Diurnal pH and temperature oscillations.

<p>Biologically induced pH fluctuation (increase during photosynthesis; decrease as result of respiration) in the present-day <i>p</i>CO₂ treatment tank (393 µatm) with (diamonds) and without sponges (circles), showing the causal relationship with the illumination phase (top); temperature fluctuation in the same tank affected by heat radiated off the metal halide lamps (bottom, triangles).</p

On the Long-run Neutrality of Demand Shocks

Long run neutrality restrictions have been widely used to identify structural shocks in VAR models. This paper revisits the seminal paper by Blanchard and Quah (1989), and investigates their identification scheme. We use structural VAR models with smoothly changing covariances for identification of shocks. The resulted impulse responses are economically meaningful. Formal test results reject the long-run neutrality of demand shocks

The geographic, geomorphological, and oceanographic framework of the study area (modified from [50]).

<p>A: The geographic framework of the study area within the Mediterranean Sea. B: The geological setting showing the Apulian Ridge as the foreland system of both the Appennines and Hellenic fold-and-thrust belts. B: The oceanographic setting showing ASW (Adriatic Surface Water), LIW (Levantine Intermediate Water), and ADW (Adriatic Dense Water) within the study area.</p

Summary of experimental settings, carbonate system parameters, nutrient levels, photosynthesis parameters, and sponge bioerosion figures (all values are given as mean values ± standard deviation for 10 days of exposure).

*<p>Carbonate system parameters computed with the software CO2SYS.</p>**<p>One contaminated sample excluded from analysis.</p

A list of the abundance of anthropogenic items and the traces identified by video analysis at each macrohabitat.

<p>Abundance is reported for each site (MS04, MS06, MS08 and ReefABC) and for the total investigated area (all sites) expressed as the number of occurrences/10 m². <i>d</i> indicates disposal (litter and solid waste, mostly plastic materials); <i>fl/n</i> indicates the rests of fishing lines and nets; and <i>t</i> indicates trawling traces.</p

Results (<i>p</i> values) from the pairwise comparison of bioerosion rates in the four <i>p</i>CO₂ treatments (Mann-Whitney test; Bonferroni corrected <i>p</i> values in lower left triangle of matrix) performed after Kruskal-Wallis analysis (H = 21.25; Hc = 21.25; <i>p</i><0.0001; n = 8 per treatment) and rejection of normal distribution for the present-day (393 µatm) and the elevated treatment (571 µatm) via Shapiro-Wilk test.

*<p>significant difference.</p

Water temperature measurement during the experiment from March 2008–2009.

<p>Dashed line marks the replacement from summer to winter platforms in October 2008. Due to platform and data loss, no water temperature is available for 15 and 250 m winter exposure, respectively.</p

Effects of Water Depth, Seasonal Exposure, and Substrate Orientation on Microbial Bioerosion in the Ionian Sea (Eastern Mediterranean)

<div><p>The effects of water depth, seasonal exposure, and substrate orientation on microbioerosion were studied by means of a settlement experiment deployed in 15, 50, 100, and 250 m water depth south-west of the Peloponnese Peninsula (Greece). At each depth, an experimental platform was exposed for a summer period, a winter period, and about an entire year. On the up- and down-facing side of each platform, substrates were fixed to document the succession of bioerosion traces, and to measure variations in bioerosion and accretion rates. In total, 29 different bioerosion traces were recorded revealing a dominance of microborings produced by phototrophic and organotrophic microendoliths, complemented by few macroborings, attachment scars, and grazing traces. The highest bioerosion activity was recorded in 15 m up-facing substrates in the shallow euphotic zone, largely driven by phototrophic cyanobacteria. Towards the chlorophyte-dominated deep euphotic to dysphotic zones and the organotroph-dominated aphotic zone the intensity of bioerosion and the diversity of bioerosion traces strongly decreased. During summer the activity of phototrophs was higher than during winter, which was likely stimulated by enhanced light availability due to more hours of daylight and increased irradiance angles. Stable water column stratification and a resulting nutrient depletion in shallow water led to lower turbidity levels and caused a shift in the photic zonation that was reflected by more phototrophs being active at greater depth. With respect to the subordinate bioerosion activity of organotrophs, fluctuations in temperature and the trophic regime were assumed to be the main seasonal controls. The observed patterns in overall bioeroder distribution and abundance were mirrored by the calculated carbonate budget with bioerosion rates exceeding carbonate accretion rates in shallow water and distinctly higher bioerosion rates at all depths during summer. These findings highlight the relevance of bioerosion and accretion for the carbonate budget of the Ionian Sea.</p></div

The experimental setup.

<p>Low-flow open system in a constant temperature room (T = 25°C) using filtered sea-water (25 µm) stored in a reservoir tank, with four treatment lines (<i>p</i>CO₂ = 339 µatm, 393 µatm, 571 µatm, and 1410 µatm) each comprising a perturbation tank connected to a gas mixing pump, leading to an illuminated (12∶12 h) treatment tank with replicate petri dishes (n = 8 per treatment, containing 4 sponge-bearing coral cores) and controls (n = 3 per treatment, containing 4 clean coral cores), terminating in the buoyant weighing unit.</p

Increasing sponge bioerosion as a function of increasing <i>p</i>CO₂.

<p>(A) Weight loss per replicate set translated to bioerosion rates for the four <i>p</i>CO₂ treatments. The linear regression of the 32 replicates (8 per treatment) is highly significant (r² = 0.76; <i>p</i><0.0001). (B) Projected percent increase in sponge bioerosion relative to the present-day level, calculated for the BERN-CC model based on the SRES A2 (red), A1B (blue), and B1 (green) emission scenarios.</p