Chlorophyll a_Lake_Maggiore_Ghiffa_Station-1984-2018

Basic Information
Related Site
Lago Maggiore - Italy
Abstract
This dataset includes Chlorophyll a concentration in μg/L. Measurements of Chl a were made on discrete water samples collected monthly in the upper 20 meters layer at sampling station Ghiffa (45°58’30’’N; 8°39’09’’E) from January 1984 to December 2018. Chl a measurements derived by spectrophotometric technique in the period from January 1984 to December 2009, while from January 2010 to December 2018 measurements derived from vertical profiling instrument (FluoroProbe).
Keywords
chlorophyll a
deep lakes
eLTER PLUS VA
phytoplankton
probe continuous measurements
Water: Chlorophyll a content
Contact
Michela Rogora
Owner/Creator
CNR - Institute of Ecosystem Study (ISE)
CNR - Water Research Institute (IRSA)
Metadata Provider
Lyudmila Kamburska
DOI
10.23728/b2share.474854262dd5494e93914523b6301adf
UUID
c857c8e2-48aa-4dcd-a7fb-e089bd4c5c4e
Dates
Date Range
-
Post date
Sunday, November 29, 2020 - 12:11
Last modified
Friday, March 3, 2023 - 11:17
Recommended citation
Recommended Citation
These data were collected within the limnological campaigns on Lake Maggiore funded by the International Commission for the Protection of Italian-Swiss Waters (CIPAIS)
Geographic
Show details for observation location(s):
Ghiffa station (deepest point)
Additional information
Method Description
Chl-a concentrations were measured by spectrophotometry following the APAT IRSA 9020 method. A measured volume of water from each treatment was filtered on a GF/C glass fibre filter and frozen until the analysis. The filters were extracted with 5 ml of a mixture of acetone and MilliQ water (90:10), centrifuged and then absorbance spectra performed with a spectrophotometer. The Chl-a concentration was then obtained with the application of the trichromatic equation proposed by Ritchie (2008).

Ritchie R.J. (2008). Universal chlorophyll equations for estimating chlorophylls a, b, c, and d and total chlorophylls in natural assemblages of photosynthetic organisms using acetone, methanol, or ethanol solvents. Photosynthetica 46: 115–126.
From 2010 the Chlorophyll a concentration was simultaneously measured also with bbe-Fluoroprobe. The FluoroProbe III measures the chlorophyll-a of suspended phytoplankton in vivo. The FluoroProbe was deployed vertically till 20 meters depth. The calculation of the distribution of the amount of Chlorophyll-a is performed by using previously stored fluorescence profiles of the known algal classes from the algae library of Lake Maggiore.
Instrumentation
Filtration system, GF/C glass fibre filters
bbe-Fluoroprobe
Quality Assurance
QA and calibration: The FluoroProbe is prepared for immediate chlorophyll determination by factory calibration using standard algae. This is performed using a special spectrofluorometer (bbe ALA) which has been calibrated using HPLC analyses of extracted algal pigments. HPLC analyses are carried out by our internal laboratory. These reference spectra of the algae used for the determination of the chlorophyll-a are stored in the FluoroProbe. Each algal class has a characteristic fluorescence spectrum (fingerprint) referring to the chl content present with regard to form and intensity. Based on the linear combination of the fluorescence signals created by the algal fluorescence of the sample algae, the measurement values obtained are compared with the reference data and distributed optimally across the different algal classes by means of a fit procedure. The total chlorophyll-a content results from the sum of the chlorophyll-a of the individual algal classes. The software allows the user to perform additional calculations by activating or deactivating different algal classes in order to improve the adaptation if necessary.
Parameters
phytoplankton biomass
Intellectual Rights
Co-authorship on publications resulting from use of the dataset
INSPIRE Data Theme
Environmental monitoring facilities
Principal and granted permission
Administration » Free for access and use upon request
Public » Other restrictions according to rules defined in intellectual rights
Research » Other restrictions according to rules defined in intellectual rights