Eye spy with my little eye, something beginning with "W"

Aerial surveying is one the many survey techniques that can be employed to assess marine population sizes, distribution and potential changes. There are both benefits and negatives associated with such a surveying techniques and room for improvement also.

Aerial Surveyors 

One of the major benefits associated with such a technique is its capability if reaching isolated nesting beaches and haul out sites without causing unnecessary stress upon animals through human interference. Such techniques of using aerial surveys are commonly employed through the use of either observers or high quality digital photography allowing for the checking of sightings and confirmation of species observed. Such as technique has been recently employed in the survey of Antarctic minke whales which distribution is large and irregular and is sometime difficult to locate amongst the pack sea ice (Kelly et al., 2009). Though aerial surveying only compromised of a small proportion of the surveys overall, in this case it was undertaken alongside boat or fixed station observation areas where seasonal migratory passageways occur, but such techniques allow for individuals to be counted that could possibly be missed by other means.

Antarctic Minke Whale amongst Ice flow

 Similarly the deployment of aerial surveying is used in establish population numbers and is commonly associated with seals and other haul out species. Such examples include the monitoring of harbour seals on the Gulf of Alaska where repeated aerial survey occurred through the course of 1995-2000 to provide a running population estimates (Boveng et al., 2003) of its decline population. In the case of using aerial surveys for population estimates or even boat surveys for that matter consideration has to be taken in relation to accounting for the individuals that are out at sea and therefore where not included. Therefore correction factors (CF) are used to calculate the proportion of individuals that are likely not to have been observed. Such CFs can be obtained through the use of other similarly sized same species colonies or in some cases researchers have tagged small proportion of the populations and used this to calculate the missing percentage and extrapolate this upwards to produce and overall estimated number.

Though it seems aerial surveys have benefits in allowing the coverage of large or secluded areas quickly the major issue is that of cost with such techniques being largely expensive. On the other hand in light of rapid technological advancements latest aerial surveys can be undertaken through the use of high quality satellite photography allowing near precise population estimates. Such a technique has been used in the surveying of emperor penguins by the British Antarctic Survey and collaborators, where computer imaging software is able to be programmed to differentiate between individual penguins, neighbours and ice and poo.

Satellite Photography of Emperor Penguin Colony