Ecosystem Services

3.3 Supporting services
3.3.1 Habitat and biodiversity
Already on his trip to the Strait of Magellan in 1834, Charles Darwin was astonished
about the diversity of the great kelp forests of South America. Darwin writes in “The
voyage of the Beagle”: I can only compare these great aquatic forests of the southern
hemisphere with the terrestrial ones in the intertropical regions. Yet if in any country a forest
was destroyed, I do not believe nearly so many species of animals would perish as
would here, from the destruction of the kelp. Amidst the leaves of this plant numerous
species of fish live, which nowhere else could find food or shelter; with their destruction the
many cormorants and other fishing birds, the otters, seals, and porpoises, would soon perish
also; and lastly, the Fuegian savage, the miserable lord of this miserable land, would
redouble his cannibal feast, decrease in numbers, and perhaps cease to exist.
The three dimensional structure of the kelp forest provides habitat, nursery
ground and food for myriad mobile pelagic and benthic organisms (Christie et al.
2003, Steneck et al. 2002).
Typically, the stipe (the kelp stem) is grown with algae, mostly red algae, but also
brown- and green algae (Figure 8). It has been found that more than 50 different epiphytic
algae exist in one single kelp stipe. In addition to epiphytic algae, there are also
large numbers of epiphytic fauna on the stipe. The most important groups are tunicates,
sponges and bryozoans, which can also cover large parts of the lamina (the kelp
leaf). Recent studies have found a surprisingly rich fauna of mobile invertebrates. Such
animal societies can consist of 2–300 different species and having densities of more
than 100 000 individuals of snails, crustaceans, clams, polychaetas and other invertebrates
per square meter (Christie et al. 2009).
Within and above the kelp forest we find during summertime large densities of different
stationary fish species, such as labridae (eng: wrasse; no: leppefisk; swe: läppfiskar)
and gobies (no: kutling; swe: smörbult). The two-spotted goby, for instance, being
no more than 10 cm long, is considered as Norway’s most numerous fish during
summertime and important in the transfer of energy from seaweed and up to larger
fish. Other large fish stocks utilize coastal ecosystems as nurseries and feeding grounds
and kelp forests are among the most important habitats for both commercial species
(e.g. cod, pollock, pike, and perch) and red list species (e.g. the coastal cod, Steneck et
al. 2002, Ottersen et al. 2010). These fish are in turn further predated by higher trophic
species, such as coastal seals and several species of seabirds (Lorentsen et al. 2010).
Ecosystem Services 41