How Humans Have Impacted The Oceans

The devastating BP oil spill is still on everyone’s minds as its ecologically dire impacts on the ocean continue to take a toll. The scale of this particular problem is huge, but unfortunately, it’s just another way humans have wrecked havoc on the sea. The ocean is crucial to global ecology. It’s not separate from those of us living on the land. Fish and aquatic life may suffer first from the effects, but we too will suffer; we are all connected, after all.

The journal Science reports just how much of an impact we humans have had on the oceans. Here are some of the effects, quoted from Change.org:

Warming: The oceans have absorbed between 25 to 30 percent of all human-generated CO2 emissions since the industrial revolution. But as seas warm, this rate of CO2 uptake slows down. This means more CO2 stays in the skies. In the future, global warming will happen faster and faster.

Acid: All that extra CO2 its turning the oceans more acidic, making it much harder for marine species to build carbonate shells. Today, ocean acidification is happening 30 to 100 times faster than ever in the recent geological past. Left unchecked, coral reefs and shelled animals, such as clams, will start literally dissolving by the end of the century. Some plankton—the base of the marine food chain—may also be wiped out.

Dead Zones: Fertilizer run-off and fossil fuel burning are creating dead zones in coastal seas. Humans are the source of about half of all nitrogen carried by rivers to the seas. Too many of these nutrients fuel oxygen-sucking algae and microbe blooms. Life up the food chain, from shrimp and oysters to fish and fisherman, suffer for it.

Toxic Blooms: This excess flood of nutrients also spur a toxic form of these algal blooms, which kill fish and make coastal residents really sick.

Suffocating Fish: There are increasingly more and much larger open ocean zones where fish struggle to catch their breath. That’s because the ocean is like a giant layer cake, where warm, fresh layers sit atop colder, saltier ones. But as surface waters warm, this stratification is becoming more pronounced, and less oxygen is moving from the rich deep waters to the oxygen-deprived ocean surface.

Seafood Threats: We are creating an acronym soup of pollutants in our oceans: POPs, DDT, and PCBs, not to mention methyl mercury. Human activities are moving unprecedented levels of these pollutants around the globe, and these accumulate in seafood we eat.

Lead: The one bright spot on this list. Since leaded gasoline was phased out in the 1970s, lead concentrations have decreased in the North Atlantic back down to early 20th century levels.

When will we begin to take better care of our planet? Will it be too late by the time we realize it?

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