Impact of leakages on marine ecosystems

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1 Impact of leakages on marine ecosystems Cinzia De Vittor

2 ph When dissolves in seawater, H2CO3 is formed. Most of the H2CO3 quickly dissociates into a hydrogen ion (H+) and HCO3- + H2O H2CO3 HCO3- + H+ A hydrogen ion can then react with a CO32- to form bicarbonate. HCO3- CO32- + H+ The net effect of adding to seawater is to increase the concentrations of H2CO3, HCO3-, and H+ and decrease the concentration of CO32- and lower ph (ph= -log[h+]) + H2O H2CO3 HCO3- + H+ CO H+ Shortly: when is introduced, ph decrease, the amount of dissolved (aqueous) and of bicarbonate increase and the number of carbonate ions decrease.

3 Task.1 Study of fatigue effects induced on micro-organisms by ph variations due to emissions Target species the coccolithophore Pleurochrysis cf. pseudoroscoffensis 10 µm 5 µm calcareous nanophytoplankton marine species isolated in the Gulf of Trieste with external calcite (CaCO3) plates (coccoliths) covering their surface Coccolithophores play key roles in: marine ecosystem as primary producers marine biogeochemistry as producers of organic carbon, carbonate and dimethyl sulphide They are major sediment formers, biostratigraphic marker fossils and valuable indicators of paleoceanographic change

(coccoliths) covering their surface Coccolithophores play key roles in: marine ecosystem as primary producers marine biogeochemistry as producers of

4 Facilities gas mixer illumination ph controller gas mixer: - 1 channel 2 cylindrical photobioreactors: coaxial geometry in Poly(methyl methacrylate) (PMMA, plexiglass) culture volume: 18 L (H=65 cm, diamex=25 cm, diamin=16 cm) internal illumination ( µe m-2 sec-1) (/) tube at the bottom for mixing and lift up timer for light:dark cycle ph controller

culture volume: 18 L (H=65 cm, diamex=25 cm, diamin=16 cm) internal illumination (

5 Experiment 1 gas mixer illumination T = 20 ± 1 C light:dark cycle 12:12 cell abundances growth rate coccolith morphological changes at scanning electron microscopy (SEM) ph controller control 1% nutrients POC TPC ph alkalinity DIC

coccolith morphological changes at scanning electron

6 Task.2 - induced variations on energy-transfer processes related to the trophic web PLANCTONIC TROPHIC WEB microzooplankton and heteronanoplankton potential predators microphitoplankton and phototroph and heterotroph nanoplankton potential prey predation of microzooplankton and heteronanoplankton on procariotes Grazing of microzooplankton lowers the apparent growth rate of phytoplankton. It is impossible to divide phytoplankton and grazers in a natural plankton sample, because both are fragile and often of the same size. But growth and grazing of autotrophic and heterotrophic natural planktonic populations can be estimated using the dilution method (Landry and Hasset, 1982).

microzooplankton lowers the apparent growth rate of phytoplankton.

7 Dilution method theory (Landry & Hassett, 1982). The dilution approach assumes that the specific growth rates of prey population is density-independent in a dilution series but that grazing mortality is proportionally reduced by dilution of predator density during an incubation period (2h). The method also assumes that population growth rate of predator and prey remains constant across treatments. Accordingly, if supposed that the growth of the prey population is being represented by the exponential equation where Pt is the density of the prey population at time t, Po is the density of the prey population at time zero, k is the prey population growth rate, and g is the prey population mortality rate due to grazing, the progressive uncoupling of growth and mortality in a series of increasing dilutions can be observed as differences in the apparent growth rates of the prey population. The exponential growth equation is converted into a linear model by log transformation and rearrangement and the apparent growth rates are plotted as a function of dilution (X) using The regression analysis of these data yields intercept values (zero grazer) for prey growth (k) and slope corresponding to consumer grazing (-g) where a significative negative slope (1-tailed t-test, p<0.05) suggests measurable predator control on prey population.

predator density during an incubation period (2h). The method also assumes that population growth rate of predator and prey remains constant across treatments.

8 Experimental design Natural population sampled in the Gulf of Trieste in the period of presumed algal bloom (February / March) 5 dilutions t0 for dilution control 5 dilutions at natural ph (3 replicates each) 2h 5 dilutions at ph ~7 (3 replicates each) 2h Parameters: Microphitoplankton Microzooplakton Autotroph and heterotroph nanoplankton Prokaryotic abundance Chemistry: ph, Alkalinity, dissolved inorganic carbon, nutrients

2h 5 dilutions at ph ~7 (3 replicates each) 2h Parameters: Microphitoplankton Microzooplakton Autotroph

9 Task.3 - -induced chemical diffusion processes at the watersediment interface ph 7 CO 2 SEDIMENT SEDIMENT Parameters: Control SEDIMENT CO 2 He Continuous monitoring : ph, T, Cond., O2, Torb. Discrete samples for analysis of: ph, alkalinity, inorganic nutrients, DIC, heavy metals. 2 replicates per treatment - total 6 aquariums

10 Task. - Accumulation of toxic substances transported by flow from sediments in bivalves Experiment conducted with the same water of the previous experiments in which metals have been mobilized by emission ph 7 Control 1 Control 2 From exp. with He Parameters: Chemical characterization (metals, carbonatic system, etc.) in water Metals accumulated in the mussels Plankton characterization

mobilized by emission ph 7 Control 1 Control 2 From exp.

11 Task.5 - Improvement of the monitoring techniques Comparison of all the data of ph and p collected with different techniques (continuous monitoring, laboratory analysis) Evaluation of instrument sensitivity and repeatability of measurements

different techniques (continuous monitoring, laboratory

12 Deliverables Del n. Deliverable name WP n. Nature Date D.1 Dataset experiment with the bioreactor A April 2013 D.2 Report on the interpretation of the effects of to algae Pleurochrysis R May 2013 D.3 Dataset of the dilution experiment A July 2013 D. Report of the effect on the planktonic trophic web R November 2013 D.5 Dataset on the pollutant mobilization experiment A August 2013 D.6 Report on the effects on the pollutant mobilization R September 2013 D.7 Report on potential bioaccumulation phenomena in shellfish R November 2013 D.8 Data report on the comparison of ph and p data obtained with different techniques R December 2013 Milestones M.1 Preparation bioreactor experiment December 2012 M.2 Preparation dilution experiment March 2013 M.3 Preparation pollutant mobilization experiment April 2013 M. Preparation bioaccumulation experiment May 2013 M.5 Comparison of ph and p dataset November 2013

6 Report on the effects on the pollutant mobilization R September 2013 D.7 Report on potential bioaccumulation phenomena in shellfish R November 2013 D.

What are the controls for calcium carbonate distribution in marine sediments?

What are the controls for calcium carbonate distribution in marine sediments? Lecture 14 Marine Sediments (1) The CCD is: (a) the depth at which no carbonate secreting organisms can live (b) the depth at which seawater is supersaturated with respect to calcite (c) the depth at which