Aquatic Conservation-Marine and Freshwater Ecosystems最新文献

Jezero Blaca is a unique spring lake situated at the northern coast of the Pelješac Peninsula near the village Duba Pelješka in South Dalmatia, Croatia. The lake supported by a karstic spring located near the Adriatic seashore is inhabited by unusually rich brackish water truncatelloid assemblage. The position of the lake near seashore evokes a model of sea invertebrate gradual adaptation to freshwater spring head allowing them to further invade the stygobiont karst conduits. Similar lakes could be the marine gateways of the extraordinarily rich Dinaric stygobiont fauna. The main aim of this study was to sample and barcode the aquatic snails found in this locality to check their species affiliation and describe conservation needs. The results confirmed that the locality hosts four interesting representatives of the gastropod superfamily Truncatelloidea, which has never been found syntopically so far. One of the species characterized by unique COI sequences and was described herein as Truncatella dalmatica new sp. The conservation need of this unique and understudied habitat type is discussed.

1. Rivers and other freshwater ecosystems have been severely changed by humans. This resulted in a distinct decline in the abundance of many aquatic organisms, as well as those living in water-dependent habitats. Our work aimed to study the habitat selection of breeding common sandpipers (Actitis hypoleucos) and the impact of river regulation on the occurrence of this species.
2. Data were collected on a 100-km stretch of the Vistula River, a semi-natural, lowland and large European river. The distribution of birds was determined based on two censuses, while environmental variables were collected based on Sentinel-2 satellite imagery classification, digital elevation model (DEM), digital surface model (DSM) and official data of river regulations.
3. The length of the shoreline of either the river or vegetated islands had a positive effect on the number of breeding territories of the common sandpiper. This indicates the importance of the presence of a natural riverbed with a complex shoreline. Moreover, sandpipers preferred islands over the river shores as nesting habitat. River regulations, such as groynes and riprap, had a negative impact on the abundance of breeding common sandpipers even though the river regulation was not intensive. The negative effect has been persisting for many years after the regulation was implemented, despite the degradation of regulatory structures over this period.

1. Marine chondrichthyans are experiencing a global decline, but identifying appropriate conservation actions is challenging due to the lack of basic biological information, such as growth parameters and reproduction. In this study, we identify biological and ecological attributes that can be both easily obtainable and are effective predictors of extinction threat.
2. A bioecological attribute database was constructed for marine chondrichthyan species, including information on maximum length, habitat, reproductive mode, trophic level and conservation status, among others. Data sources included the Shark-References, IUCN and FishBase databases. Following this, a generalized linear model was built with conservation status as the response variable and bioecological attributes as explanatory variables, and the model's accuracy was tested for each group. Then, the model was applied to species not yet classified (data deficient [DD] or not evaluated [NE]) to determine their probability of extinction risk.
3. In total, data were compiled for 1225 species of marine Chondrichthyes (537 sharks, 636 rays and 52 chimaeras); approximately 20% of these species are classified as DD or NE. The model demonstrated high accuracy overall: 95% for chimaeras, 77% for rays and 72% for sharks. Our analysis indicates that, among the species that are classified as DD or NE, 58% of rays, 44% of sharks and 66% of chimaeras may be at risk of extinction.
4. These results clearly demonstrate how bioecological attributes can serve as proxies of extinction risk in Chondrichthyes and provide a solid foundation for conservation planning and prioritization for this ecologically important yet data poor taxon.

1. Floodplains are crucial components of river landscape, essential for the biodiversity and ecological integrity of large rivers. However, they are often overlooked and underestimated when assessing the ecological status of the main river channel.
2. The main objective of this study was to identify the most relevant scheme for assessing the ecological status of side arms in the Danube floodplain (Slovakia) based on benthic invertebrates.
3. The calculation of ecological status for the Danube main channel was adapted to the environmental conditions of the floodplain as a measure of the evaluation accuracy of six taxonomically different floodplain indexes. The study was based on a comprehensive survey of benthic invertebrate diversity conducted at 19 sampling sites, covering eupotamal and parapotamal side arms.
4. Three floodplain indexes that significantly correlated with ecological status were categorised based on predicted values in relation to status class thresholds. The floodplain index based on Polychaeta, Oligochaeta, Mysida, Isopoda and Amphipoda (FI_P) showed the best result, aligning closely with the commonly used classification of lateral habitats. Although it divides the eupotamon into two subclasses, a main channel and a side arm, the inclusion of two different eupotamal habitats in the classification supports the geomorphological variability of side arms and their degree of ecological succession.
5. The shortcomings of the assessment based on the lateral habitat classification scheme are discussed, emphasising the importance of applying this method for the assessment of floodplain waters and their conservation management.