Range Of Seawater Temperatures Research Articles

Clumped isotope signatures in modern brachiopod carbonate

We present a temperature to Δ47 relationship for naturally occurring modern brachiopods, which was established using a suite of thirteen brachiopod specimens from twelve sampling localities that span a mean annual seawater temperature range of −0.8 to 29.0°C. Sample locations and depths were selected to maximize the range of temperatures covered by the calibration while minimizing the seasonal temperature variability impacting the samples. Linear least-squares regression analysis yields the following relationship expressed using the Ghosh et al. (2006) reference frame:Δ47=0.0478±0.0099⋅106/T2+0.1164±0.1203n=13;R2=0.91;95%CI.This equation lies within the 95% confidence interval of the original relationship determined using synthetic calcite (Ghosh et al., 2006), but is in better agreement with the newly revised calibration of Zaarur et al. (2013). However, despite this broad agreement, our equation has a shallower slope than the equations for synthetic calcites, and yields temperatures at the warm end of the calibration temperature range (Δ47=0.640‰) that are as much as 3.1°C offset from those predicted using the equation of Zaarur et al. (2013). On the other hand, our new equation has a steeper slope than the Henkes et al. (2013) equation for modern brachiopods and mollusks. This finding is consistent with the hypothesis that differences in the protocols employed by laboratories that use different temperatures of phosphoric acid digestion cause the observed discrepancies between the Δ47 values reported by various laboratories.

Effect of temperature on two reef-building corals Pocillopora damicornis and P. verrucosa in the Red Sea

The effects of temperature on two reef building corals Pocillopora damicornis and P. verrucosa inhabiting the Obhur Creek, a small embayment on the western, Red Sea coast of Saudi Arabia, was studied from December 2009 to November 2010. The overall annual range of seawater temperature in Obhur Creek was between 24.5°C and 33°C. Zooxanthellae abundance and diversity showed seasonal variations: the number of zooxanthellae in P. damicornis was slightly higher than in P. verrucosa, and the abundance of zooxanthellae of both species was low in summer and high during winter. The respiration rate of P. verrucosa did not vary between summer and winter, suggesting compensatory acclimation. In contrast, the respiratory rate in P. damicornis was lower in winter than in summer. During the winter season the metabolic rate was higher in both species owing to the optimum seawater temperature (30°C). As a result of the abundance of zooxanthellae and the optimum seawater temperature, the growth rates of the skeletons of the two coral species were higher in winter and lower in summer. In general, the results showed that P. verrucosa is more flexible with respect to temperature than P. damicornis. The difference in zooxanthellae thermal tolerances at 35°C may be due to the algal genotypes between the two species, resulting in P. damicornis becoming bleached as the rate of metabolism exceeds the rate of photosynthesis with increasing temperature.

Ecological relationship between environmental factors and Pacific cod (Gadus macrocephalus) catch in the southern East/Japan Sea

The habitat characteristics of Pacific cod (Gadus macrocephalus) and the ecological relationship between Pacific cod catch and environmental parameters in the southern East/Japan Sea were investigated. Pacific cod is sexually matured at age of 4–5. The highest catch of Pacific cod off the eastern Korean Peninsula occurred in seawater temperature range of 0–4°C and salinity range of 33.8–34.2 practical salinity unit at 100 m. The Cross-Correlation Function analysis showed that there was a significant negative correlation between Pacific cod catch and February seawater temperature at 75 m nearby spawning area with a time lag of 5 years in Korean waters (r = –0.360, p < 0.05). The annual catch of Pacific cod also had a significant correlation (p < 0.05) with zooplankton biomass in coastal nursery areas with a time lag, i.e., the highest ones, r = 0.432 and r = 0.452, for total zooplankton biomass in June of 5 years ago, and for euphausiids abundance in February of 4 years ago from the period when Pacific cod was caught, respectively. Furthermore, total catches of Pacific cod in the southern East/Japan Sea (i.e., sum of Korean and Japanese catches) were negatively correlated with winter Arctic Oscillation Index, and the highest negative correlation (r = –0.364, p < 0.05) was shown with a time lag of 4 years. Considering sexual maturation at ages 4–5, such statistical analyses imply that biotic and abiotic environmental factors during the early life stages of Pacific cod have a significant influence on recruitment after 4–5 years of spawning.

