Environmental Engineering Reference
In-Depth Information
Regime shifts
Regime shifts arise when a combination of climatic, biological and physical
changes lead to persistent new sets of ecosystemic characteristics that
represent deviations or shifts from the historic record. Even though regime
shifts have an extensive record in geologic time, the temporal and spatial
scales at which these shifts have occurred recently is what concerns scientists
the most. For instance changes in precipitation frequency and intensity,
ocean acidifi cation, water temperature increase, changing wind patterns,
hydrology fl uctuations and alterations, combined with anthropogenic
pollution by nutrients and toxins, all can affect water quality in estuarine
and coastal waters (Hall 2002, Gitay et al. 2002).
It has been demonstrated that for the past 20 to 30 years (in comparison
to the previous 100 years), El Niño-Southern Oscillation (ENSO) events have
increased their frequency, persistence and intensity (Gitay et al. 2002). This
basin-scale phenomenon has well-documented effects not only on coastal
regions, but effect on several teleconnections to distant areas on land and
on other ocean basins have also been established.
Global Change Effects on Biotic Components of Coastal
Ecosystems
Invasive species in coastal marine ecosystems
Non-indigenous species
(NIS;
synonyms: alien, exotic, non-native,
allochthonous) are species or lower taxa introduced outside of their (past
or present) natural range and beyond their natural dispersal potential.
This includes any (vegetative or reproductive) structure that might survive
and subsequently reproduce (Council Regulation 2007). Their presence in
a new system is due to intentional or unintentional introduction resulting
from human activities, and might have implied various pathways and/or
vectors.
Invasive alien species
(IAS)
are a subset of established NIS with
the potential or actual ability to spread elsewhere, and have an adverse
effect on biological diversity, ecosystem functioning, socio-economic values
and/or human health in invaded regions. Species of unknown origin which
cannot be ascribed as being native or alien are termed cryptogenic species
(
sensu
Carlton 1996).
Biological pollution
is defi ned as the adverse impacts
that IAS can cause on one or more levels of biological organization (Elliott
2003, Olenin et al. 2010).
IAS represent an increasing problem in marine coastal waters (Olenin
et al. 2011). In contrast to more enclosed water bodies, the openness of
marine systems indicates that once a species is in an area, then eradication
is usually impossible. When the number of species involved in the pathway
