For those of you out there who attended our presentations in Vancouver and Victoria this fall, you may remember me admitting to not fully understanding the driving forces behind the trade-winds and global currents until being some 1000 miles south west of Mexico, in the middle of the Pacific Ocean. Well, here I am, admitting that once again, I’m in a place where the winds and currents are confounding.

Up until transiting the Panama Canal, our process for selecting a site for a garbage study was relatively straight forward; go to an island situated in the trade-wind belt, make our way to a beach that faced the prevailing winds (usually easterly), and begin counting. Certainly this method has served us well thus far; it was only last month that we were in the remote San Blas Islands, downwind from much of the Caribbean, wading through un-countable amounts of plastic bottles and other debris.

But now we find ourselves on a coastline that doesn’t allow for such a straight forward approach, for the winds here blow predominately north east. Offshore. Away from land. Hmmm. where are the beaches that the litter collects going to be? To be honest, and here is where the admission is, I thought the story might get pretty boring on this coast, or at least less compelling. I mean, if the winds are blowing everything OFF shore, won’t the beaches be spotless? Isn’t all the plastic drifting merrily across the Pacific to the Tuamotu’s and the Fakarawa Atoll like we said in our presentations? Well, after visiting beaches in the Las Perlas, Isla Cebaco, and Santa Catalina, and I say no, its not. In fact, probably anyone who’s spent any time, on any beach, anywhere can tell you, there is likely to be plastic and other trash littering the shore, regardless of dominant wind direction. Undoubtedly there is a portion of the pollution from Panama getting taken west across the Pacific, but clearly a good chunk is getting deposited right here. There haven’t been any smoking guns yet to tell us exactly where it is coming from, but the major urban center that is Panama City is probably a good guess to start.

So what’s happening here? This is what I was pondering as I bobbed in the water at Cebaco waiting for the sets to come. Why, if the dominate wind direction here is north-east during the dry season, and variable during the rainy season, are such huge amounts of the trash ending up on theses beaches, tucked into a corner here in the Golfo De Chiriqui. Any easterly wind should blow floating debris AWAY from the coast, not on to it. But of course, duh, wind is only half the story. In fact, in most cases it is much less than half the story, or at least less than half the force that drives floating plastic debris around the world. The currents have a much greater roll it seems, because, similar to that fateful iceberg that sunk the Titanic, plastic trash is mostly submerged, leaving it to the whim of the water more than the wind. Combine that with large tides on the west coast of Panama, up to 6m in some places, a strong westerly setting current, a long rainy season that floods rivers, washing out garbage from far inland, and there are a multitude of forces at work carrying floating debris around these waters.

So, with all these forces at play, where do we go now? How do we select a beach that might serve as an indicator for the greater area?

Well, we can start with the dominate current in the area, a westerly current that sweeps the Gulf of Panama from Darien to the Azuera Peninsula. Combined with the huge tides in the Gulf and this effectively flushes the waters around Panama City, which might explain where all the litter we’re seeing here comes from. Only, how does it make it back inland to where we are at the moment? The engineer in me wants to consult theoretical tide and current models, cross-reference with local population densities and major river sources, but this might be a bit too high-level, and won’t really translate well to what we actually see. Probably the best bet is getting some local knowledge; work a bit more on our Spanish and talk to fisherman and anyone else who might be able to fill us in a bit. We’ll let you know what we find.