The skeletal geochemistry of the sclerosponge Astrosclera willeyana: Implications for biomineralisation processes and palaeoenvironmental reconstruction

To investigate the controls on the geochemistry of aragonitic sclerosponge skeletons, we used secondary ion mass spectrometry (SIMS) to analyse an Astrosclera willeyana specimen. The high spatial resolution of SIMS allows the independent analysis of the two key crystal structures in the skeleton i.e. the fused spherulites (formed intracellularly and fused together at the surface of the skeleton) and the epitaxial backfill (deposited extracellularly at the base of the sponge tissue). We analysed Sr/Ca, Mg/Ca and Ba/Ca across a short (~ 5 mm) transect of fused spherulites which represented several years growth. We observe cyclical variations (with a length of 0.1 to 0.6 mm in both Sr/Ca and Mg/Ca in some (but not all) sections of the transect. The observed ranges of Sr/Ca and Mg/Ca over the presumed seasonal cycles are ~ 9.5 to 11.5 mmol mol − 1 and 0.6 to 1.0 mmol mol − 1 respectively. The annual seawater temperature range at the study site is ~ 4.3 °C, so the inferred temperature sensitivity of skeletal Sr/Ca and Mg/Ca is ~ 0.5 mmol mol − 1 °C (or 5% °C − 1 ) and ~ 0.1 mmol mol − 1 °C (or 13% °C − 1 ) respectively. This is higher than observed in most previous sclerosponge studies or anticipated from studies of synthetic aragonite. This indicates that the chemistry of the A. willeyana skeleton is affected by one or more additional influences, besides temperature, which are currently unresolved. The pH of the precipitating fluid, estimated from skeletal δ 11B, is ~ 8.1–8.2 for both fused spherulites and epitaxial backfill. Epitaxial backfill contains significantly higher Sr/Ca, Mg/Ca and B/Ca and significantly lower Ba/Ca than the fused spherulites but Sr/Ca and Mg/Ca are positively correlated by the same relationship in both skeletal features. This suggests that the geochemistry of each feature is predominantly controlled by a common process. This is unlikely to be Rayleigh fractionation, which is indicated by negative correlations between Sr and Mg in aragonite.

수하식 양식장용 실시간 해양환경 관측시스템 개발 및 동해 연안의 수온변동 특성

Mass mortalities of cultivated organisms have occurred frequently in Korean coastal waters causing enormous losses to cultivating industry. The preventive measures require continuous observation of farm environment and real-time provision of data. However, line hanging aquaculture farm are generally located far from monitoring buoys and has limitations on installation of heavy equipments. Substituting battery pack for solar panels and miniaturizing size of buoy, newly developed system can be attached to long line hanging aquaculture farm. This system could deliver measured data to users in real-time and contribute to damage mitigation and prevention from mass mortalities as well as finding their causes. The system was installed off Gijang and Yeongdeck in Korea, measuring and transmitting seawater temperature at the sea surface every 30 minutes. Short term variation of seawater temperature, less than one day, in Gijang from June to July 2009 corresponded tidal period of about 12 hours and long term variation seemed to be caused by cold water southeast coast of Korea, particularly northeast of Gijang. Seawater temperature differences between Gijang station and the other station that is about 500 m away from Gijang station were <TEX>$1^{\circ}C$</TEX> on average. This fact indicates that it is need to be pay attention to use substitute data even if it is close to the station. Daily range of seawater temperature, one of crucial information to aquaculture, can be obtained from this system because temperature were measured every 30 minutes. Averages of daily range of temperature off Gijang and Yeongdeok during each observation periods were about <TEX>$2.9^{\circ}C$</TEX> and <TEX>$4.7^{\circ}C$</TEX> respectively. Dominant period of seawater temperature variation off Yeongdeok was one day with the lowest peak at 5 a.m. and the highest one at 5 p.m. generally, resulting from solar radiation.

Application of a superoxide (O 2−) thermal source (SOTS-1) for the determination and calibration of O 2− fluxes in seawater

