Hydrographic and productivity conditions of the Palagruža region in the Middle Adriatic
Abstract
Palagruža area is known from the old days as a fertile fishing ground. This paper will try to throw some more light to some specific conditions, of the area compared to the adjacent zones and will try to explain its fertility. For this reason all the data available were processed (ANDRIJA MOHOROVIČIĆ 1974—1976; B u l j a n and M a r i n k o v i ć, 1956;B u l j a n and Z o r e- A r m a n d a, 1966, 1979; CICLOPE 1911—1914; NAJADE 1911—1914, and unpublished data from the file of the Hydrographic Institute of Yugoslav Navy, Split). Data base is large, but the measurements were not always systematically undertaken, thus that some of the series are incomplete. Therefore all phenomena encountered could not be well explained.
The region investigated is located around the isle Palagruža on the Palagruža sill. This sill separates Middle Adriatic with Jabuka Pit from the South Adriatic with deep South Adriatic Pit (basin). Therefore the area investigated is subject to rather intensive exchange and mixing of waters of different origin. This is probably the most important characteristic of the region. Intensive mixing and water exchange influence the turnover of salts which in turn affects the rate of organic production as shall be seen later.
