Seaweed disease: Ice-ice On Seaweed
Cause: Environmental factors and several types of bacteria: Pseudoalteromonas gracilis, Pseudomonas spp .. and Vibrio spp.
Bio - Ecology Pathogens:
• The case of ice-ice on seaweed farming is triggered by fluctuations in water quality parameters are extreme (salinity, water temperature, dissolved organic matter and sunlight intensity).
• Other triggers are insect like fish baronang, green turtles, sea urchins and starfish cause injury to the thallus, so easily infected by microorganisms.
• In the state of stress, sea grass will release organic substances that cause thallus slimy and stimulate the bacteria grow abundantly in the vicinity.
• Growth of bacteria on the thallus will cause the thallus becomes white and fragile. Furthermore, easily broken, and the soft tissue that characterize the ice-ice disease.
• The spread of this disease can occur vertically (from seed) or horizontally through the mediation of water.
Clinical symptoms:
• The disease is characterized by the emergence of spots / red spots on some of the old thallus gradually became pale yellow and finally fade to white. Thallus become brittle and easily broken.
• Symptoms are shown slow growth. the color change becomes pale and at several branches and rotting thallus to be white.
Diagnosis:
• visual and microbiological observations.
Control:
• The use of quality seeds is a very important way to control ice-ice disease.
• Disinfection of seedlings can be dipped in the solution by PK (potassium permanganate) with a dose of 20 PPM
• Selection of farms that meet the optimum requirements for growth of seaweed.
• Application of cultivation techniques adapted to aquatic environments
• Noting the season in relation to cultivation techniques that would be applied.
source: Ministry of Maritime Affairs and Fisheries of Indonesia, Directorate General of Aquaculture, Fish and Environmental Health Directorate, 2010
