MARICULTURE DEVELOPMENTS AND USE CONFLICTS IN THE COASTAL ZONE OF REPUBLIC SLOVENIA

This paper describes basic characteristics of the marine environment and use conflicts in the coastal zone of R Slovenia. Despite its limited size the coastal area has rather an important role for the country\u27s economy providing access to the Mediterranean Sea and possibilities for development of different maritime and shore-based activities. Gross domestic product per inhabitant in the coastal region exceeds the Slovenian average, however, the economic importance of fishing and mariculture is small: its share of total value added in Slovenia was less than 0. 2 % in 2000. Due to limiteril space either onshore or in coastal waters aquaculture in Slovenia has to compete with other users, especially tourism and maritime transportation. While being sensitive to environmental problems aquaculture itself may have a negative impact on the marine environment due to pollution with inorganic and organic nutrients, with potentially toxic chemicals and through spread of disease

The depleted carbon isotopic signature of nematodes and harpacticoids and their place in carbon processing in fish farm sediments

Fish farm-originating organic matter can modify the ecological processes in a benthic ecosystem. This was investigated in the sediments of the northern Adriatic Sea by measuring delta C-13 signature of nematodes, harpacticoids, and sedimentary organic matter, and by assessing pore water nutrients and bacterial composition. In a mesocosm experiment, C-13-labeled diatoms were added on top of sediment cores and C-13 enrichment was measured as a proxy of diatom uptake by meiofauna. The delta C-13 signatures were depleted under fish farming cages compared to the reference site, as observed for sedimentary organic matter (-24.4 parts per thousand vs. -21.8 parts per thousand), for nematodes (-22.5 parts per thousand vs. -17.7 parts per thousand), and for harpacticoids (-25.3 parts per thousand vs. -20.8 parts per thousand). The direct consumption of fish feed (-22.294) was not traced in meiofauna taxa. Nematodes from the farm site likely reflect a diet comprising sedimentary organic matter, as they were enriched by 2 parts per thousand relative to the sedimentary organic matter. The nematodes from the reference site were enriched by 4.2 parts per thousand relative to the sedimentary organic matter, which implies that they rely on more enriched food sources, like diatoms, which was confirmed by their uptake of C-13-labeled diatoms. The nematode assemblage incorporated more diatom C-13 than harpacticoids, making them more important players in the carbon flux from diatoms to higher trophic levels at the reference site. Harpacticoids from the reference site were enriched by 1.1 parts per thousand compared to sedimentary organic matter, implying that this was their primary food source. Harpacticoids from the farm site were depleted by 0.9 parts per thousand relative to the sedimentary organic matter, indicating they were influenced by a very depleted food source like bacteria. Harpacticoids from both the cage and reference sites consumed C-13-labeled diatoms, which implies their diet might span a broad delta C-13 range, from bacteria to diatoms. Pore water nutrients with high dissolved inorganic carbon, phosphate, and ammonium concentration indicated an elevated microbial degradation of organic compounds under the fish farm. The denaturing gradient gel electrophoresis analysis showed a 70% similarity between sediment bacteria communities from the fish farm and reference site. The study demonstrated that fish farm-originating organic matter enters the meiofauna food chain, and that nematodes and harpacticoids use different food sources under the fish farm and at the reference site

Interannual size changes of adult Aurelia sp.5 medusae stage in the Marine Protected Area of Mljet Island South Adriatic

Aurelia aurita s.l. is the most widespread scyphozoan jellyfish that recurrently appear "en mass" and forms large aggregations mainly in coastal waters, embayments and estuaries. Beside anthropogenic factors controlling jellyfish populations climate change may play an important role. The aim of this study was to assess whether climate-related factors in absence of other anthropogenically induced stressor influence medusae size. We investigated seasonal and interannual changes in the size of Aurelia in a "jelly lake" in the National Park of Mljet Island (Croatia) where minimal human impact on the environment makes the Veliko Jezero a natural mesocosm for understanding the impact of climate change on the Aurelia population. The observed changes suggest Aurelia medusa population response to changing environment, in particular to enhanced temperature, by reduced body sizes. Comparison of Aurelia population dynamics from different regions in the Mediterranean Sea revealed the unique feature of the Veliko Jezero population. Despite the similarity of the environmental windows of medusae occurrences in the Veliko Jezero and regions in the Mediterranean Sea, medusae in the Veliko Jezero are present all year round. It seems that the lake bathymetry enables medusae to vertically migrate to deeper and cooler water layer, avoiding the limiting temperatures developed in the upper layer during the summer. These conditions may prolong the Aurelia medusae life span and together with continuous strobilation support the stability of the Aurelia medusae population all year round

