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europe
26 options + summer 2016 www.iiasa.ac.at
regional focus
Gone fishing: New stocking strategies to keep
Irrsee’s anglers busy
Recreational fishing is a popular pastime in Austria, where
every summer keen anglers head to Alpine lakes with
their—as yet—plentiful yields of whitefish. But as water
temperatures rise as a result of global warming, both the biomass
of the whole populations of these fish and that of the catch will
become increasingly affected.
IIASA researcher Rupert Mazzucco participated in a study to
see how stock management can be used to mitigate the effects of
climate change. The study centred on Lake Irrsee, whichÂ
is heavily
fished and also heavily managed—nearly all the stock that goes
in through stocking is taken out through fishing.
Using a process‑based model to project the whitefish
population under different stocking and temperature scenarios
for the next 50Â years, Mazzucco and colleagues found that
warming will reduce the total population biomass between 2.6%
and 7.9% and the catch biomass between 24% and 48%.
Rather than the established strategy of adding larvae to maximize
biomass, which makes a negligible difference to catch under
constant temperatures, theyÂ
recommend stocking one‑summer‑old
fish, which will maximize catch with rising temperatures.
Since the two stocking strategies have similar effects on catch
under constant temperatures, this finding underscores how fisheries
management strategies need to—and can—adapt to climate change.
“The alternative strategy is better for anglers, who prefer to catch fewer, butÂ
larger fish. However, a more important message is
that changing stocking strategies cannot, in the long run, prevent
an overall reduction in the biomass of cold‑water fish species,”
says Mazzucco. CW
Further info FickerÂ
H, MazzuccoÂ
R, GassnerÂ
H, WanzenböckÂ
J, DieckmannÂ
U (2016).
Stocking strategies for a pre-alpine whitefish population under temperature stress.
Ecological Modelling 320:170–176 [doi:10.1016/j.ecolmodel.2015.10.002].
Rupert Mazzucco mazzucco@iiasa.ac.at
Multiple perspectives for better risk management
By engaging citizens and experts in a participatory project, IIASA researchers have
found new solutions to a challenging quandary for landslide risk
management.The
project—the first public participatory process for addressing landslide risk
in Europe—focused on landslide risk mitigation options for the town of Nocera
Inferiore in southern Italy, which is located at the base of the landslide‑prone
Mount Albino. The most recent major slide, in 2005, caused three deaths and
major property damage. But three years later, the municipal council rejected a
proposal for a risk mitigation plan proposed by outside experts.
IIASA Risk and Resilience Program Director JoAnne Bayer led one area of the
project focused on risk management. “People have different worldviews, different
backgrounds, and different priorities. This doesn’t mean that any of these views
are wrong,” she explains.
So the researchers designed a process to take different viewpoints into
account, and help people understand others’ viewpoints so that a compromise
could be agreed upon.
They aimed to include not just technical and economic aspects, but also the social,
institutional, and regulatory context. In addition, they aimed to change the role of
“experts” from the uncontested authority on a topic, to one voice among many valid
inputs. To reach a compromise, experts co‑produced several risk mitigation options
based on their specialized knowledge, taking into account local knowledge and values.
As a result, the community has now agreed upon a set of mitigation measures to
reduce landslide risk, which are now in progress. KL
Further info Linnerooth-Bayer J, Patt A (Eds) (2016). Rethinking participatory processes:
The case of landslide risk in Nocera Inferiore. Natural Hazards 81(Suppl.1):S1–S144.
JoAnne Bayer bayer@iiasa.ac.at©
zurĂĽck zum
Buch options, Band summer 2016"
options
Band summer 2016
- Titel
- options
- Band
- summer 2016
- Ort
- Laxenburg
- Datum
- 2016
- Sprache
- englisch
- Lizenz
- CC BY-NC 4.0
- Abmessungen
- 21.0 x 29.7 cm
- Seiten
- 32
- Kategorien
- Zeitschriften Options Magazine