Ecosystem services provided by the Baltic Sea ... - Naturvårdsverket

SWEDISH ENVIRONMENTAL PROTECTION AGENCY
Report 5873 • Ecosystem services provided by the Baltic Sea and Skagerrak
Economic Marine Information
like marine aggregates and oil, their use cannot be considered sustainable. In contrary,
the are not particularly threatened.
Fodder
Current demand for fish meal may add to the fishery crisis and limited sustainability
of this service might reduce its value to the industries concerned. Today farmed
fish are typically reared on fish meal and fish oil, originating from wild-caught fish
(chapter P1). Recalling the 5 kg of wild caught fish supplies one 1 kg of salmon
filet. (158), it becomes apparent that large supplies of fodder fish are the currently
prime requisite for continuous fish farming. Meanwhile the small-pelagic fish typically
used for fodder typically provides an important function in the ecosystem,
constituting food source for many predatory fishes and seabirds. Fodder fishing is a
typical example of what’s referred to as “fishing down the food chain” (177). In
response to declines of commercially valuable stocks of larger, slower growing
species (e.g. cod), commercial fishing fleets have turned to targeting increasingly
large quantities of smaller species of fish with less commercial value. Within the
fodder fishery, sprat may be the most sustainable target species, as its stock is currently
dominating the Baltic. In fact, experiments to significantly reduce sprat
stocks in order to restore food webs are currently carried out by SBF (25).
Marine aggregates
The extraction of marine aggregates cannot be considered sustainable. It causes
considerable damage and the renewal of this resource is extremely slow. Marine
aggregate extraction increases the risk of erosion on shores where sand has been
taken. Long-term environmental impact of removing sea sand results in changes to
currents and sedimentation and possibly also locally to oxygen depletion. These
changes are likely to affect fauna, fish stocks, and seabed vegetation and erosion
patterns. An environmental impact assessment (EIA) examining proposed extraction
of rock material for harbour filling in the Gulf of Finland concluded that the
activity could significantly increase turbidity and destroy local bottom communities
(178). As an example, though not from our region, marine aggregate extraction
off Dieppe in France caused 80 % reduction in the species richness and 90 % reduction
in abundance of local macrofauna. Subsequent recovery was slow and
incomplete (179).
Oil
Oil prospecting and extraction have severe environmental consequences, not to
mention the burning of the fuels generated from the crude oil. While Sweden is
currently developing techniques for renewable energy, in order to reduce CO 2
emissions, introducing oil extraction in Swedish waters clearly appears contraproductive.
The extraction of oil from the sea bed may infer mechanic disturbance
with detrimental consequences for the maintenance of habitat and biodiversity.
Finally, subsequent transport of the oil, being a hazardous substance, always poses
increased risk to various aspects of the marine environment and the services which
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