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Novi aspekti vertikalne migracije zooplanktona u složenom ekosustavu otvorenog Južnog Jadrana

Voditeljica: dr.sc. Mirna Batistić

Dnevna vertikalna migracija (DVM) jest sinkronizirano kretanje zooplanktona gore i dolje u vodenom stupcu tijekom dnevnog ciklusa i vjerojatno je najveće prirodno dnevno kretanje biomase na Zemlji. Budući da zooplankton predstavlja trofičku vezu između primarnih proizvođača (tj. fitoplanktona u osvijetljenoj fotičkoj zoni) i viših trofičkih razina do vršnih predatora (riba), razumijevanje njihovih migracijskih obrazaca i vertikalne raspodjele biomase od ključne je važnosti za razumijevanje funkcioniranja pelagičkog ekosustava. Dosada su detaljne informacije o DVM zooplanktona u Jadranskom moru, kao i u cijelom Sredozemlju, bile vrlo rijetke. Novi pristup u istraživanju će kombiniranjem širokopojasnih akustičnih tehnika (engl. Acoustic Current Doppler Profiler, ADCP), mrežnog uzorkovanja i optičkih tehnika omogućiti dobivanje visoko razlučive vremenske serije o abundanciji i sastavu te raspodjeli zooplanktona, od površine do mezopelagičkog sloja. To omogućuje određivanje migracijskih vrsta i migracijskog ponašanja te dobivanje najtočnijih podataka za razumijevanje fenomena DVM zooplanktona. Uočeni obrasci raspodjele zooplanktona bit će povezani s fizikalnim i biološkim okolišnim uvjetima (npr. dnevnom svjetlošću, mjesečinom, BiOS mehanizmom, strujama, vertikalnim miješanjem, stratifikacijom, potpovršinskom (dubokom) maksimumu klorofila, izvoru hrane), uključujući partikularni organski ugljik (POC) sakupljen u sedimentnim zamkama. Općenito, moći ćemo procijeniti doprinos migracije zooplanktona u vertikalnom prijenosu ugljika u različitim razdobljima i ekološkim uvjetima. Unaprijeđivanje postojećih spoznaja o raspodjeli planktona, ekologiji i bioraznolikosti trebalo bi nam pomoći u praćenju budućih promjena planktonske zajednice u Jadranskom moru, a koje pokreću različiti cirkulacijski režimi i klimatske promjene. To će, također, pomoći pri praćenju sličnih učinaka na zajednice riba, što je poglavito važno za upravljanje ribarstvom i za gospodarstvo. Trajanje: 1. 3. 2020. do 29.2.2024.

Istraživačku skupinu uz voditeljicu čini 15 istraživača iz pet ustanova i tri države.

  • dr. sc. Mirna Batistić, voditeljica projekta


Suradnici:

Institut za more i priobalje, Sveučilište u Dubrovniku
  • prof. dr. sc. Nenad Jasprica,
  • dr. sc. Valter Kožul,
  • dr. sc. Rade Garić,
  • doc. dr. sc. Iris Dupčić Radić,
  • doc. dr. sc. Ana Car,
  • dr. sc. Jakica Njire,
  • dr. sc. Marijana Hure.

    Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy
    • dr. sc. Elena Mauri,
    • dr. sc. Vanessa Rossana Cardin,
    • prof. dr. sc. Miroslav Gačić,
    • dr. sc. Laura Ursella,
    • dr. sc. Giuseppe Civitarese.

      Morska biološka postaja Piran Nacionalnega inštituta za biologijo, Slovenia
      • dr. sc. Tjaša Kogovšek.

        Stazione Zoologica Anton Dohrn, Napoli, Italy
        • prof. dr. sc. Priscilla Licandro.

          Istituto di Scienze Marine - Consiglio Nazionale delle Ricerche (ISMAR - CNR), Bologna, Italy
          • dr. sc. Stefano Miserocchi.







          Papers published 2021 - 2022

           

          Marijana Hure, Mirna Batistić, Rade Garić

          Copepod diel vertical distribution in the open Southern Adriatic Sea (NE Mediterranean) under two different environmental conditions. Water, 14 (2022), 12; 1-19.

          DOI: https://doi.org/10.3390/w14121901

          Hure et.al 2022-v2


          Abstract

           

          Diel vertical migration of the copepod the community was investigated in the open South Adriatic, in June 2020 and February 2021, under two very different hydrographical conditions. The influence of a winter wind-induced mixing event on copepod vertical migration at the species level was determined for the first time and compared to the situation in June when pronounced thermal stratification was observed. The samples were collected during a 24 h cycle in four depth layers from the surface down to 300 m depth, using a Nansen opening–closing net with 250-µm mesh size. In winter, the bulk of the copepod population remained in the epipelagic zone (0–100 m) over the entire 24 h cycle, with calanoids remaining the dominant group. An increasing trend of copepod standing stocks from midnight to early morning in the surface layer found in June is in agreement with previous records of copepod day–night variations in the Mediterranean Sea. Day–night differences in diversity and the number of taxa of the epipelagic area were more pronounced in June, confirming the higher intensity of diel vertical migration in summer. Although the epipelagic community was composed of numerous weak diel vertical migrant species, for the majority of investigated copepod taxa, migration patterns differed between the environmentally contrasting seasons. A multivariate non-metric analysis showed that the copepod community was strongly affected by temperature, thus exhibiting a clear seasonal structure.

