Listed below is background material on the
Baltic Sea Large Marine Ecosystem. To keep this site up-to-date, users
are requested to provide relevant information or links to the LME webmaster .
Brief Description:
The Baltic Sea Large Marine Ecosystem
is characterized by its temperate climate. It is enriched by a high level
of nutrients. It is a semi-enclosed sea, strongly influenced by human-induced
eutrophication, river runoff and a lack of rapid exchange with the adjacent
ocean. Intensive fishing is the primary force driving the LME, with eutrophication
as the secondary driving force. The Global Environment Facility (GEF) is
supporting an LME project in the Baltic Sea, to address critical threats
to the coastal and marine environment, and to promote ecosystem-based management
of coastal and marine resources. Information is available on the GEF-sponsored Baltic Sea
LME Project. LME book chapters and articles pertaining to this LME include
Kullenberg, 1986, and Jansson, 2003.
I. Productivity:
The shallow Baltic Sea LME is one of the
largest brackish water bodies in the world. It is essentially a fjord that
is 1,500 kilometers long with an average width of 230 kilometers. The sea
is divided into basins and includes the Gulf of Finland and Gulf of Bothnia.
Large-scale meteorological conditions determine long-term fluctuations of
salinity and temperature in the deep and bottom waters. Large pulses of
North Sea water cause deeper areas to flip between oxic and anoxic conditions
(see Jansson, 2003). For hydrodynamic processes, see Jansson, 2003. The
Baltic Sea receives fresh water from river runoff, with a maximum in May
and a minimum in January or February. For more information on oceanographic
characteristics and trends, and for oxygen conditions, see Kullenberg, 1986.
The Baltic Sea LME and its catchment area have a range of ecotones and biological
diversity. Its brackish waters contain a mixture of marine and freshwater
species. The coastal areas serve as spawning, nursery and feeding areas
for several species of fish. The Baltic Sea LME is considered a Class I,
highly productive (>300 gC/m2-yr) ecosystem based on SeaWiFS global primary
productivity estimates. There are changes in the productivity of the near
coastal and offshore waters from eutrophication. See a summary of "Eutrophication
in the Baltic Sea". The traditional monitoring program for plankton used
by the countries surrounding the Baltic Sea LME has proven to be unreliable
in detecting rapid changes in the ecosystem e.g. toxic phytoplankton blooms
and marked regional variations. Despite long-time observations, the dynamics
of the system are not understood well enough to explain long-term changes
or to make reliable predictions. Dynamic models need to be developed that
can be used to investigate the response times of various ecosystem components
to marked natural events. An augmentation to the ICES inter-disciplinary
monitoring program will be implemented to improve the quality of temporal
and spatial coverage of the Baltic Sea LME. Ships of opportunity will assess
changes in the plankton communities especially in relation to fish. There
will be coordinated ICES surveys in the near shore and open sea.
II. Fish and Fisheries:
The Baltic Sea LME has both marine fish in high salinity waters and fresh water species that cannot tolerate high salinity and are found near the coast. The FAO 10-year trend shows an increase in the catch from 650,000 tons in 1990 to 900,000 in 1999 (see FAO, 2003), with a peak in 1997. The average level is 800,000 tons. The LME is characterized by predominant catches of small pelagic clupeoids (herrings, sardines and anchovies) that represent almost 80% of the total identified shelf catches. Cods, hakes and haddocks represent the second largest group. For Baltic Sea catches of herring, sprat, and cod from 1910 to 1995, see Jansson, 2003. The cod catch increased in the late 1970s, as did the total fish catch. The stocks seemingly benefited from an increased input of nutrients (see Otterlind, 1983). Degraded water quality has had an impact on the Baltic Sea LME and its productivity. The Global International Waters Assessment (GIWA) has issued a matrix that ranks LMEs according to the sustainable exploitation of fisheries and the predicted direction of future changes. GIWA characterizes the LME as severely impacted in terms of overfishing, but the impact is decreasing (see the GIWA web site). See the Baltic Sea Fishery Commission Report. The recovery of depleted fishery resources and damaged habitats can be achieved in the coastal areas and in the open sea through cooperative action by the countries bordering the LME. At present, the countries in the Eastern part of the Baltic Sea do not have the same capacity to conduct spatial and temporal fish stock or pollution impact surveys as those in the Western Baltic Sea. The Baltic Sea Regional Program of ICES and HELCOM will be implemented in part to provide financial support to the recipient eastern Baltic bordering nations (Poland, Latvia, Estonia, Lithuania, Russia) in extending the ICES fisheries surveys eastward. Action plans are being developed to determine Total Allowable Catches (TACs) for salmon, cod, sprat and herring. For long-term changes in the Baltic Ecosystem, see Kullenberg, 1986. The University of British Columbia Fisheries Center has detailed fish catch statistics for this LME.
