7. CONCLUSIONS

Overall, the author would caution the Rudjer Boskovic staff against being too “scientific”. Fish farming is still largely an art, not a science, and it is important they keep in mind that the primary goal is fish production rather than scientific research. With this proviso, however, the author recommends that the proposal to develop brackish/seawater cage farming of salmonids in Yugoslavia is sound and deserves support. It will be necessary to make amendments to details of the project document, partly in the light of the above comments and partly because time has passed and the situation has changed since the proposal was written. If possible, however, the author would recommend at least part of the support be given as soon as possible, rather than being further delayed pending revision of the project document.

Table 1
MEAN MONTHLY TEMPERATURE AT DIFFERENT DEPTHS AT THREE SAMPLING SITES IN THE RIVER KRKA ESTUARY DURING 1981 AND 1982
(TEMPERATURE SHOWN IN °C)
Locality	Depth (m)	1981						1982
Locality	Depth (m)	Jul	Aug	Sep	Oct	Nov	Dec	Jan	Feb	Mar	Apr	May	Jun
Skradin	0.5	22.3	23.8	21.0	17.4	12.4	9.8	9.2	7.6	9.8	12.5	15.9	22.4
"	2	24.0	27.6	24.3	20.0	15.0	9.9	9.5	11.1	11.1	12.6	16.5	22.9
"	4	24.0	24.8	23.1	22.6	20.1	12.0	11.8	13.5	13.3	14.0	17.3	23.2
"	6	23.2	23.1	22.9	22.7	19.6	12.7	12.3	13.7	13.6	14.6	16.8	21.7
Vrulje	0.5	23.6	24.8	21.7	17.7	10.4	8.3	8.9	7.4	10.3	13.1	18.8	24.2
"	2	25.2	26.9	24.1	18.4	14.3	8.7	9.2	9.7	10.7	13.4	19.2	23.7
"	4	23.6	24.3	23.9	23.0	18.7	11.3	11.3	12.7	12.6	14.5	18.9	23.3
"	6	23.4	21.9	22.6	22.3	18.8	11.4	12.0	12.8	13.2	14.9	17.9	22.5
Martinska	0.5	23.5	24.6	21,4	18.2	12.6	9.9	7.3	7.6	10.5	12.7	19.0	25.2
"	2	23.6	25.6	22.3	20.7	14.2	10.3	8.0	10.7	11.1	12.7	17.6	23.6
"	4	23.0	22.9	22.0	21.9	18.2	11.1	11.0	12.8	12.0	14.2	16.6	22.3
"	6	22.4	21.8	21.7	21.9	18.5	13.2	11.9	12.8	12.4	14.0	16.1	21.7

Table 2
MONTHLY AVERAGE SALINITY AT DIFFERENT DEPTHS AT THREE SAMPLING SITES IN THE RIVER KRKA ESTUARY DURING 1981 AND 1982
(SALINITY EXPRESSED IN PARTS PER THOUSAND ‰)
Locality	Depth (m)	1981						1982
Locality	Depth (m)	Jul	Aug	Sep	Oct	Nov	Dec	Jan	Feb	Mar	Apr	May	Jun
Skradin	0.5	3.2	7.2	3.2	5.5	4.1	2.4	2.1	3.6	6.3	2.8	3.4	3.8
"	2	29.9	31.8	26.4	6.1	15.3	2.5	3.6	11.4	11.9	3.0	14.4	6.6
"	4	36.5	37.0	35,4	27.8	32.2	8.2	6.6	18.9	33.3	32.0	35.1	25.6
"	6	37.4	37.4	36.7	33.5	36.4	24.2	17.8	26.2	38.5	38.5	37.1	30.3
Vrutje	0.5	7.4	13.7	17.1	5.7	9.2	7.3	3.0	11.4	10.5	5.4	5.1	7.3
"	2	33.4	34.1	25.8	6.1	19.4	7.4	5.1	16.3	13.6	5.6	11.0	8.0
"	4	36.5	36.3	34.3	22.8	34.4	15.4	12.0	29.3	32.6	29.1	33.8	26.0
"	6	36.7	37.1	36.4	30.2	36.7	18.2	26.4	29.7	37.0	38.5	35.4	30.0
Martinska	0.5	16.3	21.6	23.9	9.3	19.1	13,4	8.1	16.8	17.0	7.9	10.1	15.9
"	2	31.8	30.2	26.9	13.4	27.9	15.9	8.9	21,3	19.1	8.9	17.0	23.5
"	4	36.4	37.2	34.3	29.1	35.9	26.3	19.6	26.7	35.0	35.0	35.5	34.6
"	6	37.0	36.9	36.5	32.7	36.7	37.1	29.7	29.9	38.0	38.8	37.0	35.5

