm total inorganic C, the δ13C of similar species was ～ ?25%.. Conical stromatolites or conophytons (principally a filamentous, blue-green alga Phormidium and Chloroflexus) grew at 40°-55°C. In older, broader conophytons, Chloroflexus was the dominant organism. Their δ13C values were ～ ?18%. in a variety of hot springs. In carbonate-depositing springs, i.e., carbon dioxide saturated, conophytons and stromatolites consisting of a variety of blue-green algae and photosynthetic bacteria had the most negative δ13C values (to ?30%.). These carbon isotope ratios are directly comparable to carbon isotope ratios of kerogen from Precambrian stromatolites. The presence and activity of methanogenic bacteria or heterotrophic, aerobic and anaerobic bacteria did not alter significantly the δ13C of the original organic matter.The hydrogen isotopic fractionation between thermophilic organisms and water is 0 to ?74 for temperatures of 85° to 46°C, respectively. Acidophilic algae fractionated hydrogen isotopes to a lesser extent than did the photosynthetic organisms inhabiting neutral pH springs. Because organic matter retains some of its original isotopic signature, relationships of CO2 levels, pH, temperature, and species composition between modern stromatolites and their environment and those of the Precambrian can be inferred.  相似文献   

15.
The seasonal abundance and spatial distribution of eggs and early larvae of the bay anchovy,Anchoa mitchilli, and the weakfish,Cynoscion regalis, were determined from plankton collections taken during 1971–1976 in the lower Chesapeake Bay. Eggs and larvae of the bay anchovy,Anchoa mitchilli, dominated the ichthyoplankton, making up 96% of the total eggs and 88% of all larvae taken. A comparison of egg and larval densities from the lower Chesapeake Bay to existing data from other East Coast estuaries suggested that Chesapeake Bay is a major center of spawning activity for this species.Anchoa mitchilli spawning commenced in May when mean water column temperatures approached 17°C and abruptly ceased after August. Eggs and early larvae presented a continuous distribution throughout the study area during these months. Eggs and larvae of several sciaenid species, especiallyC. regalis, ranked second in numerical abundance. Larval weakfish were consistently taken in late summer of each sampling year but peak abundance and distribution was observed in August 1971. Sciaenid eggs exhibited a distinct polyhaline distribution with greatest concentrations observed at the Chesapeake Bay entrance or along the Bay eastern margin. Analysis of sciaenid egg morphometry and larval occurrence suggested spawning activity of at least four species. Additional important species represented by eggs and/or larvae in the lower Chesapeake Bay wereHypsoblennius hentzi, Gobiosoma ginsburgi, Trinectes maculatus, Symphurus plagiusa andParalichthys dentatus with the remaining species occurring infrequently.  相似文献   

16.
Laboratory experiments on the thermal decarboxylation of solutions of acetic acid at 200°C and 300°C were carried out in hydrothermal equipment allowing for on-line sampling of both the gas and liquid phases for chemical and stable-carbon-isotope analyses. The solutions had ambient pH values between 2.5 and 7.1; pH values and the concentrations of the various acetate species at the conditions of the experiments were computed using a chemical model.Results show that the concentrations of acetic acid, and not total acetate in solution, control the reaction rates which follow a first order equation based on decreasing concentrations of acetic acid with time. The decarboxylation rates at 200°C (1.81 × 10?8 per second) and 300°C (8.17 × 10?8 per second) and the extrapolated rates at lower temperatures are relatively high. The activation energy of decarboxylation is only 8.1 kcal/mole. These high decarboxylation rates, together with the distribution of short-chained aliphatic acid anions in formation waters, support the hypothesis that acid anions are precursors for an important portion of natural gas.Results of the δ13C values of CO2, CH4, and total acetate show a reasonably constant fractionation factor of about 20 permil between CO2 and CH4 at 300°C. The δ13C values of CO2 and CH4 are initially low and become higher as decarboxylation increases.  相似文献   

17.
The thermal expansion of anhydrite, CaSO4, has been measured from 22° to 1,000° C by X-ray diffraction, using the Guinier-Lenné heating powder camera. The heating patterns were calibrated with Guinier-Hägg patterns at 25° C, using quartz as internal standard. Heating experiments were run on natural anhydrite (Bancroft, Ontario), which at room temperature has lattice constants in close agreement with those of synthetic material. The orthorhombic unit cell at 22° C (space group Amma) has a=7.003 (1) Å, b=6.996 (2) Å and c=6.242 (1) Å, V=305.9 (2) Å3. At room temperature, the thermal expansion coefficients α and β (α in °C?1×104, β in °C?2×108) are for a, 0.10, ?0.69; for b, 0.08, 0.19; for c, 0.18, 1.60; for V, 0.37, 1.14. Second-order coefficients provide an excellent fit over the whole range to 1,000° C.  相似文献   