           

           

           

          Nenad Jasprica, Marijeta Čalić, Vedrana Kovačević, Manuel Bensi, Iris Dupčić Radić, Rade Garić, Mirna Batistić

          Phytoplankton distribution related to different winter conditions in 2016 and 2017 in the open southern Adriatic Sea (eastern Mediterranean). Journal of Marine Systems 226 (2022) 103665.

          DOI: https://doi.org/10.1016/j.jmarsys.2021.103665

           Jasprica et al. 2022

          Abstract

           

          Phytoplankton community structure and dynamics were investigated in the open southern Adriatic Sea during two winter-spring seasons (2016 and 2017) under different oceanographic and meteorological conditions. The principal environmental factor was a pronounced inflow of the Levantine Intermediate Water into the Adriatic, favoured by the cyclonic circulation of the Northern Ionian Gyre. As a consequence, high salinity values of about 38.838.9, were registered. Fifteen research cruises were undertaken in the same sampling area situated in the northern part of the Southern Adriatic Pit (SAP) with a maximum depth of 1200 m. Two specific circumstances were encountered: (i) high abundances of phytoplankton in the deep layer associated with strong downward flow in 2016, and (ii) an intense surface phytoplankton bloom in March 2017. This particular event occurred following the strong vertical convective mixing, which increased nutrient availability in the euphotic layer. High in situ Chl-concentrations (max. 1.65 mg m-3) and phytoplankton abundances higher than 105 cells L-1 are not common in the habitually oligotrophic open southern Adriatic Sea, and this study attempts to determine the driving force of that phenomenon. The phytoplankton community in SAP involved nanoflagellates and diatoms as the most abundant taxonomic groups during the March 2017 bloom. Presence of some coastal phytoplankton taxa suggests the influx of coastal water masses and transport of species either longitudinally, from the northern to the Southern Adriatic in concomitance of the Northern Adriatic Dense Water spreading, or transversal as a response to the strong mesoscale activity in the study region, comprising intense shelf - open sea interaction.

           

           

           

          Karina von Schuckmann ((Editor)), Pierre-Yves Le Traon ((Editor)), Neville Smith (Chair) ((Review Editor)), Ananda Pascual ((Review Editor)), Samuel Djavidnia ((Review Editor)), Jean-Pierre Gattuso ((Review Editor)), Marilaure Grégoire ((Review Editor)), Signe Aaboe, Victor Alari, Brittany E. Alexander, Andrés Alonso-Martirena, Ali Aydogdu, Joel Azzopardi, Marco Bajo, Francesco Barbariol, Mirna Batistić, Arno Behrens, Sana Ben Ismail, Alvise Benetazzo, Isabella Bitetto, Mireno Borghini, Laura Bray, Arthur Capet, Roberto Carlucci, Sourav Chatterjee, Jacopo Chiggiato, Stefania Ciliberti, Giulia Cipriano, Emanuela Clementi, Paul Cochrane, Gianpiero Cossarini, Lorenzo D'Andrea, Silvio Davison, Emily Down, Aldo Drago, Jean-Noël Druon, Georg Engelhard, Ivan Federico, Rade Garić, Adam Gauci, Riccardo Gerin, Gerhard Geyer, Rianne Giesen, Simon Good, Richard Graham, Marilaure Grégoire, Eric Greiner, Kjell Gundersen, Pierre Hélaouët, Stefan Hendricks, Johanna J. Heymans, Jason Holt, Marijana Hure, Mélanie Juza, Dimitris Kassis, Paula Kellett, Maaike Knol-Kauffman, Panagiotis Kountouris, Marilii Kõuts, Priidik Lagemaa, Thomas Lavergne, Jean-François Legeais, Pierre-Yves Le Traon, Simone Libralato, Vidar S. Lien, Leonardo Lima, Sigrid Lind, Ye Liu, Diego Macías, Ilja Maljutenko, Antoine Mangin, Aarne Männik, Veselka Marinova, Riccardo Martellucci, Francesco Masnadi, Elena Mauri, Michael Mayer, Milena Menna, Catherine Meulders, Jane S. Møgster, Maeva Monier, Kjell Arne Mork, Malte Müller, Jan Even Øie Nilsen, Giulio Notarstefano, José L. Oviedo, Cyril Palerme, Andreas Palialexis, Diego Panzeri, Silvia Pardo, Elisaveta Peneva, Paolo Pezzutto, Annunziata Pirro, Trevor Platt, Pierre-Marie Poulain, Laura Prieto, Stefano Querin, Lasse Rabenstein, Roshin P. Raj, Urmas Raudsepp, Marco Reale, Richard Renshaw, Antonio Ricchi, Robert Ricker, Sander Rikka, Javier Ruiz, Tommaso Russo, Jorge Sanchez, Rosalia Santoleri, Shubha Sathyendranath, Giuseppe Scarcella, Katrin Schroeder, Stefania Sparnocchia, Maria Teresa Spedicato, Emil Stanev, Joanna Staneva, Alexandra Stocker, Ad Stoffelen, Anna Teruzzi, Bryony Townhill, Rivo Uiboupin, Nadejda Valcheva, Luc Vandenbulcke, Håvard Vindenes, Karina von Schuckmann, Nedo Vrgoč, Sarah Wakelin & Walter Zupa (2021) Copernicus Marine Service Ocean State Report, Issue 5, Journal of Operational Oceanography, 14: sup1, 1-185.

