Coastal fish farms are settlement sites for juvenile fish.
Two south-west Mediterranean fish farms were monitored over a period of 22 months to test if sea-cage fish farms act as settlement habitats for juvenile fish. Twenty juvenile fish species were found to settle at farms throughout the year. Fish assemblage composition varied markedly over time and was dependent on the spawning period for each species. The most abundant species were Obladamelanura, Atherina sp., Diplodussargus, Boopsboops and Lizaaurata. Up to 3783+/-1730 individuals/cage were found closely associated with the cages. Highest densities were observed during the warmer summer and autumn months. Zooplankton sampling and stomach content analyses of the most abundant species were done to assess prey availability, selectivity and diet overlap among species. Copepods were the main prey item for all juvenile fish species, irrespective of fish size. Ivlev's Index indicated that food was not a limiting factor for juvenile fish at farms. Furthermore, food pellets from the farm affected the food chain by modifying the fatty acid profiles of farm-associated zooplankton and juveniles of L. aurata and O. melanura. These results show that aquaculture can directly influence the body composition of juvenile fish that recruit to sea-cage fish farms.
Fernandez-Jover
Damian
D
Department of Marine Sciences and Applied Biology, University of Alicante, P.O. Box. 99, E-03080 Alicante, Spain. jover@ua.es
Sanchez-Jerez
Pablo
P
Bayle-Sempere
Just T
JT
Arechavala-Lopez
Pablo
P
Martinez-Rubio
Laura
L
Lopez Jimenez
Jose Angel
JA
Martinez Lopez
Francisco Javier
FJ
D000818:Animals; D017756:Aquaculture; D019352:Censuses; D004032:Diet; D017753:Ecosystem; D004784:Environmental Monitoring; D005227:Fatty Acids / Q000032:analysis; D005399:Fishes / Q000254:growth & development* / Q000378:metabolism; D020387:Food Chain; D005766:Gastrointestinal Contents / Q000737:chemistry / Q000382:microbiology; D006799:Housing, Animal; D008055:Lipids / Q000032:analysis; D011153:Population; D015048:Zooplankton / Q000302:isolation & purification / Q000378:metabolism
D005227:Fatty Acids; D008055:Lipids