Marksizam i fenomenologija na XIV Internacionalnom kongresu za filozofiju

Squid behavior is synonymous with distinctive body patterns, postures, and movements that constitute a complex visual communication system. These communications are particularly obvious during reproduction. They are important for sexual selection and have been identified as a potential means of species differentiation. Here we present a detailed account of copulation, mating, and egg deposition behaviors from in situ observations of the squid Sepioteuthis australis from South Australia. We identified four mating types from 85 separate mating attempts: “Male-upturned mating” (64% of mating attempts); “Sneaker mating” (33%); “Male-parallel” (2%); and “Head-to-head” (1%). Intervals between successive egg deposition behaviors were clearly bimodal, with modes at 2.5 s and 70.0 s. Ninety-three percent of egg capsules contained 3 or 4 eggs (mean = 3.54), and each egg cluster contained between 218 and 1922 egg capsules (mean = 893.9). The reproductive behavior of S. australis from South Australia was different from that described for other cephalopod species. More importantly, comparison between these results and those for other populations of S. australis suggests that behavior may differ from one population to another

Near-future level of CO2-driven ocean acidification radically affects larval survival and development in the brittlestar Ophiothrix fragilis

The world's oceans are slowly becoming more acidic. In the last 150 yr, the pH of the oceans has dropped by similar to 0.1 units, which is equivalent to a 25 % increase in acidity. Modelling predicts the pH of the oceans to fall by 0.2 to 0.4 units by the year 2100. These changes will have significant effects on marine organisms, especially those with calcareous skeletons such as echinoderms. Little is known about the possible long-term impact of predicted pH changes on marine invertebrate larval development. Here we predict the consequences of increased CO2 (corresponding to pH drops of 0.2 and 0.4 units) on the larval development of the brittlestar Ophiothrix fragilis, which is a keystone species occurring in high densities and stable populations throughout the shelf seas of northwestern Europe (eastern Atlantic). Acidification by 0.2 units induced 100 % larval mortality within 8 d while control larvae showed 70 % survival over the same period. Exposure to low pH also resulted in a temporal decrease in larval size as well as abnormal development and skeletogenesis (abnormalities, asymmetry, altered skeletal proportions). If oceans continue to acidify as expected, ecosystems of the Atlantic dominated by this keystone species will be seriously threatened with major changes in many key benthic and pelagic ecosystems. Thus, it may be useful to monitor O. fragilis populations and initiate conservation if needed

Ocean Futures for the World’s Largest Yellowfin Tuna Population Under the Combined Effects of Ocean Warming and Acidification

The impacts of climate change are expected to have profound effects on the fisheries of the Pacific Ocean, including its tuna fisheries, the largest globally. This study examined the combined effects of climate change on the yellowfin tuna population using the ecosystem model SEAPODYM. Yellowfin tuna fisheries in the Pacific contribute significantly to the economies and food security of Pacific Island Countries and Territories and Oceania. We use an ensemble of earth climate models to project yellowfin populations under a high greenhouse gas emissions (IPCC RCP8.5) scenario, which includes, the combined effects of a warming ocean, increasing acidification and changing ocean chemistry. Our results suggest that the acidification impact will be smaller in comparison to the ocean warming impact, even in the most extreme ensemble member scenario explored, but will have additional influences on yellowfin tuna population dynamics. An eastward shift in the distribution of yellowfin tuna was observed in the projections in the model ensemble in the absence of explicitly accounting for changes in acidification. The extent of this shift did not substantially differ when the three-acidification induced larval mortality scenarios were included in the ensemble; however, acidification was projected to weaken the magnitude of the increase in abundance in the eastern Pacific. Together with intensive fishing, these potential changes are likely to challenge the global fishing industry as well as the economies and food systems of many small Pacific Island Countries and Territories. The modelling framework applied in this study provides a tool for evaluating such effects and informing policy development

Importance of plasticity and local adaptation for coping with changing salinity in coastal areas: a test case with barnacles in the Baltic Sea