          DOI: https://doi.org/10.1080/1755876X.2021.1946240

           Copernicus Marine Service Ocean State Report Issue 5

           

           

          Rade Garić, Mirna Batistić

          Description of Aurelia pseudosolida sp. nov. (Scyphozoa, Ulmaridae) from the Adriatic Sea. Water 202214, 135.

          DOI: https://doi.org/10.3390/w14020135

           Garić i Batistić 2021

           

          Abstract

          Until 2021, the genus Aurelia contained eleven described species (WoRMS, 2020), with many genetic species still awaiting a formal description. In 2021, ten new species of Aurelia were described almost solely from genetic data in a novel attempt to use genetic characters as diagnostic characters for species descriptions, leaving seven genetic species still undescribed. Here we present the description of a new Aurelia species from the Adriatic Sea using an integrative taxonomy approach, i.e., employing molecular as well as morphological characteristics in order to describe this new Aurelia species. The species is described based on a single medusa sampled from the town of Rovinj (Croatia), North Adriatic, amidst combined blooms of the ctenophore Mnemiopsis leidy and cnidarian Aurelia solida in the summer of 2020. Based on genetic data, the newly described Aurelia pseudosolida sp. nov. has never been sequenced in any of the previous investigations of the molecular diversity of Aurelia. This is the second species belonging to Discomedusae described from the North Adriatic in little more than half a decade, which could be yet another indication of the susceptibility of the North Adriatic to proliferation of non-indigenous gelatinous species, especially if we take into account historical as well as recent blooms of suspected non-indigenous gelatinous species such as Muggiaea atlanticaAurelia solidaMawia benovici and Mnemiopsis leidy.

          Keywords: Adriatic Sea; Aurelia pseudosolidaAurelia solidaMnemiopsis leidy; integrative taxonomy; gelatinous zooplankton; zooplankton bloom

           

           

           

           

          Planned Papers

           

          Mirna Batistić, Rade Garić and Marijana Hure

          First occurence of rare tropical hydromedusa Paracytaeis octona Bouillon, 1978 (Cnidaria: Anthoathecata) in the Adriatic Sea: A sign of climate changes?

           

          A special issue of Diversity (ISSN 1424-2818).

          This special issue belongs to the section "Biodiversity Loss & Dynamics".

          Special Issue "Gelatinous Zooplankton Diversity and Distribution in a Changing Ocean"

          https://www.mdpi.com/journal/diversity/special_issues/Gelatinous_Zooplankton_Diversity_Distribution

           

           

          Abstract

          Rare Indo-Pacific hydromedusa Paracytaeis octona (Bouillon, 1978) was collected for the first time at the open sea of southern Adriatic in December 2015. Since then, this species appears almost every year in the Adriatic Sea in similar periods. Some specimens were sequenced (COI, 16S rRNA, 18S rRNA) and the obtained sequences were searched against the GenBank database using the Blast tool but no sequence of any of species of this genus existed in GenBank. Nevertheless, this analysis confirm its phylogenetical position based on morphological characteristics that species belong to the family Cytaeididae. Unknown and morphologically different hydromedusa juveniles co-occurred with older specimens of P. octona in the samples. Through genetic analyses, we have confirmed that they are actually juvenile individuals of P. octona, which have now been described for the first time. Relatively high number of specimens were occurred in a high salinity conditions (up to 39.3) in all years when they are registered. This indicates strong inflow of warmer and saltier East Mediterranean waters into Adriatic Sea. Accordingly, this species might be a Lessepsian migrant of Indo-Pacific origin. In the last few decades relatively large number of new gelatinous zooplankton which preferred warmer water has been registered in the Adriatic Sea. This could be a sign of ongoing climate changes and possible tropicalization of the Mediteranean Sea. Our results highlight necessity of gelatinous zooplankton monitoring activities, not only large but also small species, as a standard assessments for detection of climate-induced changes in marine ecosystems in the future.

           

           

          Submitted Manuscript

          Giuseppe Civitarese, Miroslav Gačić, Mirna Batistić, Manuel Bensi, Vanessa Cardin, Jakov Dulčić, Rade Garić, Milena Menna

          The BiOS mechanism: history, theory, implications

          Progress in Oceanography, submitted by July 13, 2022


           

           

          Book Chapter

           

          Mirna Batistić

          Plankton communities and their role in the complex system of the Mali Ston Bay

          In: Kunica, V., Ipšić, I. (eds)., Mali Ston Bay, Kingdom of Oyster, p. 47-85. Stonski školjkari Ston, Ston (2022).

          https://www.malistonoyster.com/en/read-our-book

           

           

           

          Meeting presentation (Abstracts)

           

          Marijana Hure, Rade Garić, Davor Lučić

          Two new records of invasive copepod Pseudodiaptomus marinus in the Adriatic Sea.

