The importance of organic matter produced in seagrass meadows (seagrass and epiphytic algae) to the nutrition of a valuable fisheries species (yellowfin whiting Sillago schomburgkii Peters) occurring over unvegetated mudflats was measured using the isotopic composition (δ13C, δ15N) of fish, their polychaete prey, and available autotrophic sources at several locations in southern Australia durin...

We examined the diet and trophic level of Sphyrna lewini in the Gulf of California (GC) during 2001 and in the Gulf of Tehuantepec (GT) during 2005 using data from stomach content and stable isotope analysis of δ15N and δ13C. S. lewini diet was represented by pelagic and benthic prey species where the most important in weight was Scomber japonicus (27.70±4.54%) in GC, while in GT it was Auxis s...

We examined the diet and trophic level of Sphyrna lewini in the Gulf of California (GC) during 2001 and in the Gulf of Tehuantepec (GT) during 2005 using data from stomach content and stable isotope analysis of δ15N and δ13C. S. lewini diet was represented by pelagic and benthic prey species where the most important in weight was Scomber japonicus (27.70±4.54%) in GC, while in GT it was Auxis s...

Generally unseen and infrequently measured, submarine groundwater discharge (SGD) can transport potentially large loads of nutrients and other land-based contaminants to coastal ecosystems. To examine this linkage we employed algal bioassays, benthic community analysis, and geochemical methods to examine water quality and community parameters of nearshore reefs adjacent to a variety of potentia...

The carbon and nitrogen isotopic compositions of fractions of the seagrass Posidonia oceanica (L.) Delile in a Mediterranean shallow environment (Stagnone di Marsala, western Sicily) were investigated seasonally throughout 1998. The stable isotope ratios of seagrass leaves (intermediate and adult), rhizomes, leaf litter and aegagropiles were compared over 1 year in order to distinguish between ...

Bulk sediment δ15N records from the eastern tropical Pacific (ETP) extending back to last ice age most often show low glacial δ15N, then a deglacial maximum, followed by gradual decline late Holocene that is typically higher than of Last Glacial Maximum (LGM). The lower LGM has been interpreted reflect an reduction in water column denitrification. We report foraminifera shell-bound nitrogen iso...

Agricultural soils are the most important anthropogenic source of nitrous oxide to the atmosphere. We observed large shifts with time in the emission rate (from 170 to 16 ng N cm−2 h−1) and in δ15N of N2O emitted (from −46‰ to +5‰ relative to atmospheric N2) from a urea-fertilized and irrigated agricultural field in Mexico. We calculated overall instantaneous enrichment factors for the sampling...

In this study, stable carbon and nitrogen isotope ratios in the samples of pine needles collected in 2013 and 2014 from heavily urbanized area in close proximity to point-source pollution emitters, such as a heat and power plant, nitrogen plant, and steelworks in Silesia (Poland), were analyzed as bio-indicators of contemporary environmental changes. The carbon isotope discrimination has been p...

We determined both the nitrogen and carbon isotopic compositions of various vanadyl alkylporphyrins isolated from siliceous marine sediments of the Onnagawa Formation (middle Miocene, northeastern Japan) to investigate the biogeochemistry and ecology of photoautotrophs living in the paleo-ocean. The distinctive isotopic signals support the interpretations of previous works that the origin of 17...

we examined the diet and trophic level of sphyrna lewini in the gulf of california (gc) during 2001 and in the gulf of tehuantepec (gt) during 2005 using data from stomach content and stable isotope analysis of δ15n and δ13c. s. lewini diet was represented by pelagic and benthic prey species where the most important in weight was scomber japonicus (27.70±4.54%) in gc, while in gt it was auxis s...