The marine biome is primarily made up of the saltwater oceans. It is the largest biome on planet Earth and covers around 70% of the Earth’s surface.

The concentration of salt in seawater (salinity) varies with temperature, evaporation, and precipitation. Salinity is generally low at the equator and at the poles, and high at mid-latitudes. The average salinity is about 35 parts per thousand.

The salinity of the ocean varies from place to place, especially at the surface. Much of the ocean has salinity between 34 ppt and 36 ppt, but there are places that tend to be higher or lower.

As oceanographers have known for many years—but now can “see”—the Atlantic Ocean is saltier than the Pacific and Indian Oceans. Near most coastlines and inland seas in the map, waters appear much fresher or saltier than in open-ocean locations.

The ice in the Arctic and Antarctica is salt free. You may want to point out the 4 major oceans including the Atlantic, Pacific, Indian, and Arctic. Remember that the limits of the oceans are arbitrary, as there is only one global ocean. Students may ask what are the smaller salty water areas called.

the Atlantic Ocean

Theoretically, the salt water can flow 350 miles from the mouth of the Mississippi, the point where the bottom of the river reaches an elevation higher than the surface of the Gulf.

Rain replenishes freshwater in rivers and streams, so they don’t taste salty. However, the water in the ocean collects all of the salt and minerals from all of the rivers that flow into it. In other words, the ocean today probably has a balanced salt input and output (and so the ocean is no longer getting saltier).

Don Juan Pond

Can you boil salt water to make it drinkable? No, boiling saltwater alone is not enough to make that water drinkable. The process of removing salt from water is called desalination and is more than simply boiling salt water.

Salt is very stable and very few natural processes will cause it to break apart in significant quantities. Therefore the majority of the billions of tonnes of salt on Earth will recycle indefinitely and persist until our sun becomes a white dwarf.

In the 20th century salt has become a cheap everyday product, because new deposits have been opened up and production has been thoroughly economized. The techniques though are basically still the same as in centuries before.

We wouldn’t last very long. And not just us, plants and animals need salt as much as we do! The mere desalinization of our oceans would wipe out all our underwater algae, cutting photosynthesis on Earth in half.

Well, without the oceans, the world loses 97% of its water. The small amount of liquid left wouldn’t be enough to sustain the water cycle. The pools of drinkable water would evaporate pretty fast. In a matter of days, people and most animals would die from dehydration.

If the ocean dies, we all die. But food being taken from the ocean is the least of the factors that will kill us. The ocean is the life support system for the planet, providing 50 percent of the oxygen we breathe and regulating climate. The ocean is also the pump that allows us to have fresh water.

Paul Watson: The reality is that if the ocean dies, we die – because the ocean provides all of those things which make it possible for us to live on the planet. Over 70% of the oxygen is actually produced by phytoplankton in the ocean, and since the 1950 there’s been a 40% diminishment in phytoplankton population.

All life on Earth comes from the oceans… and they’re still looking after us today. The oceans have protected us from the worst impacts of global warming. Our oceans have trapped 90% of the extra heat caused by greenhouse gas emissions over the last sixty years.

An estimated 70 percent of fish populations are fully used, overused, or in crisis as a result of overfishing and warmer waters. If the world continues at its current rate of fishing, there will be no fish left by 2050, according to a study cited in a short video produced by IRIN for the special report.

Moreover, in some cases, a sea is completely landlocked. The Caspian Sea is the most famous example, though this sea, which lies between Russia and Iran, is also referred to as the world’s largest lake. Other seas surrounded by land include the Aral Sea and the Dead Sea.

The Ocean Doesn’t Die. For starters, the ocean doesn’t die—though it sure can change. Earth’s oceans formed 3.8 billion years ago (BYA) and by 3.5 BYA bacteria and photosynthesis had already evolved. The ocean simply was, and plants and animals died if they could not adapt or did not live in places that provided refuge …

Experts say that by 2050 there may be more plastic than fish in the sea, or perhaps only plastic left. Others say 90% of our coral reefs may be dead, waves of mass marine extinction may be unleashed, and our seas may be left overheated, acidified and lacking oxygen. It is easy to forget that 2050 is not that far off.

Global warming is causing sea levels to rise, threatening coastal population centers. Many pesticides and nutrients used in agriculture end up in the coastal waters, resulting in oxygen depletion that kills marine plants and shellfish. Factories and industrial plants discharge sewage and other runoff into the oceans.

1. Plastic Shopping Bags

• Plastic bags (lightweight and heavyweight) are one of the most lethal plastic killers of ocean animals.
• Small animals, seabirds and even turtles get entangled in them and drown.
• Plastic cutlery is one of the most deadly plastics for sea turtles, birds and marine animals.

PVC. Polyvinyl chloride, or PVC, is widely known as the most toxic plastic for health and the environment. In its production, it releases dioxins, phthalates, vinyl chloride, ethylene dichloride, lead, cadmium and other toxic chemicals.

If the ocean dies, we all die. The ocean is also the pump that allows us to have fresh water. It is the driving force, along with the sun, of the global circulation system that transports water from the land to the sea to the atmosphere and back to the land again.

Globally, 100,000 marine mammals die every year as a result of plastic pollution. This includes whales, dolphins, porpoises, seals and sea lions. There are two principle ways that encountering marine debris can be fatal for these creatures: ingestion (eating) or entanglement in plastic-based fishing gear.

China

Most ocean pollution begins on land. Much of this runoff flows to the sea, carrying with it agricultural fertilizers and pesticides. Eighty percent of pollution to the marine environment comes from the land. One of the biggest sources is called nonpoint source pollution, which occurs as a result of runoff.

The most visible and disturbing impacts of marine plastics are the ingestion, suffocation and entanglement of hundreds of marine species. Marine wildlife such as seabirds, whales, fishes and turtles, mistake plastic waste for prey, and most die of starvation as their stomachs are filled with plastic debris.