          In: Jelaska, S. (ed.). Book of Abstracts of the 4th Croatian Symposium on invasive species with international participation. Croatian Ecological Society, Zagreb: 29.-30.11.2021.

          p. 87-87 (poster presentation)

          http://www.ekolosko-drustvo.hr/4CSIS-Book-of-Abstracts.pdf

           

           

          Abstract

          Free-living pelagic copepod species Pseudodiaptomus marinus Sato, 1913, indigenous to the North western Pacific Ocean, is one of the most well-known zooplankton species considered to be introduced to new environments by human activities. It is generally introduced into coastal areas, primarily into ports by ballast water release. From the first observation of this species in the Adriatic Sea in November 2007 near Rimini (Northern Italy), its presence has additionally been documented along the northern and eastern Adriatic ports with a stably increasing number of records updates on its distribution. We present here additional records of P. marinus in the zooplankton samples from the two cruises in the Adriatic Sea. The first record originated from the Middle/South Adriatic western coast, in December 2015, where this invasive calanoid was found at two stations near Gargano and one station near Bari in low abundances (< 1 ind. m-3). Samples were taken with a Nansen net (250 µm mesh size) during the ESAW cruise. Average temperatures of the sampling layers (0-100 m) ranged between 14.86 °C and 15.82 °C and salinity between 37.22 and 38.61. The second record was in the coastal area (Boka Kotorska Bay, Montenegro) of the eastern South Adriatic, in October 2018. Samples were taken during the night with Nansen net (125 µm mesh size). Abundances of P. marinus were 1.44 ind. m-3 (0-61 m sampling layer) and 3.73 ind. m-3 (32-62 m), with an average temperature of 18.09 °C and salinity of 37.45. Given the large number of mega cruise ships in the area, a ship’s fouling is probably a vector of P. marinus entrance and dispersion in the Boka Kotorska Bay. Further research on ballast water composition as well as studies on the fine distribution of this species for a longer period along the Adriatic coast are needed to estimate the possible establishment of this species in the area and its consequences for local planktonic populations.

           

           

           

          Mirna Batistić, Rade Garić

          A new species of the genus Paracytaeis (Cnidaria, Hydrozoa) from the Adriatic Sea

          In: Jelaska, S. (ed.), Book of Abstracts of the 4th Croatian Symposium on invasive species with international participation. Croatian Ecological Society, Zagreb: 29.-30.11.2021.

          p. 90-90 (poster presentation)

          http://www.ekolosko-drustvo.hr/4CSIS-Book-of-Abstracts.pdf

           

           

          Abstract

          A new hydromedusa species belonging to the genus Paracytaeis (Anthoathecata, Cytaeididae) is collected from the open sea of the southern Adriatic in winters of 2016., 2020. and 2021. Only two species from this genus are known, P. octona and P. meteoris. So far, only medusa stage of both speies are described. The last one is doubtfoul species due to inadequate description of only single specimen from near the Cape Verde Islands (Atlantic Oceans). However, this new species can be distinguished from its congeners, among others features, by the number of oral tentacles in adult specimens. Specimens were sequenced (COI, 16S) and the obtained sequences were searched against the GenBank database using the Blast tool. The search showed that no identical sequence existed in GenBank. However, no data of any of two Paracytaeis species existed in the Genbank. But, this analysis confirm that species belong to the family Cytaeididae. Relatively high number of specimens (≤ 1.0 ind/m3) were occured in a very high salinity conditions (38.8 - 39.0) in all years when they are registered, indicated strong inflow of Eeast Mediterranean water into Adriatic Sea. So there is a possibility that this Paracytaeis species is Lessepsian migrant of Indo-Pacific origin.

           

          Keywords: Hydromedusa, Paracytaeis, new species, Adriatic Sea

           

           

           

          Rade Garić, Mirna Batistić, Marijana Hure

          Recent occurrence of Pyrosoma atlanticum (Thalicacea, Pyrosomatida) in the South Adriatic

          In: Jelaska, S. (ed.), Book of Abstracts of the 4th Croatian Symposium on invasive species with international participation. Croatian Ecological Society, Zagreb: 29.-30.11.2021.

          p. 89-89 (poster presentation)

          http://www.ekolosko-drustvo.hr/4CSIS-Book-of-Abstracts.pdf

           

          Abstract

          Gamulin (1979), during his investigations of thaliacean abundance and distribution in the Adriatic Sea in the period from 1947 to 1952, found only larvae of Pyrosoma atlanticum, most commonly in the tetrazooid form, and in the greatest abundance near the Vis island. Nevertheless, he states that Pyrosoma atlanticum is common in the South Adriatic were it is occasionally caught by the fishermen in the fishing nets. For the period 1974-1975 Katavić (1976) states that he found 7 tetrazooids and 3 small adult colonies in the South Adriatic. In the period from 2007 to 2020 only few tetrazooid colonies were caught by zooplankton nets and adult colonies were never observed on the surface. In 2021, during zooplankton sampling trip in the open South Adriatic on 9th and 10th of September, we observed 13 adult colonies of P. atlanticum. Three of them were caught by hand nets and their identity was confirmed by inspection under the binocular. At the time of collection the surface salinity was extremely high (39.3) and surface temperature was 25.4°C. It seems that P. atlanticum is not as common in the Adriatic now as it was in the past. It occurrence seems to vary and it is possible that it is governed by circulation changes in the Ionian Sea, most notably BiOS (Bimodal Ocillating System). Due to the termophilic nature of P. atlanticum and on-going climate changes it is possible that P. atlanticum will become more common in the Adriatic Sea than it was in last decades. Keywords: Pyrosoma atlanticum, climate change, Thaliacea, Adriatic Sea.

