Iskanje po repozitoriju

A+ | A- | | SLO | ENG

Povzetek: Molecular methods such as DNA/eDNA metabarcoding have emerged as useful tools to document the biodiversity of complex communities over large spatio-temporal scales. We established an international Marine Biodiversity Observation Network (ARMS-MBON) combining standardised sampling using autonomous reef monitoring structures (ARMS) with metabarcoding for genetic monitoring of marine hard-bottom benthic communities. Here, we present the data of our first sampling campaign comprising 56 ARMS units deployed in 2018–2019 and retrieved in 2018–2020 across 15 observatories along the coasts of Europe and adjacent regions. We describe the open-access data set (image, genetic and metadata) and explore the genetic data to show its potential for marine biodiversity monitoring and ecological research. Our analysis shows that ARMS recovered more than 60 eukaryotic phyla capturing diversity of up to ~5500 amplicon sequence variants and ~1800 operational taxonomic units, and up to ~250 and ~50 species per observatory using the cytochrome c oxidase subunit I (COI) and 18S rRNA marker genes, respectively. Further, ARMS detected threatened, vulnerable and non-indigenous species often targeted in biological monitoring. We show that while deployment duration does not drive diversity estimates, sampling effort and sequencing depth across observatories do. We recommend that ARMS should be deployed for at least 3–6 months during the main growth season to use resources as efficiently as possible and that post-sequencing curation is applied to enable statistical comparison of spatio-temporal entities. We suggest that ARMS should be used in biological monitoring programs and long-term ecological research and encourage the adoption of our ARMS-MBON protocols.
Ključne besede: 18S rRNA, COI, essential biodiversity variables, European marine omics biodiversity observation network, genetic monitoring, invasive species, ITS
Objavljeno v DiRROS: 18.04.2025; Ogledov: 48; Prenosov: 11
Celotno besedilo (3,67 MB)
Gradivo ima več datotek! Več...

Povzetek: Canopy-forming brown macroalgae (Fucales) offer numerous key ecosystem services in Mediterranean coastal areas. However, anthropogenic pressures and climate change have significantly impacted their habitats, leading to an extensive population decline. Interactions between algae and microbiota are a major ecological aspect, yet they represent a significant knowledge gap. In our baseline study, we describe the diversity and host specificity of the microbiome of two genetically identical but morphologically distinct populations of Gongolaria barbata from anthropogenically impacted northern Adriatic Sea. Our preliminary results showed that the microbiomes of G. barbata exhibited low host specificity, with 75% of the algae-associated amplicon sequence variants (ASVs) being part of the core coastal ecosystem microbiome. However, microbiomes of specific algal parts, ambient seawater, and sediment differed significantly in terms of alpha diversity and composition. In contrast, the holdfast and axis show higher similarity with sediment microbiomes, indicating potential horizontal transmission pathways. Microbiomes associated with deciduous parts of morphologically distinct G. barbata populations showed no difference in alpha diversity and composition. In contrast, higher variation in alpha diversity and lower sequence proportion of shared ASVs were observed in the holdfast and axis of the two distinct populations. Our observational study provides valuable new insights and baseline for future hypothesis-driven research on the interactions between algae and associated microbiota—a knowledge gap that needs to be addressed in the future for better understanding of the ecological and evolutionary dynamics of coastal ecosystems.
Ključne besede: ecosystem services, anthropogenic pressures, microbiome, host specificity, alpha diversity, marine biology, ecology
Objavljeno v DiRROS: 18.04.2025; Ogledov: 42; Prenosov: 13
Celotno besedilo (1,35 MB)
Gradivo ima več datotek! Več...

Povzetek: The Malaspina-2010 circumnavigation expedition on board R/V Hesperides surveyed tropical and subtropical regions of the Atlantic, Indian and Pacific oceans between December 2010 and July 2011. This article examines the relationships between the distribution of chlorophyll a (Chl a), major inorganic nutrients and other hydrographic variables. A deep chlorophyll maximum (DCM) was found at most stations between 60 and 150 m depth; it occurred close to the level of 1% surface photosynthetically active radiation and was associated with the nitracline. There was a negative relationship between total Chl a at surface and the DCM depth, and between Chl a concentration at the DCM and DCM depth. In terms of Chl a concentration, picophytoplankton was the dominant size class at all sampled light intensities (surface, 20% of surface PAR and PAR at DCM), oceans and geoclimatic zones, except at some stations influenced by upwellings or divergences. Within the Chl a concentration ranges found in this study, the proportion of picophytoplankton increased with total Chl a, in contrast with some previous findings. Vertically integrated Chl a was positively correlated with surface Chl a, with similar slopes for the whole data set and for the different oceans and zones. In turn, surface Chl a and sea surface temperature showed a negative correlation for the Indian Ocean and the subtropical zone, a positive correlation for the Atlantic, and non-significant relationships for the remaining oceans and zones.
Ključne besede: Malaspina 2010, chlorophyll a, nitracline, deep chlorophyll maximum, phytoplankton size fractionation, Atlantic Ocean, Pacific Ocean, Indian Ocean, hydrobiology, marine biology
Objavljeno v DiRROS: 04.04.2025; Ogledov: 169; Prenosov: 101
Celotno besedilo (4,04 MB)
Gradivo ima več datotek! Več...

Povzetek: Isopods are a diverse peracarid crustacean group with marine, freshwater and terrestrial representatives. Isopod species lists were typically prepared according to different habitats, which was true also for Slovenia. Here, we prepared the first unified overview of isopod species for Slovenia, which is also the first list of marine isopods in the country. We examined scientific publications, research reports and institutional databases. A total of 126 species have been recorded in Slovenia, of which 31 are marine, 21 are found in freshwater, and 74 are terrestrial. Of these, we report on seven marine and one terrestrial species for the first time. A major part of freshwater isopod richness is linked to the subterranean environment, where most endemic species for the country can be found. Among marine species, many are parasites, with potential economic impact, and two species are considered introduced. When the new species list is considered with valid national legislation, only 41 species retained the same taxonomic status. Many synonyms and invalid taxa according to recent taxonomy point out the need for revision the national red list of Malacostraca as well as other nature protection acts.
Ključne besede: Peracarida, marine, freshwater, terrestrial, subterranean, fauna
Objavljeno v DiRROS: 12.03.2025; Ogledov: 166; Prenosov: 80
Celotno besedilo (1,35 MB)
Gradivo ima več datotek! Več...

Ključne besede: Ti6Al4V alloy, high-temperature oxidation, hot-salt test, marine environment
Objavljeno v DiRROS: 21.02.2025; Ogledov: 211; Prenosov: 117
Celotno besedilo (7,91 MB)
Gradivo ima več datotek! Več...