Ecosystem Services

occur in these types of environment but only to a lesser extent compared to angiosperms
(Rosqvist et al. 2010, Snickars et al. 2009, 2010).
Lagoons, estuaries and embayments of various sizes are common coastal habitats
all over the world, including the Nordic countries. This chapter is focused on shallow
wave sheltered bays and inlets in the northern Baltic Sea, although e.g. charophytes
and angiosperms may be found in similar biotopes along the coast of Norway, in areas
strongly influenced by freshwater runoff, as well as along the German coastline.
Shallow and wave sheltered bays and inlets are primarily found in the archipelago
areas of the Baltic proper and Gulf of Bothnia, in particular along the Swedish east
coast, the Åland Islands and the Finnish coast. Within the Finnish and Swedish archipelagos,
two main gradients determine the abiotic conditions of the bays, namely the degree
of habitat isolation (i.e. flad to gloe developmental stage, which influence water
exchange with the adjacent sea), and archipelago position from the inner to the outer
archipelago. Together, isolation and position have a strong influence on vegetation and
juvenile fish composition (Appelgren and Mattila 2005, Rosqvist et al. 2010, Snickars et
al. 2009), although biotic couplings also play a vital part (Bonsdorff and Blomqvist
1993). The degree of isolation and archipelago position is correlated with salinity, which
is a particularly important driver for the large scale distribution of species in the Baltic
Sea (Sandman et al. 2012, Pecuchet et al. 2016).
6.2 Threats and challenges
Coastal development and eutrophication are among the major threats to bays and inlets
of the northern Baltic Sea (Bergström et al. 2013, Eriksson et al. 2004, Sandström et al.
2005, Sundblad and Bergström 2014), which are also poorly protected by the Natura 2000
network of marine protected areas (Sundblad et al. 2011). These ecosystems are subject
to heavy exploitation through shoreline development, and habitat degradation rates due
to constructions are accelerating (Sundblad and Bergström 2014).
Boating and navigational activities can change vegetation community composition
and have negative effects on the development of macrophytic vegetation. These activities
can decrease the height and coverage of Chara spp. and Potamogeton spp., as well
as juvenile fish abundance (Eriksson et al. 2004, Sandström et al. 2005).
Negative effects of eutrophication are related to reduced light penetration and increased
system productivity, which can occur when nutrient loads exceed the filtering
capacity of the primary producers (McGlathery et al. 2007). However the effects of eutrophication
on these habitats, serving as fish recruitment areas, and thus indirectly on
82 Ecosystem Services