Translate the following English sentence to French:
"Although the breaches in the wreck had officially been sealed, oil slicks in fact continued to wash up on the shores, showing that either new leaks had appeared or that vessels passing through the vicinity were taking advantage of the situation to empty their tanks, or, probably, that both these things were occurring at the same time."
En effet, alors qu' officiellement les brèches de l' épave étaient colmatées, des nappes de pétrole continuaient à s' échouer sur les rivages, montrant, soit que d' autres fuites existaient, soit que des navires passant à proximité en profitaient pour nettoyer leurs cuves, soit sans doute les deux à la fois.