dynamics of water and coastal substrates should be permitted, wherever possible. In
many parts of the world, for example, dunes are fixed for coastal protection purposes, even if it is not necessary. Dune areas often represent positive sedimentation
rates, and structures such as sea dikes might increase coastal challenges. Also, many
coastal ecosystems are negatively impacted by invasive species; limiting natural
seashore dynamics in combination with invasive species often has negative conservation effects.
Zero-fishery and zero-tourism zones for up to 10% of the coastline and coastal
waters may be realistic targets, since the number and range of protected areas on the
coasts are increasing worldwide. In many cases, special nature conservation
programmes and measures have to be implemented, e.g. to protect turtle nesting
sites on coastal beaches and to eradicate introduced species on islands. Ecotourism
partially has, and may have further, positive effects. This depends on the intensity of
scientific monitoring, the nature of political agreements, and the direction of economic investments.
5.2.3 Freshwater Ecosystems, Mires, Bogs, Fens and Swamps
Aquaculture and agriculture influence rivers, groundwater, lakes, and mires over
long distances. Furthermore, pollution including industrial and domestic wastewater,
washout of fertilizers, hormones, pesticides and other chemical components often
has a much stronger impact on plants and animals living in wetlands than in other
habitats, as water is not only the living space, but is also the transportation and
dispersal medium. Because freshwater habitats are often relatively isolated from
each other, the effects of human-assisted range expansions of alien and native
invasive species and pathogens can always become very problematic and should
be intensively monitored.
In many regions, wetlands are impacted by construction activities, such as dams
and barrages, or by technical regulation of the water table. Such constructions can
heavily alter or limit natural processes such as upstream dispersal of freshwater
organisms.
Freshwater habitats in Europe are less strongly impacted by new constructions
than in other parts of the world. This has to do with the fact that most of these
constructions are already in place. Additionally, the European Water Framework
Directive does not allow a declining quality with respect to chemical and ecological
conditions—theoretically. Indeed, the kinds of threats and the number of endangered
organisms living in European freshwater ecosystems are as numerous as in other
parts of the world.
The focus has to be expanded to include external factors affecting freshwater
ecosystems. Nature conservation measures that are purely associated to issues within
the water bodies and immediate vicinity will be unsuccessful on the whole.
In some parts of the industrial world, the removal or decomissioning of dams
towards original hydrological conditions has already been realized or is under
consideration.
472
C. Hobohm et al.
many parts of the world, for example, dunes are fixed for coastal protection purposes, even if it is not necessary. Dune areas often represent positive sedimentation
rates, and structures such as sea dikes might increase coastal challenges. Also, many
coastal ecosystems are negatively impacted by invasive species; limiting natural
seashore dynamics in combination with invasive species often has negative conservation effects.
Zero-fishery and zero-tourism zones for up to 10% of the coastline and coastal
waters may be realistic targets, since the number and range of protected areas on the
coasts are increasing worldwide. In many cases, special nature conservation
programmes and measures have to be implemented, e.g. to protect turtle nesting
sites on coastal beaches and to eradicate introduced species on islands. Ecotourism
partially has, and may have further, positive effects. This depends on the intensity of
scientific monitoring, the nature of political agreements, and the direction of economic investments.
5.2.3 Freshwater Ecosystems, Mires, Bogs, Fens and Swamps
Aquaculture and agriculture influence rivers, groundwater, lakes, and mires over
long distances. Furthermore, pollution including industrial and domestic wastewater,
washout of fertilizers, hormones, pesticides and other chemical components often
has a much stronger impact on plants and animals living in wetlands than in other
habitats, as water is not only the living space, but is also the transportation and
dispersal medium. Because freshwater habitats are often relatively isolated from
each other, the effects of human-assisted range expansions of alien and native
invasive species and pathogens can always become very problematic and should
be intensively monitored.
In many regions, wetlands are impacted by construction activities, such as dams
and barrages, or by technical regulation of the water table. Such constructions can
heavily alter or limit natural processes such as upstream dispersal of freshwater
organisms.
Freshwater habitats in Europe are less strongly impacted by new constructions
than in other parts of the world. This has to do with the fact that most of these
constructions are already in place. Additionally, the European Water Framework
Directive does not allow a declining quality with respect to chemical and ecological
conditions—theoretically. Indeed, the kinds of threats and the number of endangered
organisms living in European freshwater ecosystems are as numerous as in other
parts of the world.
The focus has to be expanded to include external factors affecting freshwater
ecosystems. Nature conservation measures that are purely associated to issues within
the water bodies and immediate vicinity will be unsuccessful on the whole.
In some parts of the industrial world, the removal or decomissioning of dams
towards original hydrological conditions has already been realized or is under
consideration.
472
C. Hobohm et al.