BEN-YAMI and GLASER: INVASION OF SAURIDA UNDOSQUAMIS 



Meteorology 



Air temperature (monthly averages) and pre- 

 cipitation data for 1950-70 were published by the 

 Israel Meteorological Service. These data are 

 complete and uninterrupted for the whole period. 

 Only those data which were collected at stations 

 between Tel Aviv and Ashdod (Anonymous, 

 1950-71) were chosen (Figures 3, 4). 



Presentation 



In attempting to find the relationship between 

 climatic phenomena and fish catches, it is simpler 

 to follow a calendar based on seasons with the year 



beginning in the fall, at the beginning of the rainy 

 season in this area. Thus, for the purpose of this 

 study, the environmental and most of the fisheries 

 data are given according to years which start on 1 

 September and end on 31 August, i.e., 1 Sep- 

 tember 1950-31 August 1951 forms the year 

 1950/51. 



In some instances, extreme values rather than 

 annual averages may be influential factors affect- 

 ing crops or populations. One year may be a rainy 

 year, but most of the rains may not have been 

 timely, etc. For this purpose, some data are pre- 

 sented selectively to emphasize the more critical 

 points. Thus, e.g., the average of the three coldest 

 months, whatever these months may be in each 



T°C 



28 

 27 

 26 

 25 



16 

 15 

 14 

 13 



50/51 52/53 54/55 56/57 58/59 60/61 62/63 64/65 66/67 68/69 YEAR 



Figure 3. — Air temperatures, 1950/51-1968/69 (Anonymous, 1950-70). A - Summer maxima, mean of the 

 warmest month; B - average of three coldest months. Each year starts 1 September. 



50/51 52/53 54/55 56/57 58/59 60/61 62/63 64/65 66/67 68/69 YEAR 



Figure 4.— Precipitation, 1950/51-1968/69 (Anonymous, 1950-70). A - September-January; B - January-April. 



Each year starts 1 September. 



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