Untitled

Abstract

The study, which measured the concentrations of Zn, Cu, Pb and Cd, in muscle tissue of 5 commercially important crustacean species (Penaeus monodon, Penaeus indicus, Penaeus semisulcatus, Penaeus marguensis and Metapenaeus brevicornis) collected from the UNESCO declared world heritage site Indian Sundarbans. The Indian Sundarbans at the apex of Bay of Bengal is recognized as one of the most diversified and productive ecosystems in the world located at the confluence of Hooghli-Matla estuarine complex. However, due to intense industrialization, urbanization and increase of anthropogenic activities in recent era, Indian Sundarbans have been contaminated with heavy metals which vary with seasons and often exhibit pronounced monsoonal effect. Significant variation of heavy metals in muscle tissue of 5 commercially important crustaceans or shrimp species collected from four different sampling stations (2 each in central and western sector) of Indian Sundarbans were observed. The distribution of trace metals accumulated in all the muscle tissues of shrimp species followed the order Zn > Cu> Pb> Cd. The concentration of metals exhibited significant spatial variation and followed the order station 1 >station 2 > station 3 > station 4, which may be related to different degree of contamination in different location (p < 0.01) that indicated the adverse impact of industrialization and urbanization on the edible crustaceans community. Although the concentration of selected heavy metals were within the normal range in all stations, but at station 1 the metal level has exceeded in the muscle of shrimp species as a food source for human consumption.

Analysis of Essential Elements in Commercially Important Lobster Species Collected From Coastal Areas of Karachi City, Pakistan

“…Levels of Cu in the muscle and exoskeleton of both male and female lobsters during the three year study shown in Table 2 and Figure 2a, far below the normal permissible range, i.e. 120 ppm as recommended for the crustacean tissue [12]. While in case of lobster eggs, it was found to be higher than the recommended value of Cu in sea food, which is 30 ppm [14].…”

“…Thus increasing ambient pollution levels in water do not directly affects the marine life. Copper is considered highly toxic metal after mercury and silver in marine life because the existence of a number of detoxifying and storage systems for Cu [12]. Levels of Cu in the muscle and exoskeleton of both male and female lobsters during the three year study shown in Table 2 and Figure 2a, far below the normal permissible range, i.e.…”

“…These variations are presumably due to individual samples being categories of different size, ecological niches and tropic levels. Possibly, species also have different metabolic requirements for specific element [12]. The present study focused the gender based analysis of exhibited significant spatial variation in metal level, which may be due to variations in environmental conditions for three years in Karachi region.…”

“…Zn was found to be lower than the permissible level, i.e. 400ppm in crustacean tissue for human consumption [12]. However the values were much lower than the permissible limit for human consumption, which is 100 ppm for marine sea food [12,18].…”

“…400ppm in crustacean tissue for human consumption [12]. However the values were much lower than the permissible limit for human consumption, which is 100 ppm for marine sea food [12,18]. The Food and Agricultural Organization suggest limits for Zn is 30 mg/kg for human consumption, the Turkish legislation establishes maximum levels for the Zn is not permitted above 50 mg/kg, Canadian Food Standard is 100μg/g, by Hungarian Standard is 80μg/g, Australian Standard is 10μg/g but these limits can be slightly higher in composite eggs [15,16,19,20].…”