Due to the deterioration of the environment and the mass killing of human beings, cetaceans, especially some large members, are widely killed because of their high economic value, and many cetaceans are on the verge of extinction.
The International Whaling Commission (IWC) is an international organization responsible for whaling and cetacean protection. After commercial whaling led to a sharp decline in whale population, the International Whaling Commission decided to take action to protect whales. These include a temporary ban on commercial whaling from 1986, and the establishment of Indian Ocean Whale Sanctuary in 1979 and Southern Ocean Whale Sanctuary in 1994 respectively.
British scientists use satellites to estimate the number of whales to protect them.
Counting the number of species is very important for tracking the development trend of wild animals. If species disappear or the number of species decreases, the habitat of species may have changed, or some parts of the ecosystem may be out of balance. The British Antarctic Survey organized scientists to demonstrate how to use new satellite technology to calculate the number of whales and finally estimate their number scale.
For marine life, scientific measurement and monitoring is often an arduous and expensive task, because searching in the vast ocean is like looking for a needle in a haystack. Using ultra-high resolution satellite images and image processing software, British scientists can automatically detect and calculate the number of whales breeding in New Bay of Argentina and parts of Valdez Peninsula.
This study was funded by the Natural Environment Research Council of the United Kingdom. Peter Frewell of the British Antarctic Survey, the first person in charge of this study, said that it has been difficult to estimate the number of whales, and the traditional calculation methods are often one-sided, expensive and inaccurate. This study proves that whales can be identified and calculated by satellites. Scientists automatically calculate the number of whales in a large area at a reasonable cost.
The British Antarctic expedition used the WorldView2 satellite to collect images of the Gulf area where southern right whales concentrated on mating and breeding. This whale is on the verge of extinction, and its number and scale are unknown at present. In recent years, many whales have been found dead in the breeding area of Valdes Peninsula, and the mortality rate of newborn whales has increased sharply, so it is still necessary to estimate their numbers.
In addition, in this sampling area, the sea water is calm and shallow, so there are more opportunities to catch whales from satellites.
There are three main criteria for identifying whales: the size and shape of the visible objects in the image should be consistent, and they should appear in a reasonable place (where whales like to stay). There should be no (or few) other species that may be mistaken for whales in this place.
It can be identified from the satellite images that there are 55 whales most likely, 23 whales less likely, and 13 whales with similar physical characteristics. Future satellite platforms will provide better images to distinguish whale mothers from their babies.
Baidu Encyclopedia-Cetaceans
People's Daily Online-British scientists use satellites to estimate the number of whales.