Table 3. — Concentrations of zinc, manganese, and iron in seven species of polychaetes collected 

 bimonthly from five stations near Beaufort, N.C. Each sample represents the mean of about 10 

 worms with the exception of Chaetopterus , which were analyzed individually 



Species 



Samples 



Zinc 



Manganese 



Iron 



No. 



//g./g. dry wt.^ 



Amphitrite ornata 



Diopatra cuprea 



Chaetopterus variopedatus 



Glycera dibranchiata 



Arabella iricolor 



Nereis sp 



Marphysa sp 



■"■ These values represent means and standard deviations (represented as percent) for the number 

 of samples analyzed. 



of geographical location on the elemental con- 

 centrations of the three species. Geographical 

 location did have a significant effect on the 

 concentrations of zinc in Glycera and Diopatra 

 and manganese in Amphitrite (table 4). Geo- 

 graphical location did not have a significant 

 effect on the concentrations of iron in any of 

 the three species. We are currently examining 

 the zinc and manganese content of the sediment 

 and water at each station in an effort to explain 

 the geographical differences. 



Table 4. — F- values from analysis of variance 

 showing the effect of geographical location 

 on concentrations of zinc, manganese, and 

 iron in three species of polychaetes 



No value is given because concentrations 

 were too low to measure accurately (table 3). 

 ^^•Significant at 1-percent level. 



Elemental Relations 



A direct relation between the concentrations 

 of nnanganese and iron in the species of poly- 

 chaetes collected is shown infigure 17. Species 

 which have the lowest concentrations of iron, 

 such as Glycera and Arabella , also have the 

 lowest concentrations of manganese. Species 

 which have relatively higher concentrations of 

 iron also tend to have higher concentrations of 



manganese. One species, Chaetopterus , is not 

 shown in figure 17; however, it has manganese 

 and iron concentrations (table 3) that would 

 maintain this direct relation if plotted on the 

 graph, A similar relation between the concen- 

 trations of these two elements has been re- 

 ported for sediments. 



Although a direct relation existed between 

 the manganese and iron content of the worms, 

 there was an inverse relation between concen- 

 trations of zinc and iron in the same species 

 (fig. 18). Glycera and Arabella , two species 

 with the lowest concentrations of manganese 

 and iron, have the highest concentrations of 

 zinc. Those species which have highest con- 

 centrations of iron tend to have lower concen- 

 trations of zinc. Two forms. Nereis and Chae- 

 topterus, are not shown in figure 18. Although 

 they have substantially high concentrations of 

 iron, their concentrations of zinc are sinnilar 

 to the concentrations of zinc for Diopatra , 

 Marphysa, and Amphitrite (table 3). Thus, the 

 inverse relation between zinc and iron content 

 in these worms nnay not be linear. More col- 

 lections of Nereis and Chaetopterus are needed 

 before this point can be resolved. 



Ecological Implications 



The concentrations of zinc, manganese, and 

 iron in the seven species collected in this 

 study show that polychaetes concentrate these 

 elennents to the same general level as other 

 marine organisms. Concentration factors based 

 on wet weight are about 10'' for zinc and man- 

 ganese and 10 for iron. 



The effect of geographical location on the 

 levels of zinc and manganese in several spe- 

 cies suggests that the trace element content 

 of the sediment may be an important factor in 



33 



