||Increasing human activity in the ocean has lead to an increase in anthropogenic noise
in the ocean. Beaked whales are deep-diving odontocetes known to feed in the tongue
of the ocean, Bahamas. Recent studies show that anthropogenic noise in the sea can
have significant effects on marine mammals. Of particular concern are beaked whales,
which have been shown to mass strand in response to naval sonar. The detrimental
link between naval sonar and marine mammals has been established in several court
cases, but little is known about the effects echosounders, used in scientific research,
have on marine mammals.
This master’s project investigates the effects echosounders may have on beaked whales
in the tongue of the ocean, Bahamas, as well as the policy and management implications
surrounding this issue. In 2008 an echosounder was deployed in the study area and
the corresponding beaked whale click data was obtained from the Naval Undersea Warfare
Center. The data were analyzed to determine whether a change or cessation in click
activity occurred pre-, during or post echosounder deployment.
The results indicated that no change was observed in click duration comparing pre-,
during or post echosounder deployment. The data sets for during and post echosounder
deployments were significantly smaller than pre- and could be a contributing factor
to these results. These results are preliminary and further analysis into the behavioral
effects of echosounders on beaked whales will be conducted. Alongside this, recent
studies have shown that beaked whales respond to acoustic stimuli at much lower levels
than are currently regulated for marine mammals, suggesting that there is need for
a lower threshold for beaked whales in the United States than is currently being implemented.