Survival of Atlantic cod larvae from the Barents Sea and the Western Baltic sea due to ocean acidification from two experiments

The data show the survival data of Atlantic cod larvae from two different stocks, which were measured in two separate experiments in Kristineberg, Sweden in 2013 on the Western Baltic stock and in Tromsö, Norway in 2014 on the Barents Sea stock. Survival was measured as a response to ocean acidification, control tanks were kept at ambient CO2 concentrations. CO2 concentrations and feeding concentrations are also provided.

Altered neurotransmitter function in CO2-exposed stickleback (Gasterosteus aculeatus): a temperate model species for ocean acidification research

Studies on the consequences of ocean acidification for the marine ecosystem have revealed behavioural changes in coral reef fishes exposed to sustained near-future CO2 levels. The changes have been linked to altered function of GABAergic neurotransmitter systems, because the behavioural alterations can be reversed rapidly by treatment with the GABAA receptor antagonist gabazine. Characterization of the molecular mechanisms involved would be greatly aided if these can be examined in a well-characterized model organism with a sequenced genome. It was recently shown that CO2-induced behavioural alterations are not confined to tropical species, but also affect the three-spined stickleback, although an involvement of the GABAA receptor was not examined. Here, we show that loss of lateralization in the stickleback can be restored rapidly and completely by gabazine treatment. This points towards a worrying universality of disturbed GABAA function after high-CO2 exposure in fishes from tropical to temperate marine habitats. Importantly, the stickleback is a model species with a sequenced and annotated genome, which greatly facilitates future studies on underlying molecular mechanisms.

Geotechnical properties of shelf sdiments from the Prydz Bay

This paper presents a geotechnical characterization of the glacigenic sediments in Prydz Bay, East Antarctica, based on the shipboard physical properties data obtained during Leg 119, combined with results of land-based analyses of 24 whole-round core samples. Main emphasis is placed on the land-based studies, which included oedometer consolidation tests, triaxial and simple shear tests for undrained shear strength, permeability tests in oedometer and triaxial cell, Atterberg limits, and grain-size analyses. The bulk of the tested sediments comprise overconsolidated diamictites of a relatively uniform lithology. The overconsolidation results from a combination of glacial loading and sediment overburden subsequently removed by extensive glacial erosion of the shelf. This leads to downhole profiles of physical properties that have been observed not to change as a function of the thickness of present overburden. A number of fluctuations in the parameters shows a relatively systematic trend and most likely results from changes in the proximity to the ice sheet grounding line in response to variations in the glacial regime. Very low permeabilities mainly result from high preconsolidation stresses (Pc'). Pc' values up to 10,000 kPa were estimated from the oedometer tests, and empirical estimates based on undrained shear strengths (up to 2500 kPa) indicate that the oedometer results are conservative. The diamictites generally classify as inactive, of low to medium plasticity, and they consolidate with little deformation, even when subjected to great stresses. This is the first report of geotechnical data from deep boreholes on the Antarctic continental shelf, but material of similar character can also be expected in other areas around the Antarctic.

Physiological and biochemical characteristics of polar cod (Boreogadus saida) from Kongsfjorden

Seasonality of biomarker baseline levels were studied in polar cod (Boreogadus saida), caught in Kongsfjorden, Svalbard, in April, July, September and December, 2006-2007. Physiological parameters (condition factor, gonado- and hepato-somatic indexes, energy reserves, potential metabolic activity and antifreeze activity) in polar cod were used to interpret the seasonality of potential biomarkers. The highest levels of ethoxyresorufin-O-deethylase (EROD) activity occurred concomitantly with the highest potential metabolic activity in July due to e.g. intense feeding. During pre-spawning, EROD showed significant inhibition and gender differences. Hence, its potential use in environmental monitoring should imply gender differentiation at least during this period. Glutathione S-transferase and catalase activities were stable from April to September, but changed in December suggesting a link to low biological activity. Knowledge of the biomarker baseline levels and their seasonal trends in polar cod is essential for a trustworthy interpretation of forthcoming toxicity data and environmental monitoring in the Arctic.

Effects of increased CO2 on fish gill and plasma proteome

Ocean acidification and warming are both primarily caused by increased levels of atmospheric CO2, and marine organisms are exposed to these two stressors simultaneously. Although the effects of temperature on fish have been investigated over the last century, the long-term effects of moderate CO2 exposure and the combination of both stressors are almost entirely unknown. A proteomics approach was used to assess the adverse physiological and biochemical changes that may occur from the exposure to these two environmental stressors. We analysed gills and blood plasma of Atlantic halibut (Hippoglossus hippoglossus) exposed to temperatures of 12°C (control) and 18°C (impaired growth) in combination with control (400 µatm) or high-CO2 water (1000 µatm) for 14 weeks. The proteomic analysis was performed using two-dimensional gel electrophoresis (2DE) followed by Nanoflow LC-MS/MS using a LTQ-Orbitrap. The high-CO2 treatment induced the up-regulation of immune system-related proteins, as indicated by the up-regulation of the plasma proteins complement component C3 and fibrinogen beta chain precursor in both temperature treatments. Changes in gill proteome in the high-CO2 (18°C) group were mostly related to increased energy metabolism proteins (ATP synthase, malate dehydrogenase, malate dehydrogenase thermostable, and fructose-1,6-bisphosphate aldolase), possibly coupled to a higher energy demand. Gills from fish exposed to high-CO2 at both temperature treatments showed changes in proteins associated with increased cellular turnover and apoptosis signalling (annexin 5, eukaryotic translation elongation factor 1 gamma, receptor for protein kinase C, and putative ribosomal protein S27). This study indicates that moderate CO2-driven acidification, alone and combined with high temperature, can elicit biochemical changes that may affect fish health.