(Table 1) Contents of chlorophyll a over the Northern Sea Route according to data of field measurements and estimated from MODIS data on measurement days

New maps of mean monthly distribution of chlorophyll and primary production in the Kara Sea were compiled using joint processing of CZCS (1978-1986), SeaWiFS (1998-2005), and MODIS (2002-2006) satellite data and field measurements. The annual primary production of phytoplankton is estimated at 22.3 x 10**6 t C per year or 70 mg C/m**2 per day. Results of calculations of the organic carbon budget in the Kara Sea are presented.

The influence of temperature and seawater carbonate saturation state on 13C-18O bond ordering in bivalve mollusks

The shells of marine mollusks are widely used archives of past climate and ocean chemistry. Whilst the measurement of mollusk delta 18O to develop records of past climate change is a commonly used approach, it has proven challenging to develop reliable independent paleothermometers that can be used to deconvolve the contributions of temperature and fluid composition on molluscan oxygen isotope compositions. Here we investigate the temperature dependence of 13C-18O bond abundance, denoted by the measured parameter Delta 47, in shell carbonates of bivalve mollusks and assess its potential to be a useful paleothermometer. We report measurements on cultured specimens spanning a range in water temperatures of 5 to 25 °C, and field collected specimens spanning a range of -1 to 29 °C. In addition we investigate the potential influence of carbonate saturation state on bivalve stable isotope compositions by making measurements on both calcitic and aragonitic specimens that have been cultured in seawater that is either supersaturated or undersaturated with respect to aragonite. We find a robust relationship between Delta 47 and growth temperature. We also find that the slope of a linear regression through all the Delta 47 data for bivalves plotted against seawater temperature is significantly shallower than previously published inorganic and biogenic carbonate calibration studies produced in our laboratory and go on to discuss the possible sources of this difference. We find that changing seawater saturation state does not have significant effect on the Delta 47 of bivalve shell carbonate in two taxa that we examined, and we do not observe significant differences between Delta 47-temperature relationships between calcitic and aragonitic taxa.

Conflicting effects of predator cue and ocean acidification on the mussel Mytilus coruscus byssus production

Understanding the impact of ocean acidification and warming on communities and ecosystems is a researcher priority. This can only be achieved through a combination of experimental and field approaches that would allow developing a mechanistic understanding of impacts across level of biological organizations. Surprisingly, most published studies are still focusing on single species responses with little consideration for interspecific interactions. In this study, the impacts of a 3 days exposure to three parameters (temperature, pH, and presence/absence of the predator cue of the crab Charybdis japonica) and their interactions on an ecologically important endpoint were evaluated: the byssus production of the mussel Mytilus coruscus. Tested temperatures (25°C and 30°C) were within the present range of natural variability whereas pH (8.1, 7.7, and 7.4) covered present as well as near-future natural variability. As expected, the presence of the crab cue induced an antipredator response in Mytilus coruscus (significant 10% increase in byssus secretion rate, 22% increase in frequency of shed byssus, and 30% longer byssus). Decreased pH but not temperature had a significant negative impact on the same endpoints (up to a 17% decrease in byssus secretion rate, 40% decrease in frequency of shed byssus, and 10% shorter byssus at pH 7.3 as compared with pH 8.1) with no significant interactions between the three tested parameters. In this study, it has been hypothesized that pH and predator cue have different modes of action and lead to conflicting functional responses (escape response versus stronger attachment). Functional consequences for ecosystem dynamics still need to be investigated.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Soil characteristics and decomposition of organic matter on Anchorage, Signy and Falkland Islands

Antarctic terrestrial ecosystems have poorly developed soils and currently experience one of the greatest rates of climate warming on the globe. We investigated the responsiveness of organic matter decomposition in Maritime Antarctic terrestrial ecosystems to climate change, using two study sites in the Antarctic Peninsula region (Anchorage Island, 67°S; Signy Island, 61°S), and contrasted the responses found with those at the cool temperate Falkland Islands (52°S). Our approach consisted of two complementary methods: (1) Laboratory measurements of decomposition at different temperatures (2, 6 and 10 °C) of plant material and soil organic matter from all three locations. (2) Field measurements at all three locations on the decomposition of soil organic matter, plant material and cellulose, both under natural conditions and under experimental warming (about 0.8 °C) achieved using open top chambers. Higher temperatures led to higher organic matter breakdown in the laboratory studies, indicating that decomposition in Maritime Antarctic terrestrial ecosystems is likely to increase with increasing soil temperatures. However, both laboratory and field studies showed that decomposition was more strongly influenced by local substratum characteristics (especially soil N availability) and plant functional type composition than by large-scale temperature differences. The very small responsiveness of organic matter decomposition in the field (experimental temperature increase <1 °C) compared with the laboratory (experimental increases of 4 or 8 °C) shows that substantial warming is required before significant effects can be detected.