Lots of questions these days about sargasso in Mahahual, so I decided it must be time to write a FAQ blog about the current state. So here is the latest info on sargasso in Mahahual, as well as a reasonably scientific, minimally smart and somewhat intoxicated, bar stool explanation as to the cause.
Is the sargasso bad right now?
Is it worth coming into town for from the ships?
Yes, but the experience is not its usual breathtakingly, beautiful self. The downtown beach clubs manage to do an okay job most days of cleaning their own beaches. On most normal days, we can clean our beach of all the grass in a single wheel barrel, two at the most. These days, we are hauling off a hundred a day! Yes, I said a hundred. Some days though, not all places have been able to clean their areas, and those areas can quickly begin to smell of rotting sea grass. The city government has struggled to find resources for the heavy equipment needed to haul the grass away, leaving the cost for doing so on the businesses. Not something most can afford in the low season right now. If our usual beaches are a 10, and your beach at the lake back home, is a 1, I’d say most days we are in the 5-7 range. Most days though, the downtown beach area is still very nice and enjoyable, but does take some clean up each day and the water is a bit murky for the first hour or so.
Tropicante Beach This Morning. Cleaned but the Water Is Still Murky
After Cleaning, It Clears fast. We Cleaned An Hour Before (Left) And Ours Was Beginning To Clear
Is this normal?
What about the remote beaches?
The remote beaches are really bad. The area is sparsly populated, so the beaches are not cleaned and therefore, collect grass. These ares can smell really bad, produce fish kills and make the area a general mess. Once it builds, the only real way to get rid of it is a high tide storm, that can push it far enough onto the shore that it will dry out and decompose. Sargasso is mainly water, so once it is dry, it decomposes to almost nothing.
What’s causing it?
I thought you would never ask, so pull up a bar stool, this might take a minute.
I’ve heard many theories, but little evidence to support most of them, so who knows? This is what I do know. We had this happen about 3 years ago, and it lasted for about 10 months, then stopped as mysteriously as it started. In my 8 years here prior, I had not seen anything like that event, and once it stopped, has been normal again until this last January. Then, we began to once again see the huge influx of grass that is now all over the Caribbean.
If you do not know it already, in the central Atlantic Ocean, there is a large floating mass of live sea vegetation, or “sargasso” as it is also often called, with the entire area commonly referred to as the “Sargasso Sea”. This large living vegetation mass has been there for centuries, even mentioned in the diaries of the early European sea captains, so it is not something that is new.
It is huge, so the currents that surround around it, throw small amounts of sargasso into coastal areas of the Caribbean and Atlantic all the time. The point here is that this is a natural phenomenon, and these masses are still alive and become almost their own floating eco-systems, as they head toward the beaches. But sometimes, like now, the masses get larger as they go for some reason.
Since the volume we are getting is not normal, it must have a cause and that is most logically explained via eutrophication. Remember that big word from 10th grade science? Eutrophication is what happens when a body of water experiences an abnormal amount of growth of marine plants and algae, almost always from overly enriched waters with minerals and nutrients from an outside source. The other variable is water temperature, and typically, the warmer the water, the more favorable the conditions for eutrophication. However, the real heavy source is almost always enriched river discharge, which causes normal marine plant growth, to explode with excessive growth. Much like putting fertilizer on your lawn. From the hundred wheel barrels a day we remove from our beach, I’d say we are getting some excessive growth, to say the least.
Let me first rule out climate change as a primary cause. Not saying it has no contribution, but in my search for scientific variables, it is not the 10,000 pound gorilla of evidence in the room. Why? Seems this year we have colder water temperatures in the Atlantic than the last 2 years, and since we didn’t have this volume until this year, I’ve ruled out warmer water as a root cause anyway. The 2 years prior, with warmer water temps, we had normal amounts of sargasso. If water temperature was a big variable, this would not have been the recent history.
