Candidatura Reserva da Biosfera - Santana Madeira Biosfera

Feral cat (Felis silvestris catus) and the Least weasel (Mustela nivalis) were introduced.
This set of introduced terrestrial predators cause high mortality in native species,
especially those using the cliffs as shelter and breeding area such as birds and bats. The
high predatory pressure exerted on the populations of birds and bats, can lead to
abandonment of the cliffs as preferred areas for breeding, causing a decrease in secure
areas available for these species. Besides exotic animals, introduced exotic flora species
besides competing with the indigenous plant species for substrate and nutrients are
limiting available nesting spaces for several seabirds’ species.
The discharge of untreated wastewater in coastal waters has harmful effects on
marine species due to the input of many infectious agents in the aquatic environment
that may influence the survivability of various organisms by affecting the base of the
food chain composed by plankton, zooplankton and necton and consequently the top
level predators such as mammals and seabirds.
The most damaging impact on the marine environment as a result of anthropogenic
activities, is undoubtedly the deposition of mud, from activities developed in the stream
beds, on the rocky seabed. The heavier particles are deposited on the entire marine
substrate, preventing the fixation of many organisms, especially algae, crustaceans and
molluscs, which are the main food sources for fish, while the finest fraction remains in
suspension preventing the normal penetration of solar radiation, affecting the
photosynthetic capacity of algae and their development. The effects of a lower incidence
of radiation are well known in many marine areas, particularly in the intertidal, where
chlorophytes algae disappeared from the surface layer, where they were dominant, being
replaced by ochrophyta algae, which are usually dominant on deeper levels, indicating
that the solar radiation that reaches midlittoral is the same as in clear waters would
reach the infralittoral.
12.2.4. Relevant management practices
In order to minimize existing impacts on local fauna and flora, resulting from
anthropogenic activities, some mitigation measures on the main threats and aditionally
Application of Santana, Madeira to Biosphere Reserve – UNESCO - MAB 101