Studies on technology for seaweed forest construction and transplanted Ecklonia cava growth for an artificial seaweed reef.

We installed seaweed reef for restoration of barron ground coast. We hollowed out a U-shaped groove in a cross-shaped artificial seaweed reef and covered it with a zinc sheet (U-bar) to transplant Ecklonia cava growing on Dellenia wood by hand, installing the U-bar on the artificial seaweed reef, fixing it with concrete. Thus seaweed can be attached easily, with pre-installed stainless bolts and nuts. The length of Ecklonia cava leaf transplanted to the cross-shaped reef was 7.2 cm in February 2005 reached its maximum size, 35.9 cm (n=30) by July. Thereafter, it decreased to 18.9 cm in October due to shedding. The leaf weight after the experiment was 24.8 from the initial 0.4 cm (n=30). Regression analysis showed Y=0.7875X-4.6488 (R2=0.7225) for blade length and Y=0.0025X2.6733 (R2=0.8711) for leaf weight. The high values of the R2 values for the two measurements were highly reliable, with the reliability of the linear regression function higher than that of the functions of 2 variables. The artificial seaweed forest constructed in the barren ground was highly comparable with natural seaweed forest in terms of growth, indicating that the artificial seaweed construction can be done in an easy, efficient and economically viable way. This further indicates that the technology developed by the present study can be extensively used for the project for artificial seaweed forest construction.

Effects of varying dilutions, pH, temperature and cations on spermatozoa motility in fish Larimichthys polyactis.

The objectives of this present study were to assess the effects of varying dilutions, pH, temperature and cations on spermatozoa motile parameters (SMPs) in fish Larimichthys polyactis. Optimal SMPs were observed when semen was diluted in artificial seawater (ASW) at a ratio of 1 to 100, with temperature of 10oC and pH 8.0. The spermatozoa of L. polyactis were immotile in distilled water and motile in solution containing different cations. Maximum SMPs were obtained in each solution containing 0.4 mol NaCl, 0.4 mol KCl, 0.2 mol CaCl2 and 0.2 mol MgCl2. This study provides baseline knowledge of L. polyactis spermatozoa sensitivity of pH, temperature and cationic effects.