ALBERT

Description: The data have been extracted and compiled from various sources but mainly from the ICES data base. The ICES data are from catch databases downloaded from the ICES website on 2014-01-14. These data are resolved by ICES area, country and year. During inspection of these data, it was noted that Norwegian data for years before 1950 had not been entered into the catch database on the ICES website. ICES has been notified of this omission by B. R. MacKenzie. The Norwegian data from ICES Bulletins. Statistiques has been added. Additional historical bluefin tuna catch data from other fishery reports and sources have been included in the data file for years preceding those when countries started reported their landings officially to ICES. These additional data have been reported in the literature previously (MacKenzie and Myers 2007, Fisheries Research).

Description: Owing to anthropogenic emissions, atmospheric concentrations of carbon dioxide could almost double between 2006 and 2100 according to business-as-usual carbon dioxide emission scenarios. Because the ocean absorbs carbon dioxide from the atmosphere, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states. As a consequence, it has been suggested that marine calcifying organisms, for example corals, coralline algae, molluscs and foraminifera, will have difficulties producing their skeletons and shells at current rates, with potentially severe implications for marine ecosystems, including coral reefs. Here we report a seven-week experiment exploring the effects of ocean acidification on crustose coralline algae, a cosmopolitan group of calcifying algae that is ecologically important in most shallowwater habitats. Six outdoor mesocosms were continuously supplied with sea water from the adjacent reef and manipulated to simulate conditions of either ambient or elevated seawater carbon dioxide concentrations. The recruitment rate and growth of crustose coralline algae were severely inhibited in the elevated carbon dioxide mesocosms. Our findings suggest that ocean acidification due to human activities could cause significant change to benthic community structure in shallow-warm-water carbonate ecosystems.

Description: The data are swordfish (Xiphias gladius) bycatches from the artisanal bluefin tuna fishing trap located at Milazzo, Sicily, Italy. The data have been recovered from historical records, reports and archives associated with the traps. Data records include the locations and dates for the catches and the catch in numbers and/or weight in given months. Catch data in weight are not available on specific days for these years at this site. The time period is 1896-1901. Catch data in numbers are however available on specific days for these years at this site; see accompanying data set #928996. The data have been recovered to increase understanding of the long-term dynamics of the population and its fisheries, including effects of exploitation and climate variability and change, and to provide baseline knowledge against which future variations can be compared.

Description: The data set contains swordfish (Xiphias gladius) bycatches from artisanal bluefin tuna fishing traps located at four sites in Italy. Data records include the locations and dates for the catches and the catch in numbers and/or weight on given days during 1896-2010. The data have been recovered to increase understanding of the long-term dynamics of the population and its fisheries, including effects of exploitation and climate variability and change, and to provide baseline knowledge against which future variations can be compared. There are presently few other similarly long data sets for this species in this region. The data have been recovered from historical records, reports and archives associated with the traps.

Description: This data set contains data for the start, end and duration of the fishing season for artisanal bluefin tuna fishing traps located at four sites in Italy during 1896-2010. The data have been recovered from historical records, reports and archives associated with the traps.

Description: Future anthropogenic emissions of CO2 and the resulting ocean acidification may have severe consequences for marine calcifying organisms and ecosystems. Marine calcifiers depositing calcitic hard parts that contain significant concentrations of magnesium, i.e. Mg-calcite, and calcifying organisms living in high latitude and/or cold-water environments are at immediate risk to ocean acidification and decreasing seawater carbonate saturation because they are currently immersed in seawater that is just slightly supersaturated with respect to the carbonate phases they secrete. Under the present rate of CO2 emissions, model calculations show that high latitude ocean waters could reach undersaturation with respect to aragonite in just a few decades. Thus, before this happens these waters will be undersaturated with respect to Mg-calcite minerals of higher solubility than that of aragonite. Similarly, tropical surface seawater could become undersaturated with respect to Mg-calcite minerals containing 〉=12 mole percent (mol%) MgCO3 during this century. As a result of these changes in surface seawater chemistry and further penetration of anthropogenic CO2 into the ocean interior, we suggest that (1) the magnesium content of calcitic hard parts will decrease in many ocean environments, (2) the relative proportion of calcifiers depositing stable carbonate minerals, such as calcite and low Mg-calcite, will increase and (3) the average magnesium content of carbonate sediments will decrease. Furthermore, the highest latitude and deepest depth at which cold-water corals and other calcifiers currently exist will move towards lower latitudes and shallower depth, respectively. These changes suggest that anthropogenic emissions of CO2 may be currently pushing the oceans towards an episode characteristic of a 'calcite sea.'

Description: Analysis of pelagic clay samples from Sites 576, 578, and 581 shows that physical, acoustic, and electrical trends with increasing burial depth are related to mineralogical and diagenetic changes. The properties of interest are bulk density (roo), porosity (phi), compressional-wave velocity (Vp) and velocity anisotropy (Ap), and electrical resistivity (Ro) and resistivity anisotropy (Ar). In general, as demonstrated in particular for the brown pelagic clay, the increase in roo, Vp, Ro, and to a lesser extent Ap and Ar with increasing depth is primarily caused by decreasing phi (and water content) as a result of compaction. The mineralogy and chemistry of the pelagic clays vary as a function of burial depth at all three sites. These variations are interpreted to reflect changes in the relative importance of detrital and diagenetic components. Mineralogical and chemical variations, however, play minor roles in determining variations in acoustic and electrical properties of the clays with increasing burial depth.