Studies on the Ecology and Weeding of the Algae Growing on the Sloping Salt-field.(Part 1)

Species, their Ecology and Fundamental Researches on Weeding of the Algae

Abstract

Dominant species distributed along the shore of the Inland Sea of Japan are Lyngbya aestuarii Liebm. and Rhizoclonium arenosum (Carm.) Kütz., and these brackish algae become the object of weeding. Under the peculior environmental conditions on the salt-field, salinity, temperature and quantity of the sea water are the main factors controlling the growth of the algae. Especially, low salinity and organic matters contained in the sea water promote the growth of Rhizoclonium and Lyngbya respectively. Among the various herbicides, CuSO₄, CuCI₂·Cu(OH)₂·H₂O, CuCO₃·Cu(OH)₂, Cu(OH)₂, 2, 4-D, PCP, NaClO solution, NaClO₂ and NaClO₂ are specially used for the algicides, and their critical density to algae and time of their treatment are examined within the range of 0.1-1,000 p.p.m. Sodium hypochlorite solution (NaCIO) is the most suitable algicides for the salt-field on account of its strong algicidal power and being non-poisonous to human bodies