Marenzelleria viridis vs. Nereis diversicolor: Their Effects on the Nutreint Cycling in Danish Coastal Ecosystems

Ernesto Calderon, Alexandria Essinger, Mette Lassen, Laura Niclasen & Marta Stenz

Studenteropgave: Semesterprojekt

Abstrakt

The effect of the invasive species Marenzeleria viridis and the native species Nereis dirvesicolor in the sediment nutrient dynamics was studied over the period of one month and a half. The two species were studied in a laboratory experiment separately and in combination to observe the effects on sediment metabolism (O2 uptake), and nutrient release; nitrogen (NH4+ and NO3) and phosphorous (PO43-). A 2x2, with 4 replicates design was established with 4 treatments; (1) Control, (2) Marenzelleria viridis, (3) Nereis diversicolor and (4) M. viridis and N. diversicolor. The O2 uptake was greater for N. diversicolor when compared to M. viridis alone and for the combination of the two species, the same trend follows for nitrogen and phosphorous. Pore water measurements were taken at the beginning and end to know the total amount of dissolved phosphorous and nitrogen in the sediments. Overall, more ammonium was released from the sediments than nitrate and it was found that M. viridis caused a build-up of nitrogen in the sediment, whereas N. diversicolor released higher levels of nitrogen in the pore water. The nitrate-release from the sediment was very high for N. diversicolor in comparison to M. viridis due to this species promotion of nitrification. The results of this experiment suggest that N. diversicolor increased release of phosphate, nitrate, and ammonium when compared to the invasive species M. diversicolor. Some uncontrolled factors such as the biomass of the polychaetes used may, however, have affected the results obtained.

UddannelserBasis - International Naturvidenskabelig Bacheloruddannelse, (Bachelor uddannelse) Basis
SprogEngelsk
Udgivelsesdato12 jun. 2013
VejledereGary Thomas Banta

Emneord

  • Invasive species
  • Nereis diversicolor
  • Marenzelleria viridis
  • Benthic nutrient dynamics