Superoxide (O 2 −) is an important short lived transient reactive oxygen species (ROS) in seawater. The main source of O 2 − in the ocean is believed to be through photochemical reactions though biological processes may also be important. Sink terms for O 2 − include redox reactions with bioactive trace metals, including Cu and Fe, and to a lesser extent dissolved organic matter (DOM). Information on the source fluxes, sinks and concentration of superoxide in the open ocean are crucial to improving our understanding of the biogeochemical cycling of redox active species. As O 2 − is a highly reactive transient species present at low concentrations it is not a trivial task to make accurate and precise measurements in seawater. In this study we developed the appropriate numerical analysis tools and investigated a number of superoxide sources and methods for the purposes of calibrating O 2 − concentrations and/or fluxes specifically in seawater. We found the superoxide thermal source bis(4-carboxybenzyl)hyponitrite (SOTS)-1 easy to employ as a reliable source of O 2 − which could be successfully applied in seawater. The thermal decomposition of SOTS-1 in seawater was evaluated over a range of seawater temperatures using both a flux based detection scheme developed using two spectrophotometric methods: (i) 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and (ii) ferricytochrome c (FC), or a concentration based detection scheme using a chemiluminescence flow injection method based on the Cypridina luciferin analog 2-methyl-6-(p-methoxyphenyl)3-7-dihydroimidazol[1,2-α]pyrazin-3-one (MCLA) as reagent. Our results suggest SOTS-1 is the best available O 2 − source for determining concentrations and fluxes, all detection systems tested have their pros and cons and the choice of which to use depends more on the duration and type of experiment that is required.

How cold were the Early Permian glacial tropics? Testing sea-surface temperature using the oxygen isotope composition of rigorously screened brachiopod shells

Abstract: Brachiopod carbonate from Early Permian brachiopod shells from low palaeolatitude north Iran and higher palaeolatitude Pakistan Karakorum were screened for diagenesis and analysed for oxygen isotope ratios to derive seawater palaeotemperatures. Screening techniques employed included SEM ultrastructural analysis, cathodoluminescence (CL), image analysis of CL images, trace-element (Sr, Mn, Fe) determinations, and carbon and oxygen stable-isotope determinations. The Karakorum shells were found to be diagenetically altered, but those from north Iran were judged to be pristine. Using data from pristine material, two distinct time slices were analysed: the early and middle Asselian. Two contrasting δ 18 O values for seawater (0‰ and +1.0‰ V-SMOW) were used to account for different extensions of the Gondwanan ice caps. The δ 18 O data from north Iran indicate a range of seawater temperatures from +24.3 to +30.3 °C (for δ 18 O seawater = 0‰ V-SMOW) or from +30.3 to +35.4 °C (for δ 18 O seawater = +1.0‰ V-SMOW) for the early Asselian. Results for δ 18 O from the middle Asselian indicate seawater temperatures of +24.4 to +28.0 °C (for δ 18 O seawater = 0‰) or +29.2 to +32.8 °C (for δ 18 O seawater = +1.0‰). The maximum calculated temperatures in the middle Asselian are about 2 °C lower than those for the early Asselian. The average temperature for both time slices is similar to modern tropical sea-surface temperatures, indicating that low-latitude Early Permian ocean waters in Iran did not undergo significant cooling during the final Glacial III episode of Gondwanan glaciation. This confirms other evidence based on biotic provinces, which suggests that during the Permo-Carboniferous glaciation, the low-latitude warm belt became narrower and confined to the western Tethys and Cathaysian provinces, and was not subject to a reduction in temperature, but rather a reduction in size.

Brooding of the sub-Antarctic heart urchin, Abatus cavernosus (Spatangoida: Schizasteridae), in southern Patagonia

The reproductive cycle of the sub-Antarctic spatangoid sea urchin, Abatus cavernosus, was examined during a 2-year period in southern Patagonia, Argentina. The population studied is the northernmost known coastal population in the austral oceans, and is influenced by a greater annual range of seawater temperature than other Abatus species. The sex ratio of the overall A. cavernosus population did not differ significantly from 1:1, but was not homogeneous across size classes. A clearly defined annual reproductive cycle was found. Spawning occurred from May to July and was synchronous between sexes. Females were observed to be brooding within a 9-month period, from May to February. Juveniles were released during the austral summer, from January to February. The length at which 50% of the females were brooding occurred at a test length of 25.9 mm. A. cavernosus had a large egg size (mean diameter = 1.4 mm) and low fecundity (maximum = 57 eggs per female) compared to closely related species. The number of eggs within each brood pouch was highest in larger anterior brood pouch, which is close to two gonopores, as opposed to the other anterior and two smaller posterior pouches. Significant interannual variation was observed in gonad cycles, fecundity, and embryo development such as: brood size decreased during 2001; adjusted gonad dry weight and fecundity were higher during 2003. Hypotheses concerning the gonadal and brooding cycles and fecundity of sub-Antarctic and Antarctic Schizasteridae are discussed.

