ALBERT

Description: 2014-2019: Since September 2014, temperature, salinity, pH (only 2014-2015) and oxygen data were additionally logged in 10-minutes intervals at the GEOMAR pier (54°19'48.8N 10°08'59.6E) (AANDERAA oxygen sensor 3835 & SEABIRD SBE 37-SI MicroCAT CT(D)). The sensor system is mounted to a floating platform so that a continuous depth of 1 m is guaranteed at every time point. Oxygen data were corrected for salinity, temperature and depth following the manual for Aanderaa Optodes using the salinity and temperature measurements from the SEABIRD SBE 37-SI MicroCAT CT(D) sensor. pH was also corrected for salinity, temperature and depth following Martz et al. (2010). After cleaning and other re-boots of the sensor package, temperature, salinity and oxygen data tend to deviate from true values. Hence, 60 minutes of data after any re-boot (after sensor servicing with re-deployment, data download or power failure) were deleted. Furthermore, salinity data lower than 8 and pH data lower than 5 and larger than 10 were removed from the data set as these values were identified as outliers. On May 22nd 2018 as well as on May 26th (22:00) til 27th (15:00) 2019 oxygen data were identified as outliers and removed from the data set. The logged oxygen data were plotted against titration data (doi:10.1594/PANGAEA.930974) to check for drifts in the optode's data. But no drift pattern could be detected and the fit of the regression was very good R2adj. = 0.673, p 〈 0.001)

Description: 2005-2019 CTD (48M, Sea & Sun Technology GmbH, Trappenkamp, Germany) measurements and water samples at the surface (0 m depth), at 7 m and 18 m depth were taken biweekly between 2005 and 2019 at the “Wittlingskuhle” a bit off the GEOMAR pier in the Inner Kiel Fjord (N 54°19.69, E 10°09.06). The oxygen concentration of these water samples was measured by the Winkler- iodometric titration method (Winkler 1888) in mg/L and are converted to oxygen-saturation values by correcting for temperature, salinity and pressure.

Description: This dataset is part of a dataset collection. Please read the documentation in Kiel fjord carbonate chemistry data between 2015 (February) and 2016 (January) doi:10.1594/PANGAEA.876551 for details on sampling, measurement and data processing.

Description: The stable production of high quality fry in marine aquaculture is still hampered by unpredictable mortality caused by infectious diseases during larval rearing. Consequently, the development of new biocontrol agents is crucial for a viable aquaculture industry. The bacterial energy storage compound poly-ß-hydroxybutyrate (PHB) has been shown to exhibit beneficial properties on aquatic organisms such as enhanced survival, growth, disease resistance and a controlling effect on the gastrointestinal microbiota. However, the effect of PHB on the developing immune system of fish larvae has so far not been investigated. In the present study, the effect of feeding PHB-enriched Artemia nauplii on survival, growth and immune response in European sea bass (Dicentrarchus labrax) post-larvae was examined. Amorphous PHB was administered to 28 days old sea bass larvae over a period of 10 days. The survival and growth performance were monitored and the expression of 29 genes involved in immunity, growth, metabolism and stress-response was measured. While the expression of the insulin-like growth factor 1 (igf1), an indicator of relative growth, was upregulated in response to feeding PHB, the larval survival and growth performance remained unaffected. After 10 days of PHB treatment, the expression of the antimicrobial peptides dicentracin (dic) and hepcidin (hep) as well as mhc class IIa and mhc class IIb was elevated in the PHB fed larvae. This indicates that PHB is capable of stimulating the immune system of fish early life stages, which may be the cause of the increased resistance to diseases and robustness observed in previous studies.

Description: The reliable production of marine fish larvae is one of the major bottlenecks in aquaculture due to high mortalities mainly caused by infectious diseases. To evaluate if the compound poly-ß-hydroxybutyrate (PHB) might be a suitable immunoprophylactic measure in fish larviculture, its capacity to improve immunity and performance in European sea bass (Dicentrarchus labrax) yolk-sac larvae was explored. Dietary PHB was applied from mouth opening onwards to stimulate the developing larval immune system at the earliest possible point in time. Larval survival, growth, microbiota composition, gene expression profiles and disease resistance were assessed. PHB administration improved larval survival and, furthermore, altered the larva-associated microbiota composition. The bacterial challenge test using pathogenic Vibrio anguillarum revealed that the larval disease resistance was not influenced by PHB. The expression profiles of 26 genes involved e.g. in the immune response showed that PHB affected the expression of the antimicrobial peptides ferritin (fer) and dicentracin (dic), however, the response to PHB was inconsistent and weaker than previously demonstrated for sea bass post-larvae. Hence, the present study highlights the need for more research focusing on the immunostimulation of different early developmental stages for gaining a more comprehensive picture and advancing a sustainable production of high quality fry.

Description: A HydroC® CO2 sensor was deployed from a pontoon at the waterfront of the GEOMAR west shore building into Kiel Fjord, Western Baltic Sea (Kiel, Germany; 54°19'48.78"N, 010° 8'59.44"E). Since the pontoon is floating the deployment depth of the sensor was constant at 1m. Data of two deployment intervals are published here: February 2015 – May 2015 and August 2015 – January 2016.

Description: Ovigerous females were collected by scraping from inner Kiel Fjord in July -August 2017 and kept under control constant temperature room (~20°C) until egg hatching. Newly hatched larvae were reared under different salinity treatments in order to estimate their salinity tolerance,. Experiments were conducted until larvae reached the megalopae stage (last larval stage) or died, The results of such study could give us a primary outlook on the dispersal ability of H. takanoi larvae along the Baltic Sea, and insights about the life cycle of H. takanoi specifically in the south-western Baltic.

Description: Crabs were collected from inner Kiel Fjord by scraping in November 2018, in order to study their tolerance to salinity and consequently their ability to establish a population along the Baltic Sea, in addition, their feeding rates were estimated under laboratory condition. Experiments were conducted in constant climate temperature room (~12 °C) at GEOMAR during December 2018.