18.
Recruitment- and predation-related effects on populations of salt marsh codominants mummichog (Fundulus heteroclitus) and pinfish (Lagodon rhomboides), were examined based on marsh size and landscape setting. Six island marshes—three small island marshes (SIM) ~40–1,000 m2 and three large island marshes (LIM) ~3,000–10,000 m2—were paired with six expansive fringing marshes (EFM), each >76,000 m2 in size and located within ~1.0 km of a paired SIM or LIM. Over a 2-year period, triannual collections at these sites assessed F. heteroclitus, L. rhomboides, and predator finfish populations as well as habitat characteristics. No significant population density trends were apparent for L. rhomboides young-of-year (YOY) or year-one-and-older (Y1+) cohorts based on marsh size or were any significant differences in density apparent among marsh types. F. heteroclitus YOY and Y1+ densities differed significantly among marsh types demonstrating a positive relationship between density and marsh size. Larval and juvenile F. heteroclitus abundances were significantly lower within SIM than LIM and EFM. Although larval F. heteroclitus abundances between LIM and EFM did not differ significantly, juvenile abundances did, suggesting mortality constrained LIM juvenile abundances. A significant negative relationship of F. heteroclitus to predator finfish density and a significant negative relationship of predator finfish density to low marsh area/perimeter (access restriction) estimates suggest that predation on F. heteroclitus is greater within SIM and LIM than within EFM. Habitat and landscape level attributes can affect resident nekton population regulation and these effects should be considered relative to the life history traits of targeted species when managing coastal resources.  相似文献   

19.
We experimentally evaluate the effect of migratory shorebirds on the benthic fauna of three southwestern Atlantic Argentinean stop-over and wintering sites: Bahía Samborombon (35°30′–36°22′S, 57°23′W), Mar Chiquita coastal lagoon (37°40′S, 57°26′W), and Bahía Blanca (38°48′–39°25′S, 50°–62°25′W). The experiments consisted of exclusion ceilings and controls (both 1 m2), with 10 replicates each and aligned at the same tidal level. During December 1994–May 1995 these experiments were done, twice in Bahía Samborombon, twice at two sites (Sotelo and Celpa) 4 km apart in Mar Chiquita coastal lagoon, and three times in Bahía Blanca. Three polychaete species (Laeonereis acuta, Nephtys fluviatilis, andHeteromastus similis) were found in similar densities in both areas of the Mar Chiquita lagoon.L. acuta andN. fluviatilis were affected in Sotelo, but there was no treatment effect in Celpa. In Sotelo the most abundant shorebirds were Hudsonian godwit (Limosa haemastica), American golden plover (Pluvialis dominica), and White-rumped sandpiper (Calidris fuscicollis), and in Celpa the most abundant shorebirds were White-rumped sandpiper, two-banded plower (Charadrius falklandicus), and lesser yellowlegs (Tringa flavipes). The largest polychaete densities were in the upper sediment layer (0–6 cm), which was also the most affected layer. Three polychaete species were found in Bahía Samborombon (L. acuta, H. similis, andNeanthes succinea), but onlyH. similis showed a treatment effect. The most abundant shorebirds in Samborombon were white-rumped sandpiper and two-banded plover. No effect was detected in Bahía Blanca, where the most abundant shorebirds were white-rumped sandpiper and American golden plover. In all cases, the species affected by shorebirds were the most abundant species. From the two sites of Mar Chiquita, there was a treatment effect only in Sotelo, which was also the area with higher shorebirds counts. However, much lower densities observed in Samborombon (similar to the unaffected area of Mar Chiquita) also produced a significant decrease in infaunal abundance. These evidences also suggest that just selection of study sites may produce different views of the interaction between shorebirds and benthic species.  相似文献   

20.
Speleothem fluid inclusions are a potential paleo-precipitation proxy to reconstruct past rainwater isotopic composition (δ18O, δD). To get a better insight in the extraction of inclusion water from heated speleothem calcite, we monitored the water released from crushed and uncrushed speleothem calcite, heated to 900 °C at a rate of 300 °C/h, with a quadrupole mass spectrometer. Crushed calcite released water in three not well individualised peaks between 25 and 360 °C, 360 and 650 °C and between 650 and 800 °C while uncrushed calcite released water in two distinct temperature intervals: between 25 and 550 °C and between 550 and 900 °C.Water from two speleothems from the Han-sur-Lesse cave was recovered using three different techniques: i) the crushing and heating to 360 °C technique, ii) the decrepitation by heating to 550 °C and iii) the decomposition by heating to 900 °C technique. Measurements of the δD of water recovered by the decomposition of Han-sur-Lesse calcite heated to 900 °C did not show a 20 to 30‰ offset as found by previous authors. However a difference of 7‰ was observed between water released before and after decomposition of the calcite. Water recovery from the Han-sur-Lesse samples suggests that a simple heating technique (up to 550 °C) without crushing could both (a) recover water with δD representative of that of the drip water and (b) double the water yield as compared to the crushing and heating method.Our study warns for possible contamination of the recovered inclusion water with hydration water of lime, responsible for the recovery of water with very negative δD values.  相似文献   

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