Effect of Inflowing River-water on the Farming of Laver in Chonsu Bay

Algae > Volume 1(1); 1986 > Article

Algae 1986;1(1): 259-279.

Nam-Gil Kim, Jae-Won Kang

Department of Aquaculture, National Tongyeong Fisheries Technical College, Department of Marine Biology, National Fisheries University of Pusan

ABSTRACT

The present work was carried out to make clear the effect of inflowing riverwater affecting upon the farming of laver with the review of oceanological and meterologicl factors from January to June, 1985 in Chonsu Bay. As a result, the meteorological peculiarities did not appear at the region of Sosan during the farming period, except for the low temperature in January and February. The water temperature generally was stable during the farming period. In spring and neap tides, the water velocities at the inner Bay were 11.5 and 5.0 cm/sec, and at the entrance 36.7 and 31.9 cm/sec, respectively. pH and COD were higher at the inner parts, but DO, SS and salinity were higher at the entrance of the Bay. The nutrient contents of NH sub(4)-N, NO sub(2)-N, NO sub(3)-N and PO sub(4)-P in the farming area affected by the inflowing river-water were 4.78-9.85, 0.43-0.55,6.55-11.51 and 0.94-1.13 μg-at/l, respectively. But in the area not affected by the river-water, the values of the nutrient contents were 1.50-3.17, 0.15-0.49, 1.91-3.64 and 0.36-0.81 μg-at/l, respectively. The peak absorbance appeard at 420 and 660 nm, with the maximum values of 1.364 and 0.137 at St. 6 where inflowing river water had an influence, while with the minimum vale of 0.017 and 0.006 at St. 13 where the inflowing river-water had no influence. In the area influenced by river water, the carotenoid, chlorophyll αand total chlorophyll contents of fresh laver were 0.27-0.48 μg/ml, 19.77-56.93 mg% and 20.56-64.60 mg%, respectively and int he area not influenced by river-water, 0.02-0.26 μg/ml, 0.55-10.76 mg% and 0.57-11.36mg% with maximum value at St. 6 and the minimum at St. 13. Total nitrogen contents of from 4.13 to 4.87%, respectively and were higher than those of St.. 2 and 13, showing the value of 0.89 to 2.52 and 0.88 to 1.28%, respectively, and located at the inner parts of the Bay where river-water had no influence. There were correlations between chlorophyll and total nitrogen contents of laver and nitrate-nitrogen dissolved int he sea water. Total numbers of fronds per 10 cm net string varied from 565 to 2,880 individuals due to the inclination of overseeding in the area. The lengths, widths and areas of blades in the region influenced by inflowing river-water were higher than those of the other areas. The frond shaped of laver was linear and long at inner parts of the Bay and the obovate, oblanceolate and round in the entrance where the inflowing river-water was affected.

Key words: Chonsu Bay, laver forming