Fish species recognised in the food in Europe

after

Cormorants
Phalacrocorax carbo
in Europe
a first step towards a European management plan (2. draft)


The National Forest and Nature Agengy, Denmark
&
The National reference Centre for Nature Management, The Netherlands

Many prey fish species have been recognised in diet studies. Appendix reviews and lists the fish species eaten by Great cormorants in Europe. At least 115 fishes were recognised at the species level in the food of European cormorants. In most areas only a few species are staple food. Table 4 reviews the most important prey species found in diet studies.

Compared to the total number of fish species found in the food of cormorants, the number of species thait either by mass or number "really matter" is relatively small.

In freshwater habitats about 24 fish species are important:

Eel, bream, white bream,.barbel Barbus barbus, crucian carp C. carassius, nase Chondostoma nasus, carp Cyprinus carpio, chub Leuciscus cephalus, ide Leuciscus idus, roach, rudd, tench, pike Esox lucius, smelt Osmerus eperlanus, whitefish Coregonus sp., rainbow trout, salmon, brown trout,grayling Thymallus thymallus, burbot Lota lota, three-spined stickleback Gasterosteus aculeatus, ruffe, perch, zander and flounder.

The predation on about 12 species interferes or might interfere with human commercial catches:

Eel, carp, whitefish, rainbow trout, salmon, brown trout, grayling, perch, tench, pike, roach, and zander.

In salt water habitats c. 15 fish species are important either by number or by weight:

Eel, herring, capelin Mallotus villosus, cod Gadus morhua, whiting Merlangius merlangus, haddock Melanogrammus aeglefinus, three-spined stickleback, bull-rout Myoxocephalus scorpius, sea bass,Viviparous blenny Zoarces viviparus, butterfish Pholis gunellus, black goby, plaice Pleuronectus platessa, dab and flounder.

In Mediterranean salt water habitats the following fisches seem to be important prey for the cormorant: grey mullets Mugilidae (in particular Liza ramada), sand-smelt Atherina sp., sea-bass Dicentrarchus sp. and Labridae.

Interference with human commercial yields might exist amongst:

Eel, cod, sea-bass, dab, flounder, gilthead, mullets.

In marine habitats interactions between human fisheries and the cormorants'fishing might occur only in the coastal zone. In Denmark, where, sinensis predominantly feeds in marine habitats, the cormorants catch of the commercially valuable dab reaches up to 50% of the human catch in the same area. However. the cormorants catch consists of far smaller fish than the human catch. In general; compared to human catches, cormorants at sea take only insignificant quantities of commercially important fish species.

In the Mediterranean salt water interference with human yields may exist with regard to mullets and Dicentrarchus. in artificial lagoons interference with commercial production might exist with regard to eel, mullets, sea bass and gilt-head (Génard et al. 1993).