           

           

           

          Mirna Batistić, Rade Garić

          New species of Aurelia from the Adriatic Sea

          ASLO 2021 Aquatic Sciences Meeting, Virtual meeting, June 22–27, 2021

          https://www.aslo.org/2021-virtual-meeting/

          (poster presentation)

           

           

          Abstract

          In summer 2020 a bloom of Aurelia solida occured in the Adriatic Sea. Among A. solida individuals, new Aurelia species was detected. The individual was sequenced (COI, 16S, 18S-ITS1-5.8S-ITS2-28S) and the obtained sequences were searched against the GenBank database using the Blast tool. The search showed that no identical sequence existed in GenBank. Subsequent phylogenetic analysis associated this newly discovered species the most closely to Aurelia solidaAurelia solida is a known Lessepsian migrant which is now widespread throughout Mediterranean. Given its close genetic association to the new Aurelia species it is possible that the newly discovered Aurelia species is also a Lessepsian migrant. In addition to genetic differences the two species differ most prominently in the way manubrium arms fold as well as in the morphology of the ropalium.

           

           

           

          Mirna Batistić, Rade Garić ,Marijana Hure

          Diel vertical distribution of zooplankton biomass in the open southern Adriatic (Mediterranean Sea). In: Stepnowski, P. (ed.), Book of Abstracts of the 55th European Marine Biology Symposium, September 19-23, Gdańsk (Poland) (poster presentation)

          https://embs55.ug.edu.pl/wp-content/uploads/2022/09/Book_of_abstract.pdf

           

           

          Abstract

          Zooplankton play an important role in the trophic dynamics of the deep open southern Adriatic. Detailed vertical and temporal distribution of zooplankton biomass were evaluated during the all seasons (2021/2022) at eight layers from 0 to 1200m depth during the day and the night using open-closing Nansen net (250 µm mesh size) hauls at the open southern Adriatic station. Average zooplankton biomass ranged from 0.19 - 21.34 mgm−3 by day and 0.18 - 34.02 mgm−3 by night and was differed by seasons and sampling layers. During the night, maximal values were in epipelagic layer while during the day maximal values were below 200 m, except in April. Zooplankton biomass was 1.5 to 3.0 times higher at night than during the day. These differences might be in connection with larger and faster zooplankton species which came to the surface in swarms during the night while during the day they were deeper and dispersed throughout the water column and net was not so effective to catch them.

           

           

           

           

          Mirna Batistić, Rade Garić

          Seasonal variability of Sagitta lyra (Chaetognatha) vertical distribution of abundance and biomass in the open southern Adriatic (East Mediterranean)

          ICES Annual Science Conference (ASC), September 6-10, 2021, Online

          (oral presentation)

           

           

          Abstract

          Chaetognaths comprise a phylum of marine organisms which is considered among the most important zooplankton groups, as they are often second in abundance after copepods in the mesozooplankton. Some basic aspects of chaetognath distribution and biology particularly for meso- and bathypelagic species are not well known in the Mediterranean Sea as well as other seas and oceans. Vertical distribution of Sagitta lyra abundance and biomass were studied at open-sea stations from surface to 1200 m depth in the northern part of the South Adriatic Pit during four seasonal cruises in 2019/2020.  S. lyra displayed ontogenetic vertical distributions, with older stages occurring at greater depth. They were more abundant in the upper 100 m, their abundance decreased conspicuously with depth, and were captured only rarely between 600 and 1200 m. Increase in abundance and biomss were found in early spring after winter convective events and early summer in time of intensive reproduction. Mean carbon and nitrogen content (as a percentage of dry weight) among maturity stages varied from 21.2 to 36.1% and 6.1 and 8.6% respectively. Higher values were recorded in greather depths where they consumed prey at high rates and where the contribution of older specimens increased.

           

          Keywords: zooplankton, chaetognatha, abundance, biomass, vertical distribution, ontogenetic distribution

           

           

           

          Mirna Batistić, Rade Garić, Marijana Hure

          Impact of the winter convective event on gelatinous zooplankton in the open southern Adriatic

          EGU General Assembly 2022, Vienna, Austria (poster presentation)

          DOI: https://doi.org/10.5194/egusphere-egu22-12875

           

           

          Abstract

          The southern Adriatic is the deepest part of the Adriatic Sea (1242 m) and one of three sites of open-sea deep convection in the Mediterranean. By analyzing zooplankton samples taken in the open southern Adriatic in winter and spring/summer 2021 we investigated effect of winter vertical mixing on distribution of gelatinous zooplankton. During the convection time in winter, gelatinous zooplankton abundance was low and unusual vertical distribution for some species was occurred. In the spring-summer time an increase in gelatinous zooplankton abundance in upper and deeper layer was registered. This is probably related to the early spring phytoplankton bloom enhanced by nutrient input into euphotic zone due to winter mixing phase. As a consequence of this event, there is also availability of more food for deep-sea gelatinous organisms.



