47
Many of the studies synthesised in this report were carried out by students either under the supervision of their tutors or, in the case of visiting students, at some institutions by resident researchers. Others are those by senior
researchers and consultants. Students’ reports falls under three categories. These are academic reports produced by students from the University that report results of their field exercises; reports by visiting students; and Masters
and PhD theses. Many of the studies, especially those by senior researchers, are of a good quality. The quality of studies that were closely supervised by capable scientists is also commendable. Masters and PhD theses from the
University are normally examined both locally and externally. This also ensures quality products.
2.3.2 Comparability of methods
In almost all the studies nutrient analyses were carried out by the methods presented in the Manual of Chemical and Biological Methods for Seawater Analysis
by Parsons et al 1984. These are standard methods. In this respect the methods used in these studies are comparable. This is also true for other analytical techniques such as
those used for the analysis of heavy metals and coliforms. In the case of applied studies where information gathering was through interviews and questionnaire, the basic approach was similar in all the studies, even though
variations in the interview techniques were apparent. All in all, the methods used in the various studies were comparable and hence may cause little problems in the interpretation of results in the future. It is noteworthy, as
mentioned above, that the principal methods used in various studies, though standard, are quite old and lack any sophistication. This is a common problem that can be attributed to inaccessibility of new and better techniques.
Improvement of analytical techniques will help produce better and more accurate results.
2.3.3 Publicationsgrey literature
In this synthesis, the literature is classified into seven categories. These are those that have been published in refereed journals including those published locally, booksbook chapters, papers in conference proceedings,
reports, undergraduate research reports, Diploma thesis, Masters and PhD theses. Out of the nearly 130 references that have been examined, 23 are papers in journals, 25 in conference proceedings, 1 as a book chapter, and 59
reports. These publications are mainly from work carried out by senior researchers. Other reports were by students. These include 15 undergraduate research reports, 2 MSc theses, 2 PhD thesis and 1 diploma thesis.
Consequently, reports, of which most are in grey literature, form the bulk of the references.
2.3.4 Age of information oldrecent
Research in pollution and water quality does not have a long history in Tanzania. During a literature search preceding this synthesis, the earliest records found on this aspect were from the early 1970s. A 1971 report by the
Danish Isotope Center gives results of a feasibility study that assessed receiving water supply for Dar es Salaam. Another study by Steinbach 1974 reported on the relationship between industry and environment in the
Msimbazi Valley drainage area. Ngoile et al 1978 discussed aquatic pollution in Tanzania. These studies were followed, in the 1980s, by a number of investigations on different aspects of the environment eg. Shanmungam,
1981; Shanmungam, 1983;UNIDOUNEP, 1982. Then beginning the early 1990s, there was an upsurge of publications on the topic making this period by far the most productive in terms of literature on pollution and
water quality. There is no significant difference in terms of quality of datainformation generated in the 1970s and that generated more recently. This could be said to reflect uniformity and accuracy of the methods used.
However, improvement of analytical techniques changing of technology may improve accuracy, limits of detection, and consequently overall value of the data collected.
2.4 Main findingsobservations
