By Sarah Jones, BBC News science correspondentThe next time you find yourself sitting on a beach and think about a shark, think of it this way: a lot of the time it’s a great white shark.
And then there are some very small, very good ones.
But how do sharks measure up?
That’s the question that has perplexed scientists since the 1970s, when a breakthrough was made in the lab that allowed researchers to measure the mass of a shark from a few millimetres.
This allowed them to see that a great whites’ body is actually much bigger than the mass it appears to be.
That discovery led to a lot more measurements, but it also made it clear that the mass and mass range of a great whale and other whales are also quite different.
But, says Charles Moore, a marine biologist at the University of Southampton in the UK, the mass range is only one part of the story.
The mass of an animal is a measure of its ability to move and fight.
When we measure a fish’s body mass, we’re trying to measure its ability not just to move, but also to swim.
But that’s really only a measure.
And it only takes a very small animal to be able to move in all directions at the same time, says Moore.
To get an accurate mass, scientists need to look at the entire body.
For example, if a fish is lying on a sandy beach and you measure its mass, it’s going to have a very different mass range to that of a whale.
So if you want to understand the size of an individual animal, Moore says you need to study the entire animal.
This is why scientists are now trying to develop a more accurate method to measure whale and dolphin body mass from a number of different angles.
The results of this research are published in the Journal of the Royal Society Interface, a peer-reviewed journal of science publishing in the scientific literature.
But it’s not enough to simply measure a whale’s mass, Moore adds.
For instance, an adult great white, or great white whale, can weigh between 2.7 and 3.2 tonnes.
This means the mass on a single occasion would probably be around 3,000 to 5,000 tonnes.
To put that into context, a shark’s body is around 1.6 tonnes.
That means it would be around 5,400 to 10,000 times heavier than the average shark.
What you’ll learnIn the past decade, a team of scientists from the University at Albany in New York, the University College London and the University in the US has now worked out how they can measure the whale and Dolphin body masses from different angles to get an overall picture of the size and mass of all of them.
They say this method is more precise than previous methods, and it shows that a whale or dolphin is more similar to a whale than it appears.
But the researchers are concerned that the accuracy of the measurements will depend on how accurate they are.
In particular, they are concerned about the accuracy the measurements are made on whales that are living in the deep ocean and so the sea surface might not be as uniform as it is in the surface.
What they are hoping to achieveSo what is the problem with measuring whale and dolphins?
Moore says the first issue is that there are a number different methods that scientists have developed for measuring the mass.
And different methods can give different estimates.
For example, a study published in 2013 in the journal Nature Marine Biology showed that a shark could weigh between 5,500 and 8,000 kilograms.
And if a scientist measures the mass at that site, they would get a value of between 4,200 and 5,800 tonnes.
But when they measured the mass from the surface, the estimate was 4,500 tonnes.
So the team’s goal is to develop methods that are as accurate as possible, but which can give a more precise measurement of whale and dalmatian body mass.
To do this, the researchers used the new technique to measure mass at two different locations in the ocean: one on the east coast of Australia and another on the west coast.
The two locations were in the Southern Ocean and the western Gulf of Mexico.
At the two sites, the team used a technique called a multi-frequency spectroscopy (MFT).
This involves using multiple spectroscopes to measure different things at the site.
In the Southern ocean, this involves using a different spectroscopic technique called the high-resolution, high-precision mass spectrometer (HRMS).
At this site, it involved using a second spectroscope to measure a different chemical element, called boron.
As a result, the measurement at the two locations came out with a mass estimate of about 3,700 tonnes.
So the team thinks that the total mass of the Southern and Western oceans is around 5.8 and 6.5 times more accurate, respectively, than the previous estimates.
This mass range was only one of several