By Tundi Agardy, Contributing Editor, MEAM. Email: tundiagardy [at] earthlink.net
What we are beginning to understand about the impact that plastics have on marine life (and, by extension, all life) is a parable for how humans impact the oceans in other ways. Recent research that looks beyond the accumulation of debris and its interaction with marine life shows that the effects of plastic pollution are myriad, complex, and difficult to address.
For decades those who cared about oceans and the problem of marine pollution were focused on marine debris: the gut-wrenching images of seabirds tangled in six-pack holders, sea turtles ensnared in plasticized lines, or monofilament ghost nets doing their ghoulish and wasteful murder in the depths. Campaigns to clean up beaches were a popular draw for the public around the world and a good hook for conservation organizations wanting to attract donor support. But as motivating as the images were and as popular as the beach clean-ups have become, this interest seems ephemeral – there has been little serious pressure on manufacturers to limit or improve plastic packaging or on the public to limit our own consumption of plastic products. And then it turned out that – lo and behold – the plastic problem we saw and occasionally countered with our beach clean-ups and donations to animal rehabilitation programs was really only the tip of the iceberg. It is the smaller stuff that we can't see – the polypropylene pellets and the microplastics – that are really mucking things up. Even getting into our food chain as it turns out – our man made pollution coming back to haunt us….
As we’ve developed metrics to understand the nature and the scope of the marine plastics pollution problem, we are shocked by the sheer scale of the threat. The growing accumulations of plastic out in the ocean gyres have been in the news every year for the past decade, and the recent estimate of the tonnage of plastic floating about in various forms in the world ocean has exceeded any projection made on the basis of carefully quantified beach debris collected during clean-ups. Empirical studies based on sampling and extrapolation have supported the development of sophisticated models that predict not only how much plastic is likely entering the coastal waters but also its fate vis a vis eventual location and state. And while the plastic-bag-clogging-the-intestine-of-a-sea-turtle image is alarming and makes people spring into action, improved toxicology studies are showing that the impacts plastics are likely having on the larger food web – including us – is the major, and lasting, problem.
We have to understand problems and address their root causes
The plastics pollution story is a parable about all the ways we impact our oceans and undermine the health of the planet and ourselves. The moral at the end of this parable is this – if we want to successfully solve the problem, we have to understand it and address the root cause. The same goes for nutrient pollution and eutrophication: the issue we see (algal blooms and fish kills) is really the tip of that iceberg. What really matters are the ecosystem imbalances that result from overfertilization. And the source of all those nutrients is rarely just the outmoded sewer system or combined storm drain – it’s the host of land-based sources pooled together. Ditto with disappearing wetlands: we can point the finger at coastal land conversion and cutting of mangroves for fuelwood, but the real problem may be in disrupted hydrological flows that nourish those wetlands in the first place. And the widespread issue of reduction in fish stocks – yes, the main driver may be commercial fishing, but the loss of nursery habitats and the displacement of fishers out of protected areas may be compounding the problem. For each of these issues, the solution requires a spate of interventions, made in the holistic manner that defines real ecosystem-based management.
Let’s not kid ourselves. We love our beach clean-ups and our beautiful marine parks. We love eating MSC-certified seafood and contributing to groups that empower local communities to manage their own marine resources well. But these are all band-aids. If we really want to deal with the toxins in the environment, habitat degradation, and biodiversity loss, we must commit to understanding the problem and making sacrifices so that our impact on this wounded planet is a little bit less every day.