          Paper published 2022-2024

          Martellucci, R.; Menna, M.; Mauri, E.; Pirro, A.; Gerin, R.; Paladini de Mendoza, F.; Garić, R.; Batistić, M.; di Biagio, V.; Giordano, P. et al. (2024). Recent changes of the dissolved oxygen distribution in the deep convection cell of the southern Adriatic Sea // Journal of marine systems, 245, 103988, 11. doi: 10.1016/j.jmarsys.2024.103988
          Abstract
          The dynamics of dissolved oxygen in the ocean are of crucial importance for understanding marine ecosystems, with influences ranging from exchange with the atmosphere to biological processes and ocean circulation. In this study, we focus on the southern Adriatic Sea, an essential component of the Eastern Mediterranean "conveyor belt”, to investigate long-term oxygen dynamics and its driving factors. We use cross-platform datasets from 2013 to 2020, including remote sensing data, model reanalysis and in-situ observations from Argo floats, ocean gliders and ship-based measurements. Our analysis investigate the interplay of physical, biological and atmospheric forcing that drive oxygen variability. The distribution of dissolved oxygen in the southern Adriatic Sea is influenced by vertical mixing, advection of water masses and ecosystem dynamics. In the surface layer, the variability of dissolved oxygen is triggered by annual primary production and deep convection events. The dynamics in the intermediate and the deep layers are instead primarily influenced by physical processes, such as the vertical mixing and the water masses inflow from the adjacent sub-basins, which is driven by the periodic reversals of northern Ionian Gyre circulation. In particular our study reveals that the water masses advective dynamics driving the increase and decrease of dissolved oxygen have drastically changed in recent years. The highest dissolved oxygen concentrations are currently observed during the northern Ionian Gyre anticyclonic phase, while they have been previously documented during the cyclonic phase. This change appears to be connected with the significant increase in salinity observed in the southern Adriatic Sea in the same period and contributes to a better understanding of the processes that determine oxygen distribution in the Eastern Mediterranean basin.

          Gerin, Riccardo; Martellucci, Riccardo; Savonitto, Gilda; Notarstefano, Giulio; Comici, Cinzia; Medeot, Nevio; Garić, Rade; Batistić, Mirna; Dentico, Carlotta; Cardin, Vanessa et al. 2024). Correction and harmonization of dissolved oxygen data from autonomous platforms in the South Adriatic Pit (Mediterranean Sea) // Frontiers in marine science, 11, 1373196, 16. doi: 10.3389/fmars.2024.1373196
          Abstract
          Dissolved oxygen (DO) is one of the most important drivers of ocean biogeochemical cycles and marine life, and in many areas its concentration has declined due to climate change. In recent decades, a growing number of autonomous oceanographic platforms has been equipped with sensors for direct in situ measurements of oxygen levels. However, to ensure high quality and comparable data, these observations need to be validated or, if necessary, corrected. In this paper, we compiled all the available DO data collected by Argo floats and gliders in the South Adriatic Pit (Mediterranean Sea) between 2014 and 2020. This dataset includes data for which it was not possible to apply conventional quality-control methods. Therefore, we had to apply tailored procedures based on well-established best practices for correction. The aim is to showcase how these tailored procedures allowed us to achieve the best possible quality of data and generate consistent datasets. The drift of the glider DO sensors related to storage was also estimated. The described procedure could be useful in similar cases where the conventional methods are not viable, thus making available potentially useful data.


          Garić, Rade; Batistić, Mirna (2022). Dolioletta advena sp. nov., a New Species of Doliolid (Tunicata, Thaliacea) from the Adriatic Sea. Diversity, 14,11;959,12.doi:10.3390/d14110959.
          Abstract
          The Adriatic Sea, as a part of Mediterranean, is one of the best investigated areas in the world regarding zooplankton. Nevertheless, in the last decade four new species of gelatinous zooplankton were described from the Adriatic Sea. Whether these species are newcomers or they were simply overlooked is still under investigations. Here we provide a description of a new species of Doliolida from the genus Dolioletta, Dolioletta advena sp. nov., found in the Adriatic Sea in August 2021, in a period of high sea temperatures and salinities, suggesting its thermal predilection. Its blastozooids dominated the studied doliolid blastozooid communities in the South Adriatic, except in the 50–100 m depth layer at a coastal Lokrum station. Blastozooids of D. advena sp. nov. possess unique morphological features which easily distinguish it from other doliolid species: the most prominent feature being the curved digestive tract where the intestine does not form a tight coil as in other Dolioletta species. The placement of this species in the genus Dolioletta is corroborated by COI phylogenetic analysis which showed that D. advena sp. nov. forms a well-supported monophyletic clade with Dolioletta gegenbauri (81% bootstrap support). In addition to D. advena sp. nov. COI sequence, we provide COI sequences of five doliolid and one pyrosomatid species, which will greatly improve the availability of thaliacean sequences for metabarcoding studies. The origin of D. advena sp. nov. is unknown, but given the fact that doliolids are well investigated in the Mediterranean Sea, it is likely that it arrived with sea currents either through the Suez Canal or the Strait of Gibraltar. Future investigations will confirm or reject this hypothesis.