In Situ Manipulation of Vertically Migrating Gelatinous Zooplankton Using Nighttime Blue-Water Scuba in the South-Central Adriatic Sea

Technological advance in undersea exploration (e.g. tethered cameras, remotely operated vehicles [ROVs], Autonomous Underwater Vehicles [AUVsG, and manned submersibles)have opened new windows into diversityand distribution of fragile gelatinous organisms in the vast mesopelagic realm(300 m-1000 m deep). While exstraordinary in expanding our view of its richness, mesopelagic exploration remains largely a look but don\u27t touch environment and this limits of our ability to understand these animals through physical manipulation relevant to the finer scales of the individual organism. We have been conducting a series of in situ observations and manipulations using blue-water SCUBA during the night at a 1, 200 m station centraly located in the southern Adriatic Sea. We report here on a suite of vertically migrating gelatinous animals, including the narcomedusa Solmissus albescens and the physonect siphonophores Forskalia formosa and Agalma elegans, whose ranges extend to the mesopelagic realm during the day, but reach SCUBA diving depths during the night. Our in situ approach combined with proximity to shore exploits the natural vertical migratory behavior of some mesopelagic species, and we therefore add to the widening spectrum of methods needed to evaluate these ecologically important yet difficult to study organisms

Godišnje promjene veličine adultnih primjeraka meduze Aurelia sp.5 u zaštićenom području otoka Mljeta, južni Jadran

Aurelia aurita s.l. is the most widespread scyphozoan jellyfish that recurrently appear “en mass” and forms large aggregations mainly in coastal waters, embayments and estuaries. Beside anthropogenic factors controlling jellyfish populations climate change may play an important role. The aim of this study was to assess whether climate-related factors in absence of other anthropogenically induced stressor influence medusae size. We investigated seasonal and interannual changes in the size of Aurelia in a “jelly lake” in the National Park of Mljet Island (Croatia) where minimal human impact on the environment makes the Veliko Jezero a natural mesocosm for understanding the impact of climate change on the Aurelia population. The observed changes suggest Aurelia medusa population response to changing environment, in particular to enhanced temperature, by reduced body sizes. Comparison of Aurelia population dynamics from different regions in the Mediterranean Sea revealed the unique feature of the Veliko Jezero population. Despite the similarity of the environmental windows of medusae occurrences in the Veliko Jezero and regions in the Mediterranean Sea, medusae in the Veliko Jezero are present all year round. It seems that the lake bathymetry enables medusae to vertically migrate to deeper and cooler water layer, avoiding the limiting temperatures developed in the upper layer during the summer. These conditions may prolong the Aurelia medusae life span and together with continuous strobilation support the stability of the Aurelia medusae population all year round.Aurelia aurita s.l. je najrasprostranjenija vrsta meduze unutar razreda režnjaka (Scyphozoa) koje se opetovano pojavljuje u nakupinama. Stvaraju velike agregacije većinom u obalnim vodama, zaljevima i estuarijima. Osim antropogenog, važan utjecaj na populaciju meduza mogu imati i klimatske promjene. Cilj ovog istraživanja je procjeniti u kolikoj mjeri utjecaji povezani s klimatskim promjenama, u odsutnosti drugih antropogeno induciranih stresova, utječu na veličinu meduza. Istraživali smo sezonske i godišnje promjene veličine vrste Aurelia u morskim jezerima Nacionalnog parka Mljet (hrvatska), gdje se Veliko jezero pokazalo kao idealan prirodni mezokosmos za istraživanje i razumijevanje utjecaja klimatskih promjena na populaciju ove vrste. Uočene promjene ukazuju da populacija meduze Aurelia odgovara na promjene okoliša, posebno na povišenu temperaturu smanjujući veličinu tijela. Usporedba dinamike populacije Aurelia u različitim dijelovima Sredozemlja otkriva jedinstvenu značajku populacije u Velikom jezeru. Unatoč sličnosti uvjeta okoliša u kojima se meduze pojavljuju u Velikom jezeru i ostalim područjima Sredozemlja, u Velikom jezeru su prisutne tijekom cijele godine. Očigledno, batimetrija jezera omogućava meduzama avertikalnu migraciju u dublje i hladnije slojeve, izbjegavajući površinski sloj sa povišenim vrijednostima temperature koje se razvijaju tijekom ljeta. Ovi uvjeti mogu utjecati na produžen životni vijek meduza te omogućiti stalnu strobilaciju i stabilnost populacije ove vrste tijekom cijele godine

