Effect of petroleum hydrocarbons on Atlantic cod, Gadus morhua, following chronic exposure

Abstract

Experiments were conducted to ascertain the effects of crude oils at low concentrations on Atlantic cod (Gadus morhua) following long-term exposure (3–21 weeks) in a flow-through seawater system. Control and oil-treated fish were fed to satiation. Effects were assessed by comparing condition factor, organ indices, and hematological values with those of corresponding control animals. No mortality occurred but food consumption was significantly reduced in oil-treated cod, especially during summer–autumn. Condition factor and somatic indices of some organs were lower in oil-treated fish. Gall bladders were enlarged in oil-treated fish. Effects of oil exposure were less pronounced during winter, as food intake in both groups of fish was reduced considerably. The rate of gametogenesis was slower in male cod exposed to oil fractions in summer–autumn whereas spermeation was delayed in fish treated in winter–spring. These studies provide evidence that feeding, growth, and reproduction in male cod are biologically important variables that are affected following chronic exposure to petroleum.

<b>The use of biomarkers for assessing effects of pollutant stress on fish species from a tropical river in Southeastern Brazil

“…Rypel and Bayne (2010) evaluated growth rates of six fish species correlated with PCB concentrations in a moderatelyto-heavily polluted freshwater ecosystem, and concluded that at the range of concentrations investigated, these PCBs do not exert negative impacts on growth. Conversely, decreased CF has been recorded in several disturbed sites, such as, for the Atlantic cod, Gadus morhua Linnaeus, 1758 exposed to petroleum (Kiceniuk & Khan, 1987), for white sucker (C. commersoni) in sites with high concentration of metals Cu and Zn (Munkittrick & Dixon, 1988;Miller, Munkittrick & Dixon,1992). In accordance with Liebel et al (2013), CF is an indicative of the health status and may be used to assess field contamination.…”

Effects of Polycyclic Aromatic Hydrocarbons on Sexual Maturity of Atlantic Cod, Gadus morhua, following Chronic Exposure

“…The number of fish of each sex exposed and duration of each experiment are shown in Tables 2 and 3. The method of preparation of the WAFs was described previously (Kiceniuk & Khan, 1987). Two hundred ml of Hibernia crude oil originating from the continental shelf from offshore Newfoundland, were placed each week in a 80L head tank supplied with a 2-volt motor stirrer to ensure mixing with a constant inflow, 2L/min, of seawater.…”

“…Two hundred ml of Hibernia crude oil originating from the continental shelf from offshore Newfoundland, were placed each week in a 80L head tank supplied with a 2-volt motor stirrer to ensure mixing with a constant inflow, 2L/min, of seawater. This protocol, identical to previous studies, administered 200 ml of crude oil weekly to the head tank (Kiceniuk & Khan, 1987). The WAFs were drawn off from the bottom of the head tank into the aquarium housing the experimental group.…”

“…Some stocks of cod remain permanently inshore while others in offshore locations migrate inshore in summer to feed on capelin (Mallotus villosus) and subsequently move offshore in autumn (Templeman, 1974). A previous laboratory study reported that long-term exposure to water-accommodated-fractions (WAFs) of crude oil disrupted gametogenesis in male cod (Kiceniuk & Khan, 1987). Another study noted that cod succumbed to the WAFs when infected with a hemoflagellate that occurred widely in fish on the continental shelf (Khan, 1987).…”

“…Since there is a potential of additional oil spills from two oil wells currently operating off coastal Newfoundland, the present study was designed to investigate the long-term effect of low levels of WAFs on gonadal maturation in cod, especially females that are responsible for maintaining population levels. Three month-exposure periods as used in previous studies or less was chosen to simulate the time offshore stocks remained inshore (Kiceniuk & Khan, 1987;W. Scott & M. Scott, 1988).…”