Abstract:Laminaria hyperborea is an economically and ecologically important kelp. It can grow lushly in the subtidal zone and from the seaweed forest, playing a significant ecological function. In this study, the absorption rates of nitrogen and phosphorus of L. hyperborea was determined at different temperatures (5℃, 9℃, 13℃, 17℃), as well as relative growth rate (RGR) and accumulation of selected heavy metal ions (arsenic ions As5+, cadmium ions Cd2+, lead ions Pb2+), aiming to evaluate whether L. hyperborea is a potentially feasible candidate species for marine bioremediation. The main results are as follows: (1) the experimental specimens illustrated maximum absorption rates of nitrogen and phosphorus at 9℃~13℃ after 72 h. The maximum absorption rates of phosphorus, ammonia nitrogen and nitrogen nitrate were 95%~98%, 96% and 42% respectively, indicating that the removal of nitrogen nitrate, ammonia nitrogen, and phosphorus by L. hyperborea from seawater is significant. (2) The total arsenic ions content accumulated in the L. hyperborea was 168.33 mg/kg, there was no significant difference between the surface (55%) and inner (45%) of the algae; the relative growth rate was –0.92%/d when L. hyperborea were treated with arsenic ions for 6 days. The total cadmium ions content accumulated in L. hyperborea was 15 mg/kg, and the surface content (91%) was significantly higher compared to the inner content (9%); the relative growth rate of those individuals who were treated with Cd2+ enriched solution for 6 days was 5.78%/d (lower than the control). The total lead ion content accumulated in the L. hyperborea was 320 mg/kg. The surface concentration (96.5%) was significantly higher compared to that of the inner concentration (3.5%) of the algae; the relative growth rate of those individuals who were treated in Pb2+ enriched solution for 6 days was 6.73%/d, which had no significant difference with control condition. The results suggested L. hyperborea could be an ideal candidate in marine bioremediation.
