Application of algal bioassays in the determination of eutrophic power of waste water (”Conclusions” only) [Translation from: 1g.Sanita pubbl. 31 257-267, 1975]

The best evidence for establishing the level of eutrophy of a water-body is its algal production which makes it possible to identify the type and the intensity of the eutrophication according to the kind and number of algal species present: when the number of algae exceeds half a million per litre then one speaks o an ”algal bloom”. The scope of the present research aims to verify if the alga Selenastrum capricornutum can be used as a test alga under our culture conditions and to determine the eutrophic level of the secondary effluent of a modern plant for the treatment of domestic discharge and to investigate the eventual ”limiting factors”. Finally this paper aims to study the effect on the secondary effluent of tertiary treatment carried out artificially in the laboratory.

Waste minimisation in fishing operations

Sources of wastes in fishing operations mainly include bycatch discards; processing wastes where catch is processed onboard; plastic wastes due to abandoned, lost and discarded fishing gear; bilges and other wastes from the vessel operations. Fishing systems in general have an associated catch of nontargeted organisms known as bycatch. Non-selective fishing gear that is not modified or equipped to exclude non-targeted organisms, may take a significant quantity of bycatch of non-targeted finfish, juvenile fish, benthic animals, marine mammals, marine birds and vulnerable or endangered species that are often discarded. Average annual global discards, has been estimated to be 7.3 million t, based on a weighted discard rate of 8%, during 1992-2001 period. Trawl fisheries for shrimp and demersal finfish account for over 50% of the total estimated global discards. Plastic materials are extensively used in fisheries, owing to their durability and other desirable properties, contributing to the efficiency and catchability of the fishing gear. However, plastics biodegrade at an extremely slow rate compared to other organic materials. Abandoned, lost or otherwise discarded fishing gear (ALDFG) and related marine debris have been recognized as a critical problem in the marine environment and for living marine resources. Prevention of excess fishing capacity by appropriate management measures could lead to enormous savings in terms of fuel consumption, emissions and bycatch discards from the excess fishing fleet, capital and operational investments and labour deployment in capture fisheries, with significant economic gains. In this paper, wastes originating from fishing operations are reviewed, along with their environmental impacts and possible mitigation measures