Charophyte distribution
Short description
Distribution of Charophytes (Chara spp., Nitella spp., Nitellopsis spp., Tolypella spp.) mainly based on data submission by HELCOM contracting parties. Submitted point data was originally gathered in national mapping and monitoring campaigns, or for scientific research. Also scientific publications were used to complement the data (in Curonian, Vistula and Szczechin lagoons, see reference list). Polygon data from Poland was digitized based on Polish Marine Atlas. From Estonian waters, a predictive model was used (200m resolution), that was converted to presence/absence using minimized difference threshold (MDT) criteria. All data (points, polygon and the raster presenting predicted presence of Charophytes) were generalized to 5km x 5km grid cells.
Point of contact
HELCOM Secretariat
data@helcom.fi
Spatial extent
['7.530495', '34.131647', '52.277123', '66.475422']
Type
dataset
Metadata information
Identifier
Keywords
Species distribution ; Habitats and biotopes ; GEMET - INSPIRE themes, version 1.0 ;

environment ; GEMET ;

MADS ; HOLAS2 ; ecosystem component ;

Resource provider(s)
HELCOM Secretariat
data@helcom.fi

Lineage
Data source: Denmark: Point data from national monitoring along transects (dive and video), data from 2005-2015. Data is available through Miljøportalen Estonia: Modelled distribution of Charophytes based on observations from national monitoring (dive and drop video) during 2005-2014 Finland: Point data gathered during the national marine mapping programme VELMU (2004-2015) and inventories from Åland Islands. Germany: Point data originally collated for monitoring and research purposes (video, photos, dive, wading, snorkeling), data from 2010-2015. Latvia: No reported occurrences of Charophytes Lithuania: No reported occurrences of Charophytes. Poland: Polygon data digitized based on Polish Marine Atlas http://www.iopan.gda.pl/hm/atlas/Atlas_all.pdf . Russia: No reported occurrences of Charophytes. Sweden: Point data from national monitoring and mapping surveys (1995 -2015) extracted from SMHI SHARK database. References: Brzeska, P. Wozniczka, A., Pelechaty, M., Blindow, I. 2015. New records of Chara connivens P. Salzmann ex A. Braun 1835 – an extremely rare and protected species in Polish brackish waters. Acta Societatis Botanicorum Poloniae. 84(1):143–146. Sinkevièienë, Z. 2004. Charophyta of the Curonian lagoon. Botanica Lithuanica 10(1):33-57. 2018 updates: Updated data from Sweden and Finland were included. The grid of the raster was changed to match with other benthic habitat layers used in HOLAS II. Data quality: Mapping is not exhaustive and sampling density varies between the countries. Raster value representing presence (1) or absence (0) Spatial resolution: 1 km x 1 km grid (originally 5 x 5 km).