scholarly journals A REVIEW OF THE IMPACT OF GREAT CORMORANT (Phalacrocorax carbo sinensis) ON THE FISH STOCK

2014 ◽  
Vol 72 (4) ◽  
pp. 164-173
Author(s):  
Marina Piria
Keyword(s):  
Fish Stock ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Phalacrocorax Carbo Sinensis ◽  
The Impact

scholarly journals Estimating the mortality caused by great cormorant predation on fish stocks: pikeperch in the Archipelago Sea, northern Baltic Sea, as an example

2016 ◽  
Vol 73 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Outi Heikinheimo ◽  
Pekka Rusanen ◽  
Katja Korhonen
Keyword(s):  
Age Groups ◽  
Total Mortality ◽  
Sensitivity Analyses ◽  
Fish Stock ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Fish Stocks ◽  
Archipelago Sea ◽  
Phalacrocorax Carbo Sinensis ◽  
The Impact

Estimates of the mortality rates caused by cormorants are needed to assess the impact on fish stock dynamics and fisheries. In this study, we calculated the annual instantaneous mortality caused by great cormorants (Phalacrocorax carbo sinensis) on young pikeperch (Sander lucioperca), using data from Archipelago Sea, southwestern coast of Finland. The pikeperch are vulnerable to cormorant predation mainly at the ages 2–4. The annual instantaneous mortality caused by cormorants was between 0.04 and 0.13, and the estimated effect on the pikeperch stock size at recruitment to the fishery ranged from 4% to 23%, respectively. The average annual cormorant-induced mortality accounted for 5%–34% of the total mortality in these age groups. The sensitivity analyses proved that the rates of mortality from other sources largely affect the estimated mortality from cormorant predation. In cases with strong fluctuations in the abundance of the prey fish stocks, ignoring the size and density dependence of the natural mortality may lead to overestimation of the importance of cormorants as competitors of fisheries.

Stress responses of carp pond fish stock upon hunting activities of the great cormorant(Phalacrocorax carbo sinensis L.)

2010 ◽  
Vol 42 (3) ◽  
pp. 322-330 ◽  
Author(s):  
Jiri Kortan ◽  
Jana Blahova ◽  
Kamila Kruzikova ◽  
Zdenek Adamek
Keyword(s):  
Stress Responses ◽  
Fish Stock ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Phalacrocorax Carbo Sinensis

scholarly journals Differences in the diet of breeding Cormorants Phalacrocorax carbo sinensis in an inland colony: the effect of years, breeding stages and locations within the colony

2018 ◽  
Vol 18 (4) ◽  
pp. 149-156
Author(s):  
Simone Buttu ◽  
Giulia Atzori ◽  
Francesco Palmas ◽  
Robert Gwiazda
Keyword(s):  
Fish Species ◽  
Fish Assemblages ◽  
Perca Fluviatilis ◽  
Rutilus Rutilus ◽  
Colony Development ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Phalacrocorax Carbo Sinensis ◽  
Different Seasons ◽  
The Impact

AbstractA study of the diet of the Great Cormorant Phalacrocorax carbo sinensis (fish species and size) in (1) different seasons (years), (2) breeding stages (incubation and chick rearing), and (3) breeding areas (center and edge) in the colony in the Dzierżno-Duże Reservoir (southern Poland) was carried out. Overall, 147 pellets of the Great Cormorant were analysed. The low values of the indexes of Levin (Bi) and Shannon (H’) showed a limited trophic spectrum in the diet of the Great Cormorant. Roach (Rutilus rutilus) with a percentage index of relative importance (%IRI) of 62.89, perch (Perca fluviatilis) (%IRI = 22.63) and carp (Cyprinus carpio) (%IRI = 10.43), were the most common prey. Evident changes in the diet between 2003 and 2014, with less roach and more perch and ruffe in 2014 were found. They could be probably related to changes in the fish community. Differences in the food of cormorants between breeding stages reflected dietary requirements of the chicks. During the breeding season younger chicks require feeding with smaller fish than older chicks. The proportion of fish species found in the cormorant diet differed between the edge and the centre of the colony. We concluded that the impact of Great Cormorants on native fish assemblages may be dependent on the location within the colony, development state of the chicks and season, not just fish availability.

scholarly journals Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids

2021 ◽  
Author(s):  
Nina Dehnhard ◽  
Magdalene Langset ◽  
Asgeir Aglen ◽  
Svein-Håkon Lorentsen ◽  
Tycho Anker-Nilssen
Keyword(s):  
North Sea ◽  
Fish Consumption ◽  
Gadus Morhua ◽  
Fish Stock ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
The North ◽  
Phalacrocorax Carbo Sinensis ◽  
Great Cormorants ◽  
The Baltic

Abstract Piscivorous wildlife is often perceived as competitors by humans. Great cormorants of the continental subspecies (Phalacrocorax carbo sinensis) in the Baltic and North Sea increase, while local cod (Gadus morhua) stocks decline. In contrast, numbers of the Atlantic subspecies (Phalacrocorax carbo carbo), breeding along the Norwegian and Barents Seas, have been relatively stable. We investigated the diet of both great cormorant subspecies in breeding colonies along the Norwegian Coast from Lofoten to the Skagerrak and estimated the biomass of fish consumed annually by great cormorants in Norwegian waters. The birds’ consumption was compared with estimated fish stock sizes and fishery catches. Cod and saithe (Pollachius virens) dominated the diet in the Norwegian Sea and wrasses in the North Sea and Skagerrak. Estimated total fish consumption of cod and saithe by great cormorants was <1.7% of estimated fish stocks and <9% of that of human catches and therefore considered minor. Cormorant consumption of wrasses amounted to 110% of human catches. The practice of using wrasses as cleaner fish in the salmon farming industry leads to a conflict with cormorants, and we urge for a better understanding and management of wrasse populations, taking ecosystem functioning and natural predation into account.

scholarly journals Prey detection by great cormorant (Phalacrocorax carbo sinensis) in clear and in turbid water

2008 ◽  
Vol 211 (6) ◽  
pp. 866-872 ◽  
Author(s):  
T. Strod ◽  
I. Izhaki ◽  
Z. Arad ◽  
G. Katzir
Keyword(s):  
Great Cormorant ◽  
Prey Detection ◽  
Turbid Water ◽  
Phalacrocorax Carbo ◽  
Phalacrocorax Carbo Sinensis

Hematology and Plasma Biochemistry Values of Great Cormorant (Phalacrocorax carbo sinensis) Nestlings

2013 ◽  
Vol 49 (1) ◽  
pp. 194-196 ◽  
Author(s):  
Piotr Minias ◽  
Krzysztof Kaczmarek ◽  
Tomasz Janiszewski ◽  
Janusz Markowski
Keyword(s):  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Plasma Biochemistry ◽  
Phalacrocorax Carbo Sinensis
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