Hinrichsen, Hans-Harald

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                CRUISE REPORT: 10.5.-25.5.2010  R.V. Alkor                                                     Cruise No.:Al 354  General subject of research: Physical, chemical, biological and fishery oceanography               Port calls: Saßnitz  Leibniz-Institute-Department/CAU-Institute: Marine Ecology (Fishery Biology)/ Leibniz-Institute of Marine Sciences  Chief Scientist: Hans-Harald Hinrichsen  Number of Scientists: 12  Projects: AQUASHIFT, CAVIAR, EPOCA, DFG-Mnemiopsis-Project, CALMARO    Research programme  This multidisciplinary research cruise was conducted within the framework of different inter-and nationally funded projects:  The research focus in AQUASHIFT RECONN 2 is to develop a more general picture of the influence of climatic processes on Baltic sprat population development. This includes: (i) developing process models on adult sprat growth and reproduction based on available field data, and (ii) combining output from experiments, analyses of field data as well as modelling activities (RECONN 1) in a stage-based matrix population model (life table) approach in order to resolve the influence of climate processes on the overall stock dynamics of sprat.    CAVIAR is joint Danish/German research project which aims at a detailed analysis of the climate variability of the Baltic Sea area and to investigate its impact on bio/physical processes in the central Baltic Sea. Analysing the effect of regional climate variations on coupled bio/physical processes, past and future data sets will be utilized for coupled bio-physical modelling to investigate and compare the potential impact of future climate change, especially the effect of global warming on the spatial distribution, habitat utilisation and recruitment processes of central Baltic fish and zooplankton populations.  The overall goal of the EU FP7 Integrated Project EPOCA (European Project on OCean Acidification) is to advance our understanding of the biological, ecological, biogeochemical, and societal implications of ocean acidification. EPOCA aims to document the changes in ocean chemistry and biogeography across space and time and determine the sensitivity of marine organisms, communities and ecosystems to ocean acidification. The results of the impact of ocean acidification on marine ecosystems will be used to better understand and predict the responses of the Earth system to ocean acidification in order to assess uncertainties, risks and thresholds ("tipping points") related to ocean acidification at scales ranging from subcellular to ecosystem and local to global. Within EPOCA it is planned to investigate the impact of ocean acidification on the performance, reproduction and growth in marine organisms. One of the objectives is to identify the critical stages in the life cycle of functionally important marine organisms based on performance measures as indicators of sensitivity to ocean acidification. Furthermore, physiological mechanisms of performance, acclimation capacity and tipping points are to me analyzed. One of the key species in this study is the Baltic cod, Gadus morhua, which will be obtained during the cruises with the RV ALKOR. Results will be compared to other species and functional groups for quantification of the impact of ocean acidification.   The DFG-Mnemiopsis-Project focuses on the comb jelly Mnemiopsis leidyi (Ctenophora) which recently invaded North- and Baltic Sea. 18 mo after the first occurrence, populations frequently attain >500 individuals /m3, suggesting profound consequences for the pelagic food chain. This project will study the ‘‘paradox of invasions’: how and why are supposedly genetically uniform colonizing populations so successful? - We first determine the source region(s) of Mnemiopsis populations invading North and Baltic Sea, using high-resolution genetic markers. We are then interested in processes enhancing adaptive evolution, which would exacerbate the impact that M. leidyi has on native fish populations. Taking advantage of genetic samples collected very early after first occurrence, we follow the level of genetic diversity displayed by Mnemiopsis populations across the study area over time. We test the hypothesis that the invading population is genetically less diverse than the source, while older invaded areas such as Caspian/Black Sea reveal intermediate levels. In order to address whether invading Mnemiopsis undergoes rapid evolutionary adaptation in its novel environment, genetic divergence among populations will be quantified temporally and spatially using gene-linked SNP loci in combination with genome scans.   Another focus is an additional cryptic invasion by another comb jelly, Mertensia ovum. This species co-occurs with M.leidyi in the Bornholm basin.  