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Abstract: 2023 marks the beginning of the third year of the UN Decade of Ocean Science for Sustainable Development, and we are now at a moment in time where we can start taking stock of the Ocean Decade’s early achievements. The critical role that National Decade Committees are playing at the junction of the global momentum of the Ocean Decade and the national transformation of ocean science is clear and extremely encouraging. I warmly congratulate those Member States that have led by example and created the first cohort of National Decade Committees. This Best Practice Manual for National Decade Committees is an opportunity to celebrate their dynamism, share their vision and successes, and encourage the establishment of new Committees across all 150 IOC/UNESCO Member States. The ambition of the Ocean Decade is to transform ocean science for the decades to come, thereby creating a step change in the relationship of all citizens to the ocean, and in the way that a healthy ocean contributes to sustainable development. National Decade Committees are essential to catalyse the transformation of ocean science by boosting national capacity to offer solutions to pressing challenges and working across the science-policy-society interface to inform decision makers and society at large. By bringing together diverse stakeholders and breaking down silos, National Decade Committees create a tangible and visible difference on the ground. Beyond their role to coordinate existing initiatives and catalyse new Decade Actions, National Decade Committees embody the core principles of the Ocean Decade including equity, inclusivity, and diversity, and the recognition of the importance of Indigenous and local knowledge systems. They have a particularly significant role in giving a seat at the table to Early Career Ocean Professionals, who will be the torch bearers of the legacy of the Ocean Decade post-2030.I hope that the diverse and rich experiences shared in this Manual will inspire many other Member States to actively participate in the Ocean Decade by setting up their own National Decade Committees. The existing cohort of National Decade Committees and the IOC/UNESCO stand ready to facilitate the involvement of new partners, while supporting the pioneers to go even further, and thus together achieve a key goal of the Ocean Decade to make sure no one is left behind in the endeavour to create the ocean we want by 2030.
Published in DiRROS: 12.03.2025; Views: 39; Downloads: 41
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Abstract: Life history traits of 17 species of sharks occurring in the Sea of Marmara were analysed based on Gower’s distances, Principal Coordinate Analyses, and hierarchical clustering. The analysis shows that the sharks of the Sea of Marmara can ecologically be divided into several clusters. The increasing occurrence of sharks on the Marmara continental shelf, especially in the last few years, suggests that the expected habitat compression due to deoxygenation has begun to take place. This situation, which can be considered as a “habitat trap” for sharks, should be considered as a threat that may lead to shark mortalities due to the intensification of bycatches or even the intentional killing of sharks. Available results are sufficient to predict a disturbing future for sharks of the Sea of Marmara if the factors (deoxygenation, habitat loss, bycatch, etc.) threatening the overall ecosystem do not improve.
Keywords: PCoA, ecology, sharks, habitat compression, mortality
Published in DiRROS: 12.03.2025; Views: 45; Downloads: 29
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Abstract: During mating, males and females of N. viridula (Heteroptera: Pentatomidae) produce sex- and species-specific calling and courtship substrate-borne vibratory signals, grouped into songs. Recognition and localization of these signals are fundamental for successful mating. The recognition is mainly based on the temporal pattern, i.e. the amplitude modulation, while the frequency spectrum of the signals usually only plays a minor role. We examined the temporal selectivity for vibratory signals in four types of ascending vibratory interneurons in N. viridula. Using intracellular recording and labelling technique, we analyzed the neurons' responses to 30 pulse duration/interval duration (PD/ID) combinations. Two response arrays were created for each neuron type, showing the intensity of the responses either as time-averaged spike counts or as peak instantaneous spike rates. The mean spike rate response arrays showed preference of the neurons for short PDs (below 600 ms) and no selectivity towards interval duration; while the peak spike rate response arrays exhibited either short PD/long ID selectivity or no selectivity at all. The long PD/short ID combinations elicited the weakest responses in all neurons tested. No response arrays showed the receiver preference for either constant period or duty cycle. The vibratory song pattern selectivity matched the PD of N. viridula male vibratory signals, thus pointing to temporal filtering for the conspecific vibratory signals already at level of the ascending interneurons. In some neurons the responses elicited by the vibratory stimuli were followed by distinct, regular oscillations of the membrane potential. The distance between the oscillation peaks matched the temporal structure of the male calling song, indicating a possible resonance based mechanism for signal recognition.
Keywords: animal communication, entomology
Published in DiRROS: 12.03.2025; Views: 59; Downloads: 36
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Abstract: We studied spatio-temporal distribution of hyporheic invertebrate community at the stream-reach scale in the River Bača on three sampling occasions (January, March, May) in 2005. On each sampling occasion, invertebrates were collected from the shallow hyporheic zone (RB1; depth 30-60 cm, 3 replicates), and deeper hyporheic zone (RB2; depth 60-90 cm, 2 replicates) in the river bed, and adjacent gravel bar (GB; depth 60-90 cm, 3 replicates) using Bou-Rouch piston pump. Concurrently, temperature, conductivity and oxygen were measured in the surface water and in hyporheic water at each sampling station. Differences in hyporheic community between dates and habitats were analysed by using two-way ANOVA (dates and habitats as fixed factors) and explored by principal component analysis (PCA). Altogether, 21,657 specimens from 63 taxa were collected. Cyclopoida juveniles, Leuctra sp. (Plecoptera), Chironomidae (Diptera), Acanthocyclops vernalis (Fischer, 1853) and Diacyclops languidus (G. O. Sars, 1863) were the most abundant in the samples. Two-way ANOVA showed significant differences between habitats (RB1 and GB), but no differences between dates when using taxonomic richness as dependent variable. No differences between habitats and dates were calculated when invertebrate densities were applied. PCA of hyporheic invertebrate data showed a gradient in community composition from shallow hyporheic zone (RB1) to deeper hyporheic zone (RB2) and gravel bar (GB). The differences were most probably due to different sediment composition in the studied habitats and less frequent disturbances due to floods in deeper layers and lateral gravel bars.
Keywords: stream reach, hyporheic zone, invertebrates, distribution (biology), community composition, spatial and temporal distribution
Published in DiRROS: 12.03.2025; Views: 43; Downloads: 49
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Abstract: The Asopinae (Heteroptera: Pentatomidae) are a subfamily of stinkbugs with predaceous feeding habits and poorly understood communication systems. In this study we recorded vibratory signals emitted by Picromerus bidens L. on a non-resonant substrate and investigated their frequency characteristics. Males and females produced signals by vibration of the abdomen and tremulation. The female and male songs produced by abdominal vibrations showed gender-specific time structure. There were no differences in the temporal patterns of male or female tremulatory signals. The signals produced by abdominal vibrations were emitted below 600 Hz whereas tremulatory signals had frequency ranges extending up to 4 kHz. Spectra of male vibratory signals produced by abdominal vibrations contained different peaks, each of which may be dominant within the same song sequence. Males alternated with each other during production of rivalry signals, using different dominant frequency levels. We show that the vibratory song repertoire of P. bidens is broader than those of other predatory stinkbugs that have been investigated. The emission of vibrational signals with different dominant frequencies but the same production mechanism has not yet been described in heteropteran insects, and may facilitate location of individual sources of vibration within a group.
Keywords: substrate-borne vibrational communication, signal production, signal frequency variation
Published in DiRROS: 12.03.2025; Views: 31; Downloads: 25
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