Spatial changes in zooplankton communities in a strong human-mediated river ecosystem

Area of Science:

• Ecology
• Limnology
• Freshwater Biology

Background:

• River damming reduces water current velocity, favoring organisms typically found in still waters.
• Zooplankton communities in rivers can be significantly influenced by adjacent carp pond ecosystems.

Purpose of the Study:

• To investigate the hypothesis that zooplankton from carp ponds colonize river impoundments.
• To determine if river impoundments increase zooplankton richness through the development of new species.

Main Methods:

• Monthly zooplankton sampling in the Barycz River (lotic and impounded sections) and carp pond outlets from April to September 2013-2014.
• Comparison of zooplankton richness and abundance across different riverine habitats and in relation to current velocity.

Main Results:

• Impounded river sections showed the most significant changes in zooplankton richness and abundance, correlated with lower current velocities.
• Carp pond outlets exhibited similar abundances of pelagic zooplankton (rotifers, cladocerans, copepods) as downstream river sites.
• The influence of carp pond outlets on zooplankton abundance in both dammed and lotic river sections was significant.

Conclusions:

• River impoundments create favorable conditions for retaining and colonizing zooplankton from carp ponds.
• These impoundments support the development of zooplankton species not found upstream, thereby increasing overall riverine zooplankton richness.