2005년 하계 완도 연안 냉수대 발생시 식물플랑크톤의 분포 특성

The data of temperature, chlorophyll a, phytoplankton and NOAA/AVHRR satellite data were analyzed about 7 stations around Wando Island area on August 30, 2005. The sea water temperature range was from to , and there was a cold water mass from the station 1 to 5 around the outside of Chungsando Island, the water temperature was lower at the bottom than surface. The salinity was , DO was , but the concentration of chlorophyll a was 1ug/L higher at the bottom than surface. Total phytoplankton appeared from the whole stations were 47 genus, 80 species and diatoms were dominant. A lot of dinoflagellates Ceratium forca and diatoms Thalassithrix spp. mostly appeared in the cold water mass were turned up from the station 1 to 5. 4 groups of phytoplankton clusters were shown in the surface, and 3 groups of phytoplankton clusters were shown at the bottom according to the water temperature. On the ground of the result analyzed with NOAA/AVHRR satellite data, the SST around Wando Island was , it was formed by thermohaline front latitudinally

Response of benthic foraminifera Rosalina leei to different temperature and salinity, under laboratory culture experiment

Live specimens of benthic foraminiferal species Rosalina leei were subjected to a combination of temperature (25°C, 30°C and 35°C) and salinity (25‰, 30‰ and 35‰) to assess its differential response to the annual range of seawater temperature and salinity reported at the sampling site. A total of 216 specimens were used for the experiment. Within the range of temperature and salinity, to which R. leei specimens were subjected as part of the present experiment, growth increased with increasing salinity, whereas increase in seawater temperature resulted in retarded growth. Maximum growth was reported in the specimens kept at 25°C temperature and 35‰ salinity while the rest of the specimens maintained in 30‰ and 25‰ saline water, showed comparatively less growth. The specimens kept at 30°C and 35°C temperature and different salinities showed much less growth as compared to the specimens maintained at 25°C temperature. However, none of the R. leei specimens subjected to the present experiment reproduced during the course of the experiment. The absence of reproduction under the present set of temperature and salinity conditions, probably indicates that R. leei reproduces at a very narrow range of temperature and salinity which is different from the temperature and salinity conditions in the present experiment. It is further inferred that under the present set of temperature–salinity conditions, 25°C temperature and 35‰ saline water is most suitable for the growth of R. leei. Results are significant as the responses of benthic foraminifera to different temperatures and salinity are being used for palaeoclimatic reconstruction.

Modern‐age buildup of CO2 and its effects on seawater acidity and salinity

The impacts of increases in atmospheric CO2 since the midst of the 18th century on average seawater salinity and acidity are evaluated. Assuming that the rise in the planetary mean surface temperature continues unabated, and that it eventually causes the melting of terrestrial ice and permanent snow, it is calculated that the average seawater salinity would be lowered not more than 0.61‰ from its current 35‰. It is also calculated –using an equilibrium model of aqueous carbonate species in seawater open to the atmosphere‐ that the increase in atmospheric CO2 from 280 ppmv (representative of 18th‐century conditions) to 380 ppmv (representative of current conditions) raises the average seawater acidity approximately 0.09 pH units across the range of seawater temperature considered (0 to 30°C). A doubling of CO2 from 380 ppmv to 760 ppmv (the 2 × CO2 scenario) increases the seawater acidity approximately 0.19 pH units across the same range of seawater temperature. In the latter case, the predicted increase in acidity results in a pH within the water‐quality limits for seawater of 6.5 and 8.5 and a change in pH less than 0.20 pH units. This paper's results concerning average seawater salinity and acidity show that, on a global scale and over the time scales considered (hundreds of years), there would not be accentuated changes in either seawater salinity or acidity from the observed or hypothesized rises in atmospheric CO2 concentrations.

Deciphering kinetic, metabolic and environmental controls on stable isotope fractionations between seawater and the shell of Terebratalia transversa (Brachiopoda)

