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Urban green spaces are among the relatively few places to connect with nature in cities and represent locations where city dwellers can experience a variety of critical ecosystem services. As urbanization increases, deepening our understanding of the connections between city dwellers and the natural environment has become critical. In this study, we investigated the social values for ecosystem services by demonstrating an approach that combines a visitor-employed photography (VEP) method with the Social Values for Ecosystem Services (SolVES) mapping tool and applying this method to an urban wetland park. As a result, a quantified value index (VI) informs managers of the type and extent of urban ecosystem services (UESs) acknowledged by the public. Social values for each UES and environmental variable are delineated in a quantitative and spatially explicit manner. These outcomes could help planners and managers target specific areas in need of construction or improvement. Notably, public perceptions in this study are derived from photographs taken by invited park visitors. Real-time and on-site visiting experiences tend to be more effective and robust than recalling points of interest after visiting and manually marking them on maps via questionnaires. All the data used in this study are likely available in other green spaces. This approach can be generally extended to UES assessments elsewhere.

Muddy coasts downdrift of large river mouths trap fine-grained sediments supplied from these rivers and have provided important settlement sites for prehistoric people, although the evolutionary history of such environments has not been well described. In this study, we integrate multi-proxy analyses (lithology, particle size, sedimentary structure, bioturbation, microfossil, and AMS 14C) on two new sediment cores (CC and ZF) from the Ningbo Plain, southeast of Hangzhou Bay, east China, with results from previous studies to explore the early to mid-Holocene sedimentary history of the palaeo-Ningbo Bay in response to post-glacial sea-level rise. The results show that the early to mid-Holocene stratigraphy in core CC was characterized by a muddy embayment succession before 7.3 cal kyr B.P. and an aggradational tidal flat to coastal marsh succession after that time. Rapid sediment accumulation occurred before ca. 7.7 cal kyr B.P. and at 7.3–7.2 cal kyr B.P., whereas periods of reduced sediment supply are recorded between 7.7 and 7.3 cal kyr B.P. and after 7.2 cal kyr B.P. At site ZF, in contrast, only sediments of coastal freshwater marsh overlay the last glacial stiff muds after ca. 7.5 cal kyr B.P. We suggest that the sheltered embayment favoured trapping of the fine-grained sediments during the early to mid-Holocene, while geometric changes of the bay in response to a phase of accelerated sea-level rise at ca. 7.7 cal kyr B.P. resulted in a reduced sedimentation rate and increased tidal energy. Abundant, large, and diverse (0.5–1.0 cm wide, 5–24 cm long) vertical burrows are present in core CC during 8.9–7.9 cal kyr B.P. and the trace fossils declined abruptly at 7.9 cal kyr B.P. We suggest this may have been induced by the exploitation of seafood by Neolithic people settled in the sheltered embayment, as supported by archaeological remains found at the Neolithic site. Rapid progradation of tidal flats and coastal marsh occurred since ca. 7.2 cal kyr B.P. in the palaeo-bay, which may reflect a response to a stable sea level after that time. The development of a thick early to mid-Holocene sediment sequence in the palaeo-Ningbo Bay and its relationship to sea-level changes indicate that such muddy embayments downdrift of large river mouths should be considered important in reconstructing the Holocene depositional system of the adjacent coast.

This study investigated the polycyclic aromatic hydrocarbons (PAHs) occurrence, and their impact on the microbial community and PAH-degrading genera and genes in the Knysna Estuary of South Africa. The results reveal that the estuary exhibits low PAH levels (114.1–356.0 ng g−1). Ignavibacteriae and Deferribacteres, as well as Proteobacteria and Bacteroidetes, are keystone phyla. Among measured environmental factors, total organic carbon (TOC), nutrients such as nitrite and nitrate, metals as Al, Cr, Cu, Ni, Pb and Zn, and environmental properties (pH and salinity) are primary contributors to structuring the bacterial community assemblage. The abundance of alpha subunit genes of the PAH-ring hydroxylating dioxygenases (PAH-RHDα) of Gram-negative bacteria lies in the range of (2.0–4.2) × 105 copies g−1, while that of Gram-positive bacteria ranges from 3.0 × 105 to 1.3 × 107 copies g−1. The PAH-degrading bacteria account for up to 0.1% of the bacterial community and respond mainly to nitrate, TOC and salinity, while PAHs at low concentration are not significant influencing factors. PAH degraders such as Xanthomonadales, Pseudomonas, and Mycobacterium, which play a central role in PAH-metabolization coupled with other biogeochemical processes (e.g. iron cycling), may contribute to maintaining a healthy estuarine ecosystem. These results are important for developing appropriate utilization and protection strategies for pristine estuaries worldwide.