Table 3
PHYSICO-CHEMICAL CHARACTERISTICS OF WATER AT SKRADIN (RIVER KRKA ESTUARY) DURING 1982
	0,5 m			2 m			4 m			6 m
Depth	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 O₂	S ‰
Month	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 O₂	S ‰
VII	25,4	9,1	4,3	26,5	9,4	23,1	27,1	7,8	26,6	24,8	8,3	31,1
VIII	24,4	9,3	8,0	26,9	9,5	25,3	25,1	8,1	37,0	24,2	8,6	39,0
IX	22,2	8,2	4,8	25,3	8,2	25,0	24,7	7,2	37,0	24,0	6,3	38,9
X	18,9	10,3	3,5	21,3	9,6	18,5	22,8	7,0	35,3	22,8	6,2	36,5
XI	13,7	12,2	3,0	14,1	12,2	10,8	19,4	7,1	30,3	20,6	4,7	37,3
XII	11,4	11,1	2,7	12,7	11,2	2,7	16,7	3,9	34,0	17,8	8,7	37,0

Table 4
PHYSICO-CHEMICAL CHARACTERISTICS OF WATER AT SKRADIN (RIVER KRKA ESTUARY) DURING 1983
	0,5 m			2 m			4 m			6 m
Depth	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 0₂	S ‰	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 O₂	S ‰
Month	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 0₂	S ‰	Temp. °C	mg/1 O₂	S ‰	Temp. °C	mg/1 O₂	S ‰
I	9,3	12,43	2,4	9,7	12,48	2,6	13,4	7,95	26,3	15,0	6,35	33,0
II	8,9	11,99	1,0	9,9	11,93	1,1	11,3	9,99	11,0	12,6	7,69	22,3
III	9,8	9,96	2,0	10,2	10,96	2,0	13,0	8,77	22,4	13,6	7,31	32,3
IV	12,5	11,92	2,0	12,8	12,49	2,0	13,4	11,96	11,9	14,3	10,24	30,8
V	17,3	11,48	1,8	17,4	11,11	2,0	18,3	10,96	31,3	17,8	11,40	35,3
VI	20,3	9,63	2,4	21,1	10,39	11,6	21,1	10,44	29,8	20,6	9,88	33,6
VII	25,2	9,25	2,5	25,6	11,95	11,7	23,5	9,39	30,0	21,9	8,80	35,0
VIII	24,1	8,90	7,6	26,4	9,04	15,8	25,4	8,83	32,0	24,1	8,83	36,0
IX	22,5	11,33	4,0	24,9	11,28	18,0	25,8	9,57	34,7	24,6	7,59	37,0
X	15,3	9,42	7,0	17,5	8,31	27,0	21,2	7,45	33,0	20,8	6,19	35,0
XI	11,4	10,51	14,0	14,8	9,89	19,0	17,2	7,31	35,0	17,0	3,19	39,0
XII	10,0	11,44	20,0	11,9	8,58	34,0	12,5	7,49	38,0	13,0	8,34	38,0

Table 5
MEAN MONTHLY TEMPERATURES (°C) AT DIFFERENT DEPTHS AT ST. NIKOLA IN THE KRKA ESTUARY DURING 1982 AND 1983
Depth (m)	1982					1983
Depth (m)	Jul	Aug	Sep	Nov	Dec	Jan	Feb	Mar	Apr	May	Jun	Jul
0.5	25.6	23.8	23.0	13.9	10.6	9.7	8.5	10.9	14.4	18.9	21.6	24.7
2	25.1	23.2	23.3	17.2	13.1	12.7	12.0	12.5	14.3	18.6	20.6	22.7
4	24.6	23.0	23.1	18.3	13.7	14.2	13.0	13.0	14.2	17.6	20.0	22.1
6	23.9	22.8	22.8	19.0	14.6	14.7	13.4	12.8	14.2	17.7	19.8	21.5

