Waste Not, Want Not

At least one small species is benefiting from the giant patch of plastic garbage in the North Pacific. According to a study in Biology Letters, the mass of junk has given an ocean-dwelling insect plenty of new places to lay eggs.

The North Pacific Subtropical Gyre is a huge collection of plastic debris floating in the ocean. Much of the debris is made up of small particles called “microplastic,” which can be swallowed by fish or help transport invasive species. Scientists wondered if microplastic might also affect populations of invertebrates. Such changes “could have ecosystem-wide consequences,” the authors note.

To investigate, the team compared North Pacific microplastic levels in 1972-1987 to levels in 1999-2010. The researchers also examined samples of the insect Halobates sericeus collected in 1972-1973 and 2009-2010.

Microplastic concentrations increased a hundred-fold over the last four decades, the authors report. In 2009-2010, microplastic concentration was linked to the number of H. sericeus eggs on the plastic bits, as well as numbers of adult and juvenile insects. The researchers found the insects’ eggs on microplastic pieces about 0.002 to 0.054 square centimeters in size.

If the amount of plastic continues to rise, species that live or breed on hard surfaces could flourish, the authors suggest. Meanwhile, their prey species, such as zooplankton, could suffer.Roberta Kwok | 9 May 2012

Source: Goldstein, M.C., M. Rosenberg and L. Cheng. 2012. Increased oceanic microplastic debris enhances oviposition in an endemic pelagic insect. Biology Letters doi: 10.1098/rsbl.2012.0298.

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