          Civitarese, Giuseppe; Gačić, Miroslav; Batistić, Mirna; Bensi, Manuel; Cardin, Vanessa; Dulčić, Jakov; Garić, Rade; Menna, Milena (2023). The BiOS mechanism: history, theory, implications. Progress in oceanography, 216, 103056, 28 doi:10.1016/j.pocean.2023.1
          Link za rad Civitarese et. al 2023:


          Abstract
          Over the past four decades, the understanding of Mediterranean oceanography has evolved considerably. From a purely stationary view, there has been a shift to a concept that considers the Mediterranean as a highly dynamic sea in which ocean-typical processes occur on smaller spatial and temporal scales. The recent discovery of the mechanism called BiOS (Adriatic-Ionian Bimodal Oscillating System) has further highlighted the highly variable nature of Mediterranean oceanography and the interconnectedness of its sub-basins. The BiOS is a mechanism by which the deep thermohaline cell of the eastern Mediterranean, originating in the southern Adriatic, is connected to the upper circulation of the Northern Ionian Gyre via positive feedback, causing a decadal circulation change that leads to a redistribution of salt throughout the Mediterranean. The effects of this variability are manifold: decadal modulations of the intensity of winter convection in the southern Adriatic, with variations in the volume and thermohaline properties of the dense water produced; variations in preconditioning in the eastern Mediterranean, affecting the salinity of the intermediate Levantine waters; influence on biodiversity in the Adriatic due to the import of Lessepsian organisms or those of western Mediterranean and Atlantic origin; variations of the trophic regime in the Ionian Sea due to the different vertical dynamics of the nutricline during the cyclonic or anticyclonic circulation of the Northern Ionian Gyre; significant contribution to the preconditioning of the northwestern Mediterranean Sea by the salinity variability of the Levantine Intermediate Water. In this study, the BiOS mechanism, the underlying theory, and the implications for the oceanographic features of the Mediterranean Sea are presented, based on the extensive literature published in the last three decades and some new analyses.


          Marijana Hure, Mirna Batistić, Rade Garić
          Copepod diel vertical distribution in the open Southern Adriatic Sea (NE Mediterranean) under two different environmental conditions. Water, 14 (2022), 12; 1-19.

          Abstract
           
          Diel vertical migration of the copepod the community was investigated in the open South Adriatic, in June 2020 and February 2021, under two very different hydrographical conditions. The influence of a winter wind-induced mixing event on copepod vertical migration at the species level was determined for the first time and compared to the situation in June when pronounced thermal stratification was observed. The samples were collected during a 24 h cycle in four depth layers from the surface down to 300 m depth, using a Nansen opening–closing net with 250-µm mesh size. In winter, the bulk of the copepod population remained in the epipelagic zone (0–100 m) over the entire 24 h cycle, with calanoids remaining the dominant group. An increasing trend of copepod standing stocks from midnight to early morning in the surface layer found in June is in agreement with previous records of copepod day–night variations in the Mediterranean Sea. Day–night differences in diversity and the number of taxa of the epipelagic area were more pronounced in June, confirming the higher intensity of diel vertical migration in summer. Although the epipelagic community was composed of numerous weak diel vertical migrant species, for the majority of investigated copepod taxa, migration patterns differed between the environmentally contrasting seasons. A multivariate non-metric analysis showed that the copepod community was strongly affected by temperature, thus exhibiting a clear seasonal structure.

          Pasković, Nika ; Dupčić Radić,  Iris
          First record of the dinoflagellate Tripos rotundatus in the Adriatic Sea // Acta botanica Croatica, 82 (2023), 2; 8311, 4. doi: 10.37427/botcro-2023-012
          Abstract
          This report presents the first record of Tripos rotundatus (Jørgensen) Gómez in the Adriatic Sea. The species was found in the net sample in the layer of 50 – 100 m depth, on July 2021 at the coastal southern Adriatic Sea. The species T. rotundatus was probably previously mistaken as morphologically similar species T. digitatus (Schütt) Gómez.


          Albaina Aitor, Garić Rade, Yebra Lidia (2024) Know your limits; miniCOI metabarcoding fails with key marine zooplankton taxa. Journal of plankton research, accepted for publication.
          Abstract
          Eleven years after the publication of the first work applying deoxyribonucleic acid metabarcoding to zooplankton communities, the commonly known "miniCOI” barcode is widely used becoming the marker of choice. However, several primer combinations co-exist for this barcode and a critical evaluation of their performance is needed. This article reviews the misperformance of miniCOI metabarcoding with marine zooplankton communities, comparing them to microscopy and/or other universal markers. In total, misperformances were reported for 26 zooplankton taxa, including 18 copepods and 5 tunicates. We report a detection failure with Class Appendicularia and contrasting performances for Oithona similis (from good correspondence to detection failure), two worldwide abundant taxa with a crucial role in the marine pelagic realm. A combination of forward primer mismatches, the presence of long poly-T inserts and a low number of reference sequences would explain the failure to detect appendicularians. However, the contrasting performance with O. similis would correspond to distinct numbers of mismatches in the forward primer in dierent lineages within this cryptic taxon. This is reinforced by the report of similar patterns with other locally abundant zooplankton taxa. Therefore, we strongly call for the use of miniCOI in combination with alternative methods capable of addressing these limitations.




