Does salinity affect growth and carrageenan yield of Kappaphycus alvarezii (Gigartinales/Rhodophyta)?

Temporal variation of the growth, carrageenan yield and quality of Kappaphycus alvarezii (Rhodophyta, Gigartinales) cultivated at Sepetiba bay, southeastern Brazilian coast

“…The negative effect of salinity on the growth (daily growth rate and productivity) was not in accordance with what was observed in other studies since the salinity (30 to 35) registered at Marambaia bay was within the range which was described to be tolerant for K. alvarezii (Doty 1987;Paula and Pereira 2003;Ask 2006;Hayashi et al 2007aHayashi et al , 2010Reis et al 2010).…”

“…Temporal variations of the growth and carrageenan quality and yield at Marambaia bay can be associated to changes in environmental factors as commented in other studies with carragenophytes (Rees 1969; Ask and Azanza Hayashi et al 2007a, b;Reis et al 2008Reis et al , 2010Hayashi et al 2010). The K. alvarezii productivity (43.9 g dwt m −2 day −1 ) at 50 cm below the water surface, density of 12 seedlings m −2 , in 44 days of cultivation observed by Hayashi et al (2007a) was similar to our productivity results (39.32±18.51 gdwt m −2 day −1 ).…”

“…After that the samples were maintained in 0.06% NaClO solution for 30 min (25°C) and washed again with fresh water to remove residues and finally dried in an oven (60°C) until constant weight, a pH 8.4 was maintained during the procedure (Góes and Reis 2011;Reis et al 2010). …”

“…The quality of the carrageenan was measured as viscosity and gel strength using a gel (n=6) obtained by the carrageenan dilution (1:70 proportion) with distilled water, subsequently, homogenized and maintained in a water bath (80°C) for 30 min (Nova Ética, model 500/3D) and maintained at 5°C for 24 h. The viscosity was measured at 75±5°C (Fungilab, model Visco Basic Plus) and the gel strength in a digital texture analyzer (Stable Micro System, standard model) (Góes and Reis 2011;Reis et al 2010). …”

Seaweed cultivation on the Southern and Southeastern Brazilian Coast

“…The temperature must be above 20 o C and the optimum temperature is between 25 and 28 o C (Doty, 1987;Ask & Azanza 2002;Paula & Pereira, 2003), salinity between 30 and 40 (Ask & Azanza, 2002;Reis et al, 2010) and irradiation of 100 to 1000 µmol.photons.m 2 .s -1 (Granbom et al, 2001). In the Brazilian northeast, the presence of coral reefs could be an environmental risk for K. alvarezii aquaculture.…”