In order to carry out the program of protection and rational exploitation of Kovilj Marsh (Serbia, Yugoslavia), which is a part of special natural reserve called the Marsh of Kovilj and Petrovaradin, we have done an ecological analysis of the fish community. The research was conducted during the period of "low water", in the autumn 2000, on the following locations: Slajz, Tonja and Arkanj, and we have established the presence of 12 species from 6 different families. The saprobic index of the majority of bioindicative species shows that the water belongs to the beta-mesosaprobic type (the saprobic index according to Pantle-Buck is 2.1). The presence and abundance of certain ecological groups of fish is examined in relation to migration, type of food and type of substrate on which the fish lay their eggs. The results of this examination point to main features of certain localities in this floodplain, as well as to the necessity of taking appropriate measures of protection of this valuable water resource.

The present study was undertaken to assess the impact of a candidate mosquito larvicide, spinosad (8, 17 and 33 μg L−1) on a field population of Daphnia magna under natural variations of water temperature and salinity, using Bti (0.16 and 0.50 μL L-1) as the reference larvicide. Microcosms (125 L) were placed in a shallow temporary marsh where D. magna was naturally present. The peak of salinity observed during the 21-day observation period may have been partly responsible for the decrease of daphnid population density in all the microcosms. It is also probably responsible for the absence of recovery in the microcosms treated with spinosad which caused a sharp decrease of D. magna abundance within the first two days following treatment whereas Bti had no effect. These results suggest that it may be difficult for a field population of daphnids to cope simultaneously with natural (water salinity and temperature) and anthropogenic (larvicides) stressors.

Atmospheric phosphine (PH₃) fluxes from typical types of wetlands and PH₃ concentrations in adjacent atmospheric air were measured. The seasonal distribution of PH₃ in marsh and paddy fields were observed. Positive PH₃ fluxes are significantly related to high air temperature (summer season) and increased vegetation. It is concluded that vegetation speeds up the liberation of PH₃ from soils, while water coverage might function as a diffusion barrier from soils or sediments to the atmosphere. The concentrations of atmospheric PH₃ (ngm⁻³) above different wetlands decrease in the order of paddy fields (51.8±3.1)>marsh (46.5±20.5)>lake (37.0±22.7)>coastal wetland (1.71±0.73). Highest atmospheric PH₃ levels in marsh are found in summer. In paddy fields, atmospheric PH₃ concentrations in flourishing stages are higher than those in slowly growing stages.

We measured the temporal and spatial trajectory of oiling from the April, 2010, Deepwater Horizon oil spill in water from Louisiana's continental shelf, the estuarine waters of Barataria Bay, and in coastal marsh sediments. The concentrations of 28 target alkanes and 43 target polycyclic aromatic hydrocarbons were determined in water samples collected on 10 offshore cruises, in 19 water samples collected monthly one km offshore at 13 inshore stations in 2010 and 2013, and in 16–60 surficial marsh sediment samples collected on each of 26 trips. The concentration of total aromatics in offshore waters peaked in late summer, 2010, at 100 times above the May, 2010 values, which were already slightly contaminated. There were no differences in surface or bottom water samples. The concentration of total aromatics declined at a rate of 73% y−1 to 1/1000th of the May 2010 values by summer 2016. The concentrations inside the estuary were proportional to those one km offshore, but were 10–30% lower. The oil concentrations in sediments were initially different at 1 and 10 m distance into the marsh, but became equal after 2 years. Thus, the distinction between oiled and unoiled sites became blurred, if not non-existent then, and oiling had spread over an area wider than was visible initially. The concentrations of oil in sediments were 100–1000 times above the May 2010 values, and dropped to 10 times higher after 8 years, thereafter, demonstrating a long-term contamination by oil or oil residues that will remain for decades. The chemical signature of the oil residues offshore compared to in the marsh reflects the more aerobic offshore conditions and water-soluble tendencies of the dissolved components, whereas the anaerobic marsh sediments will retain the heavier molecular components for a long time, and have a consequential effect on the ecosystems.

In 2010, an estimate 4.1 million barrels of oil were accidentally released into the Gulf of Mexico (GoM) during the Deepwater Horizon (DWH) Oil Spill. One and a half years after this incident, a set of subtidal and intertidal marsh sediment cores were collected from five stations in Barataria Bay, Louisiana, USA, and analyzed to determine the spatial and vertical distributions and source of hydrocarbon residues based on their chemical composition. An archived core, collected before the DWH oil spill from the same area, was also analyzed to assess the pre-spill hydrocarbon distribution in the area. Analyses of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs) and stable carbon isotope showed that the distribution of petroleum hydrocarbons in Barataria Bay was patchy and limited in areal extent. Significant TPH and ΣPAH concentrations (77,399 μg/g and 219,065 ng/g, respectively) were detected in the surface sediments of one core (i.e., core A) to a depth of 9 cm. Based on a sedimentation rate of 0.39 cm yr−1, determined using 137Cs, the presence of anthropogenic hydrocarbons in these sediment core deposited ca. 50 to 60 years ago. The historical background hydrocarbon concentrations increased significantly at the sediment surface and can be attributed to recent inputs. Although the oil present in the bay's sediments has undergone moderate weathering, biomarker analyses performed on core A samples likely indicated the presence of hydrocarbons from the DWH oil spill. The effects of oiling events on Barataria Bay and other marsh ecosystems in this region remain uncertain, as oil undergoes weathering changes over time.

