Salinity vs. depth profiles are different in different parts of the ocean, so there is really no one correct answer to this question.
It is because that salt is rarer than the water & below because of the green plants & fishes.
It is saltier at the bottom of the ocean because saltier water is more dense and sinks to the ocean floor.
The top most layer has more salinity. But ignoring thermo-haline currents.
the most dense part of the water is in the pacific ocean. it is located near the middle of the ocean. go 50 miles past the middle and you there. Make sure you go north though. It's an ocean trench. HOPE THIS HELPS>>>>>EVEN THOUGH IS'T WRONG...
The oceanic crust composed of sima, mafic rocks and basalt. This is the top layer of the lithosphere which is found in the ocean floor.
Because of the solidification of the water under low temperatures. The water is "turned" into ice, leaving the salt behind. So the salt is left in the water, with the freshwater turned into ice floating on top. If the glaciers melt, the salinity will decline, because this new freshwater will dilute the salty waters.
In sedimentation the thickest layer goes to the bottom,and the thinner they are the higher to the top it is layered.
The higher the saline content in water the heavier the water. This causes it to sink towards the bottom and water with lower levels will rise to the top. It will remain so unless stirred vigoriouly and often. Many animals live, and thrive in this setting, such as salt marshes, springs, also some ponds and lakes.
Dissolving salts in water increases the density slightly. Ocean waters have an average density about 2.5% greater than fresh water. The Dead Sea has a much higher density, somewhere roughly near 20% greater than fresh water due to its 30% salinity level.
The top layer of soil is the most fertile layer. It is the best for growing crops.
That would be the 2nd layer, the stratosphere layer with the ozone at top.
The density of surface seawater ranges from about 1.020 to 1.029 g·cm-3, depending on the temperature and salinityThe average density of seawater at the surface of the ocean is 1.025 g/ml; seawater is denser than freshwater (which reaches a maximum density of 1.000 g/ml at a temperature of 4°C) because of the added mass of the salts.
The skin layers from top to bottom are the epidermis (top layer), dermis (middle layer), and hypodermis (bottom layer).
Because the leaves and branches of the top layer block sunlight from reaching the bottom layer.