With the help of the Autonomous Underwater Vehicle (AUV), scientists are collecting information that would have been almost impossible to gather in the past. Geologists, biologists, mathematicians, computer scientists, and engineers are all benefitting from the data collected by AUVs.
The Need for a Smart AUV
Runde, an island off the coast of Norway, is known for its seabird populations. The birds include Atlantic puffins and Northern Gannets. In recent years, the bird numbers on the island and in much of the North Atlantic have dropped, and scientists are scrambling to find out why.
A team of scientists from the Norwegian University of Science and Technology (NTNU) is using an autonomous underwater vehicle to gather data on phytoplankton. Phytoplankton are at the base of the marine food chain and scientists suspect a change in their population could be affecting the seabird populations.
In the past, phytoplankton have been difficult for scientists to enumerate – it’s like counting specks of dust in the air. But thanks to the AUV, scientists are able to collect information on phytoplankton populations.
Mapping Phytoplankton Populations with the AUV
Phytoplankton are microscopic and tend to collect in patches. The AUV used by NTNU is programmed to navigate on its own to areas where phytoplankton are present. It chooses its own course to zoom in on patches to get the most accurate samples. This information is used to create a 3D map of hot spots for phytoplankton.
The “patchiness” of phytoplankton is related to a number of factors, including currents, turbulence, and biological processes, including how many other creatures are feeding on the phytoplankton. Even when in a “hot spot,” this patchiness can make it difficult to count the number of marine organisms in the area.
When researchers study from a boat, there is the possibility of dropping the sampler in a sparse spot, leading to an underestimation of the population. Or, if scientists drop the sampler in the middle of a patch, the population can be overestimated.
The autonomous underwater vehicle can explore and make a 3D map of the patches with better accuracy. Knowing where the patches are can help scientists identify characteristics in the area that contribute to the patch being present. Factors like salinity, temperature, or other effects may keep the phytoplankton where they are.
How the AUV Counts Phytoplankton
NTNU’s AUV has sophisticated programming and is equipped with a special measuring device. The device doesn’t count phytoplankton, but detects the amount of chlorophyll present by exposing it to light. The AUV maps out a 700x700 meter area of phytoplankton and detects the area that has the most chlorophyll a.
Phytoplankton are not easy to sample because they are in a changing environment, and timing is important to fish and bird populations. Fortunately, AUVs can help scientists conduct more frequent detailed sampling. They can then detect changes and identify whether or not phytoplankton are contributing to the declining seabird populations.
Autonomous Underwater Vehicles (AUV) make it possible for scientist to gather critical scientific data to understand marine life and population changes in certain species.