Abstract
Eggs and larvae of cod have been exposed to oil levels (water soluble fraction of Statfjord crude oil) of 50 - 300 ppb from day 2-7 after fertilization. Yolk osmolality, body content of inorganic (Na, K, Cl) or organic solutes (ammonia, free amino acids, protein, ninhydrin positive substances), water permeability, and larval drinking rate have been measured. The data obtained were compared statistically with those of the control groups to assess the effect of the oil-exposure. In essence, the measured parameters showed no consistent and statistically significant difference between the control and the oil exposed groups. For the free amino acids, however, the data were not unambiguous and new analyses of eggs reared under strict temperature control are recommended. With this reservation it is concluded that oil-exposure at the chosen levels does not adversly affect the osmoregulatory capability of developing cod eggs or yolksac larvae.