Nalazi meduze Aequorea cf. forskalea u Jadranskom moru: usporedba povijesnih i recentnih podataka

Jellyfish are becoming an increasingly important component of studies of the global marine environment, as their frequent mass phenomena affect ecosystem performance and have economic and health consequences. Recent research has focused primarily on mass occurrences of scyphozoans and ctenophores, while less attention has been paid to hydromedusae blooms, which can also have significant impacts on the marine ecosystem with economic consequences. Like many members of the Scyphozoa and Ctenophora, Aequorea species can be numerous and form blooms. Based on surveys from 2000 to 2020 and information provided by marine professionals, we examine the (multiannual) variability, seasonality, and spatial distribution patterns of the poorly studied temperate species Aequorea cf. forskalea (Hydrozoa: Leptothecata). We hypothesized that this macrogelatinous jellyfish with a bipartite life cycle (benthic polyps and planktonic medusae) is sensitive to seasonal and long-term temperature fluctuations, particularly because temperature has been shown to play a critical role in mediating transitions in the life cycle of cnidarians. The cold-water affinity of A. cf. forskalea was confirmed by a significant negative correlation with temperature and the most frequent occurrence during the winter-spring period. For the northern Adriatic (Gulf of Trieste), sea temperature data and semi-quantitative plankton data are available for the first decade of the 20th century, allowing comparison of the historical data (1900-1911) with our current data set. Compared to historical records, the current occurrence of A. cf. forskalea differs significantly. With the warming of the northern Adriatic Sea since the beginning of the 20th century, the current phenology of A. cf. forskalea has changed, probably related to the delayed production of medusae by hydroids in autumn, the absence of medusae in this season and their less frequent occurrence in winter.Meduze postaju sve važnija komponenta globalnog proučavanja morskog okoliša, budući da njihove česte masovne pojave utječu na održanje ekosustava, a imaju ekonomske i zdravstvene posljedice. Najnovija su istraživanja usmjerena prvenstveno na masovnu pojavu režnjaka (Scyphozoa) i rebraša (Ctenophora), dok se manje pažnje posvećuje masovnim pojavama hidromeduza, koje također mogu imati veliki utjecaj na morski ekosustav sa značajnim ekonomskim posljedicama. Poput mnogih pripadnika Scyphozoa i Ctenophora, vrste roda Aequorea se mogu javljati u visokim brojnostima te njihovu pojavu možemo opisati kao masovnu („bloom“). Na temelju podataka prikupljenih tijekom istraživanja Jadrana u razdoblju od 2000. do 2020. godine te informacija dobivenih od stručnjaka koji se bave istraživanjem mora, razmatrali smo višegodišnju i sezonsku varijabilnost kao i obrasce prostorne raspodjele slabo proučavane vrste Aequorea cf. forskalea (Hydrozoa: Leptothecata) koja nastanjuje umjerena klimatska područja. Pretpostavili smo da je ova makro-želatinozna meduza, s bipartitnim životnim ciklusom (bentoski polipi i planktonske meduze), osjetljiva na sezonske i dugoročne promjene temperaturne, budući da temperatura igra ključnu ulogu za izmjenu generacija u životnom ciklusu žarnjaka (Cnidaria). Afinitet A. cf. forskalea prema hladnoj morskoj vodi potvrđuje značajna negativna korelacija s temperaturom te učestalo pojavljivanje tijekom zimsko-proljetnog razdoblja. Podaci o temperaturi mora i abundancijama vrste su dostupni za sjeverni Jadran (Tršćanski zaljev) za prvo desetljeće 20. stoljeća, što je omogućilo usporedbu povijesnih podataka (1900.-1911.) s novim setom podataka. U usporedbi s povijesnim zapisima, recentna se pojava A. cf. forskalea značajno razlikuje. Sa zatopljenjem sjevernog dijela Jadranskog mora od početka 20. stoljeća se mijenja sadašnja fenologija vrste A. cf. forskalea, što je vjerojatno povezano sa zakašnjelom proizvodnjom meduza u jesen, izostankom tijekom jeseni i njihovom rjeđom pojavom tijekom zime