III. Pollution and Ecosystem Health:
The Baltic Sea has a drainage basin area that is four times larger than the Sea itself. For a map of the Baltic Sea’s drainage basin, see Jansson, 2003. The Baltic Sea’s ecological deterioration has been caused in recent years by an increase of point source industrial and non-point source agricultural pollutants and by the non-sustainable use of living marine resources. The increase in anthropogenic impacts is leading to environmental change and degradation. The need to address the problem of agricultural inputs into the Baltic Sea LME has been highlighted in the Baltic Sea Joint Comprehensive Environmental Action Program (JCP). There is a degradation of coastal water quality from pollution, harmful algal blooms and contaminant loading. It has been subject to outbreaks of fish kills, marine mammal and seabird mortalities and invasive species. The pollution problems are transboundary and difficult to address on an individual country basis. For more information on eutrophication, metals in sediment and fish, PCB and DDT pollution, see Jansson, 2003. Anoxic conditions are on the rise due to climatic variations (see Pedersen, 1982), and the increase of organic material (see Anon., 1984). Data collection is fragmented, although ICES (the International Council for the Exploration of the Sea) has developed a program for measuring the effects of pollution and natural environmental changes on the productivity of Baltic living marine resources. For an understanding of eutrophication in the Baltic Sea, see this document. See a study of "Present conditions in the Baltic Marine Environment".
IV. Socio-economic conditions:
Baltic 21 is an initiative on the part
of the Prime Ministers of the Baltic Sea Region to develop an Agenda 21 for
the Baltic Sea Region (see www.ee/baltic21/).
Baltic 21 statistics indicate that the fishery industry contributes significantly
to the regional and local economy. Sustenance fishing is critical to the
social and economic welfare of the coastal communities in the eastern Baltic
Sea. The countries bordering the Baltic Sea must develop effective strategies
for the management of their shared resources and promote sustainable fishery
practices. Sustainable management is needed to provide social and economic
benefits to farming, coastal and fishing communities, and sectors such as
businesses and tourism. Few but large population centers and harbors are
found along the eastern and southern borders of the Baltic Sea (see Bruneau,
1980). There are conflicting human uses of the Baltic Sea with waste disposal,
sea transportation, fishing, aquaculture, and recreation.
V. Governance:
The coastal countries involved in this
LME’s governance are Sweden, Finland, Estonia, Latvia, Lithuania, Poland,
Russia, Denmark and Germany. However, the Baltic Sea catchment area is vaster
and includes non-coastal countries such as Belarus, Ukraine, the Czech Republic
and the Slovak Republic (see Kindler and Lintner, 1993, map page 9). The JCP (see above) was prepared under the coordination
of the Helsinki Commission (HELCOM). It was adopted as a strategic action
program for the region by the Ministers of Environment in 1992, and was
updated in 1998. The JCP recognizes the need to use an ecosystem-based management
approach that recognizes the freshwater, coastal and marine resources together.
The Global Environment Facility (GEF) is supporting an LME project in the
Baltic Sea (see above). Agencies collaborating in the GEF project include
the Baltic Sea Fisheries Commission and ICES. The project integrates land,
coastal and open sea activities and aims to strengthen local and regional
capacity. The project brings jointly-planned monitoring and assessment surveys.
The JCP considers agricultural inputs as a priority issue. For more information
on institutional evolution for meeting sustainable development, see Jansson,
2003. There is a need to develop the technical, scientific, and local capacity
of the eastern Baltic countries in order for them to fully participate with
western Baltic countries in improving the long-term sustainability and socioeconomic
benefits for this LME. Institutional evolution has resulted in the banning
of hazardous substances and in programs for decreasing emissions of nutrients
and wastes from industries and the transportation sector.
