Macrobenthic community at type and age-different artificial reefs located along the Korean coast of the East Sea.

Two types of artificial reefs, one for simple (S-AR), another for complex artificial reef (C-AR), were installed on a Korean coast of the East Sea (Sea of Japan) where a barren ground was progressive. Compared with macrobenthic organisms at NHB (natural hard bottom) control, AR (artificial reef) enhanced seaweed composition, reducing echinoderm composition, mostly sea urchins, the causative animal of the barren ground. Composition of the two mutually exclusive communities was AR type-specific, the C-AR exerting betterfunction over S-AR by enhancing higher seaweed composition. However this ecosystem-sound composition at C-AR was maintained only within 10 years. Another negative aspect of the AR was an unexpectedly higher composition of tunicates that canbe a sign of nutrient-rich environment in the Korean waters. Overall, CAR was more agreeable when simply based on its function excluding construction cost.

Comparative efficacy of brown, green and red seaweeds in the control of root infecting fungi and okra

The effect of soil amendment by brown, green and red seaweeds was studied in controlling the root rot infecting fungi of okra seedlings in the greenhouse. The soil amendment with seaweeds Stokeyia indica, Padina pavonia [brown], Solieria robusta [red], at 1% w/w reduced Macrophomina phaseolina, Rhizoctonia solani and Fusarium solani infection on okra roots. Codium iyengarii [green] at 0.5% w/w was effective against F. solani, while at 1% w/w was found phytotoxic. S.robusta showed better control of F. solani infection when used with Pseudomonas aeruginosa than either used alone. S. robusta produced better plant height and fresh weight of shoot than P. aeruginosa. Results of the present study suggest that the use of brown seaweeds S. indica and P. pavonia alone and S. robusta alone or in combination with P. aeruginosa have great potential to control root-infecting fungi of okra with enhancement of plant growth. These seaweeds alone or in combination with P. aeruginosa may be utilized as biological control of root infecting fungi of okra