The Effect of PCBs on the Spawning Migration of European Silver Eel (Anguilla anguilla L.)

Abstract

A quatic Toxicology jo u rn al hom epage: w w w .e lse vier.co m /lo cate /aq u a to x PCBs and the energy cost of m igration in the European eel (Anguilla anguilla L.) ARTICLE INFO ABSTRACT The effect of polychlorinated biphenyls (PCBs) on the energy consum ption of fasting silver European eel (Anguilla anguilla L.) was studied over a 27-day period during w hich the anim als w ere at rest or were sw im m ing 800 km in Blazka sw im tunnels. Three-year-old female hatchery eels (silver stage) betw een 73 and 80 cm long weighing around 1 kg w ere dosed intraperitoneally w ith PCBs at a nom inal dosage of 10x the consum ption standard as a m ixture representative for planar (7 ^gPCB126/kgeel), non-planar (5 m g PCB153/kg eel) and m etabolizable PCBs (50 ^ g PCB77/kg eel) found in wild eel, or only w ith the vehicle (corn oil, 10 m l/kg eel). Four m ajor observations were m ade: (1) PCB-exposed anim als lose less w eight com pared to their unexposed controls; (2) PCB-concentrations on a lipid basis are 2.8-14 tim es higher in sw im m ing com pared to resting anim als; (3) the standard m etabolic rate is significantly lower in the PCB-exposed anim als than in unexposed controls. In addition, PCB-exposure significantly reduces oxygen consum ption during swim m ing, and starting at 4 0 0 k m (18 days) this effect increases w ith tim e; (4) the relative spleen and liver w eight significantly increased in the PCB-swim anim als but not in the PCB-rest animals. The sw im m ing anim als lost about 75% m ore w eight com pared to resting anim als and had about 50% lower plasm a fat content. Hematocrit, haem oglobin, plasm a pH, ion levels (sodium and potassium), and plasm a lactate w ere not affected by PCB-exposure or swim m ing. Apparently, the current levels of PCBs and other dioxin-like com pounds m ay seriously im pair the reproduction of the European eel.