International Journal of Aquaculture, 2017, Vol.7, No.21, 134-138
136
Where, DGR = Specificy growth rate (%/day), W
t
= weight gain at the end of study (g), W
0
= initial weight of
seaweed (g), t = Duration of culture (day)
2.5 Water quality
The water quality such as nitrate, phosphate were measured using Spectrophotometer in the laboratory.
2.6 Data analysis
Daily growth specific and carrageenan content data during the research were analyzes using analysis of Variant
(ANOVA). Due to the effect of treatment is highly significant (P<0.05) then the data were analyzed using the
Tukey test.
3 Results and Discussion
3.1 Prevalence
The exsistence of a disease of seaweed cause by epiphyte can promote the bacteria attract the seaweed which
found in the waters environment (Vairappan, 2006). Furthermore it is said that sometimes the presence of
epiphytic followed by ice-ice disease presence. The results of the research in the field observations indicate that
the prevalence of epiphytes can reach 70-75%. It is in accordance with Borlongan et al. (2011). The research
indicates that also ice-ice decreases the production of seaweed from 25-40%. It is in accordance with Trono (2003)
and Mendoza et al. (2003). Epiphytic disease is one disease parasite on seaweed that can cause crop failure. The
disease is caused by parasite
Neosiphoniaapiculata
, (Vairappan et al., 2008), also due to drastic changes in
salinity and temperature (Vairappan, 2006). Epiphytic infection can occurred on the entire surface thallus of
seaweed (Figure 1). The data obtained showed that the epiphytic also affects the ability of seaweed to survive on
the ropes of thallus stretch of submarine maintenance during the culture period. The ice-ice disease, infection
starts at the base thallus as well as the end of the end portion of thallus (Figure 2).
The ice-ice disease characterized by the affected part is white and very fragile, if the disease attacks at the base of
a binding seaweed, it can cause the release of the rope stretch. From the results of this study show that low ability
of seaweed hang on rope stretch lead to less than 20% that can survive on the ropes stretch during culture period
(Figure 3). The ice-ice and epiphyte diseases can cause both high mortality and decreasing of quality of
carrageenan that is the viscosity, gel strength (Mendoza et al., 2003).
Figure 1 (a) The infection of epiphyte on the surface thallus of seaweed; (b) The thallus of seaweed infected by ice-ice
(a)
(b)
