A study investigating the effects of human water usage on Tursiops truncatus abundance and behaviour in New Quay

Matthew Jones MSc Conservation Biology, University of Derby

Abstract

Humans are ever increasing in their use of the world’s oceans. This has been seen to have negative and detrimental effects on the environment with effects on organisms in all levels of the food chain. Cetaceans are subject to many threats to their populations and long term survival and coastal areas inhabited by Tursiops truncatus often have an enhanced vulnerability over the open ocean. The aim of this study was to assess the impact of human water usage in New Quay bay, Cardigan Bay West Wales on the T. truncatus population and whether sea conditions can cause observer error. The T.truncatus population in New Quay were observed over the month of June (30 days) to record their abundance and interactions with boats. The results showed that there was a statistical significant difference between sea state and number of T.truncatus observed. There was no statistical significant difference found between abundance of boats and abundance of T.truncatus. There was no statistical significant difference found between boat types and T.truncatus abundance. There was no statistical significant difference between distance of boat interaction and change in T.truncatus behaviour. There was no statistical significant difference between distance of interaction with boat and type of T.truncatus behaviour. There was no statistical significant difference between boat type and change in T.truncatus behaviour. There was no statistical significant difference between boat type and type of T.truncatus behaviour. There was a statistically significant difference in change in T.truncatus behaviour with boat action. There was no statistical significant difference between boat action and all types of behaviour. These results suggested that sea state affects T.truncatus sightings. It appears that T.truncatus behaviour and abundance is not affected by type of boat, number of boats or proximity to T.truncatus. Type of behaviour does however appear to affect T.truncatus.

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