The first “Perils of Plastic” article presented a brief introduction to the North Pacific Gyre (NPG) and the Great Pacific Garbage Dump (hereafter referred to as the GPGD). This article dives in a little deeper.
If you are not so great at geography, time to pull out the globe. The NPG is an area of high atmospheric pressure located between the equator and latitude 50 degrees North. Most of you know where the equator lies (if not, it is that line on a globe that separates the northern hemisphere from the southern hemisphere – near the Pacific Ocean it runs through Ecuador and Columbia in South America). In North America, latitude 50 degrees North runs through British Columbia and Vancouver Island in Canada. Geography buff, or not, one can only be amazed by the enormous size (about 20 million square kilometers) of the NPG.
No condescension intended, but perhaps the word gyre should be defined as it is rarely used in any normal conversation (except in verb form, as in, ”Elvis gyrated when he danced.” – this is a hint).
TheFreeDictionary.com defines gyre as:
1. A circular or spiral form; a vortex: “rain swirling the night into tunnels and gyres”(Anthony Hyde).
2. A circular or spiral motion, especially a circular ocean current.
The NPG occurs because four major oceanic currents (i.e., North Pacific Current on the north, North Equatorial Current on the south, California Current on the east, and Kuroshio Current on the west) converge in the center of the Pacific Ocean. As stated in the previous article, the currents flow clockwise. If you are a person in pursuit of trivia, the question is: Why do ocean currents flow clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere? The answer is: the Coriolis Effect.
The convergence of the four currents create a nearly stagnant zone where trash can accumulate. Hence, the GPGD.
The Southern California Coastal Research Project (SCCRP), a public environmental agency studying the GPGD, cites that more than 100,000 marine animals die each year due to ingestion or entanglement in NPG debris. Additionally, small plastic particles accumulate toxic chemicals such as polychlorinated biphenyls (PCBs), DDE (a pesticide), and nonylphenols. These are, in turn, ingested by fish (remember Zoe?)… and birds. According to the SCCRP, nearly 57 percent of bird species examined across the planet contained non-food debris particles in their stomachs.