The Elemental Composition of Demospongiae from the Red Sea, Gulf of Aqaba

Abstract

Trace elements are vital for the growth and development of all organisms. Little is known about the elemental content and trace metal biology of Red Sea demosponges. This study establishes an initial database of sponge elemental content. It provides the necessary foundation for further research of the mechanisms used by sponges to regulate the uptake, accumulation, and storage of metals. The metal content of 16 common sponge species was determined using ICP measurements. A combination of statistical methods was used to determine the correlations between the metals and detect species with significantly high or low concentrations of these metals. Bioaccumulation factors were calculated to compare sponge metal content to local sediment. Theonella swinhoei contained an extremely high concentration of arsenic and barium, much higher (at least 200 times) than all other species and local sediment. Hyrtios erecta had significantly higher concentration of Al, Cr, Fe, Mn, Ti and V than all other species. This is due to sediment accumulation and inclusion in the skeleton fibers of this sponge species. Suberites clavatus was found to contain significantly higher concentration of Cd, Co, Ni and Zn than all other species and local sediment, indicating active accumulation of these metals. It also has the second highest Fe concentration, but without the comparably high concentrations of Al, Mn and Ti that are evident in H. erecta and in local sediment. These differences indicate active uptake and accumulation of Fe in S. clavatus, this was also noted in Niphates rowi. A significantly higher B concentration was found in Crella cyatophora compared to all other species. These results indicate specific roles of trace elements in certain sponge species that deserve further analysis. They also serve as a baseline to monitor the effects of anthropogenic disturbances on Eilat's coral reefs.

Marine sponges as a powerful tool for trace elements biomonitoring studies in coastal environment

“…These results were higher than those reported in the present study for Cd and Cu, lower for Ag and overall comparable for Zn and As. Mayzel et al (2014) analyzed 16 sponge species and reported BCF consistently lower than 1 for Ba (except for one specie) and V; additionally, the study shows BCF > 1 for As, Cd and Zn. A significant As BCF of 477 was previously measured in only one sponge specie, Theonella swinhoei, which was explained by the presence of a particular bacterium (Mayzel et al, 2014).…”

“…BCF obtained for V, Pb, Ba and Ni were lower than 1 (or close) regardless of the sponge species, leading to the conclusion that these elements are more accumulated in sediments than in sponge' tissue. Ba was demonstrated to be toxic for some sponges (Ostrom and Simpson, 1978;Tompkins-MacDonald et al, 2009), and its BCF were already reported lower than 1 in several sponges species (Mayzel et al, 2014), thus implying its non-essential role in sponges' biological activities. In the same manner, a similar assumption can be made for V, which showed the same behavior in other sponge species, as reported by Mayzel et al (2014).…”

“…For all the other TEs (Cu, Zn, As, Mo, Ag, Cd), BCF were consistently higher than one. Cd and Cu were found to be accumulated by several sponges species collected in the Red and Mediterranean seas (Pan et al, 2011;Mayzel et al, 2014;Cebrian et al, 2007), highlighting their essential role in sponges' metabolism. The high Zn bioaccumulation is likely to be associated not only to its geochemical availability, but also to its crucial role in multiple biological processes as well as to its higher uptake rate for species of this family (Rainbow, 2002).…”

“…According to the definition given by Rand et al (1995), the bioconcentration is defined as the uptake of a chemical by an organism from the abiotic environment (non-living chemical and physical components of the environment that affect the living organisms, for instance sunlight, soil, water and pollution). Usually BCF for sponges are calculated as the ratio between the chemical concentrations measured in the organism and the one measured in local sediment (Negri et al, 2006;Mayzel et al, 2014;Pan et al, 2011). Value of 1 was set as threshold for all analytes, with results equal or above 1 being considered indicative of bioconcentration.…”

Comparative study on the bioaccumulation and biotransformation of arsenic by some northeastern Atlantic and northwestern Mediterranean sponges

“…On hard substrata, sponges are one of the top spatial competitors (Bell, 2008) and have recently been proposed as model organisms to monitor aquatic contamination, in addition to the already existing and well known "Mussel Watch Program" (Genta-Jouve et al, 2012). The bioaccumulation of trace elements in sponges was suggested to differ according to sponge species and the element of interest (Batista et al, 2014;Mayzel et al, 2014;Patel et al, 1985). Only few studies focused on As bioaccumulation in sponges (Aly et al, 2013;Araújo et al, 2003;Batista et al, 2014;Denton et al, 2006;Keren et al, 2015;Keren et al, 2016;Keren et al, 2017;Padovan et al, 2012;Pan et al, 2011;Perez et al, 2005;Schaeffer et al, 2006;Shiomi et al, 1988;Vaskovsky et al, 1972;Venkateswara Rao et al, 2009;Yamaoka et al, 2001;Yamaoka et al, 2006).…”