Aquatic Conservation-Marine and Freshwater Ecosystems最新文献

Confined disposal facilities (CDFs) are diked structures used to contain dredged materials and prevent their release into the environment. Wildlife species such as freshwater fish that live in these facilities may be affected by contaminants or impaired water quality conditions that impact their health, welfare and conservation. We performed health assessments and characterized freshwater fish assemblages at two sites in southwestern Lake Erie: a CDF at the mouth of the Black River in Lorain, Ohio (LCDF) and a protected coastal marsh near Port Clinton, Ohio (PCM). Over two sampling days at each site, we used fyke nets to capture 2984 individual fish representing 13 species and two hybrid sunfish species. Species diversity and evenness were higher at PCM than LCDF, with only two species found at LCDF: golden shiners (Notemigonus crysoleucas) and goldfish (Carassius auratus). External parasite prevalence, especially of digeneans, was significantly higher at PCM than LCDF (p = 0.013). Estimated total white blood cell counts were higher at PCM than LCDF, but the difference was not statistically significant (p = 0.058). Overall, the golden shiners and goldfish living at LCDF were apparently healthy with low ectoparasite prevalence and unremarkable haematology parameters. Future research here and at other CDFs in this region should further investigate the impacts of dredging on wildlife conservation and ecosystem health.

The China's Blue Carbon Plan has made substantial strides since its inception in 2014 and has garnered positive feedback from the domestic surgical technology sector throughout its implementation. This initiative plays a pivotal role in China's goals for carbon peak and carbon neutrality. This paper employs data from the Belt and Road Initiative and 62 Asia-Pacific countries spanning 2005 to 2021 and applies the PSM-DID method to empirically assess the impact of China's Blue Carbon Plan on the carbon emissions of Belt and Road and Asia-Pacific countries. The results show that (1) Blue Carbon Plan can promote carbon emission reduction and per capita carbon emission reduction in the Belt and Road countries and countries in the Asia Pacific region; (2) Blue Carbon Plan can reduce the future carbon emissions of the Belt and Road countries and countries in the Asia Pacific region, but the policy effect shows a certain weakening trend; (3) Blue Carbon Plan can reduce national carbon emissions through four pathways: fishery aquaculture production, fishery fishing production, fishery trade volume and ship fuel consumption. These results provide valuable insights into the effectiveness of blue carbon initiatives and underscore the potential of scaling up such policies to achieve broader regional and global carbon reduction targets.

To assess the impact of the Laluo Hydropower Station on fish community structure and spawning habitat, hydraulic and ecological surveys were conducted in typical upstream and downstream of the station, and the physical biotopes distribution and fish community composition were obtained. By comparing the differences in fish community structure and spawning environment factors between the natural river sections and the downstream river section of the dam, analyse the impact of the station on the spawning grounds of fish in the downstream reaches of the dam and extract the main influencing factors. Results showed that the fish community in the study area is composed of Schizopygopsis younghusbandi, Schizothorox waltoni and Triplophysa spp., with S. younghusbandi being the dominant species. The physical biotopes of the spawning grounds for S. younghusbandi includes pools or glide, with a water depth of 0.3 ~ 1.0 m, flow velocity < 0.3 m/s and a substrate primarily consisting of fine particles such as sand and fine gravel. Downstream, the number of sexually mature individuals was low, with a skewed sex ratio, indicating significant spawning ground degradation. Water temperature, altered by the station's operation, was identified as the main factor disrupting spawning. This study contributes to the existing body of data and case studies in the field, advancing research on fish habitats in plateau rivers. It holds significant implications for the conservation of fish resources and the preservation of healthy aquatic ecosystems in these regions.