Table 6
MONTHLY AVERAGE SALINITY (‰) AT DIFFERENT DEPTHS AT ST. NIKOLA IN THE RIVER KRKA ESTUARY DURING 1982 AND 1983
Depth (m)	1982					1983
Depth (m)	Jul	Aug	Sep	Nov	Dec	Jan	Feb	Mar	Apr	May	Jun	Jul
0.5	25.3	29.0	21.0	15.4	7.3	11.0	14.5	14.8	10.8	13.8	21.0	25.6
2	30.3	34.3	35.0	28.6	21.2	19.3	22.8	21.0	17.1	23.0	27.2	31.3
4	35.0	37.5	38.5	39.5	26.4	31.3	29.5	34.0	30.1	35.3	33.6	37.0
6	34.3	38.0	38.0	38.8	33.8	35.3	37.3	38.6	35.8	36.5	37.0	38.0

Table 7
QUALITATIVE STRUCTURE OF PHYTOPLANKTON POPULATIONS IN THE WATER AT SKRADIN (RIVER KRKA ESTUARY) FROM JANUARY TO DECEMBER 1983
Species	Trophic status (oligo./beta-meso.)	Month
Species	Trophic status (oligo./beta-meso.)	1.	2.	3.	4.	5.	6.	7.	8.	9.	10.	11.	12.
CYANOPHYTA
Lyngbya sp.			+		+	+	+	+	+		+	+
Oscillatoria geminata Menegh.			+			+			+
Oscillatoria irrigua Gom.			+	+	+	+
Phormidium sp.				+					+			+	+
CHRYSOPHYTA
Chrysophyceae
Dinobryon cylindricum Imh.					+	+				+	+
Dinobryon sertularia Ehr.	o
Bacillariophyceae
Amphora ovalis Kütz.	o-b				+
Achnanthes brevipes Ag.							+	+
Asterionela formosa Hass.	o-b	+	+	+	+	+	+			+	+	+	+
Bacteriastrum comosum Pav.			+						+	+		+	+
Chaetoceros sp.		+	+					+	+	+	+	+	+
Cocconeis placentula Ehr.	b	+	+		+	+	+	+
Cocconeis scutelum Ehr.				+		+			+
Cyclotella comta (Ehr.) Kütz.	o	+	+	+	+	+	+	+	+	+	+	+	+
Cyclotella kützingiana Twait.	b	+		+	+	+	+		+	+	+	+	+
Cyclotella melosiroides Lemm.					+	+	+	+	+	+	+	+	+
Cyclotella striata Grun.		+	+		+	+	+			+		+
Cymbella ventricosa Kütz.	b		+	+		+	+		+			+
Diatoma anceps Grun.	o	+	+	+	+						+
Diatoma elongatum Agar.	b-o	+	+	+	+	+	+		+	+	+		+
Diatoma vulgare Bory	b		+	+								+	+
Fragilaria crotonensis Kitt.	o-b		+	+	+	+	+			+	+	+	+
Fragilaria brevistriata Grun.		+	+	+	+	+			+	+	+	+	+
Gomphonema olivaceum (Lyng.) Kütz.	b		+	+				+	+				+
Gomphonema olivaceum v. calcareum Cl.	b	+						+				+
Melosira moniliformis v. subglobosa Grun.			+	+			+		+		+
Melosira varians Ag.	b	+	+	+		+			+	+
Navicula sp.			+		+			+
Navicula gracilis Ehr.	b-o	+	+				+
Navicula radiosa Kütz.	o-b		+	+
Nitzschia paleacea Grun.			+		+		+		+
Nitzschia longissima (Breb.) Ralfs						+						+
Nitzschia sigmoidea (Ehr.) W.Sm.	b									+
Pleurosigma sp.													+
Rhizosolenia alata f. gracillima Grun.		+	+		+		+		+		+
Rhizosolenia solterfortii Per.			+							+
Rhizosolenia longiseta Zahn.	o				+	+				+	+
Synedra fulgens (Grev.) W. Sm.			+			+				+			+
Synedra ulna (Nitzsch.) Ehr.	b	+	+	+		+		+					+
Rhoicosphenia curvata Grun.	b	+	+	+	+	+	+	+	+		+	+	+
Tabellaria fenestrata (La.) Kütz.	o-b	+		+	+		+		+		+		+
PYRROPHYTA
Ceratium sp.			+			+
Ceratium fusus v. seta (O.F.M.) Jörgensen			+			+					+
Ceratium hirundinella (C.F.M.) Schrank	o					+	+	+	+	+
Ceratium tripos v. atlanticum Nitzsch.					+			+	+	+	+
Peridinium sp.			+		+

