60 

Dry matter 






ON 900 > 
1908 1909 Average im Ike 
Herring... OL (80) 1,400 2000 1,700 | 5 
SEE RG SSR kg. | 47,200 24,000 35,600 17,800 
Places rele ere > 75,000 81,000 78,000 19,500 
Code SR >» 52,500 47,500 50,000 10,000 
ROD ster SNE » 550 325 » > 
Brava Ser aser > 3,900 500 > > 
Various. 5 rekte > 550 350 > > 
or ca. 50,000 kg. dry matter on an area of 11,843 Tdr. land (1 Tdr. — 1.4 
acres) or about 65 million m.? 
The percentage of dry matter in the fishes varies somewhat according to 
their condition; from experiments made by Boysen Jensen the percentage of 
dry matter for the plaice is about 25/,, cod 209/,, the eel varying from 28.6 to 
60.:/,, here taken at 50%,. The quantities of the remaining animals captured 
are so small, that I have taken no regard for them at all in the calculation in 
round numbers. The quantity of dry matter for the eel, cod and plaice caught in 
Thisted Bredning on an area of 6åd million m.? was ca. 50,000 kg. or about 0.7 
gm. per m.?; thus 7.7 gm. per 10 m.? This value may now be compared directly 
with the numbers given for the dry matter of the lower animals in Table V. 
First of all, however, some information may be given with regard to what 
has been found in the stomachs of the different fish species im Thisted Bredning. 
In the cod: Buccinum (soft parts and opercula), Idothea, Proto ventricosa, 
Stenorhynchus, Crangon, Aphrodite, Nemertines (?), Mya truncata, Solen, Åbra, Actiniæ 
and (7obrus. 
In the eel: Acera, Philine, Cerithium, Solen, Cardtum, Nucula, Pectinaria, 
Nereidæ, Priapulus, Nemertines (?) and Idothea. 
In the plaice: Mya truncata, Abra alba, Solen pellucidus, Cardtum fasciatum, 
Nucula mitida, Corbula gibba, Pectinaria, Chaetopoda, & few times Ophroglypha and 
very seldom AÅcera bullata, AÅstertas rubens, Philime, Tellina baltiea, Crangon, Dria- 
stylis, Gammaridæ, Aphrodite. The first 8 far exceed the last mentioned. In 
addition to the Chaetopoda it is especially young Mya, Abra, Solen and Cardium 
which are by a long way the commonest food animals. 
Ås will be seen, a number of the fishes seek their food in the plant belt, 
most of the Crustacea are taken there, as Idothea, Proto and Stenorhynchus, and 
the eel and especially the cod certainly find' a part of their food there; both are 
very fond also of making hunting expeditions in here, whilst the flat-fishes come 
here but seldom. The cod certainly feeds also on many gobies and other fishes 
and Buccinum; it is certainly not so closely bound to the soft bottom as the eel 
and plaice. 
I would thus refer only the eel and the plaice to the fishes, which find 
their food among the smaller animals of the soft bottom-soil, but even if we include 
the cod here with its 10,000 kg. dry matter, it is not much compared with the 
total quantity for the eel and plaice, namely ca. 40,000 kg. of dry matter, or 6.2 
gm. per 10 m. 
Comparing now this 6.2 gm. of fish dry matter with the quantity of dry 
matter contained in the animals these fish feed on, as shown by Table V, we see 