Background:Salinity plays an important role in shaping coastal marine communities. Near-future climate predictions indicate that salinity will decrease in many shallow coastal areas due to increased precipitation; however, few studies have addressed this issue. The ability of ecosystems to cope with future changes will depend on species’ capacities to acclimatise or adapt to new environmental conditions. Here, we investigated the effects of a strong salinity gradient (the Baltic Sea system – Baltic, Kattegat, Skagerrak) on plasticity and adaptations in the euryhaline barnacle Balanus improvisus. We used a common-garden approach, where multiple batches of newly settled barnacles from each of three different geographical areas along the Skagerrak-Baltic salinity gradient were exposed to corresponding native salinities (6, 15 and 30 PSU), and phenotypic traits including mortality, growth, shell strength, condition index and reproductive maturity were recorded.ResultsWe found that B. improvisus was highly euryhaline, but had highest growth and reproductive maturity at intermediate salinities. We also found that low salinity had negative effects on other fitness-related traits including initial growth and shell strength, although mortality was also lowest in low salinity. Overall, differences between populations in most measured traits were weak, indicating little local adaptation to salinity. Nonetheless, we observed some population-specific responses – notably that populations from high salinity grew stronger shells in their native salinity compared to the other populations, possibly indicating adaptation to differences in local predation pressure.ConclusionsOur study shows that B. improvisus is an example of a true brackish-water species, and that plastic responses are more likely than evolutionary tracking in coping with future changes in coastal salinity

Double-edged sword of desalination: Decreased growth and increased grazing endanger range-margin Fucus populations

Coastal ecosystems worldwide are facing intense and diverse pressures caused by anthropogenic climate change, which compromises physiological tolerance of organisms, as well as causes shifts in their biotic interactions. Within-species genetic variation plays an important role in persistence of populations under such changes by providing building blocks for adaptation. The brackish-water Baltic Sea is predicted to experience a significant desalination by the end of this century. The Baltic Sea is dominated, in terms of biomass, by a few species with locally adapted populations, making it a suitable model for studying shifting biotic interactions under changing abiotic conditions. We exposed two foundation species of brown algae, Fucus vesiculosus and Fucus radicans, to end-of-the-century projected salinity together with grazing pressure in experimental tanks. We measured growth, grazing and phlorotannin content and compared these traits between the current and projected future salinity conditions, between Fucus species, and between high and low genotypic diversity groups. Grazing, phlorotannin content and growth of both F. radicans and F. vesiculosus all showed genotypic variation. Future decreased salinity hampered growth of F. vesiculosus irrespective of genotypic diversity of the experimental population. Furthermore, the growth response to desalination showed variation among genotypes. F. radicans was more susceptible to grazing than F. vesiculosus, and, in the high genetic diversity group of the latter, grazing was higher in the future than in current salinity. Climate change induced hyposalinity will thus challenge Fucus populations at their range margins in the Baltic Sea both because of the growth deterioration and changes in grazing. Differences between the species in these responses indicate a better ability of F. radicans to cope with the changing environment. Our results emphasize the complexity of biotic interactions in mediating the climate change influences as well as the importance of genetic diversity in coping with climate change

Indiscriminate Males: Mating Behaviour of a Marine Snail Compromised by a Sexual Conflict?

Background: In promiscuous species, male fitness is expected to increase with repeated matings in an open-ended fashion (thereby increasing number of partners or probability of paternity) whereas female fitness should level out at some optimal number of copulations when direct and indirect benefits still outweigh the costs of courtship and copulation. After this fitness peak, additional copulations would incur female fitness costs and be under opposing selection. Hence, a sexual conflict over mating frequency may evolve in species where females are forced to engage in costly matings. Under such circumstance, if females could avoid male detection, significant fitness benefits from such avoidance strategies would be predicted. Methodology/Principal Findings: Among four Littorina species, one lives at very much higher densities and has a longer mating season than the other three species. Using video records of snail behaviour in a laboratory arena we show that males of the low-density species discriminate among male and female mucous trails, trailing females for copulations. In the high-density species, however, males fail to discriminate between male and female trails, not because males are unable to identify female trails (which we show using heterospecific females), but because females do not, as the other species, add a gender-specific cue to their trail. Conclusions/Significance: We conclude that there is likely a sexual conflict over mating frequency in the high-densit

