Decomposition of macroalgae and the release of nutrient Admiralty Bay, King George, Antarctica

On land and in the shore zone macroalgae are a source of organic matter and of nutrients. A crumbled mixture of macroalgae and 10 selected species of macroalge were used in investigations. In long (22-69 days) and short (11-52 hours) term experiments the quantities of released nutrients per 1 kg of dry mass of identified macroalgae were: for nitrogen 10.6-93.7 mg NO2--N, 12.9-406 mg, NO3--N, 74.0-7890 mg NH4+-N, and 1110-22000 mg total-N; for phosphorus the figures were: 718-6110 mg reactive-P and 1370-13400 mg total-P. The amounts of ammonium-N, total-N, reactive-P and total-P, released from the mixture of disintegrated algae collected on the beach, were lower than those from fresh algae. Nitrate-N, reactive-P and total-P were liberated most readily. From the total amounts of nutrients in the long and short term experiments about 80% were released during the first 3 days and the first 3 hours respectively. The decomposition of macroalgae may improve the fertility of poor soils and inland water as well as of sea water, being a source of nutrients

Effects of starvation on the biochemical composition of blood and body tissue in the Antarctic fish Notothenia coriiceps (Richardson, 1844) and excreted metabolic products

The study was carried out at the Polish Academy of Science H. Arctowski Polar Station during the 29th Antarctic Expedition in 2005. The experiment involved 18 individual Notothenia coriiceps caught in Admiralty Bay. Prior to experimentation, blood was sampled from 12 individuals (six females and six males) and assayed for protein, glucose, triacylglycerol, cholesterol plus cholesterol-HDL fraction levels. Body tissue was also analysed for approximate biochemical composition. Six individuals (four females and two males) were placed in a 400-dm3 aquarium of constantly aerated seawater at 0.0±0.5℃ and starved for 52 days, from mid-April to early June. At the end of the experimental period, blood and body were re-assayed. Starving resulted in body weight reduction and a decrease in blood crude protein content of both males and females. Both males and females showed a significant (P<=0.05) increase in glucose levels. Triacylglycerol content was reduced-significantly (P<=0.05) in females and highly significantly (P<=0.01) (and it is I<=0.01) in males-and was accompanied by a reduction in total cholesterol. On the other hand, HDL-cholesterol levels increased significantly (P<=0.05) both in males and females. The seawater in which the fish were maintained was also assayed for various chemicals. Nitrogen and phosphorus levels were elevated relative to those in clean seawater