This study presents carbon and oxygen stable isotope data obtained from high-resolution sampling (<500 μm) of the brachiopod Terebratalia transversa from the San Juan Islands (Washington State, USA). The aim of this study is to unravel the respective effects of physiological and environmental controls on the stable isotopic composition of brachiopod shell calcite. Based on an SEM study of the shell, a three-dimensional sampling was performed in order to investigate carbon and oxygen isotope variations along isochrons and ontogenetic transects.The primary as well as the outer part of the secondary shell layer display large and variable isotopic offsets as high as −7‰ for δ13C and −6‰ for δ18O relative to expected equilibrium values. The significant positive correlations between δ18O and δ13C values indicate that the isotopic compositions of these shell domains are mainly controlled by kinetic isotope fractionation effects. The ontogenetic δ13C and δ18O variations can be used to establish a growth curve of the studied specimen whose age is estimated close to 8 years. The extent of apparent O-18 disequilibrium observed in this study is about as large as any yet measured in any organism, which makes this brachiopod an interesting and important case.The carbon and oxygen isotope compositions increase from the outer towards the inner part of the secondary layer, where they reach values of 0–0.8‰ and −0.8‰ to −0.2‰, respectively. Corresponding calculated temperatures are between 12 and 13.8 °C and fall in the range of seawater temperatures recorded off the San Juan Islands (7–13 °C). These results suggest that the calcite fibres were secreted more and more slowly during the thickening of the shell throughout the animal's life, finally approximating isotopic equilibrium.This study illustrates that the stable isotopic composition of the modern brachiopod T. transversa is predominantly influenced by kinetic fractionation and, to a minor degree, by metabolic effects. Except for the innermost part of the shell, the measured isotope ratios do not reflect environmental conditions during shell precipitation. It remains to be tested by comparable studies whether other modern brachiopod species or even fossil brachiopods reflect comparable fractionation effects. These results point out the need for re-examination of Paleozoic oceanographic conditions.

The seasonal and vertical distribution of living planktic foraminifera in the NW Arabian Sea

Abstract The NW Arabian Sea is characterized by a strong seasonal contrast in surface water hydrography. During the SW monsoon of 1992, we encountered strong coastal upwelling characterized by low sea surface temperatures (SST), high nutrient concentrations, a shallow thermocline and a near-surface chlorophyll maximum. By contrast, the hydrography during the NE monsoon of 1993 was characterized by a relatively warm nutrient-depleted surface mixed layer and a deep chlorophyll maximum. We show that the faunal composition, depth habitat and abundance of living planktic foraminifera respond to the hydrographic changes controlled by the seasonally reversing monsoon system. Total shell concentrations (&gt; 125 μm) ranged from 4 to 332 individuals (ind.) m −3 during upwelling and from 3 to 85 ind. m −3 during the non-upwelling season. During upwelling, the fauna was dominated by Globigerina bulloides . During non-upwelling the fauna was characterized by relatively high concentrations of tropical symbiont-bearing species such as Globigerinoides ruber, Globigerinoides sacculifer and Globigerinella siphonifera , whereas concentrations of Globigerina bulloides were an order of magnitude lower. Factor analysis on 15 species yields an upwelling assemblage (UA), a tropical assemblage (TA) and a subsurface assemblage (SA). A fourth factor represents the distribution of the species Globigerina falconensis , which is mainly found in subsurface waters during the non-upwelling period (NE monsoon). A model is presented to calculate the base of the productive zone from the vertical shell concentration profile of a given species. The model is validated by comparing the range in calcification temperatures of G. bulloides , derived from its δ 18 O, with the in situ sea-water temperature range of the productive zone as predicted from the model. It appears that shell growth (calcite precipitation) is restricted to the productive zone as defined by this method. The average calcification temperature of G. bulloides corresponds to the point of maximum change in the shell concentration profile (i.e. the inflection point). For most shallow-dwelling species, the inflection point is found at or below the depth of the chlorophyll maximum, although above the main thermocline. This study indicates that the depth habitat and abundance of different species varies seasonally. Consequently, the abundance and stable isotope composition of specimens in the fossil record reflects a mixture of specimens that were produced at various depths during the different seasons.

Kinetics of methyl halide production by reaction of DMSP with halide ion

Abstract Kinetic and thermodynamic properties of the reactions of DMSP + X − a3 CH 3 X + CH 3 SCH 2 CH 2 COO − are obtained by time series measurements of methyl halide (CH 3 X) production by the reactions of DMSP with halide ions (X − ). Thermodynamically, DMSP reactions with halide ions to produce methyl halides are not favoured because they are endothermic and Δ G ° > 0 over the range of seawater temperature. Both kinetic and thermodynamic studies suggest that methyl halide production by DMSP + X − can only contribute a very small proportion of the currently estimated oceanic source of methyl halide (

Responses of Cultivated Porphyra Thalli to Water Temperature and Water Current-I. Effects of Water Temperature on the Growth of Red Alga Porphyra yezoensis from. narawaensis (Nori) Cultivated in an Outdoor Raceway Tank.

