Great cormorant (Phalacrocorax carbo sinensis) occurrence in carp aquacultural ponds: a case study from the South Bohemia (Czech Republic) pond region

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60076658%3A12520%2F22%3A43904573" target="_blank" >RIV/60076658:12520/22:43904573 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1007/s10499-022-00917-4" target="_blank" >https://doi.org/10.1007/s10499-022-00917-4</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10499-022-00917-4" target="_blank" >10.1007/s10499-022-00917-4</a>

Result language

angličtina

Original language name

Great cormorant (Phalacrocorax carbo sinensis) occurrence in carp aquacultural ponds: a case study from the South Bohemia (Czech Republic) pond region

Original language description

The impact of piscivorous predatory species is an important factor negatively influencing the prosperity of inland aquacultural facilities. In this regard, carp (Cyprinus carpio) pond stocks suffer predation pressure from both migrating and nesting great cormorant (Phalacrocorax carbo sinensis) populations, which utilise easily available fish prey cultured in carp ponds at densities incomparably higher than found in natural water bodies. Previous studies dealing with conflicts between cormorants and inland fisheries have usually focused on direct and/or indirect effects of cormorant predation, or descriptions of total size, long-term trends, and movements/dispersal of European populations. Though the results gained through comprehensive pan-European projects are valuable and usually applicable at larger scales, more detailed case studies from carp pond regions can provide a different viewpoint on such issues. In this case study from the Trebon pond region in the Czech Republic, we examine cormorant count data from 2019 (whole year), performed by fish farmers as a requirement for compensation of losses caused by cormorant predation, and examine them in relation to variables such as pond size and distance from breeding colony, along with economic (financial) aspects of cormorant predation. The total whole-year count was the highest at larger ponds (&gt; 50 ha), where more than 5,000 cormorants per day (corm/day) were recorded, with highest figures exceeding 7-9,000 corm/day at ponds &gt; 150 ha. Maximum daily cormorant counts during the spring and autumn peaks reached up to 450 birds at the largest ponds (&gt;= 200 ha), though the highest daily per ha abundance was recorded at smaller ponds (&lt; 20 ha), with maxima exceeding 20 corm/ha. The highest counts were recorded during the spring and autumn flyway migrations, with a smaller summer peak also noticeable as young birds left the nests. This &quot;young-bird&quot; peak was most pronounced at &lt; 50 ha ponds situated &lt;= 10 km from the colony. Predation pressure per ha of pond was clearly highest at &lt; 5 ha ponds, with levels decreasing with increasing pond size. Financial losses at smaller ponds were further increased due to the higher price of young fish cultured in small (&lt; 5 ha) nursing ponds.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10613 - Zoology

Project

<a href="/en/project/QK1920102" target="_blank" >QK1920102: Automation and objectivization of fish predators monitoring</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Aquaculture International

ISSN

0967-6120

e-ISSN

1573-143X

Volume of the periodical

30

Issue of the periodical within the volume

5

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

16

Pages from-to

2541-2556

UT code for WoS article

000819311700001

EID of the result in the Scopus database

2-s2.0-85133194449