A crucial step towards understanding potential impacts of the Deepwater Horizon oil spill to marsh ecosystems was to quantitatively determine the toxicity of oil remaining in the sediment. The objective of this study was to assess the potential injury to benthic species using standardized toxicity bioassays. Sediments were collected from locations with differing degrees of oiling based on previous assessments. Less than 13% of the 315 toxicity tests resulted in toxicity to amphipods, mysid shrimp, or sea urchins. There was no relationship among toxicity test results, oiling category or measured total polycyclic aromatic hydrocarbons (PAHs). Equilibrium partitioning sediment benchmarks and additive toxic units (ESBTUs) were applied as an additional line of evidence to evaluate the potential adverse effects based on PAH concentrations in field sediments. The ∑ESBTUs based on 34 PAHs at the 64 nearshore sampling locations were <1, indicating PAHs in sediments were unlikely to cause adverse impacts.

Constructed coastal marsh regulates land-born nitrogen (N) loadings through salinity-dependent microbial N transformation processes. A hypothesis that salinity predominantly controls N removal in marsh was tested through incubation in a closed system with added-15NH4+ using sediments collected from five sub-marshes in Shihwa marsh, Korea. Time-course patterns of concentrations and 15N–atom% of soil-N pools were analyzed. Sediments having higher salinity and lower soil organic-C and acid-extractable organic-N exhibited slower rates of N mineralization and immobilization, nitrification, and denitrification. Rates of denitrification were not predicted well by sediment salinity but by its organic-C, indicating heterotrophic denitrification. Denitrification dominated N-loss from this marsh, and nitrogen removal capacity of this marsh was estimated at 337 kg N day−1 (9.9% of the daily N-loadings) considering the current rooting depth of common reeds (1.0 m). We showed that sediment N removal decreases with increasing salinity and can increase with increasing organic-C for heterotrophic denitrification.

Large databases of fecal indicator bacteria (FIB) measurements are available for coastal waters. With the assistance of satellite imagery, we illustrated the power of assessing data for many sites by evaluating beach features such as geomorphology, distance from rivers and canals, presence of piers and causeways, and degree of urbanization coupled with the enterococci FIB database for the state of Florida. We found that beach geomorphology was the primary characteristic associated with enterococci levels that exceeded regulatory guidelines. Beaches in close proximity to marshes or within bays had higher enterococci exceedances in comparison to open coast beaches. For open coast beaches, greater enterococci exceedances were associated with nearby rivers and higher levels of urbanization. Piers and causeways had a minimal contribution, as their effect was often overwhelmed by beach geomorphology. Results can be used to understand the potential causes of elevated enterococci levels and to promote public health.

Phytoremediation is considered the most appropriate technique to restore metal polluted soil, given its low cost, high efficiency and low environmental impact. Spartina densiflora and Sarcocornia perennis are perennial halophytes growing under similar environmental conditions in San Antonio marsh (Patagonia Argentina), therefore it is interesting to compare their phytoremediation potential capacity. To this end, we compared concentrations of Pb, Zn, Cu, and Fe in soils and in below- and above-ground structures of S. perennis and S. densiflora. It was concluded that both species are able to inhabit Pb, Zn, and Cu polluted soils. Although Sarcocornia translocated more metals to the aerial structures than Spartina, both species translocated only when they were growing in soils with low metal concentrations. It seems that the plants translocate only a certain proportion of the metal contained in the soil. These results suggest that both species could be considered candidates to phytostabilize these metals in polluted soils.

Three one-off burial treatments were designed in intertidal zone of the Yellow River estuary to determine the effects of sediment burial on decomposition and heavy metal levels of Suaeda salsa. Sediment burial showed significant effect on decomposition rate of S. salsa. With increasing burial depth, Cu, Zn, Cd and Co levels generally increased, while Cr and Mn levels decreased. Except for Zn, Mn, Cd and Co, stocks of Pb, Cr, Cu, Ni and V in S. salsa among burials were greatly different. The S. salsa in three burials was particular efficient in binding V and Co and releasing Pb, Zn and Cd, and, with increasing burial depth, stocks of Cr, Cu, Ni and Mn shifted from accumulation to release. In future, the eco-toxic risk of Pb, Cr, Cu, Zn, Ni, Mn and Cd exposure might be serious as the strong burial episodes occurred in S. salsa marsh.