Hopes and expectations: theconceptual course of future for marine ecosystems and fishery
Latvian Institute of Aquatic EcologyLatvian Fish Resources Agency
UL Institute of BiologyUL Faculty of Biology
Expected outcomes of WP work
• Improved knowledge on possible processes;• Participation in constructing environmental
legislation;• Recommendations for management and
adaptation strategies.
Gulf of Riga – future scene
Gulf of Riga – ecosystem projections
Winters without ice cover - • Earlier development of plankton communities,
higher biomassShift from Achnantes taeniata to Thalassiosira
baltica, Chaetoceros spp., Melosira nummuloides
• Shift in breeding time of benthic species, mostly amphipods
Gulf of Riga – ecosystem projectionsSprings with faster
stratification –• Dominance of
dinoflagellates or ...nothing special;
• Higher share of small size fraction in zooplankton.
0
4000
8000
12000
mg/
m3
0
10
20
30
40
119. st.
0
4000
8000
12000
mg/
m3
0
10
20
30
40165. st.
30.0
1.24
.02.
14.0
3.29
.03.
11.0
4.27
.04.
9.05
.18
.05.
31.0
5.
30.0
1.25
.02.
14.0
3.29
.03.
11.0
4.24
.04.
9.05
.18
.05.
30.0
5.
C yanophyceae
D iatom ophyceae
D inophyceae
Cryptophyceae
Chlorophyceae
Pârçjâs
H lorofils a
16.0
6.27
.06.
14.0
6.27
.06.
17.0
7.25
.07.
16.0
7.25
.07.
10.0
8.7.
08.
29.0
8.29
.08.
6.09
.28
.09.
4.09
.28
.09.
15.1
0.15
.10.
8.11
.8.
11.
27.1
1.5.
12.
27.1
1.5.
12.
18.1
2.19
.12.
Gulf of Riga – ecosystem projectionsWarmer summers: two options
Increased wind intensity:• Frequent upwellings,
productive coastal areas;• Reduced cyanobacterial
blooms.
Calm weather dominating:
Gulf of Riga – ecosystem projections
• Zooplankton Acartia bifilosa, Limnocalanus macrurus,
Evadne nordmanni, Pleopsis polyphemoides Daphnia spp., Cyclops spp.
• Macrozoobenthos Gammarus sp., Bathyporeia pilosa, Marenzelleria viridis, Macoma baltica
• Phytobenthos ???
Gulf of Riga - fisheries• Gulf of Riga
herring – growth expected and forecasted, still – spawning stock biomass hardly above the mean;
• Reason – high fishing mortality, low recruitment.
0
20000
40000
60000
80000
100000
120000
140000
1977
1980
1983
1986
1989
1992
1995
1998
2001
2004
2007
Nār
sta
bar
a b
iom
asa,
t
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
paaudze
milj
on
i
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
The Baltic Sea – ecosystem projections in conditions of reduced salinity and higher
temperature• Species structures
gradually similar to the Gulf of Riga;
• Coastal areas – level of human activities significant: nutrient loads;
• Further reduction of inhabited bottoms.
The Baltic Sea - fisheries
• The Eastern Baltic cod – fishing mortality as a key factor
1980 2000 2020 2040 2060 2080 2100
020
040
060
0
F = 1.08
Year
SS
B (
thou
sand
tons
)
w ithout climate changew ith climate change
1980 2000 2020 2040 2060 2080 21000
200
500
F = 0.7
Year
SS
B (
thou
sand
tons
)
1980 2000 2020 2040 2060 2080 2100
040
010
00
F = 0.3
Year
SS
B (
thou
sand
tons
)
1980 2000 2020 2040 2060 2080 2100
010
0020
00
F = 0
Year
SS
B (
thou
sand
tons
)
Conclusions
• Coastal zone would strengthen its position as a key area in the aspect of productivity and biodiversity;
• The Gulf of Riga and the Baltic Sea would continue being attractive for invasive species;
• The climate change would intensify or mask the impact of key factor - human activities.
Recommendations:• elaborate and implement the load reduction activities as soon as
possible in all related areas (agriculture, water resources management etc.);
• create zonation of the coastal underwater areas with various level of protection according to the functional importance of the site;
• perform regular observations of marine environment and provide model calculations of processes, based on the observations for flexible management decisions;
• reduce the fishing mortality via exclusion of illegal fishing;
• follow the international regulations preventing the distribution of non-native species.
Thank you for your attention!