Nitrogen and phosphorus release during fish decomposition and implications for the ecosystem of maritime Antarctica

Abstract

Nitrogen and phosphorus release during decomposition of Notothenia coriiceps (Richardson, 1844) fillets kept in seawater was examined in the laboratory. Amounts of N–NO2 −, N–NO3 −, N–NH4 +, total inorganic nitrogen, total organic nitrogen (TON), total nitrogen (TN), total reactive phosphorus, total organic phosphorus (TOP), and total phosphorus (TP) released during a 5-day exposure were measured. The highest average release (from the standard 100 g fillet wet weight) was typical of TON and TN (2.574 and 2.703 mgN dm−3, respectively) as well as of TOP and TP (1.526 and 2.648 mgP dm−3, respectively). The release was observed to be most intense during the initial 120 min of decomposition. As shown by the accumulation rate coefficient, the highest rate of nutrient accumulation in water was typical of organic forms of N and P (0.827 and 1.329, respectively). Organic nitrogen and organic phosphorus accounted for 94 and 54 % of TN and TP release, respectively. In the experiment, nitrogen and phosphorus were released from the fish remains with leached chemicals, which may form important chemical cues for scavengers.