Annual and spatial variability in gains of body weight in Macoma balthica (L.): Relationships with food supply and water temperature

Long-term patterns in fish phenology in the western Dutch Wadden Sea in relation to climate change

The effect of climatologic conditions and reservoir releases on downstream conditions was determined by means of statistical and graphical analyses of stream-temperature variations measured in the upper Delaware River basin, May-September 1964-67. Climatologic conditions normally increase water temperatures from February through July and decrease them from August through January. Summer releases from New York City's Cannonsville Reservoir were observed to decrease water temperatures by 13?C (Celsius) in 8.1 miles and by 1?C, 55.9 miles downstream from this reservoir. Releases from New York City's Pepacton Reservoir were observed to decrease water temperatures by 11?C in 31.0 miles and between 1?-3?C in 71.0 miles downstream from this reservoir. The influence of releases from these reservoirs is dependent upon five factors: thermal stratification in the reservoir, depth at which water is withdrawn from the reservoir, rate of release, distance downstream from the reservoir, and climatologic conditions.

Calcimass and carbonate production by molluscs on the tidal flats in the Dutch Wadden Sea: I. The tellinid bivalve Macoma balthica

Monthly mean water temperatures in the River Danube at Linz, Austria during the period 1901–1990 have been investigated in relation to equivalent information on air temperature and river discharge. Statistical analysis revealed a significant increase in monthly mean water temperatures of 0.8 °C and showed strongest rises in mean values for autumn and early winter months. No statistically significant trends were evident for air temperature or river discharge, and rising water temperatures are likely to reflect increasing human modification of the river system. A strong overall correlation between monthly mean water and air temperatures at Linz was made up of a series of more scattered and less steep water/air temperature relationships for individual months, while the influence of snowmelt runoff depressed average water temperatures in the spring and early summer period by 1.5 °C. Multiple regression relationships developed for individual months from data on air temperature, river discharge and time trend during the study period were able to predict monthly mean water temperatures in 1991 and 1992 with a root mean square error of 0.5 °C. These regression equations, when combined with scenarios of future changes in air temperature and river flow as a consequence of global warming, suggest that only modest rises in monthly mean water temperature will be experienced in the River Danube by the end of the present century, but that increases of > 1 °C for all months, and > 2 °C for the autumn period of low flows, can be anticipated by the year 2030.

Effects of temperature on the length of the annual growing season in the tellinid bivalve Macomabalthica (L.) living on tidal flats in the Dutch Wadden Sea

The population of Sanderlings Calidris alba along the East Atlantic flyway has grown considerably during the last decades. Perhaps reflecting this augmented population size, increasing numbers of Sanderling have been reported to stage in the Wadden Sea during spring and autumn migration. Estimates of the numbers of Sanderlings in the Wadden Sea have previously been based on a limited number of counts that were not corrected for the turnover of individuals. In this study, we accounted for turnover using estimates of the probability that individually colour-ringed Sanderlings are still present two days after a sighting. In combination with daily counts during high tide, we estimated the total number of Sanderlings that used the island Griend and surrounding mudflats, in the western Dutch Wadden Sea, during southward passage in 2013 and 2014. We also estimated minimal staging durations of Sanderlings at Griend. Non-moulting birds were significantly heavier upon capture, which suggests that they were refuelling for long non-stop migratory flights. Winter sightings confirmed that the non-moulting Sanderlings winter in sub-Saharan Africa and that the moulting Sanderlings spent the winter in Europe or northern Africa. With an average minimal stay in the western Dutch Wadden Sea of 9 days in 2013 and 12 in 2014, non-moulting Sanderlings stayed for a much shorter time than moulting Sanderlings, which stayed for 32 days in 2013 and 36 days in 2014. Non-moulting individuals were less likely to be resighted between years. Estimates of minimal staging duration are likely underestimates of the true staging duration, and we propose that moulting Sanderlings probably complete their wing moult in the Wadden Sea. We estimated that the total number of Sanderlings using the western Dutch Wadden Sea before migration to European or African wintering areas were 27,546 (95% Cl 22,739–41,449) in 2013 and 22,574 (95% Cl 16,436–46,114) in 2014. This would amount to 11–14% of a total flyway population of 200,000 individuals, representing an amazing degree of concentration for what is regarded as a rather widely and thinly spread shorebird species.