References cited:
Articles
and LME volumes:
Baltic 21. www.ee/baltic21/
FAO, 2003. Trends in
oceanic captures and clustering of large marine ecosystems—2 studies based
on the FAO capture database. FAO fisheries
technical paper 435. 71 pages.
Jansson, B.-O., 2003.
The Baltic Sea. In: K. Sherman and G. Hempel, Large Marine Ecosystems of
the World – Trends in Exploitation,
Protection and Research.
Kullenberg, G. 1983.
The Baltic Sea. In Estuaries and Enclosed Seas, Ed. By B.H. Ketchum, vol
26, Ecosystems of the World, Elsevier,
Amsterdam, 500 pp.
Kullenberg, Gunnar. 1986.
"Long-term changes in the Baltic Ecosystem." In Kenneth Sherman and Lewis
M. Alexander (eds.), Variability
and Management of Large Marine Ecosystems (Boulder: Westview, 1986).
AAAS Selected Symposim 99.
Other references:
Anonymous, 1984. Iltsvind
of Fisksedod I 1981. Omfang og Arsager. In Danish; Miljostyrelsen, Strandgade 29, 1401 Copenhagen K. 247pp.
Bianchi, TS, P. Westman,
T. andren, C. Rolff and R. Elmgren, 2000. Cyanobacterial blooms in the Baltic
Sea: natural or human induced? Limnol.
Oceanogr. 45:716-726.
Bonsdorff, E., E. Blomqvist,
J. Mattila and A. Norkko, 1997. Coastal eutrophication—causes, consequences and perspectives in the archipelago
areas of the Northern Baltic Sea. Estuar. Coastal Shelf Sci. 44:63-72.
Brugmann, L. 1981. Heavy
metals in the Baltic Sea. In The State of the Baltic, Ed. By G. Kullenberg,
Mar. Pollut. Bull. 12 (6):214-218.
Bruneau, L. 1980. Pollution
from industries in the drainage area of the Baltic. Ambio, Special issue
on the Baltic p. 145-152.
Dybern, B.I. and Fonselius,
S.H. 1981. Pollution. In The Baltic Sea, pp. 351-382. Ed. By A. Voipio.
Elsevier Oceanography Series 30, Amsterdam.
418 pp.
Ehil, U. 1981. Hydrology
of the Baltic Sea. In The Baltic Sea, pp. 1230-134. In The Baltic Sea, pp.
123-143. Ed. By A. Voipio. Elsevier
Oceanography Series 30, Amsterdam. 418 pp.
Flinkman, J., Aro, E.,
Vuorinen, I., and M. Viitasalo, 1998. Changes in northern Baltic zooplankton
and herring nutrition from 1980s to
1990s: top-down and bottom-up processes at work. Mar. Ecol. Prog. Ser. 165:127-136.
HELCOM, 1996. Third Periodic
Assessment of the State of the Marine Environment of the Baltic Sea, 1989-93; Background document. Balt. Sea Environ,
Proc. No. 64B. Helsinki Commission - Baltic Marine Environment Protection
Commission. 252 p.
ICES. 1980. Assessment
of the marine environment of the Baltic Sea Cooperative Research Report
63, ICES, Copenhagen, 97 pp.
Jansson, B.O. 1978. The
Baltic - a systems analysis of a semi-enclosed sea. In Advances in Oceanography,
pp 131-184. Ed. By H. Charnock and
G. Deacon, Plenum Press, Oxford.
Jansson, B.O. 1984. The
Baltic Sea and the nutrients. In The Baltic Sea - an environment worth protecting.
Symposium in Karlskrona, Sweden. June
1984.
Kindler, J. and S.F.
Lintner, 1993. An Action Plan to clean up the Balitc. Environment, volume
35, number 8, pp. 7-31.
Otterlind, G. 1983. Ostersjon
och overgodningen. Yrkesfiskaren no. 18-20, in Swedish, Marine Research
Laboratory, 45300 Lysekil, Sweden.
Pawlak, J. 1980. Land-based
inputs of some major pollutants to the Baltic Sea. Ambio Special issue on
the Baltic, pp. 163-167.