MAP Technical Reports Series No. 106 UNEP

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and 83,000 t/year, respectively (cf. Table 6). Adding another 10% to 20% for unaccounted
domestic, industrial and other direct sewage sources, and to phosphorus another 50% to 100
% to account for polyphosphates in detergents, the respective totals increase to between
750,000 and 820,000 t for nitrogen, and to between 145,000 to 185,000 t for phosphorus. Of
these one can expect that a some 50% to 60% are discharged into waterways and into the
Mediterranean Sea. Accordingly, the maximum loadings from the sources mentioned would rang
from between 390,000 to 470,000 t for nitrogen, and 80,000 to 100,000 t for phosphorus.
Effective Basin:
Resid. Population:
Basin Coeff. (kg/sqkm.y):
Popul. Coeff. (kg/inh.y):
Table 8
Load Estimate applied to the Mediterranean Basin as a whole
using the coefficients of Table 5a
1.25E+06
1.54E+08
Load Estimates: N
kg/y
Basin
Population
1.15E+09
3.39E+08
sqkm
inh
Nitrogen
920
2.2
P
kg/y
5.00E+07
5.39E+07
Phosphorus
40
0.35
(cf. Table 7)
N/P N P
% Contribution
23.0
6.3
Total 1.49E+09 1.04E+08 14.3
77%
23%
48%
52%
Diffused Sources: Contrary to domestic and related sources, estimates about diffused
sources are uncertain, and for the most tentative. Also, the distinction between point and diffused
sources is not always easy.
Fertilizers: Fig. 8 and Table 9 report the most recent information on land distribution and
fertilizer application in countries bordering the Mediterranean Sea, and these are confronted with
data from selected countries North of the Alps. The data listed refer to total commercial fertilizer,
and hence, are not directly comparable to the model data used; still, they reflect the correct
proportions. Except for France, average fertilizer application in all the Northern Mediterranean
countries is substantially below that of Transalpine countries, and that of countries bordering the
Mediterranean South and East is generally very low except for Egypt and Israel. It is extremely
difficult, however, to estimate with any degree of confidence the amounts that are exported from
this source to the Mediterranean Sea. Rather than to give any figure, this question is left open,
yet, the quota of fertilizer application is used in a subsequent model estimate.
Animal husbandry: Variations between countries of animal husbandry relative to
population are also substantial (cf. Table 10), and regional differentiation becomes even more
apparent if data are ordered according to high and low agronomic activity sectors (Table 11).
Arab and non-Arab countries differ clearly with regard to pig rearing; cattle raising is generally
high in Northern Mediterranean countries and in Turkey (except Greece), while sheep and goat
raising is high except in Malta, Israel, Egypt and Italy.