Trace metals with seasonal considerations in coastal algae and molluscs from Beirut, Lebanon

Abstract

Twelve species of intertidal algae and molluscs from Ras Beirut, Lebanon have been investigated for their heavy metal content. Atomic absorption spectrophotometric analysis showed that the algae and molluscs concentrated similar levels of most metals. However, of the twelve organisms, Brachydontes variabilis had the highest copper, Patella coerulea and Colpomenia sinuosa had the highest iron, and Pinctada radiata had the highest zinc values with rather elevated cadmium. Cystoseira spinosa concentrated the lowest levels of zinc, and nickel was variable in all organisms.Seasonal comparisons of metal levels were also considered in three algae and three molluscs studied previously. The only signs of seasonal variation in the algae were with nickel and iron in Halimeda tuna and lead in Pterocladia pinnata. Both cadmium and lead were generally lowest in the spring samples of the algae. Lead and nickel concentrations in the molluscs were generally highest in the summer and lowest in the spring. Slight seasonal trends were seen with lead and iron in Brachydontes variabilis and lead in Monodonta turbinata.The lack of comparison data from the Mediterranean, particularly the eastern basin, makes it essential that studies of this nature be continued.

Metal accumulation in a biological indicator (Ulva rigida) from the lagoon of Venice (Italy)

“…Seasonal fluctuations in metal contents are described for many algal species (Shiber 1980;de Lacerda 1985;Sawidis and Voulgaropoulos 1986;R6nnberg et al 1990;Shimshock et al 1992;Miramand and Bentley 1992;Malea et al 1994) and are due to their biological cycle which in turn depends on external parameters such as temperature, light exposure, oxygen, pH, and the presence of natural organic complexing agents. Variations in pH may be effective in the first stage of uptake, In U. lactuca (Gutknecht 1963), increasing the pH from 7.3 to 8.6 promoted Zn 65 uptake and retarded Zn 65 loss.…”

Biogeographical homogeneity in the eastern Mediterranean Sea. II. Temporal variation in Lebanese bivalve biota

“…Early pioneering papers provided accurate data on shelled molluscs from 1856 to 1938, while the following decades were rather unfertile until 1971. From then up until 2013, less than 30 papers, notes, abstracts and non-peer-reviewed articles have provided additional scattered information on Lebanese marine bivalve molluscs (Puton 1856, Brusina 1879, Pallary 1911, 1912a, 1919, 1933, 1938, Gruvel & Moazzo 1929, Gruvel 1931, Moazzo 1931, Spada 1971, Fadlallah 1975, Shiber & Shatila 1978, Shiber 1980, Zibrowius & Bitar 1981, Bogi & Khairallah 1987, Bitar 1996, 2013, Bitar & Kouli-Bitar 1995a,b, 1998, 2001, Nakhlé et al 2006, Bitar et al 2007, Bariche 2012, Crocetta & Russo 2013. However, wide-ranging overviews of the temporal trends and the long-term faunal changes occurring in the area are still lacking.…”

Size dependent metal concentrations in two marine gastropod species

“…For instance, NEVO et aL (1986) and KARNAUKHOV et aL (1977) studied the tolerance of Cerithium to heavy metals, and SALIBA and VELLA (1977), AXIAK and SCHEMBRI (1982) and VERRIOPOULOS et al (1989) used Monodonta in toxicity experiments. The bioaccumulation of a small number of metals was examined in some species including Monodonta (CI-IABERT and VICENTE, 1982;SHIBER, 1980;SHIBER and SRATILA, 1978). Recently, N~CO-LAIOOU and NOTT (1990) studied in more detail the uptake of heavy metals both by Cerithium and Monodonta in the proximity of a ferronickel smelting plant and found important differences between the two species.…”