Aliens Newsletter - ISSG

“Beaufort Scale” for bioinvasion impacts
Sergej Olenin & Aleksas Narsˇčius
Why a standardized bioinvasion impact assessment
system?
More than two hundred years ago Sir Francis Beaufort,
a British admiral and hydrographer, introduced
a scale of sea state to oblige his naval officers reporting
weather observations in a standardized way.
It seems that bioinvasion science and management
needs something similar in order to reduce subjectivism
in assessment and reporting the impacts
caused by Invasive Alien Species (IAS). So far such
assessments have been based on expert judgment.
Even in the listings of worst invaders their impacts
often are being reported without indication on how
severe the impact is.
On another side, a standardized description and
evaluation of impacts is needed for many applications,
e.g. for compilation of “black” lists of target
IAS and comparative account of their harmful effects;
prioritization of management options, which
involve species that can be practically managed in
some way; for compassion of the same IAS in different
ecosystems; and even for overall environmental
status assessments taking into account the
bioinvasion effects in particular territories or water
bodies.
Theory: a biopollution level index
The approach to estimate the magnitude of bioinvasion
impacts or “Biopollution level” (BPL) index
was developed by a team of researchers within two
recent EU funded projects, ALARM and DAISIE
(Olenin et al., 2007). Biological pollution is defined
as the impact of alien species on ecological quality
and includes (but is not confined to) the genetic
alteration within populations, the deterioration or
modification of habitats, the spreading of pathogens
and parasites, competition with and replacement of
native species, etc.
The BPL method takes into account the abundance
and distribution range (ADR) of alien species in relation
to native biota and aggregates data on the
magnitude of the impacts in three categories: 1) impacts
on native communities, 2) habitats and, 3)
ecosystem functioning. ADR varies within five
classes, ranking an alien species from low abundance
in a few localities (A) to occurrence in high
numbers in all localities (E). After ADR is established,
three categories of impacts are considered,
whose magnitude is ranked on five levels ranging
from no impact (0) to massive impact (4) based on
qualitative changes in an invaded ecosystem. The
theoretical justification uses several well established
ecological concepts, e.g. “key species”, “type specific
communities”, “habitat alteration, fragmentation
and loss”, “functional groups”, “food web
shift”, etc. BPL aggregates the results of the assessment
into five categories: “No bioinvasion impact”,
“Weak”, “Moderate”, “Strong” and “Massive”.
The assessment should be performed in a defined
assessment unit (a coastal lagoon, a lake, an island,
etc) and for a defined assessment period. Primarily
the method was designed for aquatic environment,
but now it is being adapted for terrestrial
species and ecosystems as well.
Implementation
The theoretical background was used to develop a
system aimed at translation of existing data on miscellaneous
invasive species impacts into uniform
biopollution measurement units: BINPAS (Biological
Invasion Impact / Biopollution Assessment System).
The experimental version of BINPAS was
published in early 2008. The application and database
is hosted by the server of the Coastal Research
and Planning Institute, Klaipeda University, Lithuania.
Since then BINPAS is being developed using
open source web technologies (Apache, PHP5) and
MySQL relational database management system.
The system is freely accessible by internet at
http://corpi.ku.lt/databases/binpas/.
Registration to BINPAS is open for all willing to
contribute with their data. On login to BINPAS a
registered user can create a new assessment unit ac-
52 29/2010