Lake Orta is a deep subalpine lake, located in Northern Italy, at a mean altitude of 290 m a.s.l. Its perimeter is 33,8 km, surface area 18,14 km2, volume 1,29 km3. Lake Orta has a maximum depth of 143 m and a mean depth of 71 m. Lake Orta is well known for being polluted by industrial discharges (copper sulphate and ammonia) since the late 1920: as a consequence, the pH of the lake water dropped down till 4 and the food web was almost completely destroyed, except for some few, strongly adapted species. The pollution stopped around mid 1980s and a liming intervention was carried out in 1989-1990, to neutralize the acidic waters of the lake. The recovery was very fast, new species started to colonise the lake just after the liming. The lake, however, is still at risk, due to the large amount of heavy metals stored in the sediments.

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General Characteristics, Purpose, History

Site Status:

existing

Year Site Established:

1960

Size :

1 814.00ha

Purpose of Site :

Long-term changes of temperature, heat content and of mixing depth of the lake water. Seasonal monitoring of hydrochemistry and phytoplankton. Analyses of sediment cores: algal and bacterial pigments, fossil remains of thecamoebians, diatoms, and cladocerans, pollen, metals (particularly mercury and copper). Analysis of perifiton during the lake evolution. Other research topics: Laboratory testing on adaptation and clonal selection of zooplanktonic organisms in different stages of lake pollution and recovery. Comparison of the response of organisms obtained from resting eggs preserved in sediment cores compared to that of present-day zooplanktonic organisms (resurrection ecology and biology). Estimation of changes in the size and composition, and of the genetic fingerprint, of the bank of resting stages during the lake evolution through analysis of lake sediment cores. Comparison of periphyton and phytoplankton communities in relation to trophic and chemical evolution. Functional analysis of phyto-and zooplankton communities 20 years after the liming.

Research Topics:

Parameters:

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Geographic

Coordinates:

Latitude: 45.817692000000
Longitude: 8.400248000000

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Site Details

Ecosystem and Enviromental Characteristics

Elevation Range FROM:

350.00msl

Elevation Range TO:

1 643.00msl

Elevation - Average:

290.00msl

Temperature Range (Monthly Minimum) FROM:

6.00°C

Temperature Range (Monthly Maximum) TO :

25.00°C

Temperature: Average Annual:

15.00°C

Precipitation Minimum Monthly :

0.00mm

Precipitation Annual :

1 221.50mm

Precipitation Maximum Monthly :

200.00mm

Biome :

Fresh Water Lakes

GEO-BON Biome:

Fresh water lakes

Ecosystem and Land Use:

Lakes
Fresh Water Lakes
Large lakes

Biogeographic Region:

Subalpine

Geology:

Siliceous basin

Hydrology:

The lake is included in the drainage basin of Lake Maggiore and is fed by many small streams. It water renewal time was estimated in 8.5 years

Network Affiliation

Networks/Projects:

LTER
National Network

Site Type (Spatial Design):

Simple Site

Short name :

IT08-003-A

LTER related

LTER Site Code:

LTER_EU_IT_042

LTER Site Classification/Category:

Regular

Protection Status and Resource Management

0 - 25%

Management of Resources :

Yes

Design and Scale of Site

Scale of Observation:

sub-catchment within catchment

Design of Observation:

mainly observation

Scale of Experiments:

plot scale

Design of Experiments:

no experimentation

Infrastructure

Value of the Infrastructure :

More than 5000 k

Accessible All Year :

Yes

All parts of Site Accessible:

Yes

Access Type:

boat

Permanent Power Supply:

Yes

Infrastructure:

Data infrastructure › Data storage › Unstructured file

Operation

Operations Cost:

10-30 k

Permanent Operation:

Sampling Interval:

Every 90 days

Maintenance Interval: