North Aegean Sea Kostas Tsiaras, Chris Smith, George ... - meece

North Aegean Sea
Kostas Tsiaras, Chris Smith, George Petihakis,
George Triantafyllou
H.C.M.R
Scenario definition Workshop
Bologna, June 2010

N. Aegean Coupled model
Hydrodynamic model: POM (Blumberg and Mellor, 1983)
Biogeochemical model: ERSEM-II (Baretta et al., 1995)
POC
DOC
N, P, Si
PicoPhyto Flagellates
NanoPhyto Diatoms
Bacteria
Heterotr.
Flagellates
Microzoo
Pelagic Model
Mesozoo
Si
CO 2
NO 3
PO 4 NH4
Sedimentation
Benthic Model

Hindcast simulation 1985-2007 (spin-up 1980-1985)
Atm. Forcing: 1980-2001 ERA40 Downscaled (0.5 o x 0.5 o ), Hermann and Somot, 2008
2000-2008 HCMR POSEIDON operational (6-hour, 1/10)
Rivers: Q, NO3, PO4 from SESAME, Ludwig et al. 2009, Dumont et al., 2005
Initial Condition: NO3, PO4 from Medatlas 2002 climatology +spin-up
Open sea productivity
~ vertical mixing variability
+ net nutrient flux across boundary
-Dense water formation events (EMT)
-SST increase around 1998 (~0.7 o C)

Climatic time-slice simulations 1990-2000 & 2090-2100 (A1B)
to be extended to 20 years (1980-2000 & 2080-2100)
Atm. Forcing: INGV-SXG (A1B, 1.2 o x 1.2 o ), Scoccimarro, 2007
to be compared with IPSL forcing
Rivers: Q, NO3, PO4 from SESAME (A1B scenario),
Ludwig et al. 2009, Dumont et al., 2005
Initial Condition: from hindcast simulation
Increase in SST (~1 o C) +similar SSS
increased stratification
decrease in River discharge (~46%)
+increase in nutrients concentrations ->
~similar nutrient river load (~8% decrease)
weak productivity decrease in
open sea (1%) and
river influenced areas (3%)

Implementation of Acidification module
-Setup of Mediterranean carbonate system model and preliminary simulations
-Validation against DYFAMED and SESAME data
-further calibration/validation in progress
DYFAMED data SESAME data
Begovic et al., 2002
Krasakopoulou et al., submitted

Biomass (tonnes)
ERSEM-POM coupling with OSMOSE
Coupling Setup done
Mapping of the area,
Link of LTL model (ERSEM) with OSMOSE (7 phyto-zooplankton groups)
Test case with 3 key species (anchovy, sardine, Scomber japonicus)
140000
120000
100000
80000
60000
40000
20000
0
1 3 5 7 9 11
Year
13 15 17 19
Anchovy
Sardine
In progress
-setup of genetic algorithm to calibrate OSMOSE
-finalize parameter set for all N. Aegean species
Chub Mackeler Species Landings (Kg) % A
Engraulis engrasicolus 23,502,489 43.7
Sardina pilchardus 13,221,956 24.6
Merluccius merluccius 4,406,099 8.2
Boops boops 2,708,538 5.0
Scomber japonicus 2,706,409 5.0
Trachurus sp. 1,548,909 2.9
Spicara smaris 1,149,183 2.1
Scomber scombrus 1,137,496 2.1
Sarda sarda 999,290 1.9
Total 53,734,618

Fisheries
Coupled ERSEM-OSMOSE model - possible fishing scenarios:
1) Equilibrium (no change, constant harvesting of species)
2) Different changes in effort (Fishing days, No. of boats)
3) Change in closed fishing areas (geographical or depth related)
4) Change in closed fishing seasons (Purse seines, trawlers)
5) Fisheries pressure on specified species
Species Fishing Gear Open Season
Engraulis engrasicolus Purse seine 1 Mar - 15 Dec
Sardina pilchardus Purse seine 1 Mar - 15 Dec
Merluccius merluccius Trawl 1 Oct - 30 May
Boops boops Purse seine, Trawl 1 Mar - 15 Dec / 1 Oct - 30 May
Scomber japonicus Purse seine 1 Mar - 15 Dec
Trachurus trachurus
Trachurus mediterraneus
Spicara smaris
Scomber scombrus
Sarda Sarda

Eutrophication/Land-based inputs – Thermaikos gulf
Possible scenarios
different water discharge (Climatic change)
different nutrient loads and N/P from Axios river based on EUROCAT project
(simulated by MONERIS catchment model under different assumptions regarding policies, agriculture
development etc)
• Fertiliser plants
• P-free detergents
• Urban waste
• 1. BAU
Nikolaidis et al., 2009
2. Policy Target
3. Deep green

Eutrophication/Atm-Deposition - Aegean
Atmospheric deposition plays a significant role in the oligotrophic Aegean Sea as is one of
the main routes of nutrients into the marine environment
Possible scenarios
different atmospheric deposition (Climatic change of rainfall ±10%)
different nutrient load composition in the deposition
Land-based inputs/Acidification
different Alkalinity input (provided by WP1?)
Organic pollutants (Thermaikos)
Possible scenarios
different loads (Marco?)

Session 3. GES indicators for the N. Aegean
Descriptor 3: Populations of all commercially exploited fish and shellfish are within
safe biological limits, exhibiting a population age and size distribution
that is indicative of a healthy stock.
Level of pressure of the fishing activity
Descriptor 4: All elements of the marine food webs
Productivity (production per unit biomass) of key species or trophic groups
Abundance /distribution of key trophic groups/species
Descriptor 5: Human induced eutrophication
Nutrient levels
Direct effects of nutrient enrichment
Descriptor 8: Concentration of contaminants are at levels not giving rise to pollution
effects
Effects of contaminants

Session 4. Scenarios
Fisheries
Coupled ERSEM-OSMOSE scenarios:
Equilibrium (no change, constant harvesting of species)
Different changes in effort (Fishing days, No. of boats)
Change in closed fishing areas (geographical or depth related)
Change in closed fishing seasons (Purse seines, trawlers)
Eutrophication/Land-based inputs/Atm-Deposition
Thermaikos riverine inputs - variation in discharge and nutrient load
N. Aegean atmospheric inputs - variation in inputs and quality (?)
Pollution
Thermaikos riverine inputs – variation in organic pollutants load