AACL Bioflux, vol: 12,1 (2019)
Zinc content in water, sediment, and soft tissue of green mussel Perna viridis in Demak, Indonesia
Afandi M.F., Widowati I., Ambariyanto A.
Abstract
Coastal region of Demak is an important area for fishermen, for mussel fishing, mainly green mussels (Perna viridis). However, industrial activities and household waste disposal around the waters affects coastal water quality. This study investigates zinc content in water, sediment, and soft tissue of P. viridis, as well would like to determine safe limit consumption of the mussels collected from Demak coastal area. All samples (water, sediment and mussels) were collected from 5 stations, and each station was divided into 3 substations as repeated sampling. Stations 1 to 5 are located at Sayung River, river mouth, right breakwaters area, offshore, and left breakwaters area, respectively. P. viridis samples were divided into three groups based on shell length (SL) namely, small (<4 cm SL), medium (4-6 cm SL) and large (>6 cm SL). Analysis of heavy metal content was performed by using AAS (Atomic Absorption Spechtrophotometer). The results showed that Zn content of in the water at all stations exceeding the threshold value of sea water quality standard. Similarly, Zn content in the soft tissue of the mussels at each station has exceeded the threshold which has been determined by Indonesian Government. There is a positive relationship between shell length and heavy metal content in soft tissue of P. viridis. The maximum tolerance to consume small size of P. viridis (size that mostly caught by fishermen) for people with an average weight of 45 kg can consume small size of mussels up to 3,980.1 g/week. While for those with an average weight of 60 kg can consume small size of P. viridis up to 5,306.8 g/week.
Keyword: Bivalves; Heavy metal zn; Maximum consumption; Pollution; Threshold