Table 8
GROWTH OF RAINBOW TROUT (EXPERIMENTAL GROUP 5) IN BRACKISH WATER AT SKRADIN (RIVER KRKA ESTUARY) OVER A 5-MONTH PERIOD
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean Length (mm)
06.01.83.	286		35.7	125
08.02.83.	285	1	53	186	61	17.3	21.7
07.03.83.	280	5	65	232	46	12	25.4
05.04.83.	274	6	88	322	90	23	28.9
05.05.83.	270	4	128	474	152	40	31.0
06.06.83.	261	9	151	580	106	23	35.3

Table 9
GROWTH OF RAINBOW TROUT (EXPERIMENTAL GROUP 1) IN BRACKISH WATER AT SKRADIN (RIVER KRKA ESTUARY) THROUGH 8 AND 14 MONTHS DURING 1982–1983
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
06.10.82.	490		41	84
05.11.82.	489		65	133	49	24
06.12.82.	488		111	227	94	46	253	1 missing
05.01.83.	488		135	278	54	26	270
04.02.83.	458	26	175	382	101	40	311	4 missing
07.03.83.	446		204	458	76	31	316	12 missing
05.04.83.	445		270	607	149	66	352	1 missing
05.05.83.	440		323	734	127	53	367	5 missing
06.06.83.	420	5	336	800	66	25	393	15 missing Experiment completed
06.06.83.	100		80	800				Growth study carried out on reduced number of fish until sexual maturity
07.07.83.	88	12	84	950	150	4	417
08.08.83.	71	17	74	1.040	90	-10	427
08.09.83.	68	3	75	1.110	70	1	440
06.10.83.	68		83	1.215	105	8	444
02.11.83.	68		104	1.533	318	21	480
04.12.83.	68		128	1.882	349	24	505

Table 10
GROWTH OF RAINBOW TROUT (EXPERIMENTAL GROUP 2) IN BRACKISH WATER AT SKRADIN (RIVER KRKA ESTUARY) THROUGH 8 MONTHS DURING 1982–83
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
06.10.82.	421		50	118
05.11.82.	410	11	85	207	89	35
06.12.82.	409		135	330	123	50	277	1 missing
05.01.83.	402		168	418	88	33	304	7 missing
04.02.83.	368	29	187	508	90	19	333	5 missing
07.03.83.	363	5	210	578	70	23	347
05.04.83.	344	1	258	750	172	48	365	18 missing
05.05.83.	344		326	948	198	68	396
05.06.83.	332	12	344	1.036	88	18	421

Table 11
GROWTH OF RAINBOW TROUT (EXPERIMENTAL GROUP 3) IN BRACKISH WATER AT SKRADIN (RIVER KRKA ESTUARY) THROUGH 8 MONTHS DURING 1982–83
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
06.10.82.	384		76	197
05.11.82.	379	5	120	316	119	45
06.12.82.	379		187	493	177	67	317
06.01.83.	378		215	569	76	29	340	1 missing
04.02.83.	368	10	226	614	45	11	350
07.03.83.	363	5	238	656	42	12	352
05.04.83.	363		262	777	121	44	368
05.05.83.	342	3	330	965	188	48	403	18 missing
06.06.83.	337	5	348	1 034	69	18	417

