Responses of nematodes to oil contamination in a mangrove sediment: A microcosm study

The effects of oil pollution on nematode assemblages were investigated in a mangrove sediment. Microcosms comprised 350 mL plastic jars filled with 250 g sediment. In the oiled treatments (O), 15 mL oil were added to the soil. In the oil and fertiliser treatments (O + F), oil and fertiliser (N: P: K: 3: 2: 5) were added to the soil. After four weeks, nematodes were extracted and identified. The number of nematode taxa was highest in the C (61), intermediate in the O + F (59) and significantly lower in the O (25) treatment. Taxa present in the C but absent in the O treatment were oil-intolerant. Taxa present in the O treatments were oil-tolerant. Five taxa survived oiling probably due to fertiliser amendment. Oiling eliminated oil-intolerant taxa and favoured those that were resistant. In the O+ F treatment, the number and species of nematodes increased significantly.