Concentration of Cadmium, Copper, Lead, Zinc and Mercury were determined in the muscles, gills and liver of ten fish species ( Epinephelus areolatus , Epinephelus radiates , Anthias squamipinnis , Plectorhinchus chaetodonoides , Snubnose emperor , Dicentrarchus labrax , Acanthopagrus bifasciatus , lutjanus kasmira , lutjanus ehrenbergii and Acanthurus gahhm ) as well as three specimens of crustaceans ( Metapenaeus dalli , Panulirus penicillatus and Portunus petagicus ) and two Specimens of squids ( Parateuthis tunicate and Chtenopteryx sicula ) collected from Jeddah coastal water during 2014. The obtained results declared that, the average concentrations of heavy metals were as follows: Cd (0.098, 0.20, 0.106), Cu (0.358, 0.327, 1.536), Pb (0.3, 0.257, 0.196), Zn (3.00, 7.390, 4.999) μg/g wet weight in the muscle, gills and liver, respectively. While, the concentration of Hg was invariably undetectable in all samples of different organs of the collected fish species. The average concentration of Cd, Cu, Pb, Zn and Hg in the soft part of the investigated crustaceans ( Metapenaeus dalli , Panulirus penicillatus and Portunus petagicus ) and squids (Parateuthis tunicate and Chtenopteryx sicula ) were relatively higher compared with the muscle tissues in the examined fish species. The results of bioconcentration factor (BCFs) indicated that among examined metals Zn was the most readily absorbed by fish and the highest BAFs for examined fish species were determined in gill of Snubnose emperor .
Jeddah was first inhabited about 2500 years ago as a small fishing settlement and has long been a center for traders and sailors. From that time, importance of Jeddah was gradually increased and consequently increment the number of inhabitants and visitors. As already known, fishes are the main aquatic products of Jeddah area, seafood lovers from all walks of life can be found browsing through the colourful variety of tender meat that the Red Sea offers. It was estimated that the total fish and shrimps consumption in the kingdom is about 100,000 tons per annum; approximately 49,000 tons are produced locally. In public media, there is a doubt that fishes were contaminated with organic and inorganic pollutants due to the strategic location of Jeddah as one of the international shipping centers and a large number of toxic chemicals and effluent-producing industries are located in and around Jeddah City. Unfortunately, at present, due to discharging high volume of various types of petrochemical industries wastewater as well as wastewater resulting from washing of ships and tankers, the estuary environment could be severely compromised. Also the rapidly developing industrial and municipal development around Jeddah area have caused serious pollution problems in Jeddah coastal waters. Heavy metal pollutions are particularly hazardous contaminants in food and a significant problem in the environment. Several organizations have pointed out the need for monitoring trace metal levels in the marine environment [
The bioaccumulation of heavy metals varied between species, ages, sex and organs. In general, the target tissues of heavy metals are metabolic active ones which accumulate high levels of metal in fish such as liver and gills, whereas in muscles where the metabolic activity is relatively low accumulates less level of heavy metals.
The measurement of heavy metal concentrations in bio-indicators has been recognized as highly relevant in ecotoxicological terms because of the reflection of bioavailability in the ecosystem that reasonable measurement for public health standards from animals health point of view [
Ten fish species (Epinephelus areolatus, Epinephelus radiates, Anthias squamipinnis, Plectorhinchus chaetodonoides, Snubnose emperor, Dicentrarchus labrax, Acanthopagrus bifasciatus, lutjanus kasmira, lutjanus ehrenbergii and Acanthurus gahhm) as well as three Specimens of Crustaceans (Metapenaeus dalli, Panulirus penicillatus and Portunus petagicus) and two specimens of squids (Parateuthis tunicate and Chtenopteryx sicula) have been collected from Jeddah coastal water.
The gills, liver and muscle tissue were isolated and weighed in separate containers, dissected and washed with distilled water. The collected samples were stored in precleaned plastic bags and stored in a freezer at ?20˚C until the performance of chemical analysis and analyzed for heavy metals according to UNEP/FAO/IAEA/IOC (1984) [
The exact weights of each sample tissue were digested in microwave oven using HNO3 acid in Teflon PTFE tube. The samples were cooled to room temperature and then were transferred to a 25 ml volumetric flask and diluted to 25 ml with 2% HNO3 in a volumetric flask, then diluted to level with de-ionised water appropriately in the range of standards which were prepared from stock standard solution of the metals (Merck). Before analysis, the samples were filtered through a 0.45 µm nitrocellulose membrane filter.
All digested solutions were analyzed in triplicate by Atomic Absorption Spectrophotometer (Shimadzu Model 6800 with graphite furnace, Hydride unit was used for determination of mercury). The instrument setting and operational conditions were done in accordance with the manufacturers specifications. All determinations were in triplicates and sample blanks were prepared in the laboratory in a similar manner to the field samples. The concentrations of heavy metals were expressed as mg/L of water and μg/g dry wt for fish samples.
The bioconcentration factor (BCF) was calculated for each metals, as the relation between the metal concentrations in fish organs (FC) and its concentration in the water (WC) according to equation: BCF = FC/WC [
In the present study, gills and liver are chosen as target organs for assessing metal accumulation higher than the muscle tissue, which usually exhibits a low accumulation potential of metals. Therefore, muscle is chosen because it is the part consumed.
Heavy metal concentration in the muscles, gills and liver of fish species collected from Jeddah coastal waters were illustrated in
The distribution pattern of Zn in the current study in fish muscles, gills and livers ranged from 1.059 to 10.669 µg∙g−1, from 1.34 to 13.417 µg∙g−1 and from 0.155 to 9.069 µg∙g−1 respectively.
In the present study, Zn was the highest metal in the muscle, gill and liver of analyzed species followed by Cu as the dominant two metals compared with other determined metals. On the other hand, Hg was generally the lowest (
Zn toxicity is rare, yet it can be toxic above the limit of 50 µg∙g−1 wet weight in muscle. It appears to have a protective effect against the toxicities of both cadmium and lead [
The zinc concentration in the samples compares well to the earlier report on the fish species from the Black Sea coasts (9.5 - 22.9 mg∙kg−1) [
Cu concentration in all examined fish species varied from 0.01 ± 0.001 to 10.29 ± 0.01 µg∙g−1 dry weight and Acanthopagrus bifasciatus recorded the highest concentration of Cu in the livers among all the fish species studied.
Cu levels in the present study are in good agreement with previous recorded values of fish species where the values ranged from 0.23 to 9.49 mg∙kg−1 for fish from Marmara Sea [
Comparing our average values of Cu with Food and Agricultural Organization’s limits for Cu is 30 µg∙g−1 [
The concentration of Cd in all fish species varied from 0.001 ± 0.0004 to 1.19 ± 0.002 µg∙g−1 dry weights. The highest level of Cd was recorded in the gills of Snubnose emperor compared to other species studied.
Cd contents in gills of Epinephelus areolatus, Epinephelus radiates, Anthias squamipinnis, Snubnose emperor, Dicentrarchus labrax and lutjanus ehrenbergii were remarkably higher than muscle and liver.
A lot of researchers have reported that metals accumulate in high concentrations in the gill, the liver and the intestine, because these organs have relatively higher potential for metal accumulation than muscle [