Agriculture Reference
In-Depth Information
I
NTRODUCTION
Currently, the consumption of fishery products, including seaweeds, to acquire health
benefits has steadily increased steadily worldwide. Because of this situation, there has been in
increase in the amount of fishery wastes, primarily from industrial processing. Seaweeds are
known to be a favorite food in Asian countries (Rouxel et al., 2001). In Korea, approximately
one quarter of the total amount of domestically produced seaweeds (approximately 800,000
tons) is discarded annually. However, large quantities of fishery wastes, including seaweeds,
have not been efficiently utilized to date. This fishery waste disposal problem greatly affects
the local environment. Customarily, the unused fishery wastes are disposed via landfills,
incineration, or by dumping into the sea. In addition, the cost for the disposal of the fishery
wastes has remarkably increased in Korea since 2012 when dumping wastes into the sea
became prohibited according to the London Convention (International Maritime
Organization, 2006). Therefore, this situation urgently requires an ecologically acceptable
means for the reutilization of fishery wastes.
Conventional methods for the reutilization of fishery wastes are the production of high-
protein meals by ensilation (Faid et al., 1997), the recovery of chitin (Cira et al., 2002) and
carotenoids (Sachindra et al., 2007) from shrimp waste ensilation, fishmeal production (Hall,
1992; Keller, 1990), the production of protein by fermentation (Hassan & Heath, 1986),
composting (Liao et al., 1997), the production of nutrients for lactic acid bacteria by acid
hydrolysis (Gao et al., 2006), the production of high-quality fishmeal by fermentation (Yano
et al., 2008) and the production of low-salt fish sauce by the fast fermentation of squid
processing by-products (Xu et al., 2008). Recently, an eco-friendly means to convert fishmeal
wastewater and fish waste into liquid fertilizer has been demonstrated (Kim & Lee, 2009;
Kim et al., 2010; Dao and Kim, 2011).
Seaweeds have been consumed by humans and animals since 600 BC, and seaweeds are
often used in fertilizer, fungicides, herbicides, and phycocolloids, such as alginate,
carrageenan, and agar (Chapman & Chapman, 1980). Seaweeds or their products (extracts,
composts, soil conditioners) have been commonly used in agriculture to enhance plant growth
and crop productivity. These compounds have been reported to have beneficial effects on
seed germination, plant yield, root growth, tolerance to plant stress and plant resistance to
infections or insect attack (Abetz, 1980; Blunden, 1991; Sivasankari et al., 2006). These
beneficial effects are because these products can contain growth-promoting hormones, trace
elements, organic compounds, such as carbohydrates, amino acids and vitamins, and
stimulatory and antibiotic substrates (Crouch & van Staden, 1993). Seaweeds also have been
used for the preparation of composts, and seaweed compost has been proposed as an
amendment for horticultural soil (Eyras et al., 2008). Therefore, the use of seaweeds or their
products can minimize the use of chemical fertilizers, maintain fertility and overcome nutrient
deficiency (Papenfus et al., 2013). Recently, the co-composting of seaweed and fish waste has
been reported to produce a fertilizer for use in organic agriculture (López-Mosquera et al.,
2011). Seaweed compost with a good fertilizer quality has also been demonstrated using
halotolerant and alginate-degrading bacteria (Tang et al., 2011).
The disposal and utilization of seaweed wastes have become a worldwide issue to
preserve the marine environment and to recycle organic substances. In the same manner, the
Korean government recognized this issue, and accordingly, the Ministry of the Environment
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