Science

The way an animal gets around in the sea and or in the air depends, fundamentally, on the density and viscosity of its milieu. Birds use the low density and viscosity of the atmosphere to fly or glide, with the range of their movement being limited only by their endurance and the height to which they can fly. This is similar to the fishes and similar marine creatures who can also move three-dimensionally within their aqueous milieu though unlike the terrestrial creatures which live on the, essentially, two dimensional surface of the earth. The latter have evolved locomotive mechanisms which are suited to movement dominated by gravity. In the case of humans, for example, a two-legged mode of locomotion suited to this situation has evolved. To a certain extent, birds may seem to be independent of gravity as they fly around in the air. However, unlike marine creatures in their aqueous milieu, if they stop flying they immediately crash to the ground – unless, of course, they can glide for a little while.

There has been much discussion in recent years about the effect of increasing global temperatures on marine fauna (see also the last issue of this magazine).

However, it has often been overlooked t

We have previously looked at the various properties of water which have an effect on aquatic fauna, some of them a bit out of the ordinary, such as surface tension. However, one of the most important

We have written much here in this magazine about the different properties of water. Some of them, such as surface tension, are of importance to the ability of aquatic fauna to function in their given environment.

For example, surface tension permits water skaters to skate on the surface of the water where its habitat is neither
the water below the surface nor the air above.

However, more than a purely physical phenomenon, osmosis
is of importance for life itself, for no physical phenomenon
has any greater importance in biology than does osmosis. Without osmosis neither animal cells nor plant cells could function. Not only this, osmosis also appears in many different guises in our everyday existence. So, what is this strange phenomenon?

How the snapping shrimp makes itself heard.

You might expect the oceans below the surface to be a quiet and still place, they are far from being so. Submerged hydrophones show that there is a cacop

Aquatic animals, like their land-based relatives,
can communicate in a number of ways. For example, in one form of communication, organisms can emit and detect certain organic molecules which can fun

Water is obviously important as a basic necessity for maintaining life. Quite simply, if you don’t regularly take in water you can die within a few days.

Fundamentally, this all depends on the fact that water has a great ability to dissolve things. These solvent properties of water are vital in human biology, because many biochemical
reactions take place only within aqueous solutions.

The Black Sea is interesting not only for tourism and diving but also from the scientific and historical point of view. Atlantis? The Flood? If you are a fan of myths and mysteries then the Black Sea has something for you, too.

The Black Sea is an unusual
sea. Nearly one third of the land area of continental Europe drains into this sea into which seven large rivers flow, including the major rivers of the Danube, Dnieper and Don. However, its only outlet is the narrow channel of the Bosphorus, which is only about 70 metres deep and 700 metres wide. The depth of the Black Sea itself is more than 2,000 metres in places.