Effect of Depth on the Growth and Carrageenan Content of Seaweed Kappaphycus alvarezii Cultivated Using Verticulture Method

Petrus Rani Pong-Masak,Nelly Hidayanti Sarira,A Isnansetyo,N Huda,A Dwi Jayanti,I Dewi Puspita,R Ida Adharini,D Wahyu Kartika Sari,Mgs M Prima Putra,R.C Bhujel

doi:10.1051/e3sconf/202014701011

Abstract

Seaweed of Kappaphycus alvarezii is generally cultivated by the long line method through the water surface. The verticulture method might be an alternative method by using water column. This research aimed to evaluate the effects of depth on the growth and carrageenan content of K. alvarezii which was cultivated vertically. Cultivation was carried out in the floating raft (10 x 10 m)2 contained of 36 vertical nets. The size of each net was 5 x 2 m2 whereas the depth was 0.2, 1, 2, 3, 4, and 5 m. Seaweed seedlings of 50 g was each tied to the vertical nets; the distance between the knot was 20 cm. The results showed that the depth was significantly different to the daily growth rate of K. alvarezii (p<0.05) but did not affect carrageenan content (p>0.05). Therefore, this method might be applied as an alternative method to optimally increase seaweed production in narrow area without affecting seaweed quality.

Highlights

The type of red seaweed (Rhodophyceae) becomes the main commodity in fisheries and marine sector of Indonesia
Until today, seaweed is mostly cultivated using long-line method. Applying this method means that seaweed farming is performed only on the water surface, while seaweed is ecologically able to grow in the water column on the condition that it still receives sunlight to perform photosynthesis
The objective of this study is to investigate the effect of depth on the growth and carrageenan content of seaweed cultivated using verticulture method by using vertical net

Summary

Introduction

The type of red seaweed (Rhodophyceae) becomes the main commodity in fisheries and marine sector of Indonesia. Carrageenan is commonly used as stabilizer, gelling agent, emulsifier, and many more. These properties are utilized in many industries, such as food, pharmaceutical, cosmetic, textile, paint, toothpaste, and other industries [1,2]. Kappa-carrageenan in K. alvarezii seaweed produces stronger/thicker gelling agent, it costs higher and becomes the main commodity that generates foreign exchange for Indonesia [3]. Until today, seaweed is mostly cultivated using long-line method. Applying this method means that seaweed farming is performed only on the water surface, while seaweed is ecologically able to grow in the water column on the condition that it still receives sunlight to perform photosynthesis. If the long-line construction is too long the shipping lane is hindered

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Conclusion