I’ve also read where some think the large amounts of African dust we have experienced this year, the reason for the cooler water temperatures in the Atlantic, have also dropped many nutrients into the water, causing a double stimulant to the sargasso growth. Again, perhaps a variable, but I am very familiar with this dust, I’m very allergic, and that dust came months after the sea grass started, so again, maybe a variable, but no gorilla there.
The 10,000 gorilla in the room nobody wants to look at, probably because then they would then need to admit the problem is man made, and therefore, might need to do something about it, is river discharge. If you look at the mouth of every major river running into the ocean, the level of eutrophication is always proportional to the amount of development along that river. The Mississippi River in the US is a perfect example. For centuries it has been used as a commercial shipping connection, and the ocean to the west of it, the direction of the ocean’s currents, is a very unhealthy piece of ocean. From New Orleans to Houston, the ocean is gray and lifeless compared to the rest of the gulf, and it is the result of decades of massive eutrophication.
Many things can cause a river to discharge enough enriched nutrients to bring about eutrophication. A drought can cause river levels to fall to such low levels, that it dredges up the nutrient rich bottom sludge of the river and washes it into the ocean, and causing everything from shark attacks in the Carolinas, to green algea takeovers in Florida. But the usual culprits are simply development residue, mainly fertilizers and sewage. They flow into the ocean, get picked up by the currents, and get spread throughout the ocean. Oceans have constant currents that run is the same basic directions, so the effects of a river’s eutrophication discharge would follow that current. A look at the map below showing the ocean currents, shows a current flows right past the mouth of the Amazon and directly toward us.
Normal Ocean Currents
The last event we had, 3 years ago, was finally attributed to eutrophication as a result of discharge from the Amazon River in Brazil. Unintended consequences of their trying to be a clean and energy independent country. At that time, Brazil opened 3 new hydro-electric power plants that were located on tributary rivers along the Amazon, and the discharge they produced, caused massive eutrophication to the normal sargasso. It took 10 months for the water to come out clean, and then the problem stopped.
To build a power plant, you must build a dam, then flood the area behind it to build a lake, or water source, for the flow to produce hydro-electric power. Prior to flooding, the land is clear cut and much of the brush and vegetation, is left to be flooded. It decomposes as the water levels slowly cover the area and the decomposition becomes part of the dam’s rich early discharge, once they open the gates and let the water flow. That rich water flows into the ocean, meets the ocean currents and pushes that enriched water right into the normal floating sargasso, fertilizing it, and the result is that as the currents move it, it grows at the abnormal rate. While Brazil gets clean energy, but we get dirty beaches!
Amazon River Basin Where Many Rivers, All With Power Plants, Discharge
Brazil made energy independence a goal many years ago and to do that, they developed one of the largest hydro-electric power generation systems in the world. Most feed into the Amazon or Amazon Basin eventually. However, Brazil also began development of bio fuel and the increase in crop production needed to do that, undoubtedly has created more agricultural runoff. According to a marine biologist at the University of Southern Mississippi, Jim Franks, he and other researchers had discovered what they call a new “large Bloom” of sargasso off the coast of Brazil and yes, right in line with the ocean currents on the chart above.
No, I do not know what is actually the variable causing the abnormal growth of sargasso we are seeing wash up along our shores. Could be lots of things. But it also doesn’t take a genius to understand a simple ocean current flow chart and the effects of basic downstream eutrophication. What is flowing out of the Amazon, producing this “bloom” as scientist are referring to it, is in the water that flows toward us. Hard to say what is the cause, but if you’re a betting man, you’d bet that cause was the Amazon.
So until some egg head who is a lot smarter than I, can better explain why we have a hundred wheel barrels a day of sargasso instead of two each day, I think my explanation will have to do. Something is causing this, and if I apply the old “duck test”, if it walks like a duck, and talks like a duck, then it must be a duck, then this sargasso situation is the result of eutrophication, and the Amazon discharge is waddling like duck. So if you’re listening Brazil or Jeff Bezos, or whoever owns all things Amazon these days, can you please put a sock on it, and maybe that will catch some of that sediment before it gets to the sargasso, and save my back, and beaches, in the process. Gracias from all of us in Mexico!