Microplastics are small, degrade slowly, and easily persist in the water column because they are close to neutrally buoyant. Understanding the distribution of microplastics is fundamental to evaluating the ecological risks that they cause and to identifying ways to control microplastics pollution. Most of the existing research on the distribution of microplastics in the coastal zone has focused on large spatial and temporal scales. To build on past work, we investigated variation in microplastics in a tidal flat of the Yangtze Estuary on small spatial (sediment depth, mudflat vs. vegetation zone) and temporal (fortnightly and semidiurnal) scales. Microplastics were more abundant in surface (0–2 cm) sediments during neap versus spring tide cycles, likely indicating increased deposition during periods with calm waters and increased suspension when water was more turbulent, but did not vary at greater depths in the sediment. Individual microplastics particles were also larger during neap versus spring tide periods. In contrast to the variation between spring and neap tide periods, we found no variation in the abundance of microplastics on the semidiurnal scale. Microplastics were also more abundant in the transect in the vegetation than at slightly lower elevations in the adjacent mudflat. Across all samples, the abundance of microplastics was negatively correlated with the strength of hydrological processes such as submergence time and flow velocity. Our results showed that sampling of microplastics in the intertidal environment needs to consider variation among spring and neap tide cycles, and also among different intertidal habitats that may differ only slightly in elevation. We encourage coupling sampling with direct measures of hydrological processes so that variation in microplastics abundance and size can be rigorously linked to hydrological processes.

We analyzed the effects of various levels of sediment-slurry addition on the restoration of the macroinvertebrate community and its related habitat (i.e., sediment and vegetation) 7 years after application to a subsided Louisiana salt marsh affected by sudden marsh dieback. Moderate sediment additions restored macroinvertebrate species richness, diversity, density, and total biomass to levels equivalent to those in reference marshes, although individual species and taxa had variable recovery depending on treatment-level. Total aboveground plant biomass and live Spartina alterniflora biomass, stem density and height were equivalent to those in reference marshes. In contrast, total belowground biomass had not yet reached equivalency with reference marshes. Although moderate sediment application created conditions that were ecologically equivalent with reference marshes for most macroinvertebrate and plant variables, degraded areas that received high sediment addition had impaired recovery across all metrics, even 7 years after sediment application. Thus, when sediment-slurries are applied to proper elevations, the macroinvertebrate community, as well as aboveground marsh vegetation, can recover to reference conditions. However, too much sediment impairs recovery. Consequently, greater consideration must be given to establishing suitable post-construction marsh elevations to insure successful ecosystem restoration.

Based on the fishing net surveying data about anguillid elver of the Yangtze estuary collected in 2006 and historical data from previous research of the region, this study was focused on analyzing the fishing effort and catch variations of the elver, revealing the effects on fishery resources caused by elver fishing activities. It was found that the elver fishing activities took place in the tidal area of the Yangtze estuary from January to April. The yearly elver catch in 2000–2006 was 3 times greater than that in the 1970s–1980s. The catch per unit effort (CPUE) (ind./net/day) of the elver had some characteristics of temporal variation. It was higher in spring tide periods than that in neap tide periods, and the CPUE in February and March was 3–4 times greater than that in January. Twenty-eight fish species, 6 shrimp species, 2 crab species and 8 other invertebrates were found in the by-catch of the eel nets. Among the fishes, shrimps and crabs, the individual proportion of fishes is the highest, and they are mostly juveniles or small-size fishes, while the shrimps and crabs also make up a certain proportion. Most of the individuals in the by-catch were juveniles and were dead when they were harvested. It was proven that the activity of elver fishing has a great negative effect on regional fishery resources, though it has brought great commercial benefit. Relevant management and conversation should be reinforced.

Over the course of a year, we conducted a study on future restoration work in the Sanyang wetland, a degraded permanent river wetland that is close to the center of Wenzhou city, China. Our main objective was to plan the restoration by using both structural indices and a valuation of the wetland's ecosystem services, thereby linking the science to human welfare. Based on field surveys and research into the history of the study area, we calculated both the potential and current values of the main ecosystem services. The results showed that the potential value at the Sanyang wetland was 55,332 yuan ha −1 yr −1 , while the current value was only 5807 yuan ha −1 yr −1 . In other words, 89.5% of the service value needs to be restored for the wetland to reach its potential value. We recommend that the service provided by the wetland's ability to purify the environment needs to be the top priority in restoration. In addition, water and sediment quality should also be greatly improved.