Simulating the fate of molinate in rice paddies using the RICEWQ model

PDF HTML阅读 XML下载 导出引用 引用提醒 亚热带河口陆基养虾塘水体溶解性碳浓度及沉积物-水界面碳通量时空动态特征 DOI: 10.5846/stxb201702210284 作者: 作者单位: 福建师范大学,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金面上项目（41671088）；福建师范大学亚热带河口生物地球化学创新团队项目（IRTL1205）；福建师范大学地理科学学院研究生出国（境）访学资助计划（GY201601） Spatial-temporal variations of water column dissolved carbon concentrations and dissolved carbon flux at the sediment-water interface in the shrimp ponds from two subtropical estuaries Author: Affiliation: Fujian Normal Universities,School of Geographical Sciences, Fujian Normal University,School of Geographical Sciences, Fujian Normal University,School of Geographical Sciences, Fujian Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以福建闽江和九龙江河口陆基养虾塘为研究对象，通过野外原位观测和室内模拟培养实验，开展了河口陆基养虾塘养殖期间水体溶解性有机碳（DOC）和溶解性无机碳（DIC）及养虾塘沉积物-水界面碳交换通量变化特征的研究。结果表明：时间变化上，养虾塘水体溶解性碳浓度及沉积物-水界面碳通量在闽江河口呈现8月中旬 > 10月中旬 > 6月中旬的特征，在九龙江河口表现为随养殖阶段推移而增加的趋势；空间变化上，闽江河口养虾塘水体溶解性碳浓度及沉积物-水界面碳通量显著高于九龙江河口；沉积物释放溶解性碳速率与水体溶解性碳浓度呈现显著正相关关系，沉积物碳释放过程是引起养虾塘水体溶解性碳浓度时空变化的重要因素。表明河口区水产养虾塘碳循环研究时需考虑不同形态碳生物地球化学循环的时空差异性。 Abstract:Aquaculture ponds play an important role in the global carbon cycle. In order to understand the dynamics of carbon in the shrimp ponds, dissolved carbon (dissolved organic carbon[DOC] and dissolved inorganic carbon[DIC]) concentrations in the pond water column, and the exchange fluxes of dissolved carbon across the sediment-water interface, were investigated in the Min River estuary (MRE) and Jiulong River estuary (JRE) on the southeast coast of China. Water and sediment samples were collected using a hydrophore and sediment sampler from three shrimp ponds in June, August, and October 2015, respectively. Meanwhile, water-quality indicators (water temperature, pH, dissolved oxygen, and salinity) were measured in situ using a portable instrument. The dissolved carbon concentration in water was analyzed using a SHIMADZU TOC-VCPH/CPN analyzer. Sediment oxygen and nutrient exchange (SONE) incubation techniques were used to measure the rates of dissolved carbon fluxes. The results showed that dissolved carbon concentrations in the pond water, and fluxes across the sediment-water interface from the estuaries of shrimp ponds greatly varied in spatial and seasonal dynamics. Mean dissolved carbon concentrations and fluxes were significantly higher from the shrimp ponds in the Min River estuary than in the Jiulong River estuary (P < 0.05). Average seasonal dissolved carbon concentrations (or fluxes) in the Min River estuary and Jiulong River estuary followed the order:August > October > June and October > August > June, respectively. The variations in dissolved carbon concentrations in the water were significantly positively correlated with the dissolved carbon fluxes across the sediment-water interface, indicating that the process of dissolved carbon release in the sediment affects the dynamic variation of dissolved carbon concentrations in the water column. Overall, the dynamic variation of dissolved carbon concentrations and fluxes in the shrimp ponds could be due to the synthetic action of abiotic factors (e.g., temperature and salinity), the foraging and metabolic activity of shrimp, and feed supply. Our study highlights the need to consider the spatio-temporal difference of carbonic biogeochemical cycles to better understand the dynamic of carbon cycling from the aquaculture ecosystems in the estuaries. 参考文献 相似文献 引证文献

As in the past, water temperature in rivers that showed difference between water and atmospheric temperatures is used in the snow-melting ditches for snow management.Recently, for the purpose of providing air and hot-conditioning system and hot water supply system, the use of water temperature in rivers has been given much attention. To utilize water temperature, understanding its fluctuation is necessary. As such, water temperatures at six points in the Uono River are measured by recorders, their fluctuations are investigated, and water and atmospheric temperature relationships are studied.The water temperature fluctuation repeats every one year period and every one day period. However, both periodic phases in water temperature fluctuation start a little later than that of the atmospheric temperature. Likewise, both amplitudes are less than that of the latter. Regression analyses between the daily mean water and atmospheric temperature fluctuations are examined. Principally, atmospheric temperature influences water temperature. Thus, for the daily mean water and atmospheric temperatures, a high correlation is obtained. However, residuals due to snowfall, melting snow and yearly phase differences between water and atmospheric temperatures are observed. As such, multiple regression analyses are conducted where three predictor variables are used, namely, the daily mean atmospheric temperature, the moving mean atmospheric temperature and the depth of snowfall during the preceding day. Results showed a higher correlation than that obtained from simple regression analyses. Hence, it is possible to predict the daily mean water temperature by using these multiple regression equations.

Scale and intensity of intertidal habitat use by knots Calidris canutus in the Western Wadden Sea in relation to food, friends and foes

Bromoform concentrations in water of the slush layer that developed at the interface between snow and sea ice were measured during the seasonal warming in Lützow-Holm Bay, East Antarctica. Mean bromoform concentration was 5.5 ± 2.4 pmol l-1, which was lower than that of the under-ice water (10.9 ± 3.5 pmol l-1). Temporal decrease in bromoform concentrations and salinity with increasing temperature of the slush water suggest that the bromoform concentrations were reduced through dilution with meltwater input from the upper surface of sea ice. In contrast, bromoform concentrations in the under-ice water increased during this period while the salinity of the under-ice water decreased. It is speculated that the sea ice meltwater input contained high bromoform concentrations from the brine channels within the sea ice and from the bottom of the ice that were contributed to the increased bromoform concentrations in the under-ice water.

