As the first day of autumn passes and another summer officially enters the past, our memories of time spent at the beach fade away, but we shouldn’t let them wander too far. All of us, especially those who were lucky enough to swim, fish, snorkel or surf this summer, need to recognize a fact that is becoming clearer with each passing season: Our oceans are in trouble, and that’s putting it lightly.

To us terrestrials, it may seem like the ocean is in fine shape, as long as there aren’t too many Coke bottles floating in our vicinity. We’re used to looking at its surface, where the only discernible difference is the height of the waves and its hue of blue or green or gray.

Beneath the surface, however, are reactions to forces much greater and more destructive than a particular day’s sun and wind, many of them rooted in human waste and abuse. The ocean provides a variety of benefits, from sustenance to recreation but its existence as we know it is in jeopardy.

The simplest problem that confronts our ocean is over-fishing. It’s a matter of mathematics. If you catch fish at a rate faster than the rate at which they reproduce, there will be fewer of them. If you do that for a couple decades, there will be a lot fewer.

The journals of explorers that sailed the ocean centuries ago tell of turtles “covering the sea” and large fish so numerous that they could be caught by hand. Today, the ocean is crossed by commercial long-line fishing boats that let out up to 60 miles of long line – fishing line with multiple hooks and branches that catch the target fish such as tuna or sea bass, as well as turtles, marine mammals and sharks.

A 2004 United Nations study stated that 70 percent of all fish species are either overexploited or depleted. The study also reported a 95-percent drop in commercial fish stocks in the Northern Atlantic fisheries. According to another 2004 study, the number of tuna capable of spawning had fallen to 19 percent of 1975 levels. The statistics are clear: We need to regulate our fishing fleets or there won’t be anything to left to fish.

While we’re fishing the oceans empty, we’re filling them up with pollutants. Untreated wastewater from sewage systems, toxic runoff from commercial farming and a variety of garbage from all the cruise ships and oil tankers that cross the ocean are poisoning the complex ecosystems from which we gain so much. Nitrogen, phosphorus and other elements used in commercial farms enter runoff and end up in the ocean where they cause algal blooms. After these algae bloom and die, they are eaten by bacteria that absorb massive amounts of oxygen from the water, making the water uninhabitable and creating “dead zones” where marine life is rare or nonexistent.

Off the shores of Louisiana, an 8,000-square-mile dead zone grows as the Mississippi empties vast amounts of agricultural runoff into the Gulf of Mexico. Similar dead zones grow in the Bay of Bengal, the Arabian Sea and the Baltic Sea. In terms of just plain litter, the UN estimates that there are 46,000 pieces of plastic litter floating on every square mile of the ocean, a threefold increase since the 1960s. Fishing for plastic is getting to be easier these days than fishing for fish.

Global warming, which wreaks havoc on land with droughts and changing climates, is also manifesting itself detrimentally in the ocean. As the atmosphere warms, so does the ocean, making survival difficult for various ocean species. Coral reef ecosystems, often referred to as the rainforests of the sea because of their stunning biodiversity, are hit the hardest.

Coral reefs are formed by polyps which rely on photosynthesizing algae for food and give the reefs their amazing colors. When ocean temperatures rise, even by small amounts, the polyps react by ejecting the algae, causing them to lose their colors and become “bleached.” If a coral remains bleached, it becomes unable to sustain the vibrant ecosystem it normally would and eventually dies. Researchers in the Seychelles recorded a 92-percent drop in coral reef cover over their 60,000-square-yard survey area, causing four types of fish to appear to be locally extinct.

The rising levels of CO2 in the atmosphere that cause global warming are also forcing too much CO2 into oceans. As atmospheric CO2 levels rise, the ocean must absorb more CO2 in order to maintain an equilibrium, which raises the acidity of the water, affecting the delicate process through which many animals such as mollusks and clams create their calcium carbonate shells.

While scientists believed that the truly corrosive pH levels would remain at the bottom of the ocean, where absorbed CO2 adds to CO2 produced by bottom-dwelling organisms, until after 2050, corrosive levels have recently been recorded on the northern California coast and negative effects have already been documented in marine algae and free-floating plants and animals.

In spite of all this, the oceans still look the same to us. What we have to realize is that catastrophic events with irreversible results are already happening beneath the waves. If we don’t act soon to change our relationship with the ocean, it will cease to exist as the place that we enjoy in summer months.

Somerset Perry is a senior in the College. He can be reached at perrythehoya.com. BIODEGRADABLE appears every other Friday.

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