Quantitative comparison of levels of organic wastes from four major sources at four scales along the Newfoundland coastline

Cull, Deneen Jane (2000) Quantitative comparison of levels of organic wastes from four major sources at four scales along the Newfoundland coastline. Masters thesis, Memorial University of Newfoundland.

[English] PDF (Migrated (PDF/A Conversion) from original format: (application/pdf)) - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (20MB) [English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. (Original Version)

Abstract

This study compared the levels of organic wastes released along the Newfoundland coastline From four different sources during the period 1992-1996. These sources include offal from fish plants, domestic sewage, aquaculture wastes (wasted feed and faeces) and sawmill wastes (bark, shavings, wood chips, slabs, sawdust). The total amount of organic wastes entering coastal waters had never been quantified before this study, and hence, comparisons of levels of wastes from different sources had not previously been made. The scattered information on sources of organic wastes was assembled in order to determine and compare the four major sources in Newfoundland. This study also determined whether spatial scale is a factor in determining the greatest and smallest sources of organic wastes released. The level of organic wastes released were quantified and compared at four scales along the Newfoundland coastline. Three hypotheses were addressed concern concerning the relative importance of the sources of the wastes: i) The level of organic wastes released from coastal sawmills is lower than that released from the other three sources. ii) At the spatial scale of the entire island the largest levels of organic wastes are from sewage, followed by fish plant offal, and finfish aquaculture. iii) The relative level of organic wastes released from sewage, aquaculture, and offal differs according to spatial scale. As the scale studied becomes smaller (from the entire island, to coastal regions, to fisheries statistical areas, to fisheries statistical sections) either of the three sources could be the major contributor of organic wastes. -- At the largest spatial scale examined, the entire island, offal was the largest contributor of organic wastes, followed by sewage and sawmill wastes, with aquaculture as the smallest contributor of wastes. The region of the island with the greatest amount released into the coastal waters was the Avalon Peninsula, while the Northern Peninsula had the least amount of wastes being released. Two interesting trends were found in this investigation. First, aquaculture wastes are increasing at a high, steady rate in Newfoundland at a very localized coastal scale. This was not evident for the other sources of wastes studied. Secondly, although the offal levels for the entire island only increased slightly over the period studied, the form of the released offal changed greatly since the moratorium on Atlantic cod in 1992. Currently, there is a predominance of inorganic shells being released, which are more resistant to degradation than the flesh and viscera of fish. -- The next smallest spatial scale, coastal region (the coastline was divided into five regions) showed the same results as the scale of the entire island. Offal was the largest contributor of organic wastes and aquaculture the smallest contributor. The two smallest spatial scales studied, fisheries statistical area (the coastline was divided into 14 areas) and fisheries statistical section (the areas were divided into 49 sections), showed variation within the two larger coastal scales. The results for the area and section scales corresponded with those for the region scale in that the places with the greatest levels of release (St John’s, Southern Shore, Conception Bay) were on the Avalon Peninsula, and the places with the lowest levels of release were on, or very near, the Northern Peninsula (Bonne Bay, Gros Morne Park area, Strait of Belle Isle area). Overall, most areas had offal as the greatest contributor and aquaculture as the smallest. However, the importance of spatial scale was evident from the increased variability in type and level of organic wastes released as the coastal scale examined became smaller. This was due to variation in the population and in level and type of industry between places along the coast

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