Although I understand that these methods are still in use, I believe that there is a migration toward the use of passive acoustic tags.
Given there is a significant technology difference between the two approaches I have been wondering what studies have been conducted around the following areas...
Whether in a "Continuous" mode the Shark is affected in any way that may influence its behaviour...I understand that 69KHz is a higher frequency than its auditory range however given its complex multi-sensory capabilities (Acoustico Lateralis) is there any chance that this pulsed frequency causes any issues? Furthermore given the configurable options available on these tags, has any research been undertaken to identify optimal pulse timings (other than to save battery life)?
I understand that White Sharks sometime predate on Pinnipeds...I also understand that some Pinnipeds auditory range falls between 75Hz and 75Khz.. Could this mean that given the 300-500m range of the tag that this Prey is automatically warned of the Shark's presence thereby meaning that local colonies may thrive even with a number of White Sharks in relative proximity ?
Finally, from what I have read White Sharks may have a sophisticated "Navigation" system that allows them to travel long distances in a straight line. It also seems that this capability is achieved in some way through using the earth's electromagnetic fields.....My question is, has any research been conducted to ascertain whether this continuous tone might affect its ability to navigate effectively and change its migratory routes?
In my research I note that some material has been published on the potential direct anatomical issues that might arise from any attachment or insertion of a device, however I donít see anything that probes the potential neurological or bio-acoustic consequence.
As you will see I have no qualifications or formal knowledge in this area, however having attempted this research in the specific area of "Acoustic" Biotelemetry for Apex predators I can't seem to find any answers through public domain research...