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of nitrate, ammonium, phosphate, diatoms, flagellates,
cyanobacteria, zooplankton, detritus, and oxygen:
BALTSEM [5,6], ERGOM [7], and RCO-SCOBI [8]. The
models are structurally different in that ERGOM and RCO-
SCOBI are 3D circulation models comprising sub-basin
scale processes while BALTSEM resolves the Baltic Sea
spatially in 13 sub-basins. The biogeochemical sub-models
are of similar type but the process descriptions differ. For
the case studies in the Gulf of Finland and Vistula Lagoon
two regional models forced with lateral boundary data from
the basin-wide models are used during selected time slices.
Food web modeling
The food web of the Baltic Sea will be simulated by
applying the ecological software EwE (www.ecopath.org).
An existing food web model for the Baltic Sea has already
been used, and contains 15 functional groups from primary
producers to seals and fishery [9]. The model was
parameterized with a focus on fish (sprat, herring and cod).
EwE is an excellent tool to: a) address ecological questions;
b) evaluate ecosystem effects of fishing; c) explore
management policy options; d) evaluate impact and
placement of marine protected areas; and e) evaluate effects
of environmental changes.
The regional results from the focus study sites will be
scaled up to the Baltic Sea scale. This will support the
charting of socioeconomic implications from different
climate scenarios (e.g. [15,16]). Especially, the costs of
nutrient load reductions of defined ecological targets of
Baltic Sea water quality in present and future climates will
be calculated with the Nest economic model [17]. The
metric difference between the results will provide us with
a first estimate of costs related to changing climate.
3. First results
First results from scenario simulations of biogeochemical
cycles are now available calculated with the coupled
physical-biogeochemical model RCO-SCOBI. The ocean
model is forced with atmospheric and hydrological fields
from the regional climate model RCAO driven with lateral
boundary from ECHAM4/OPYC3 (or HadAM3H, not
shown). As an example Figure 2 shows annual mean
phytoplankton concentrations in present and future
climates assuming four socioeconomic scenarios with
corresponding nutrient loadings from land. The results
suggest that climate change may have a significant impact
on the ecosystem and needs therefore to be considered in
the Baltic Sea management.
At present, process-based and statistical models for Baltic
Sea fish species can link climatic forcing and lower trophic
level processes to fish dynamics. These models will be
integrated within ECOSUPPORT by linking them to outputs
from physical-biogeochemical models. Dynamics of cod,
herring and sprat have been shown to be driven partly by
fluctuations in climate, eutrophication and lower trophic
level processes, including those which directly affect
reproductive success [10], feeding and survival of larvae,
and feeding and growth of adults [11].
We will generate Bioclimatic Envelope Models (BEMs)
for key species in the Baltic Sea system (and in the models
used here) to assess the susceptibility of these taxa to rangeextension
and possible local extinction arising from climate
change. BEMs will be constructed using statistical
modelling (CART, [12]) trained with historical distribution
data for key taxa, and corresponding oceanographic
environmental data [13].
Socioeconomic impact assessment
For the focus study sites, Gulf of Finland, Vistula Lagoon
and the Polish coastal waters, we will conduct assessments
of the impact of climate change on the regional and local
development. The economic assessment of the ecosystem
goods and services delivered from key ecosystems/habitats
within the Baltic Sea (Fucus beds, mussel beds, seagrass,
shallow soft bottom habitats) and processes (benthic-pelagic
coupling, filtration) follows the methods of [14]. In order to
develop management strategies for sustainable use and
conservation in the marine environment, reliable and
meaningful, but integrated ecological information is needed.
Biological valuation maps that compile and summarize all
available biological and ecological information can be used
as baseline maps for future spatial planning at sea. Rather
than a general strategy for protecting areas that have some
ecological significance, biological valuation is a tool for
calling attention to areas which have particularly high
ecological or biological significance and to facilitate
provision of a greater-than-usual degree of risk aversion in
management of activities in such areas.
Fig. 2: Annual mean phytoplankton concentration
[mgChl/m 3 ] (0-10m). Present climate (upper panels),
future climate according to ECHAM4/A2 for 2071-2100
(lower panels), reference conditions of nutrient supply
during 1969-1998 (first column), nutrient load scenarios
following the most optimistic (best) case (second column),
the Baltic Sea Action Plan (third column), and the most
pessimistic case assuming business as usual (fourth
column). The nutrient load scenarios have been developed
by the Baltic Nest Institute.
References
[1] Räisänen et al. 2004, Clim. Dyn., [2] Lindström et al.
1997, J. Hydrol., [3] Robertson et al. 1999, J. Appl.
Meteor., [4] Engardt & Foltescu 2007, SMHI Meteorologi
No. 125, [5] Gustafsson et al. 2008, Göteborg University,
Report No.C82, [6] Savchuk & Wulff 1999,
Hydrobiologia, [7] Neumann et al. 2002, Global
Biogeochemical Cycles, [8] Eilola et al. 2009, J. Mar.
Sys., [9] Österblom et al. 2007, Ecosystems, [10]
MacKenzie & Köster 2004, Ecology, [11] Casini et al.
2006, Oikos, [12] Breiman et al. 1984, Wadsworth,
Belmont, [13] Lima et al. 2007, Global Change Biology,
[14] Weslawski et al. 2006, Oceanologia, [15] Kaivo-Oja
et al. 2004, Boreal Env. Res., [16] Holman et al. 2005,
Climatic Change, [17] Gren and Wulff 2004, Regional
Envi-ron. Change