Temporal and spatial variations in lice numbers on salmon farms in the Hardanger fjord 2004-06.
J Fish Dis
; 32(1): 89-100, 2009 Jan.
Article
en En
| MEDLINE
| ID: mdl-19245633
ABSTRACT
The long and narrow Hardanger fjord in western Norway has a high density of salmon farms and has had severe salmon lice, Lepeophtheirus salmonis, problems. In the years 2004-06, salmon lice numbers were recorded in selected salmon farms in the fjord as part of a larger research project. Most farm sites participated in a strategic control programme and were deloused between November and January in each year. The aim of the programme was to achieve a mean abundance of <0.3 adult female lice at this time and to minimize the infection pressure on wild smolts in the spring. Dedicated teams carried out detailed counting of lice on farmed fish in April-September each year. Temperature conditions were fairly similar throughout the fjord and amongst years, but wide variations in salinities were observed. The two innermost zones, B and C, had the lowest lice mean abundances, whereas the outermost zones, D and E, consistently had more lice. General linear model analyses showed that differences in adult female lice abundance between the zones were associated with differing levels of salinity and emamectin benzoate treatments strategically administered. Mean fish weight was significantly positively correlated with mean abundance of adult female lice.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
3_ND
Problema de salud:
3_zoonosis
Asunto principal:
Salmón
/
Copépodos
/
Infestaciones Ectoparasitarias
/
Enfermedades de los Peces
/
Explotaciones Pesqueras
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Fish Dis
Asunto de la revista:
BIOLOGIA
/
MEDICINA VETERINARIA
Año:
2009
Tipo del documento:
Article
País de afiliación:
Noruega