THE ECOLOGY AND BEHAVIOR OF NAUTILUS-POMPILIUS IN THE PHILIPPINES

Volume: 15Start Page: 75End Page: 8

Data from: Investigating a possible role for the bacterial signal molecules N-acylhomoserine lactones in Balanus improvisus cyprid settlement

Increased settlement on bacterial biofilms has been demonstrated for a number of marine invertebrate larvae, but the nature of the cue(s) responsible is not well understood. We tested the hypothesis that the bay barnacle Balanus improvisus utilises the bacterial signal molecules N-acylhomoserine lactones (AHLs) as a cue for the selection of sites for permanent attachment. Single species biofilms of the AHL-producing bacteria Vibrio anguillarum, Aeromonas hydrophila and Sulfitobacter sp. BR1 were attractive to settling cypris larvae of Balanus improvisus. However, when AHL production was inactivated, either by mutation of the AHL synthetic genes or by expression of an AHL-degrading gene (aiiA), the ability of the bacteria to attract cyprids was abolished. In addition, cyprids actively explored biofilms of E. coli expressing recombinant AHL synthase genes, but not on E. coli that did not produce AHLs. Finally, concentrations of synthetic AHLs similar to those found within natural biofilms (5 µM) resulted in increased cyprid settlement. Thus, the attraction of B. improvisus larvae to biofilms appears to be mediated by AHL signalling bacteria in the laboratory. This adds to our understanding of how quorum sensing inhibition may be used as a means of biofouling control. Nonetheless, the significance of our results for larvae settling naturally in the field, and the mechanisms that underlay the observed responses to AHLs, are as yet unknown

Havsplanering med hänsyn till klimatförändringar : An Assessment of the Theoretical Basis, and Practical Options, for Incorporating the Effects of Projected Climate Change in Marine Spatial Planning of Swedish Waters

