Do Water Management and Climate-Adapted Management of Wetlands Interfere in Practice? Lessons from the Biebrza Valley, Poland - Wetlands and Water Framework Directive: Protection, Management and Climate Change - page 57

Biebrza and its tributaries flowing in the near neighborhood of the Natura 2000

sites, if the hydromorphology of rivers was properly maintained. Reported con

fl

icts
at the interface of river management and the requirements of environmental con-
servation (Biere

fl

noj-Bazille and Grygoruk 2013 ; Mioduszewski and Okruszko
2012 ) showed, however,

ż

wka, Kli-
maszewnica), where hydromorphology of river channels was decently disrupted as
a result of social-demand of river management, the decrease of volumes of lowest
fl

that in cases of certain rivers (e.g. Brzoz ó

ows (and though — the environmental fl flows) can be expected and underlay a

signi cant risk to aquatic species. Hence, also in the dimension of river manage-

ment implemented so far in the area of research, regarding possible mitigation of
climate-affected increasing recurrence of droughts, no actions were taken in order to
minimize the negative effects of climate-related pressures to ecosystems ' state.

cant, climate-driven pressures to biota in the area ana-
lysed there are temporal changes of the spring thaw

Among the most signi

fl floods (Ignar et al. 2011 ;

Grygoruk et al. 2013b ) which were de ned as a threat to migratory birds and sh

spawning. Due to the earlier occurrence of spring floods and projected decrease in

their volume and duration (Grygoruk et al. 2014a ), the role of Biebrza Valley as a
stopover spot for waterfowl birds is expected to lose its relevance. Moreover, if the
balance of

fl

flooded and dry areas was considered as an important aspect of biotopes
for certain species of birds of prey (e.g. Spotted Eagle and Lesser Spotted Eagle),
this climate-related process may affect the condition of their population (Macio-
rowski and Mirski 2014 ). In a long run, the affected populations of migratory birds
in the Biebrza Valley are expected to result in the decrease of tourism intensity, and
though

fl

— a partial loss of the international importance of Biebrza Wetlands. In the

case of fish, especially the European pike (Esox lucius), and concerning the fact that

the spring

floods were observed and are expected to keep decreasing in terms of
volume and duration, the lack of appropriate spawning habitats (

fl

fl ooded meadows)

may invoke the need of stocking. So far, as the population of fish in the Biebrza

river and its principal tributaries (lower E ł k, lower Jegrznia) developed with no

signi sh

supply, stocking was not required and considered environmentally negative for the
native populations. Facing the pressures originating in changing climate,

cant genetic and structural disturbances originating from the arti cial

sh
stocking and the related restoration of aquatic habitats and spawning grounds may
be required in order to mitigate the negative impacts related to the altered fl ow

regime.
Presented feedbacks of climate-induced challenges to aquatic and wetland
ecosystems require special attention of water management authorities. Focusing at
so-far planned and implemented actions for the Biebrza Catchment originating from
the National Water-Environment Programme, one can conclude that a vast majority
of threats originating in climatic drivers remains

— —

however not anticipated.