The EU project CALMARO involves initial Training Network aims at improving the career perspectives of early researchers by offering structured training in the field of Calcification by Marine Organisms as well as providing complementary skills and exposing the researchers to other sectors including private companies. CalMarO comprises investigation of calcareous structures as well as calcification processes and the sensitivities to changes in environmental conditions at all scales ranging from cellular, organism, population to ecosystem, and regional to global levels.   Gears used:  Hydrography: CTD, Water sample rosette  Zooplankton and jelly fish: Babybongo-Net (50 and 150 µm), Multinet (1/4 m2; 50 µm), WP-2 (200 µm), Apstein (50 µm)  Ichthyoplankton: Bongo-Net (335 and 500 µm), Mulitnet (1/2 m2; 335 µm),   Fish: Young fish trawl   Hydroaccoustic: 38 and 200 kHz-ecosounder      Scientific crew:   - Hans-Harald Hinrichsen (Chief Scientist) IfM-Geomar Kiel  whole cruise  - Jörn Schmidt    University Kiel  Kiel-Saßnitz - Max Stoeven    University Kiel  Kiel-Saßnitz - Svend Mees     IfM-Geomar Kiel  whole cruise - Martina Lohmann    IfM-Geomar Kiel  whole cruise - Gregor Steffen    IfM-Geomar Kiel  whole cruise - Franziska Heidemann   IfM-Geomar Kiel  whole cruise - Cathrin Clemmesen    IfM-Geomar Kiel  whole cruise - Marko Freese    IfM-Geomar Kiel  whole cruise - Viola Neumann    DTU AQUA, Denmark whole cruise - Carolin Hauer    University Hamburg  whole cruise - David Pena     University Kiel  Saßnitz-Kiel   Report of cruise Al354 with technical details  Monday 10/05/10 0800-1300 Loading of ship  1300 Steamning to Bornholm Basin  Thursday 11/05/10 00800             Beginning of pelagic fishery  and hydroaccoustic survey in the Bornholm Basin   Friday 14/05/10 1000 Interruption of sampling and steaming to Saßnitz  because of engine repairment and exchange of scientific crew 1400 Leaving Saßnitz into direction central Bornholm Basin 2300 Continuation with pelagic fishery and hydroaccoustic survey in the Bornholm Basin  Tuesday 18/05/10 0000  Start with hydrographic, hydroaccoustic and plankton  sampling in the Bornholm Basin and in the Stolpe Trench  Friday 21/05/10 1000 Interruption of sampling and steaming to Saßnitz, consultation of hospital due to illness of a crew member, exchange of crew member   Saturday 22/05/10      1000 Leaving Saßnitz  into direction of the central Bornholm Basin  Sunday 23/05/10 0100  Continuation with station grid in the Bornholm Basin                                Sunday 23/05/10         2100 Start with hydrographic, hydroaccoustic and              plankton sampling in the Arkona Basin                         Monday 24/05/10 0800  End of scientific program, Steaming to Kiel 2000  End of cruise Al354 in Kiel   Summary of cruise   Due to the almost perfect weather conditions and despite of some technical problems of the vessels engine, sampling was very successful.   The physical measurements of this cruise were designed to investigate the quasi-synoptic three-dimensional distribution of temperature, salinity, oxygen and pH within the Arkona- and Bornholm Basin. The station grid in the Bornholm Basin covered the area enclosed by the 60 m isobath and was regularly spaced with a distance of 10 nm in N/S-and 8.5 nm in E/W-direction. Data of these physical observations will be used in future to analyse the three-dimensional distribution of biological parameters (e.g. zooplankton, fiah egg and larval abundance, fish abundance) with respect to variability of the physical environmental conditions. A total number of 87 CTD casts were performed on the survey, from which 6 were located Arkona Basin, 71 in the Bornholm Basin and 10 in the Stolpe Trench region (Table 3).   The mixed layer water masses in the observation area revealed temperatures of about 6°C and in the winter water body (between 35 and 45 m) temperatures down to less than 1°C were observed. In the western deep water area of the basin extremely cold and well oxygenated water masses were transported from  the western Baltic and the Arkona Basin during winter time. In the central and eastern parts of the Bornholm Basin below the halocline temperature increased to  almost 10°C, but only low oxygen concentrations (< 2 ml/l) were found. Thus, the thickness of the spawning layer defining the vertical range with conditions allowing successful cod spawning  was low and mainly influenced by temperature. Generally, the deep water areas of Stolpe Trench revealed similar temperatures. In comparison to hydrographic measurements available from cruises in 2009 within the upper part of the Bornholm Basin the hydrographic situation significantly changed due to the severe conditions of the previous winter.   