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every year.

During the bloom accumulation, the total

microcystin (cyanobacterial hepatotoxin) concentration

in the water could increase up to 30 µg L

-1

Studies

using sensitive molecular methods based on the detec-

tion of genes involved in the synthesis of microcystin

showed that the genotypes of microcystin-producing

cyanobacteria occurred throughout the period of moni-

toring, and their number increased with deteriorating

environmental conditions for the development of cyano-

bacteria.

This demonstrates that the availability of

phosphorus is a driving factor determining the intensity

of cyanobacterial blooms in the reservoir.

Phosphorus

concentration (annual average: 0.078- 0.215 mg TP/l)

strongly depends on the discharge pattern of the main

tributaries and the chemical composition of the river’s

water, which both determine the nutrient load entering

the reservoir (average 87-693 t TP/year).

The reduction of nutrient fluxes from the catchment is

a fundamental measure for reducing toxic blooms. Due to

various cumulative impacts from agriculture, urban zones

and recreation, actions aimed at reducing the development

of cyanobacterial blooms must be based on cooperation

between scientists, decision makers and stakeholders.

In order to reverse eutrophication of a reservoir, its

water balance and nutrient flows should be considered in

the context of a whole catchment basin. The MONERIS

model for the Pilica River Basin showed that only around

6.5 per cent of the phosphorus loads were from point

sources, with around 18.4 per cent from urban areas.

Three quarters of the phosphorus load came from the

landscape, mainly associated with soil particles and

organic material eroded during flow events.

Reducing the nutrient loads coming from the landscape

due to a high complexity of water-soil-plant-society inter-

actions has been much more complicated than controlling

the loads originating from the point sources. The preser-

vation or construction of riparian land/water buffer zones

(ecotones) is widely recommended to reduce the impact

of nutrients present in the landscape on freshwater ecosys-

tems. These linear belts of permanent vegetation adjacent

to an aquatic ecosystem permit the improvement of water

quality by trapping and removing various non-point

source pollutants from both overland and shallow subsur-

face flow pathways. Phosphorus retention in ecotones is

controlled by a range of physical, geochemical and biologi-

cal processes, including sediment deposition, adsorption

to iron and aluminium oxides or precipitation of calcium

phosphates, and plant uptake.

Highly effective buffer zones were designed and imple-

mented in the direct catchment of the Sulejów Reservoir,

an area characterized by heavy groundwater pollution,

with phosphorus arising from non-point source pollu-

tion from illegally leaking septic tanks. This demo site of

the LIFE+EKOROB project

is located in a recreational

area, where the shoreline is surrounded by cottages. The

seepage of groundwater heavily contaminated with phos-

phorus was observed below the water level in the reservoir

shoreline. Average phosphate concentration in groundwa-

ter reached 3.1 mg PO

/l, exceeding the threshold value

management of water and nutrient dynamics from the landscape

to aquatic ecosystems, with the ecohydrological aim of enhancing

carrying capacity, must take place through harmonizing traditional

hydroengineering solutions with biotechnology.

Due to the complex-

ity of synergetic and mutually interacting hydrological processes, the

implementation of biotechnological solutions to ensure the regulation

of catchment-scale water must lead to enhancement of the self-organi-

zation function of ecosystem/nutrient dynamics,

and must be carried

out using an adaptive assessment and management methodology.

Recently applied scientific approaches and the methodologies

used in conservation, restoration, ecological engineering and ecohy-

drology represent progress in understanding the ecological structure

and dynamics of ecosystems and the impact of human activities.

They embody a move from a species-structure-oriented perspective

towards a more progressively process-oriented approach, exempli-

fied by ecological engineering and ecohydrology.

The goal of ecohydrology as a problem-solving science is to deter-

mine why the biosphere is drying and soil fertility is declining, and

how these trends can be reversed. The major challenges are:

• slowing the transfer of water from the atmosphere to the sea

(prioritizing flood and drought control)

• reducing input and regulating the allocation of excess nutrients

and pollutants in aquatic ecosystems to improve water quality,

biodiversity and human health

• enhancing ecosystem carrying capacity (water resources,

biodiversity, ecosystem services for society and resilience) by

dual regulation towards harmonization with societal needs.

The proposed highly-complex approach must be transferred to society,

decision makers and politicians through transdisciplinary education.

In the case of the highly-complex environmental problems that we

experience today there is an urgent need to move away from special-

ization in education and add a knowledge integrating element,

enabling a broader understanding of the complexity of environmen-

tal processes. Integration of the knowledge garnered across different

disciplines should be facilitated on the basis of a common methodo-

logical background. Parallel educational efforts are needed to raise

the consciousness of society concerning possible realistic scenarios

for harmonizing societal needs with enhanced ecosystem potential:

water, biodiversity, ecosystem services for society and resilience.

Reducing cyanobacterial blooms: Sulejów Reservoir

Modification of the biogeochemical cycles on a catchment scale –

resulting from degraded biocenosis structure and increased emissions

of nutrient and pollutants combined with climate change – seems

to be the main reason for acceleration of the eutrophication process,

including the presence of cyanobacterial blooms in freshwater and

coastal ecosystems. An important indicator for assessing the threat

of cyanobacteria to the environment and humans is the activity of

toxic genotypes, which are responsible for producing cyanotoxins that

can cause skin irritation, impaired breathing (neurotoxin), diarrhoea,

acute gastroenteritis, and kidney and liver damage (hepato- and cyto-

toxins).

Thus, the molecular monitoring of toxigenic strains of

cyanobacteria acts as a precise indicator of the possible health threat.

The Pilica River in Central Poland is a global reference site for

ecohydrology under the United Nations Educational, Scientific and

Cultural Organization International Hydrological Programme. The

river’s Sulejów Reservoir is a dam reservoir with progressive anthro-

pogenic eutrophication, in which cyanobacterial blooms appear