Coming to grips with the jellyfish phenomenon in the Southern European and other Seas : research to the rescue of coastal managers

Jellyfish swarms in the Southern European Seas (SES: Mediterranean and Black Seas) are a recurrent phenomenon which is attracting a groundswell of scientific and societal interest, with potential repercussions for public health, recreation, tourism, fisheries, aquaculture and marine ecosystem health. But this phenomenon also occurs in other areas of the globe, necessitating a collaborative framework which extends beyond the SES. The goal of this International Workshop is thus to bring together people involved in jellyfish research and in management for two full days, and to open the discussion to a wider community than that simply found within the SES. The Workshop will tackle ecosystem services and potential societal benefits provided by jellyfish and their blooms, and detrimental impacts of jellyfish and their aggregations on PERSEUS study areas and other oceans. The main focus of the Workshop is to review the state of our understanding of jellyfish blooms and their dynamics, and to discuss the development of observational systems that will eventually enable better management of their impacts. Some of the topics that will be addressed in Cadiz are the following: · how to strengthen our observational capacities to monitor jellyfish over time? (so as not to rely solely on citizen science for distribution and abundance data over time) · how can we make use of recent technological advances for research and monitoring of jellyfish blooms? · how to incorporate jellyfish in routine monitoring programmes that are carried out by specialists? (like for example phytoplankton or copepods) · what knowledge gaps we still need to bridge in order to be able to advance our conceptual understanding of jellyfish blooms and to enhance predictive abilities? · how to quantify the impact of jellyfish blooms within the context of Good Environmental Status achievement?peer-reviewe

Who cares about ocean acidification in the Plasticene?

Plastics is all the rage, and mitigating marine litter is topping the agenda for nations pushing issues such as ocean acidification, or even climate change, away from the public consciousness. We are personally directly affected by plastics and charismatic megafauna is dying from it, and it is something that appears to be doable. So, who cares about the issue of ocean acidification anymore? We all should. The challenge is dual in the fact that is both invisible to the naked eye and therefore not felt like a pressing issue to the public, thereby not reaching the top of the agenda of policy makers; but also that it is framed in the climate change narrative of fear - whereby it instills in a fight-or-flight response in the public, resulting in their avoidance of the issue because they feel they are unable to take action that have results. In this article, we argue that the effective global environmental governance of ocean acidification, though critical to address, mitigate against and adapt to, is hindered by the both this lack of perception of urgency in the general public, fueled by a lack of media coverage, as well as a fight-or-flight response resulting from fear. We compare this to the more media friendly and plastics problem that is tangible and manageable. We report on a media plots of plastics and ocean acidification coverage over time and argue that the issue needs to be detangled from climate change and framed as its own issue to reach the agenda at a global level, making it manageable to assess and even care about for policy makers and the public alike?Agência financiadora European Cooperation in Science and Technology (COST) ITC Conference Grant within the COST Action OCEANGOV COST-ITCCG-CA15217-372 Horizon 2020 project GoJelly 774499 SINTEF Ocean project SEEINGSHORE NORTE-01-0145-FEDER-031893 NORTE 2020 Portugal 2020 European Union (EU) Portuguese Foundation for Science and Technology Portuguese Foundation for Science and Technology SFRH/BPD/108949/2015 CLIMFISH project n2/SAICT/2017 Horizon 2020 Framework Programme of the European Unioninfo:eu-repo/semantics/publishedVersio