Potential phosphorus mobilization from riparian vegetation following freezing

Year-to-year variability in the biomass of macrobenthic animals on tidal flats of the Wadden Sea: How predictable is this food source for birds?

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 573:143-156 (2017) - DOI: https://doi.org/10.3354/meps12122 Long-term changes in annual growth of bivalves in the Wadden Sea: influences of temperature, food, and abundance J. J. Beukema1,*, R. Dekker1,2, J. Drent1,2, J. van der Meer1,2 1NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands 2Utrecht University, 3508 TC Utrecht, The Netherlands *Corresponding author: jan.beukema@nioz.nl ABSTRACT: We report on results of a long-term (1978-2015) field study on between-year variability in annual weight growth of 1 yr old individuals of 4 dominant bivalve species on tidal flats in the western part of the Wadden Sea: 3 filter-feeders (Cerastoderma edule, Mytilus edulis, and Mya arenaria) and 1 filter/deposit-feeder (Macoma balthica). Relationships between individual weight gain during the growing season and 2 environmental factors (temperature, food supply) in the growing season (March to August) were studied. Weight gains varied strongly from year to year (by an order of magnitude in all species) and showed significant correlations with water temperatures (negative in M. balthica, positive in the other 3 species). Chlorophyll concentrations in the water showed a significant positive relationship with growth only in M. balthica. In the other 3 species, year-to-year fluctuations in growth were synchronized, showing a consistent pattern with elevated values between 1991 and 2005. The abrupt change to faster growth in the early 1990s may have been caused by the nearly complete disappearance in the western Wadden Sea of mussel beds for a period of several years, starting in 1990. The change to declining growth rates in the early 2000s took place simultaneously with a decline in chlorophyll concentrations and a rapid increase in stocks of the invasive bivalve Ensis directus. In all 4 studied species, growth rates were strongly reduced in 2012, a year with exceptionally high numbers of filter-feeding bivalves on the tidal flats. KEY WORDS: Seasonal weight gain · Long-term data series · Chlorophyll concentration · Cerastoderma edule · Mytilus edulis · Mya arenaria · Macoma balthica Full text in pdf format PreviousNextCite this article as: Beukema JJ, Dekker R, Drent J, van der Meer J (2017) Long-term changes in annual growth of bivalves in the Wadden Sea: influences of temperature, food, and abundance. Mar Ecol Prog Ser 573:143-156. https://doi.org/10.3354/meps12122 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 573. Online publication date: June 21, 2017 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2017 Inter-Research.

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 287:149-167 (2005) - doi:10.3354/meps287149 Decline of recruitment success in cockles and other bivalves in the Wadden Sea: possible role of climate change, predation on postlarvae and fisheries J. J. Beukema*, R. Dekker Royal Netherlands Institute for Sea Research, PO Box 59, 1790AB Den Burg, Texel, The Netherlands *Email: janb@nioz.nl ABSTRACT: In the last ~15 yr, frequent recruitment failures in the main bivalve species in the western Wadden Sea led to insufficient food supply for some specialised bird species, sharpening conflicts between nature conservationists and fishermen. To study possible causes of the recent recruitment failure in bivalves, we compare long-term data sets (1973 to 2002) of annual abundance of spat of 3 of the most important species of bivalves (cockle Cerastoderma edule, gaper clam Mya arenaria, and Baltic tellin Macoma balthica) on Balgzand, a tidal-flat area in the westernmost part of the Wadden Sea. In the 3 species, recruitment success declined significantly over the period of observation, particularly at offshore sampling sites which were characterized by low intertidal levels and sandy sediments. In these areas, we found high biomass values of a predator of bivalve postlarvae, the shrimp Crangon crangon. In each of the 3 bivalve species, annual recruitment (estimated as numerical density of spat in August) in these areas was negatively related to shrimp biomass at the time of settlement of postlarvae (May/June). Shrimp biomass has increased over the last ~30 yr. High near-shore flats showed invariably low shrimp biomass values and appear to serve as a refuge for postlarval bivalves in years of high predation pressure. Only in this coastal part of Balgzand was no decline in bivalve recruitment found; in fact, cockle recruitment even increased. Alternative explanations for the observed changes in recruitment of bivalves are discussed, including changes in sediment composition and bottom-disturbing fishing for cockles, mussels and lugworms. It is concluded that the recruitment trends on Balgzand (and other parts of the Wadden Sea) are governed primarily by natural processes, in particular increases in predation pressure on early benthic stages, which in turn appears to be largely governed by the warming climate. KEY WORDS: Epibenthic predators · Crangon crangon · Cerastoderma edule · Macoma balthica ·Mya arenaria · Tidal flats · Fishery disturbance · Sediment composition Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 287. Online publication date: February 18, 2005 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2005 Inter-Research.