On 57 stations covered, ichthyo- and mesozooplankton was sampled with a Bongo and a Babybongo (equipped with 150, 335 and 500 µm nets) by means of double oblique hauls and on 15 stations with vertically resolving multinets. Compared to the cruise in April 2010, the Bongo samples from the Bornholm Basin revealed higher abundances of fish eggs and larvae. The 500 µm samples from the Bongo have been checked for cod and sprat larvae on board. All fish larvae had been frozen at -80°C to enable evaluation of their nutritional status by RNA/DNA analysis in relation to otolith microstructure. The WP2 net was utilized to investigate the spatial distribution and the genetic markers of Mnemiopsis leydi and Mertensia ovum., on several stations a WP2-net and vertical as well as towed multinet hauls were performed (see Table 3).  27 pelagic fishery hauls were performed to determine the spatial distributions of sprat, cod and herring in the Bornholm.Length and weight distributions of sprat and herring were recorded as well as maturation stages on every fishery station. To describe the predation on ichthyoplankton by pelagic fish, herring and sprat stomachs have been sampled by pelagic trawling. Additionally, herring and sprat were frozen for bioenergetic analysis. For cod length and weight measurements were performed, maturation stages recorded and otoliths collected. The catch rates of cod were three times higher than in April, indicating an increase in spawning migration from the winter feeding grounds towards the spawning ground in the deep Bornholm Basin. From the cruise it was also obtained that compared to April 2010, the spawning activity of sprat had fully started, i.e., the catch rates of sprat was considerably higher than in preceding years. Hydroacoustic recordings did not reveal any different spatial distributions in abundance, indicating an overall relatively high abundance. Cod fertilisation success and egg development at different salinities was assessed using egg batches from different females and semem from different males. Furthermore, the impact of ocean acidification on the fertilisation success was evaluated by using different water with different pH values.                            Tables  Table1: Hydrographic stations Arkona Basin   Station Breite Länge H01 55  7.0 12 49.0 H02 55  4.0 13 16.0 H03 55 14.5 13 30.0 H04 55  7.0 13 30.0 H05 55  7.0 13 48.0 H06 55  9.0 14  2.0 H07 55  7.0 14 15.5 H08 55 22.0 14 21.5 H09 55 21.0 14 30.0 H10 55 20.0 14 39.5 H11 55 15.0 14 30.0 H12 55 10.5 14 25.0 H13 55  6.5 14 33.5 H14 55  4.5 14 21.0 H15 54 58.5 14 16.0 H16 54 52.0 14  2.0 H17 55  1.0 14  2.0 H18 54 56.5 13 47.0 H19 54 47.0 13 47.0 H20 54 47.0 13 30.0 H21 54 56.5 13 30.0 H22 54 57.5 13 15.0 H23 54 53.5 13  5.0 H24 54 48.5 13 15.0 H25 54 44.0 13  2.5 H26 54 44.0 12 47.5 H27 54 54.5 12 47.5 H28 54 50.0 12 37.0 H29 54 43.0 12 29.5 H30 54 37.0 12 17.0 H31 54 24.0 12 10.0 Table 2: Hydrographic stations Bornholm Basin   station latitude longitude Basin1 55 27.5 14 45 BB2 55 37.5 14 45 BB3 55 37.5 15 00 BB4 55 37.5 15 15 BB5 55 37.5 15 30 BB6 55 37.5 15 45 BB7 55 37.5 16 00 BB8 55 47.5 16 00 BB9 55 47.5 16 15 BB10 55 37.5 16 15 BB11 55 47.5 16 30 BB11a 55 47.5 16 45 BB11b 55 47.5 17 00 BB12 55 37.5 16 30 BB12a 55 37.5 16 45 BB12b 55 37.5 17 00 BB13 55 27.5 16 30 BB14 55 27.5 16 15 BB15 55 27.5 16 00 BB16 55 27.5 15 45 BB17 55 27.5 15 30 BB18 55 27.5 15 15 BB19 55 27.5 15 00 BB20 55 17.5 15 00 BB21 55 17.5 15 17 BB22 55 17.5 15 30 BB23 55 17.5 15 45 BB24 55 17.5 16 00 BB25 55 17.5 16 15 BB26 55 17.5 16 30 BB27 55 07.5 16 30 BB28 55 07.5 16 15 BB29 55 07.5 16 00 BB30 55 07.5 15 45 BB31 55 07.5 15 30 BB32 55 07.5 15 15 BB33 54 57.5 15 15 BB34 54 57.5 15 30 BB35 54 57.5 15 45 BB36 54 57.5 16 00 BB37 54 57.5 16 15 BB38 54 47.5 16 00 BB39 54 47.5 15 45 BB40 54 47.5 15 30 BB41 54 47.5 15 15 BB42 54 47.5 15 00 BB42b 54 47.5 14 45 BB43 54 37.5 15 15 BB43a 54 37.5 15 00 BB43b 54 37.5 14 45 BB44 54 37.5 15 30 BB45 54 37.5 15 45 BB  BB – Bornholm Basin                                               Table 3. Number and type of samples taken during AL354   Basin      Type   Number Arkona Basin     CTD    6         WP2    6       Multinet   6  Bornholm Basin    CTD   71       WP2   50       Bongo/Babybongo 41         Multinet  28       Watersampler   9       Helgoland Larvalnet 11       Apstein net   7        Fishery trawls  27 Stolpe Trench     CTD   10         Bongo/Babybongo 10       WP2   10                             Figures  Fig 1: Stations  Arkona Basin                      Fig 2: Stations  Bornholm Basin and Stolpe Trench        

Cruise report: 10.5.-25.5.2010 R.V. Alkor Cruise No.: AL 354

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