Den globala klimatförändringen orsakar omfattande förändringar i arters utbredning, ekosystemens samhällsstruktur och ekosystemtjänster. Uppvärmningen av havsvattnet flyttar arters utbredning norrut, och stressar fastsittande arter som t.ex. koraller. Havsförsurning påverkar redan kallvattensarter och hotar många andra arter och ekosystem. Inom vår region har temperaturen i Östersjön under de senaste 150 åren stigit med 1-2 grader och årstidsväxlingar har förändrats, med tidigare (och längre) somrar med varma temperaturer under de senaste fyra decennierna. Andra beräkningar baserade på modeller visar på fortsatt ytterligare förändring mot slutet av detta sekel, med ytterligare genomsnittlig uppvärmning med 2-4 °C, genomsnittlig utsötning med upp till 2 salthaltsenheter, och genomsnittlig minskning av syrekoncentrationer i djupvattnet med 0,5-4 mgO2 .ml-1. Dessa modeller visar också att förändringar kommer att variera mycket över rumsskalor från 10 till 100 kilometer. Modellprognoser indikerar också att 50-80% av havsisen i norra Östersjön kommer att gå förlorad i slutet av seklet. Även om litteraturen om klimatförändringseffekter i svenska kustvatten fortfarande är relativt liten är det tydligt att klimatförändringarna redan har effekter på svenska marina arter, och att prognoserna indikerar större effekter under de kommande årtiondena. Förutom direkta effekter på enskilda arter har klimatförändringar också indirekta effekter, och potentiellt också kaskadeffekter, på nyckelarter i ekosystemet, vilket för Östersjön kan vara betydande. Sannolikheten för stora förändringar i marina ekosystem och den biologiska mångfalden i hela svenska kustvatten är således hög. Dessa förändringar i ekosystemets sammansättning och mångfald är kritiska eftersom många skyddade områden är etablerade för att bevara viktiga arter och eftersom ekosystemets funktion och motståndskraft mot klimatförändringarna är starkt relaterade till biologisk mångfald. Förlust av biologisk mångfald har visat sig minska ekosystemets funktion, vilket leder till förlust av produktivitet, resurskollaps och ökad känslighet för störningar.  Att införliva relevant teori i havsplanering för att behålla viktiga ekosystemtjänster under ett förändrat klimat är givetvis klok resursanvändning. Vi vill dock påpeka att teori så väl som empirisk kunskap – särskilt när det gäller biologisk mångfald, ekosystemets funktion och klimatets konsekvenser för tillhandahållandet av marina ekosystemtjänster – fortskrider snabbt. För att behålla det framtida värdet av våra marina resurser bör kunskapen uppdateras regelbundet. I detta PM sammanfattar vi relevant teori och kunskap för att ta itu med åtgärder som inriktar sig mot målarter, biologisk mångfald, populationers avgränsningar och potentialen för att arter kan få skydd mot miljöförändringarna i sk ”klimatrefuger”.Global climate change is causing widespread shifts in species distributions, community composition, and ecosystem services (Pereira et al., 2010, Pereira et al., 2012). In the oceans, warming is shifting species distributions toward cooler waters (Molinos et al., 2016, Pinsky et al., 2013) and stressing sessile species in-situ (e.g. coral bleaching (Donner et al., 2017), while acidification is already impacting some cold-water species (Manno et al., 2017) and threatening many other species and ecosystems (Pecl et al., 2017, Sunday et al., 2017). Patterns of climate change at regional scales are far less well understood, not least because global climate signals interact with regional processes to produce more complex patterns. Nonetheless, there are many relevant data and regional climate models for Scandinavia that have addressed these issues. Recent analysis shows that over the last 150 years or so the Baltic1 has warmed by 1-2 degrees (Meier et al., 2014), and there have been marked shifts in the seasonality of Baltic waters, with earlier onset (and longer periods) of warm temperatures over the last 4 decades (Kahru et al., 2016). Results from a comprehensive suite of projections from regional atmosphere:ocean models (Meier et al., 2012a, Meier, 2015, SMHI, 2017) show even greater future change, with average additional warming by 2-4°C average additional freshening by up to 2 salinity units, and average decrease in deep oxygen concentrations by 0.5-4 mg O2.ml-1 by the end of this century (Meier et al., 2012c, Neumann, 2010, Vuorinen et al., 2015). These models also project that changes will be highly heterogeneous over scales of 10’s to 100’s of kilometers. Model projections indicate with a relatively high degree of certainty that 5080% of winter sea ice in the northern Baltic will be lost by the end of the century (Andersson et al., 2015).  These shifts in seasonality and climate are already having effects on some species in Swedish coastal waters (Appelqvist et al., 2015, Appelqvist & Havenhand, 2016), and are projected to have even greater impacts in the coming decades (Meier et al., 2012b). Notable among these projections are freshening-driven shifts in the range boundaries of key species such as eelgrass, blue mussels, and cod (Vuorinen et al., 2015; and see Fig 1), substantial ice-loss driven reductions in populations of ringed seal (Sundqvist et al., 2012), and combinations of changing ice-cover, salinity, and temperature leading to range-shifts of key crustacean species (Leidenberger et al., 2015). Although the literature on climate-change effects in Swedish coastal waters is still relatively small, it is clear that climate change is already having effects on Swedish marine species, and that projections indicate greater effects in coming decades [with the caveat that there is likely a strong reporting bias toward significant effects: studies that found small, or no, effects of projected climate on species distributions in Swedish coastal waters (e.g. Laugen et al., 2015) are less frequently reported]. In addition to direct effects on individual species, climate change also has indirect – and potentially cascading – effects on interacting species in the ecosystem, which for the Baltic may be substantial (Vuorinen et al., 2015). Thus, the likelihood of substantive shifts in marine ecosystem composition and diversity throughout Swedish coastal waters is high (Elliott et al., 2015, Niiranen et al., 2013).  These likely shifts in ecosystem composition and diversity are critical because many marine protected areas are established to protect key species, and because ecosystem functioning and resilience to climate change are strongly related to biodiversity (Gamfeldt et al., 2015, Lefcheck et al., 2015). Loss of biodiversity has been shown to reduce ecosystem functioning, leading to loss of productivity, resource collapse, and greater sensitivity to disturbance (Cardinale et al., 2012, Worm et al., 2006). Thus, in a broad sense, biodiversity confers resilience on ecological communities (Campbell et al., 2011) and is therefore also critical to the long-term sustainability of ecosystem services in the face of environmental change (Loreau & Mazancourt, 2013)