The impact of the ‘Sea Empress’ oil spill on seabass recruitment

Abstract

Young-of-the-year (0-group) sea bass ( Dicentrarchus labrax L.) were collected during 1996 from 12 inshore sites in the Bristol Channel in order to investigate possible effects of the Sea Empress oil spill on their growth and survival. 0-group bass were more abundant on the south side of the Bristol Channel than in South Wales nurseries, and particularly scarce within Milford Haven. Some bass caught in nursery areas on the north Cornish coast had spawned in early March, but only fish spawned after late April appeared in South Wales nurseries, where the first arrival date of bass post-larvae was later than in nursery areas in north Devon and Cornwall. 0-group bass grew faster within the latter nurseries than on the north coast of the Bristol Channel, where a much higher proportion of fish failed to reach 60 mm, the critical length for survival through the first winter. There were no significant differences in fish condition or in the weight of their stomach contents between sites. Whilst the Sea Empress oil spill may have contributed to the differences in the survival of early-spawned bass larvae and the abundance of 0-group bass in nursery areas on either side of the Bristol Channel, these differences are likely to be less significant than the year to year variation due to natural causes.