          Meeting presentation (Abstracts)



          https://imp-du.com/images/DiVMAd_Kongresi%20i%20simpoziji_2022_2024.pdf

          The first year of the project, 01 March 2020 to 28 February 2021

           

          Field investigations (cruises) by research vessel Naše more (University of Dubrovnik) and Palagruža (Hydrographic Institute of the Republic of Croatia):

          1st cruise, 25 - 26 June 2020: Nets samples, Niskin bottle samples and CTD-profiles (CTD multiparametric probe) were taken at investigated depths and layers, throughout day-night, R/V Naše More.

          2nd cruise, 18 -19 December 2020: Niskin bottle samples and CTD-profiles (CTD multiparametric probe)were taken at investigated depths and layers, throughout day-night, R/V Palagruža.

          3rd cruis, 17 -19 February 2021: Niskin bottle samples and CTD-profiles (CTD multiparametric probe) were taken at investigated depths and layers, throughout day-night, R/V Naše More.






          The second year of the Project, March 1, 2020 to  August 31, 2021

          Field investigations (cruises) by research vessel Naše more (University of Dubrovnik):

           

          2021.

          1st Cruise, June 07-09, 2021: Nets samples, Niskin bottlesamples and CTD-profiles (CTD multiparametric probe) were taken at investigateddepths and layers, throughout day-night, R/V Naše More.

          2nd Cruise, August 23, 2021: CTD-profiles (CTD multiparametric probe) weretaken at investigated depths and layers. Zooplankton samples were taken.Jelly-co zooplankton recording was taken, R/V Naše More.

          3rd Cruise, September 9-11, 2021:Nets samples, Niskin bottlesamples and CTD-profiles (CTD multiparametric probe) were taken at investigateddepths and layers, throughout day-night, R/V Naše More.

          4th Cruise, October 20, 2021: CTD-profiles (CTD multiparametric probe) weretaken at investigated depths and layers. Zooplankton samples were taken.

          5th Cruise, December 22-24, 2021: Nets samples, Niskin bottle samples andCTD-profiles (CTD multiparametric probe) were taken at investigated depths andlayers, throughout day-night, R/V Naše More.

           

          2022.

          6th Cruise, March 3-4, 2022: Nets samples, Niskin bottle samples andCTD-profiles (CTD multiparametric probe) were taken at investigated depths andlayers, throughout day-night, R/V Naše More.

          7th Cruise, April 13-15, 2022: Nets samples, Niskin bottle samples andCTD-profiles (CTD multiparametric probe) were taken at investigated depths andlayers, throughout day-night, R/V Naše More.

          8th Cruise, June 28-29, 2022: Nets samples, Niskin bottle samples andCTD-profiles (CTD multiparametric probe) were taken at investigated depths andlayers, throughout day-night, R/V Naše More.

          7th Cruise, July 04-05, 2022: Nets samples, Niskin bottle samples andCTD-profiles (CTD multiparametric probe) were taken at investigated depths andlayers, throughout day-night, Jelly-co and BlueRov zooplankton recording wastaken, R/V Naše More.





























          The third year of the Project

          The third year of the Project, September 1, 2022 to August 1, 2024

          Field investigations (cruises) by research vessel Naše more (University of Dubrovnik):

          2022.

          1st Cruise, October 24-26., 2022: Nets samples, Niskin bottle samples and CTD-profiles (CTD multiparametric probe) were taken at investigate depths and layers, throughout day-night, R/V Naše More.

          2023.

          2nd Cruise, February 16–18, 2023: Nets samples, Niskin bottle samples and CTD-profiles (CTD multiparametric probe) were taken at investigate depths and layers, throughout day-night, R/V Naše More.3rd Cruise, May 8-10, 2023: Nets samples, Niskin bottle samples and CTD-profiles (CTD multiparametric probe) were taken at investigateddepths and layers, throughout day-night, R/V Naše More.

          4th Cruise, September 18-20, 2023: Nets samples, Niskin bottlesamples and CTD-profiles (CTD multiparametric probe) were taken at investigateddepths and layers, throughout day-night, R/V Naše More.

          2024.

          5th Cruise, July 17, 2024: BlueRow zooplankton recording was taken.



          Multi-net plankton sampler acquired in 2024 withfunds from two HRZZ projects SpaTeGen and DiVMAd.




          (E2M3A) site. The secondary mooring line houses an instrument chain with sensors at different depths for physical and chemical measurements from the seabed to the mixed layer (in collaboaration with project members from the OGS InstituteNational Institute of Oceanography and Applied Geophysics, OGS, Trieste. (photos: web OGS).