The blue water ocean refers to the deep, open ocean where the water appears blue. This is the part of the ocean far from coastlines and continental shelves. Blue water oceans make up about two thirds of the planet’s ocean area. They are found across the major ocean basins – the Pacific, Atlantic, Indian, Southern, and Arctic Oceans. The blue color comes from the water absorbing the red and green wavelengths of visible light more than the blue wavelengths. The exact tone of blue depends on the water depth and amount of suspended particles. Blue water oceans are home to diverse marine life and are an important part of the earth’s climate system. Tracking where they are found and monitoring changes provides insight into ocean health.
Distribution of Blue Water Oceans
Blue water oceans are distributed across the major ocean basins, away from coastlines and over deep ocean floors. The main locations of blue water oceans are:
– Most of the Pacific Ocean – The vast expanse of the Pacific contains large blue water areas stretching from Australia to South America. This includes the deep ocean areas around Hawaii.
– Most of the Atlantic Ocean – Blue waters extend from the coast of North America across to Europe and Africa. The Sargasso Sea is a distinctive blue water region in the North Atlantic.
– Much of the Indian Ocean – Large portions of blue water stretch south from India to Australia and west towards Africa.
– Southern Ocean surrounding Antarctica – The waters around Antarctica have a distinct deep blue appearance.
– Sections of the Arctic Ocean – Though much of the Arctic is characterized by seasonal sea ice, there are also large blue water regions such as the Canada Basin.
In total, blue water oceans cover around 139 million square kilometers or 36% of the earth’s surface. The average depth is 3,730 meters or 12,230 feet. The deepest point is found in the Pacific’s Mariana Trench at around 11,000 meters or 36,000 feet.
Characteristics of Blue Water Oceans
Blue water oceans have the following defining characteristics:
– Deep water – Blue water areas are found in waters over 200 meters deep. This distinguishes them from relatively shallow coastal waters.
– Low nutrient levels – The water contains low levels of nutrients like nitrates and phosphates. This contrasts with productive coastal upwelling zones.
– Low biological productivity – The lack of nutrients results in low phytoplankton growth and less biological productivity overall compared to coastal seas.
– Clear water – With fewer organisms and particles, blue water has high clarity, allowing light to penetrate deeper.
– Low temperature – Being away from warming influences of land, blue waters maintain cold temperatures of 0-3°C.
– High oxygen – The cold, circulating waters are highly oxygenated throughout.
– Salinity of 34-37 ppt – Evaporation exceeds precipitation, resulting in high salinity.
– Slow currents – The water generally moves in slow, deep currents rather than rapid surface flows.
– Sea ice free – Blue waters tend to be located where seasonal sea ice does not form.
– Lower human impact – With distance from land, blue waters experience less runoff and human activity impacts.
Marine Life in Blue Water Oceans
The clear, cold, deep waters of the blue ocean provide unique habitat for specially adapted marine lifeforms:
| Type | Examples |
|---|---|
| Large pelagic fish | Tuna, marlin, swordfish |
| Forage fish | Anchovies, herring, sardines |
| Invertebrates | Krill, jellyfish, cephalopods |
| Seabirds | Albatrosses, petrels, shearwaters |
| Marine mammals | Whales, dolphins, seals |
| Sharks & rays | Great white, whale shark, manta ray |
Some species migrate long distances across blue waters following food sources or heading to breeding grounds. Other organisms like cephalopods and jellyfish drift in deep scattering layers, rising closer to the surface at night. The blue ocean waters themselves host diverse microscopic plankton and bacteria sustaining ocean food webs.
While less productive for fisheries than coastal seas, blue water ecosystems still provide humans with valued tuna, billfish, forage fish, krill and other harvests. Their carbon absorption and oxygen production also benefits the global climate.
Threats to Blue Water Oceans
While more remote than nearshore areas, blue water oceans face growing threats from human activities:
– Overfishing – Industrial fleets extensively harvest tuna, billfish, sharks and other apex predators.
– Ship traffic impacts – Transoceanic shipping generates noise, pollutants and the risk of invasive species transfers.
– Climate change – Warming waters alter phytoplankton communities and deoxygenate blue water regions.
– Plastic pollution – Trash accumulates in giant ocean gyres and is ingested by marine life.
– Oil drilling – Offshore oil platforms introduce drilling chemicals and chronic hydrocarbon leaks.
– Acidification – Increased carbon dioxide absorption makes waters more acidic.
– Mineral mining – Plans are underway to mine deep sea manganese, copper, nickel, cobalt and rare earth deposits.
Protecting the ecological integrity of blue water oceans requires sustainable fishing quotas, shipping lanes away from sensitive areas, reducing plastic waste entering the sea, transitioning away from fossil fuels, and preventing unregulated deep sea mining. International cooperation is needed to properly manage and conserve these shared global ocean resources.
Conclusion
Blue water oceans comprise about two thirds of global ocean area across the Pacific, Atlantic, Indian, Southern and Arctic basins. Their deep blue color comes from absorbing more red and green light. Blue waters are defined by cold, clear, oxygenated water far from coasts and sea ice. These regions support specialized pelagic fish, mammals, seabirds and plankton. While less impacted by humans than coasts, blue waters face growing threats from overfishing, pollution, climate change and ocean acidification. Conserving these vibrant, important ocean ecosystems requires sustainable management practices and reducing human impacts across the interconnected global ocean.
