Surfacing characteristics and dive data gathered through visual surveys have inherent shortcomings.
The presence of the research vessel in the vicinity of the whale may cause a bias in the data that has not been accounted for through this study.
Our data was collected only during daylight hours and therefore does not account for diurnal variations in behaviour, though population surveys are generally conductedduring daylight hours.
The risk of missing surfacings, the inability to collect data in the presence of multiple animals due to confusion between the focal animal and others, the inability to collect data in the presence of multiple vessels at close range that move unpredictably, the inability to work in sea conditions exceeding Beaufort Sea State 3 (this is also impacted by the height of the observer platform and therefore the vessel being used), and the ability to collect surfacing data reliably over only one cycle because the long duration of a deep dive makes it hard to predict where and when a whale will surface are all acknowledged disadvantages.
The use of archival tags such as D-tags that collect sub-surface and acoustic data from the whale and its surroundings (Johnson and Tyack, 2003) would provide insight into the interactions between the whales and anthropogenic influences such as high-intensity sounds and vessel traffic and enable the calculation of more precise correction factors. However, despite the short-comings associated with the visual techniques described here, it is the first attempt to quantify these variables for blue whales in Sri Lankan waters and provides a baseline from which estimates of abundance can be conducted with considerably increased precision, an important first step to informing conservation and management of this unique population
Surfacing characteristics and dive data gathered through visual surveys have inherent shortcomings. The presence of the research vessel in the vicinity of the whale may cause a bias in the data that has not been accounted for through this study. Our data was collected only during daylight hours and therefore does not account for diurnal variations in behaviour, though population surveys are generally conductedduring daylight hours. The risk of missing surfacings, the inability to collect data in the presence of multiple animals due to confusion between the focal animal and others, the inability to collect data in the presence of multiple vessels at close range that move unpredictably, the inability to work in sea conditions exceeding Beaufort Sea State 3 (this is also impacted by the height of the observer platform and therefore the vessel being used), and the ability to collect surfacing data reliably over only one cycle because the long duration of a deep dive makes it hard to predict where and when a whale will surface are all acknowledged disadvantages. The use of archival tags such as D-tags that collect sub-surface and acoustic data from the whale and its surroundings (Johnson and Tyack, 2003) would provide insight into the interactions between the whales and anthropogenic influences such as high-intensity sounds and vessel traffic and enable the calculation of more precise correction factors. However, despite the short-comings associated with the visual techniques described here, it is the first attempt to quantify these variables for blue whales in Sri Lankan waters and provides a baseline from which estimates of abundance can be conducted with considerably increased precision, an important first step to informing conservation and management of this unique population
การแปล กรุณารอสักครู่..

Surfacing characteristics and dive data gathered through visual surveys have inherent shortcomings.
The presence of the research vessel in the vicinity of the whale may cause a bias in the data that has not been accounted for through this study.
Our data was collected only during daylight hours and therefore does not account for diurnal variations in behaviour, though population surveys are generally conductedduring daylight hours.
The risk of missing surfacings, the inability to collect data in the presence of multiple animals due to confusion between the focal animal and others, the inability to collect data in the presence of multiple vessels at close range that move unpredictably, the inability to work in sea conditions exceeding Beaufort Sea State 3 (this is also impacted by the height of the observer platform and therefore the vessel being used), and the ability to collect surfacing data reliably over only one cycle because the long duration of a deep dive makes it hard to predict where and when a whale will surface are all acknowledged disadvantages.
The use of archival tags such as D-tags that collect sub-surface and acoustic data from the whale and its surroundings (Johnson and Tyack, 2003) would provide insight into the interactions between the whales and anthropogenic influences such as high-intensity sounds and vessel traffic and enable the calculation of more precise correction factors. However, despite the short-comings associated with the visual techniques described here, it is the first attempt to quantify these variables for blue whales in Sri Lankan waters and provides a baseline from which estimates of abundance can be conducted with considerably increased precision, an important first step to informing conservation and management of this unique population
การแปล กรุณารอสักครู่..
