During 1936 and 1937 extensive physical and faunistic studies of the Tamar Estuary were made by several workers at the Plymouth laboratory. These investigations, though conducted independently and with different immediate aims, proved to have considerable bearing on one another, and each worker benefited by occasions for co-operation. As the work proceeded it became clear that one of the most important aspects of each investigation was the bearing it had on the balance of life in the estuary as a whole. It was decided to publish the results of these studies in a series of papers in which each contributor should lay due emphasis on data having possible bearings on the problems studied by the others, so as to present as complete a picture as possible.

Studies have been made of salinity, temperature, penetration of daylight, macro- and micro-fauna of the intertidal zone, the sessile flora and fauna of the buoys, the fishes and their food, and the birds which frequent the flats and channels. Other studies are contemplated. In the work on light penetration and on quantitative estimates of the fauna of the mud-flats, no comparable data have hitherto been procured in this country.

The Tamar is the largest of the rivers which flow into the west end of Plymouth Sound. It is tidal for nearly 19 miles (30 km.) of its course. Rather over 3 miles (5.5 km.) from the sea it is joined by the River Lynher to form the Hamoaze, an estuary common to the two rivers.