A proteomic analysis of the statocyst endolymph in common cuttlefish (Sepia officinalis): an assessment of acoustic trauma after exposure to sound.

Recent studies, both in laboratory and sea conditions, have demonstrated damage after sound exposure in the cephalopod statocyst sensory epithelium, which secretes endolymph protein. Here, the proteomic analysis of the endolymph was performed before and after sound exposure to assess the effects of exposure to low intensity, low frequency sounds on the statocyst endolymph of the Mediterranean common cuttlefish (Sepia officinalis), determining changes in the protein composition of the statocyst endolymph immediately and 24 h after sound exposure. Significant differences in protein expression were observed, especially 24 h after exposure. A total of 37 spots were significantly different in exposed specimens, 17 of which were mostly related to stress and cytoskeletal structure. Among the stress proteins eight spots corresponding to eight hemocyanin isoforms were under-expressed possible due to lower oxygen consumption. In addition, cytoskeletal proteins such as tubulin alpha chain and intermediate filament protein were also down-regulated after exposure. Thus, endolymph analysis in the context of acoustic stress allowed us to establish the effects at the proteome level and identify the proteins that are particularly sensitive to this type of trauma.

Distribution and risk assessment of radionuclides released by Fukushima nuclear accident at the northwest Pacific.

In order to understand the impact of Fukushima Nuclear Accident (FNA) on the marine environment, seawater and a composite squid (Ommastrephe bartrami) sample were collected on the monitoring cruise XT01 during June 16-July 4, 2011. The concentration levels of Cesium-134, Cesium-137, Strontium-90, Silver-110 m, Cobalt-58 and Cobalt-60 were measured both for the seawater and squid samples. The elevated activity levels of Cesium-134 and Cesium-137 were found in the sampling area. Cesium-134 and Silver-110 m, which were usually undetectable before FNA, were also found in the squid sample, with the activity levels of 1.65 ± 0.13 Bq/kg-wet and 0.07 ± 0.01 Bq/kg-wet, respectively. The radiological assessment result showed that the radioactive release from the FNA would not have a significant adverse effect on marine biota at the population level.

Levels of ²¹°Po and ²¹°Pb in fish and molluscs in Slovenia and the related dose assessment to the population.

²¹°Po and ²¹°Pb activity concentrations in fish from the Slovenian part of Adriatic Sea, in the vicinity of a former uranium mine at Zirovski vrh and from the Slovenian market were determined. In addition, ²¹°Po and ²¹°Pb activity concentrations in squid from the Slovenian market and in mussels from the Slovenian part of the Adriatic Sea were also determined. Fish, squid and mussel consumption in Slovenia was assessed from the data available from Eurostat and Food and Agriculture Organisation (FAO) and the data used for the corresponding dose calculation. Fish species with the highest activity concentrations were grilled to assess possible loss of ²¹°Po during the food preparation process. Samples were freeze dried and radiochemical separation of ²¹°Po and ²¹°Pb was performed. Measurements of ²¹°Po were performed by alpha spectrometry and ²¹°Pb by a low background gas-flow proportional counter. ²¹°Po activity concentrations in fish, squid and mussels were from 0.039 to 35.0 Bqkg⁻¹ fresh weight and ²¹°Pb activity concentrations were from 0.08 to 3.03 Bqkg⁻¹ fresh weight. Grilling of fish resulted in no significant loss of ²¹°Po at 90°C. The assessed combined annual effective ingestion dose due to ²¹°Po and ²¹°Pb for fish, squid and mussels consumed in Slovenia is 47.6 µSv year⁻¹.