Table 12
GROWTH OF RAINBOW TROUT (EXPERIMENTAL GROUP 4) IN BRACKISH WATER AT SKRADIN (RIVER KRKA ESTUARY) THROUGH 8 AND 14 MONTHS DURING 1982–83
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
06.10.82.	166		50	301
05.11.82.	164	2	89	543	242	39
06.12.82.	164		130	793	250	41	376
06.01.83.	162		150	926	133	20	386	2 missing
04.02.83.	158	1	156	987	61	6	405	3 missing
07.03.83.	158		168	1.063	76	12	419
05.04.83.	154	1	195	1.266	203	27	423	3 missing
05.05.83.	153		218	1.425	159	23	444	1 missing
06.06.83.	149	4	242	1.629	204	24	492
								Experiment completed
06.06.83.	100		163	1.629				Growth study carried out on reduced number of fish until sexual maturity
07.07.83.	88	12	153	1.738	109	-10	497
08.08.83.	65	23	117	1.807	69	-36	498
06.09.83.	65		121	1.861	54	4	501
06.10.83.	65		135	2.080	219	14	516
02.11.83.	65		143	2.200	120	8	530
04.12.83.	64	1	154	2.400	200	11	541

Table 13
GROWTH OF RAINBOW TROUT FROM EYED EGGS UNTIL 5 MONTHS OLD FRY IN FRESH WATER AT GRACANSKI HATCHERY DURING 1983
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
16.1.83	12 638		1	0.09			2.1	Eggs
8.2.83	11 570	1 068	2	0.19	0.1	1		Larvae
28.3.83	10 658	912	8	0.76	0.6	6	42	Fingerlings
27.4.83	10 535	123	24	2.27	1.5	16	57
30.5.83	10 492	43	51	4.85	2.6	27	75
23.6.83	10 466	26	78	7.45	2.6	27	84	Trouts sent to Novo Mesto

Table 14
GROWTH OF RAINBOW TROUT FROM 5 MONTHS UNTIL 1 YEAR OLD AT NOVO MESTO FISH FARM DURING 1983
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
23.06.83.	10.466		78	7,5			84
29.07.83.	10.454	12	176	16,8	9,35	98	114
31.08.83.	10.443	11	261	25,0	8,20	86	134
23.09.83.	10.436	7	325	31,2	6,15	64	148
28.09.83.	2.260*		8.176
29.10.83.	2.258	2	110	48,7	17,63	41	148
25.11.83.	2.250	8	129	57,5	8,69	19	182
28.12.83.	2.244	6	146	64,9	7,46	17	190

* Remaining trouts sent to Skradin for comparative experimental breeding

Table 15
GROWTH OF RAINBOW TROUT IN BRACKISH WATER AT SKRADIN (RIVER KRKA ESTUARY) DURING 1983–84
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean Length (mm)
29.09.83.	8.176	2.062*		(31.2)			(148)	Data from Table 9
06.10.83.	6.114		200	32,7			147
02.11.83.	6.111	3	404	66.8	33,4	204	178
04.12.83.	5.915	196	787	133,0	66,9	396	218
05.01.84.	5.903	12	1.133	192,0	66,4	390	247

* Cause of mortality unexplained. After washing the newly impregnated net, the fish were transferred to another location and the situation improved. The reason could be either poison from the impregnated net or some other poison in the water

Table 16
GROWTH OF RAINBOW TROUT STOCKED IN FLOATING CAGES AT DIFFERENT DENSITIES, i.e., GROUP 6: 3.1 kg/m², GROUP 7: 6.3 kg/m², GROUP 8: 12.5 kg/m² AND GROUP 9: 18.8 kg/m², IN BRACKISHWATER AT SKRADIN
Group	Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean Length (mm)
VI	04.12.83	398		50	126			218
VI	05.01.84.	397	1	76	193	67	26	242
VII	04.12.83.	796		100	126			218
VII	05.01.84.	795	1	149	188	62	49	246
VIII	04.12.83.	1.593		200	126			218
VIII	05.01.84.	1.590	3	294	185	60	94	244
IX	04.12.83.	2.388		300	126			218
IX	05.01.84.	2.384	4	461	194	68	162	255

Table 17
AVERAGE CHEMICAL COMPOSITION OF MEAT OF RAINBOW TROUT PRODUCED a) IN BRACKISHWATER AT SKRADIN (KRKA ESTUARY), b) IN FRESH WATER (AT DVOR PRI ZUZENBERGU)
a) Group	Mean weight (g)	Mean length (mm)	water (%)	Protein (%)	Fat (%)	Ash (%)	Calorific value (KJ/g)
I	673	373	73.06	19.59	4.24	1.34	501
III	1 109	426	71.65	19.69	8.93	1.22	687
b)
I	710	384	73.57	19.15	6.05	1.27	564
III	1 086	436	75.03	20.89	4.87	1.27	548

