Interactions between petroleum hydrocarbons and the polychaetous annelid, Neanthes arenaceodentata : effects on growth and reproduction, fate of diaromatic hydrocarbons accumulated from solution or sediments

Abstract

The effects of water soluble fractions (WSFs) from No. 2 Fuel Oil on growth and reproduction in a laboratory strain of Neanthes arenaceodentata (Moore, 1903) were studied in experiments simulating conditions of acute and chronic sublethal exposure. Effects were defined relative to concentrations of specific diaromatic hydrocarbons (naphthalenes) and total dissolved hydrocarbons present in WSFs. There were 2 ppm total naphthalenes and 8 ppm total dissolved hydrocarbons in a 100% WSF of No. 2 Fuel Oil. Hatching success of metatrochophore larvae was inversely related to WSF concentrations greater than 50%. Hatching success was also inversely related to the length of time larvae were exposed prior to hatching. Growth of metatrochophore larvae into 32-segment juveniles was unaffected by WSF concentrations equal to or less than 8%. Inhibition of larval growth by 16% WSF was reversible upon return of larvae to hydrocarbon-free sea water. Growth of juveniles into adult polychaetes was inversely related to WSF concentrations equal to or greater than 3%. Rate of development to the feeding juvenile stage (18-segment animals) was not affected by WSF concentration in three successive generations of polychaetes continuously exposed to WSF. Oocyte maturation rates in all 4 WSF concentrations increased with each successive generation. Chronic exposure to all WSF concentrations suppressed fecundity in each generation. Fecundity in females exposed to 10 and 25% WSF was less than that in females exposed to 5 and 2.5% WSF. Survival to the 32-segment juvenile stage was inversely related to WSF concentration in first generation animals. Brood mortality in all WSF concentrations decreased with successive generations thereafter..