Aquatic Conservation-Marine and Freshwater Ecosystems最新文献

Seagrass restoration has shown mixed results, even in suitable environments, indicating ongoing needs for improved techniques. This study tracked intertidal eelgrass (Zostera marina) dynamics at two donor sites, differing in elevation, and one transplant site over multiple years. Based on 0%, 50%, 80% and 100% removal from 4 m² plots, recovery times increased with collection intensity at both donor sites, taking up to 2 years when plots were completely cleared. Collected shoots were transplanted at four plot sizes (0.0625, 0.25, 1, 4 m²) and three densities (25, 64, 125 m⁻²) on tidal flats dominated by bioturbating shrimp (Neotrypaea californiensis). Initial establishment was reduced at higher shoot densities; only the smallest plots showed no advantage of low density. Despite initial density differences, all plots converged to ~60 m⁻² after 1 year and 110 m⁻² after 2 years, except 0.25 m² low-density plots (initially six shoots). For total shoot counts, including those extending outside the original plots, proportional increases were inversely related to plot size and density, but a three-way statistical interaction appeared in both years. Because low-elevation shoots showed negative density dependence even in the 0.0625 m² plots, whereas high-elevation shoots did not, the 2-shoot transplants from low elevation had by far the fastest population growth, reaching an average of roughly 190 shoots after 2 years. Both donor sites proved viable for restoration, though performance differences emerged under specific planting configurations, suggesting that planting strategies may be more important determinants of restoration success than donor characteristics in environments suitable for eelgrass.

The Mediterranean killifish, Aphanius fasciatus, is an euryhaline species that inhabits aquatic habitats characterized by extreme physiochemical parameters, such as salinity and temperature. Previously, seven populations of A. fasciatus were recognized in Croatia. The distribution range of this species is highly fragmented, with all previously recorded sites being isolated from one another due to the limited number of suitable habitats. This study reports the presence and status of a new population of A. fasciatus on the Istrian Peninsula in Croatia. The objectives of this study were to describe the morphological characteristics and genetic diversity of the population in the Šćuza Bay, determine the phylogenetic position and relatedness to other populations and propose conservation measures for the survival of the population. To determine the phylogenetic relationships among populations, a phylogenetic reconstruction was performed based on cytochrome b gene sequences using the maximum parsimony, maximum likelihood, Bayesian inference and median-joining methods. In addition, population viability analysis was conducted to determine which threats have the greatest effect on population survival. The results place the studied population of A. fasciatus within the northern Adriatic group. A moderate genetic diversity was found, somewhat higher than in other populations on the eastern Adriatic coast. Habitat degradation (such as filling up and covering the coast and the seafloor with solid material and wastes) was identified as the greatest threat to the survival of the population.

Subtropical wetlands are considered biodiversity hotspots due to their complex and diverse habitats; however, their ostracod communities remain underexplored, particularly in the Northeastern Argentina (NEA) region. This study presents the first regional survey that combined previously published literature with field sampling of ostracod communities. Five families and 30 ostracod species were identified from 28 wetlands across the NEA region, including water bodies with different anthropogenic influences, plant compositions and water regimes, such as temporary and permanent lakes, streams and paddy fields. Seventeen out of the 30 species were recorded for the first time in Argentina, and a further two are new records for the region, increasing to 84 species the ostracod fauna reported for the country. Some taxa are left in open nomenclature, highlighting the need for further taxonomic research, species identification and broader field sampling to fully understand the diversity and ecological roles of these invertebrates. This study provides a valuable baseline for future studies contributing to wetlands conservation efforts and sustainable management in this biodiverse but vulnerable region.

Gongolaria barbata (Stackhouse) Kuntze (syn. Cystoseira barbata (Stackhouse) C. Agardh), a species of brown macroalgae (seaweed), plays a crucial role in the coastal marine ecosystems. Its ability to form complex three-dimensional structures is fundamental for supporting rich biodiversity and diverse habitats, making a significant contribution to primary production and carbon sequestration, highlighting its vital importance in maintaining the health and balance of these coastal marine environments. It is a bioindicator species for water quality and environmental conditions. Recently, a concerning decline in the species population has been reported, attributed to pollution, eutrophication, climate change, human activities and the introduction of invasive species. In this context, the conservation and restoration of these environments are crucial for maintaining their ecological integrity. Our research required the development of an in vitro protocol for multiplication, based on both direct and indirect regeneration. Seven different protocols for explant sterilisation and 21 media variants were used for in vitro induction of the multiplication protocol. The satisfactory results of this study indicate that natural seawater supplemented with 0.5 mg L⁻¹ BAP and 1 mg L⁻¹ GA₃ induced direct regeneration by forming buds, and PES medium added with 0.5 mg L⁻¹ BAP and 1 mg L⁻¹ 2,4-D induced callus mass. Our study is unique in Romania and in the western part of the Black Sea. It represents a starting point for improving protocols for the multiplication of this species with the aim of its conservation purposes.