Table 18
GROWTH OF COHO SALMON FROM EYED EGGS TO 8 MONTHS OF AGE AT GRACANSKI HATCHERY (GENERATION 1982)
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean Length (mm)
24.02.82.	11.448		2,7	0,2			7	Eggs supplied to Gracanski
08.03.82.								Hatching began
18.03.82.	11.148	300						All eggs hatched
20.03.82.	11.148		3,8	0,3	0,1	1,1	24	Larvae
05.04.82.	11.005	143^*1	4,1	0,4	0,1	0,3	32	Fingerlings
24.04.82.	10.926	79	8,0	0,7	0,3	3,8	39
07.05.82.	10.900	26	9,4	0,9	0,2	1,4	44
21.05.82.	10.847	53	15,2	1,4	0,5	5,8	49
23.06.82.	10.688	159	33,1	3,1	1,7	17,9	73
22.07.82.	10.586	102^*2	69,0	6,5	3,4	35,9	86
30.08.82.	10.529.	57	102,1	9,7	3,2	33,1	112
23.09.82.	10.526	3	124,3	11,8	2,1	22,2	110
25.10.82.	10.521	5	172,2	16,4	4,6	47,9	125
25.11.82.	10.511	10^*3	195,9	18,6	2,2	23,6	129

*1 - 50 deformed
*2 - 70 taken for experiment
*3 - squashed during capture

Table 19
GROWTH OF COHO SALMON IN FRESH WATER AT DVOR PRI ZUZENBERGU FISH FARM FROM 26 NOVEMBER 1982 TO 29 NOVEMBER 1983 (GENERATION 1982)
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
26.11.82.	7.799		143	18			128	Transported from Gracana
27.12.82.	7.770	29	151	19	1	7,4	130
27.01.83.	7.654	116	152	20	0,5	1,8	130
01.03.83.	7.557	97	147	19	-0.5	-5,7	132
25.03.83.	7.453	104	173	23	4	25,9	133
28.04.83.	7.305	148	182	25	1	6,8	158
27.05.83.	4.758	2.547	161	34	9	-18,0	164
30.06.83.	4.627	131	291	62	29	13	175
30.07.83.	4.361	266	366	84	21	75	195
27.08.83.	4.064	297	447	110	25	80	209
29.09.83.	2.360*	9	287	122	12	28	234

* - the loss of 1 695 specimens is unexplained

Table 20
GROWTH OF COHO SALMON PARR IN FRESH WATER AT GRACANSKI HATCHERY FROM 26 NOVEMBER 1982 TO 25 SEPTEMBER 1983 (GENERATION 1982)
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
26.11.82.	2.500		45	18			12
23.12.82.	2.499	1	48	19	1	2,6	13
24.01.83.	2.499		55	22	2	7,3	13
24.02.83.	2.499		68	27	5	13,2	14
28.03.83.	2.499		87	35	8	19,2	15
27.04.83.	2.496	3	102	41	6	14,5	16
30.05.83.	2.489	7	135	54	13	32,5	18
23.06.83.	2.483	6	166	67	13	31,6	19
26.07.83.	2.469	14	207	84	17	40,8	20
23.08.83.	2.455	32*	247	100	16	39,7	21
29.09.83.	2.423	2	308	126	26	63,6	23

* 25 specimens taken for experiment

Table 21
GROWTH OF COHO SALMON IN BRACKISH WATER AT SKRADIN (KRKA ESTUARY) AFTER TRANSPORTATION FROM GRACANSKI HATCHERY (GENERATION 1982)
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
6.10.83	2 525		300	119			227
2.11.83	2 494	31	329	132	13	34	236
4.12.83	2 484	10	450	181	49	122	261
5.1.84	2 482	2	594	239	58	145	281

