Open AccessFish production in the Jarama River, Central Spain
Author(s) -
LobonCervia J.,
Penczak T.
Publication year - 1984
Publication title -
ecography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.973
H-Index - 128
eISSN - 1600-0587
pISSN - 0906-7590
DOI - 10.1111/j.1600-0587.1984.tb01113.x
Subject(s) - electrofishing , leuciscus , salmo , barbus , fishery , brown trout , biology , biomass (ecology) , population , trout , ecology , fish <actinopterygii> , cyprinidae , demography , sociology
Fish production was estimated at three sites on the Jarama River, a small, typical upland river in Central Spain. Population estimates were made by the successive removal method of electrofishing. The same six species were recorded at each of the sites: Chondrostoma polylepis, Barbus barbus bocagei, Leuciscus cephalus pyraenaicus, Salmo trutta m. fario, Gobio gobio and Cobitis paludicola , with the first three species always dominant. Density, biomass, production (assuming that N o is the total number of eggs spawned), and available production were, respectively: 13502‐85776 ind. ha −1 , 178.6–221.3 kg ha −1 , 221.7–583.6 kg ha −1 yr −1 , 118.1–271.9 kg ha −1 yr −1 . Production estimates based on mortality curves were 7.9–19.5% (mean: 13.7) lower than those based on estimated from the number of eggs laid. Production per unit of area was highest at the widest and deepest site. Brown trout production contributed only 2–4% of the total production for all sites.