In order to examine effects of seawater temperature on the growth of Porphyra foliose thalli, outdoor raceway tanks with circulating water were newly designed, and provided the experimental condition simulating Nori cultivation farms in the sea. Frozen seed nets of Porphyra yezoensis form. narawaensis were set in the raceway tanks. During the period of the two experiments, December in 1985 and February in 1986, mean seawater temperature ranged from 8.0 to 23.4°C. Standing crop of foliose thalli increased normally at 10-17°C, but the increase rate of standing crop lessened at the temperature higher and lower beyond these limits. Visible absorption spectra of living foliose thalli, indicating concentrations of photosynthetic pigments, did not vary much within the range of seawater temperature from 8 to 20°C. The optimum seawater temperature for the growth of Porphyra foliose thalli ranged from 10 to 17°C in the raceway tanks. This temperature range confirmed results obtained through in vitro experiments but was higher than that in Nori cultivation farm.

Correlation of embryonic temperature sensitivity of sea urchins with spawning season

In the coastal waters of Japan, from the subtropical area to the subfrigid area, there are several species of sea urchin with a different biogeographic distribution. The present study investigated the temperature sensitivity, as represented by the range of temperature optima for the embryos, and the dependence of developmental velocity on temperature within that range, for each of eight species of sea urchin, Echinometra mathaei, Diadema setosum, Anthocidaris crassispina, Clypeasterjaponicus, Pseudocentrotus depressus, Hemicentrotus pulcherrimus, Strongylocentrotus nudus and Strongylocentrotus intermedius. For all of these species, the optimal temperature range was confirmed to correspond well with the range of seawater temperature during the spawning season. The distributions of these sea urchins were generally correlated with their embryonic temperature sensitivities but exceptions to this correlation were found. This departure from the correlation as well as the flexibility of embryonic temperature sensitivity are discussed.

Differences in Temperature Dependence of Early Development of Sea Urchins with Different Growing Seasons

Three species of sea urchin, Hemicentrotus pulcherrimus, Anthocidaris crassispina, and Hemicentrotus depressus, inhabit the tidal areas around the Misaki Marine Biological Station, on the Pacific coast of Japan. These sea urchins have different breeding seasons and hence their embryos show differences in temperature sensitivity. In this study, differences in the temperature dependence of their embryogenesis were examined. It was found that the upper and lower limits of the optimal temperature range for embryogenesis in each animal were species-specifically determined, and that the range of seawater temperature during the breeding season was within this optimal temperature range. A quasi-linear relationship was obtained between temperature and relative developmental velocity, which was defined as the ratio against the maximal velocity attained at the highest temperature within the optimal temperature range. Based on this result, a form of graphical analysis was devised to represent the differences in species-specific developmental temperature sensitivity. The physiological and ecological significance of species-specific temperature sensitivity was also discussed.

Oxygen and carbon isotope composition of cold-water Berriedale Limestone (Lower Permian), Tasmania, Australia

The Berriedale Limestone formed at about 80°S paleolatitude and contains many glacial dropstones. It formed during a period of major Gondwana deglaciation. The Berriedale Limestone contains mostly bryozoans, brachiopods and bivalves, with some intraclasts and rare pellets. The faunal diversity is low and the fauna are similar to the modern cold-water foramol faunal assemblage. Micrite, microspar and spar occur as equant to well developed rhombs of calcite. The coarse spar cements are bored and are ruptured by dropstones, indicating submarine origin of low-Mg calcite at water-temperatures of around 3°C. The mixing zone cementation was preceded by erosion of early formed crystals. The eroded crystals occur as inclusions in mixing zone cements. The fauna are characterized by heavy δ 13C and light δ 18O. The whole-rock field of δ 18O- δ 13C falls at the edge of “Normal Marine Limestone” and deviates to lighter δ 18O values (down to −16.7‰ PDB). Lightest δ 18O values ( ∼ −22‰ PDB) of fresh-water sparry calcite cement are similar to those in the Early Permian continental tillites, suggesting that the Permian sea was diluted by isotopically light melt waters. Micrite δ 18O values (−9.2 to −12.6‰ PDB) are within the range of whole-rock values. The δ 18O values of calcite in shales are lighter than limestone values. The δ 18O values of the fauna give an unrealistic range of sea-water temperatures because the fauna have equilibrated with variable amounts of melt waters. However, calculated original δ 18O values of the fauna indicate temperatures < 4°C. The heaviest δ 18O of fauna gives cold temperatures of 9°C (with δ w −2.8‰) and −3°C (with δ w −6‰ ). The lightest values of sparry calcite cements ( −22‰ PDB) indicate that the limestone reacted with cold melt waters. The δ 18O of Permian sea is estimated to be about +1.2‰ and was diluted by melt waters as light as −27‰ SMOW.