Table 22
GROWTH OF COHO SALMON IN BRACKISH WATER AT SKRADIN (KRKA ESTUARY) AFTER TRANSPORTATION FROM DVOR PRI ZUZENBERGU FISH FARM (GENERATION 1982)
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean length (mm)
6.10.83	2 360		288	122			228
2.11.83	2 336	24	392	168	46	108	251
4.12.83	2 327	9	598	257	89	207	273
5.1.83	2 326	1	710	305	48	112	297

Table 23
GROWTH OF COHO SALMON FROM EGGS TO 6 MONTHS OF AGE AT GRACANSKI HATCHERY (GENERATION 1983)
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean Length (mm)
16.01.83.	16.538		4,1	0,25			7,5	Eggs supplied to Gracanski
30.01.83.								Hatching began
04.02.83.	13.605	2.933						All eggs hatched
24.02.83.	13.238	367*	5,9	0,45	0,2	1,8		Transferred to basins
28.03.83.	13.187	51	16,2	1,2	0,7	10,3	45	Fingerlings
27.04.83.	13.694	123	33,9	2,3	1,2	17,4	61
30.05.83.	13.545	149	63,2	4,7	2,1	29,2	78
23.06.83.	13.483	62**	93,0	6,9	2,2	29,6	89

* -

Table 24
GROWTH OF COHO SALMON PARR FROM 6 TO 12 MONTHS OF AGE AT NOVO MESTO HATCHERY (GENERATION 1983)
Date	Total number	Deaths	Total weight (kg)	Mean weight (g)	Mean growth (g)	Total growth (kg)	Mean Length (mm)
23.06.83.	13.483		93	6,9	2,2	30	89
29.07.83.	13.425	58	174	12,9	6,0	80	92
31.08.83.	13.389	36	257	19,2	6,3	83	120
23.09.83.	13.353	59	273	20,5	1,3	16	126	Started descaling
29.10.83.	13.283	70	305	23,0	2,5	32	126
25.11.83.	13.220	63	383	29,0	5,6	78	143	Stopped descaling
28.12.83.	13.182	38	316	24,2	-4,3	-67	143	No food

Table 25
PHYSICO-CHEMICAL CHARACTERISTICS OF WATER IN CRIKVENICE BAY DURING 1983
Date	Temperature (°C)	pH	Oxygen (mg/L)	Solinity (%.)
11 May	9.4	7.3	13.1	3.8
3 June	13.2	7.4	12.1	16.9
19 July	17.1	7.5	10.2	18.4
2 August	18.8	7.5	10.1	17.3
18 August	20.0	7.2	10.6	16.5
29 Sptember	18.4	7.1	9.3	17.0
26 November	12.4	7.2	12.4	13.0

Fig. 1 Map of the River Krka estuary; showing water depths, siting of experimental rainbow trout and coho salmon farms and sampling stations for physico-chemical parameters of the water

Fig. 2 Temperature of water at different depths at the experimental cage site at Skradin (Krka estuary) during 1983

Fig. 3 Salinity of water at different depths at the experimental cage site at Skradin (Krka estuary) during 1983

Fig. 4 Oxygen content of water at different depths at the experimental cage site at Skradin (Krka estuary) during 1983

Fig. 5 Growth of rainbow trout in fresh water and in brackish water following transfer of different size-groups of fish to floating cages. (Solid lines are the best and worst mean growth of fish in commercial fresh water trout farms in Yugoslavia)

Fig. 6 Growth of rainbow trout, of different mean weights at stocking, in cages in brackish water at Skradin (Krka estuary)

Fig. 7 Comparative growth of rainbow trout (experimental group 1) in brackish and fresh water over a 14-month period

Fig. 8 Comparative growth of rainbow trout (experimental group 4) in brackish and fresh water over a 14-month period

Fig. 9 Growth of rainbow trout from eyed eggs to 1 year old in fresh and brackish water

Fig. 10 Map of the Yugoslav coast from the Italian border to Zadar, showing water depths, positions of operating marine fish farms, and areas of special interest for brackish water salmonid culture in cages

Fig. 11 Map of the Yugoslav coast from Zadar to Ston, showing water depths, positions of operating marine fish farms, and areas of special interest for brackish water salmonid culture in cages

Fig. 12 Map of the Yugoslav coast from Ston to the Albanian border, showing water depths, positions of operating marine fish farms, and areas of special interest for brackish water salmonid farming in cages