Effects of Estuarine Log Storage on Juvenile Salmon

J.G. Reade was Librarian of the Dalhousie Ocean Studies Programme, Dalhousie University, Halifax.

Effects of Estuarine Log Storage sets out the results of an experiment conducted in 1980 and 1981 in the North Arm, Middle Arm, and Main Arm of the Fraser River, British Columbia, to determine the population of juvenile salmon. Of the three sites on the North Arm at which samples were obtained, one was located at the Point Grey log storage area. The object of the experiment was to determine if conditions in this particular area were detrimental to the growth of juvenile salmon, as compared with conditions at other sampling sites.

The first series of tests conducted were to discover what species of salmon were to be found at the various sampling sites. Experiments were also conducted to discover the abundance and variety of epibenthic invertebrates at each site and, by analysis of stomach contents, the proportion of each consumed by the fish.

After calculation of fish densities, it was discovered that densities in the area of the log store were similar to others taken on the North Arm. It seemed there was no avoidance by the juvenile salmon of the area where the logs were kept. However, analysis of stomach contents showed that in the Point Grey area, the proportion of adult and juvenile insects in the diet was less than in other areas, while the proportion of epibenthic invertebrates was greater, since these were more abundant in the storage location.

The study concluded that there was no negative effect on fish populations resulting from the log storage area. There were no decreases in fish abundance or fish growth that could be attributed to the existence of the log booms kept there.

Effects of Estuarine Log Storage is quite up to the standard of other reports in this series, with clear illustrations, figures, and tables. Apart from chapters on fish abundance and size characteristics and benthic invertebrate distribution and abundance, the report contains a synopsis of existing literature on the effects of log storage on estuarine fish populations. The conclusion of the report also briefly lays out some possible areas for research in the future.