Species and habitats - Raja Clavata - Mature Female - Mean abundance, standard deviation, and summed kriging error maps during BTS (1989 - 2010)

Date(s) (Publication)
Custodian(s): CHARM Consortium
Point of contact(s): David Stephens
Affiliation(s) 1 : Center for Environment, Fisheries & Aquaculture Science
2 : CHARM Consortium
Credit CEFAS
Abstract Biologic data have been expressed in abundance (numbers or density values (nbr/kmĀ²)) and always required to be log-transformed using a log10(x+1) transformation. Abundance mean (mean) and standard deviation (st) have been calculated. The sum of the kriging error for each yearly kriged abundance fits to the kriging error (v).
Keywords Species data set, CHARM, Habitats et biotopes, ressource halieutique
Lineage The standard survey has a total of approximately 100 tows or stations (75 are in ICES division VIId,25 are in ICES division Ivc). A commercial 4m beam trawl fitted with a chain mat, flip-up ropes, and a 40 mm cod-end liner is used.The gear is towed at 4 knots (ground speed) for 30 minutes on a warp length appropriate to the depth of water. At each sampling station (only daylight), all the fish species are sorted, weighed, counted and measured.
Utilisation research-only
Temporal Extent 1989-01-01 - 2010-12-31