The South American annual killifish of the Austrolebias sensu lato constitute an extensive species group and serve as a remarkable evolutionary model, inhabiting riparian wetlands in the La Plata River grasslands. This region contains three major areas with allopatrically distributed local and regional endemic species assemblages. At present, the IUCN Red List includes nearly 75% of the species in the Austrolebias genus group. A synapomorphic characteristic of this group is their expanded genome size. Vicariance/dispersal and secondary contact have played key roles in the diversification of most genera within this group, explaining their current distribution across endemic areas. Riparian wetlands are transitional zones that support exceptionally high levels of biodiversity and productivity. The effective conservation of biodiversity in these zones enhances connectivity between river corridors and floodplains, linking aquatic and wetland habitats where annual killifish inhabit, while ensuring the long-term evolutionary potential of populations. Due to these unique characteristics, the annual killifish of the Austrolebias genus group could be an umbrella species, providing benefits in the conservation of riparian wetlands in the temperate regions of the La Plata River grasslands, and ensuring both biota integrity and long-term evolutionary processes.

Citizen science is a valuable tool for large-scale ecological research, and community-based approaches enhance scientific data while fostering environmental awareness among local residents. In 2021, the Taoyuan Algal Reef in Taiwan became a national focus during a referendum, yet public understanding of its ecology remained limited. To bridge this gap, we partnered with nearby residents to conduct a coastal habitat survey using a simple, standardized data collection method. Participants received training, and even after our team concluded the project, locals continued monitoring independently using the same method. To verify the reliability of data collected with and without scientific supervision, we compared the datasets statistically using coefficients of variation. Results showed no significant differences, demonstrating that independently collected data were reliable. This enabled us to combine the datasets for further biodiversity analysis, examining organism abundance, species richness, and the Shannon index. Findings revealed that pebble habitats had the highest Shannon index, whereas sand habitats exhibited the lowest values for abundance, richness, and diversity. Organism abundance peaked in the mid tide zone, with summer and autumn showing the highest abundance, richness, and Shannon index values. Using species accumulation curves with twice the sample size, we predicted richness and Shannon index across habitats, tidal zones, and seasons. Predictions largely aligned with quadrat-scale findings, except that the sand habitat's predicted richness and diversity exceeded those of the algal reef habitat. Our research provides reliable, citizen science-based insights to deepen understanding of this region, which has been a focal point of debate in Taiwan.

Telmatobius fronteriensis is a microendemic species from the arid Puna of northern Chile and is currently classified as Critically Endangered by the IUCN Red List. Here, we provide ecological information for T. fronteriensis. We evaluated its microhabitat, density, biometry, diet, presence of emerging pathogens, temporal changes in its habitat and conservation status. The habitat of T. fronteriensis is restricted to a small thermal-water stream in its type locality, covering a total area of 2.7 km². The species has a moderate density, with no differences in body condition between males and females across seasons. The diet varied between seasons, as did the preference for certain prey items. There is an apparent absence of Batrachochytrium dendrobatidis and Ranavirus. The information obtained is valuable for the management and conservation of this microendemic species, considering that water use pressure and mining activities are the primary threats to this Andean water frog. Future actions should consider the implementation of a binational conservation plan, as well as in situ and ex situ conservation programs to protect the species.

Sympatric species that occupy similar niches use a variety of strategies to minimise competitive exclusion. Bottlenose dolphins and harbour porpoises are both small cetaceans that occur in coastal areas and, in many areas where there is overlap, have been shown to use the habitat in different ways or at different times. In the New York–New Jersey Harbour Estuary (NY–NJ Harbour Estuary), bottlenose dolphins and harbour porpoises are found seasonally. We used passive acoustic monitoring to compare the acoustic presence of dolphins and porpoises from October 2018 to October 2020 in the NY–NJ Harbour Estuary, which revealed spatiotemporal differences in habitat use between the two species. The peak in acoustic presence for bottlenose dolphins occurred during summer and autumn, while porpoises were primarily detected during winter and spring. Porpoises were more acoustically active during the daytime, with some variability across months, while dolphins were consistently more active at night. Generally, dolphins were more commonly detected than porpoises, but porpoises were detected more often in the Upper Bay where bottlenose dolphin detections were rare. Dolphins and porpoises were more acoustically active around ebb and slack tides, respectively. Establishing baselines for species occurrence and identifying possible ecological influences on spatiotemporal patterns is important and time-sensitive given current and forthcoming anthropogenic activities, including activities related to offshore wind development.