I am enjoying so much working on this journal. Topics arrive like magic! I go to bed trying to figure out a topic for the next day, but sometimes when I wake up, something happens that redirects my interest. This is one of those days.
The topic came courtesy of a girl who had her dad write a question in our forum (the 'Ask the Team' tab). As I began to answer the question, I thought that a lot of people might be interested in this topic and decided to move it to the journal and make it more visible. The question is,
' What are the main polluting substances for the oceans and where do they come from, particularly in the Southern Seas? I only managed to say that many metals (Hg, Mg, etc), and increasingly CO2 levels, but can you bring the light up to our ignorance?'
The question is good, and the answer is pretty close. The words of a zoology professor I had as an undergrad resonate here 'All and nothing can be a poison(pollutants), it all depends on its concentration'. You will read here that the waters around Antarctica are not polluted, and that we are trying our best to leave them like that. I chose a picture of a recently sighted iceberg to illustrate the pristine waters around here,
Antarctic waters remain very clean.
In the global scale, most pollutants that arrive to the oceans arrive from the atmosphere, like CO2 and mercury (Hg on his answer). At coastal scale, rivers and runoff can have a very big impact depending on what they dump. Here is another way of viewing it:
- Pollution has a bigger impact in coastal areas where rivers dump all sorts of things. Our knowledge on this topic here on the ship is very biased to the US. I have heard that rivers in different countries are allowed to dump different chemicals, but I do not know more than that.
One example of coastal pollution is a large area with very low levels of dissolved oxygen on the Gulf of Mexico due to fertilizers arriving to the ocean though rivers (Mississippi, mainly) and over production of plankton that ends up using most of the oxygen. The result, an anoxic (low oxygen) area with little life.
Pharmaceutical drugs: believe it or not, all those medications that people flush in the toilet when they do not need them or that have expired are having an impact on organisms in coastal waters. It is important to properly dispose unused medications. There are places in the US that collect and dispose of them. If you live in the US, check with your town or city government for more information.
There is pollution in areas close to the coast that do not involve rivers or runoff. An example is oil spills in production areas. Massive oils spills like the one in the Gulf of Mexico last year called a lot of attention, but there are many low level spills we do not hear about. One of our experts on the ship says that these spills have short time impact (on the scheme of things, decades is short time for these processes), since there are naturally occurring bacteria that take care of the spills in the long run. For our everyday lives and the lives of the organisms that live in spill areas, these are important pollutants.
Plastics. This is the biggest large scale pollutant that does not arrive by the atmosphere. There are large areas in some parts of the oceans where the currents collect a lot of floating debris (they correspond to the center of the subtropical gyres). As a result, there are very large areas with tons of plastic that range from very large chunks to very tiny pieces that are floating in a thick layer below the surface. The most famous is the very large Pacific patch, but there is also one in the Atlantic Ocean. There is a strong movement, again in the US, to curtail the use of plastic bags. I encourage everybody to use the least amount of plastics as possible to prevent our plastic patches from increasing.
Ocean acidification: I would consider ocean acidification a consequence of CO2 pollution from the atmosphere. I find the chemistry that explains the CO2 flow to the oceans very complicated, but the net effect is that the ocean is becoming more acidic.
The problem with ocean acidification is that acids dissolve certain minerals like calcium carbonate. You can see this by adding a few drops of vinegar on a teaspoon of baking powder, which has calcium bicarbonate. There are many planktonic organisms that have calcium carbonate skeletons, as well as bigger organisms, like seashells and corals. We do not know yet if they will be able to adapt to a new acidic ocean. We are measuring pH levels (acidity) on these waters as part of the effort to study ocean acidification
- Metals: We have heard that sea animals on the high end of the food chain contain lots of mercury. Our expert on metals here on the ship had this to say:
'Man has increased the delivery of mercury to the oceans by about a factor of 3-4, so that if nothing else had changed, fish would have 3-4 times more mercury than before. Top predators (the ones that eat fish) will accumulate the most mercury, and would have always had the highest mercury levels. But man's increase in mercury delivery makes the problem even worse.
You mentioned Magnesium (Mg). Magnesium is one of the major ions in seawater, and contributes to the salinity we measure. It is not a pollutant. There is no evidence that any other heavy metal, except lead (Pb), has increased in the vast majority of the ocean. Pb has been decreasing now since we took Pb out of gasoline, but even at it's highest point, it was never at a level to harm the organisms. In restricted bays, or where many naval ships are based, we see higher levels of copper (Cu) and tin (Sn) since that is used in the paint of the ships hulls to keep organisms from colonizing the hulls. Hull paint with tin has been disallowed for many years, but I believe our Navy still uses it because it works better than paint with copper in it.'
People I talked with on the boat believe that Antarctic waters are very clean. There is not much human activity nearby. The only pollutants must come from the air. A big objective of this cruise is to quantify the amount of CO2 that goes into these waters as a result of the increase in atmospheric CO2.I recommend yo look at a nice website that explains in more detail the CO2 fluxes:
http://carboncycle.aos.wisc.edu/
About the waters around Antarctica, the human activities taking place around Antarctica are in ships and research stations. The very strict international rules that govern Antarctic waters (south of the Antarctic Circumpolar Current, ACC) and the continent stipulate that nothing can be dumped in these waters. I wrote a journal entry about how McMurdo Station complies with these rules (February 17), perhaps it is time to check how we do it on the ship.
We burn all of our trash in an incinerator aboard the N.B. Palmer, except for materials that are hazardous to burn, like the chemicals that we use in the laboratory, and others that are explosive, like batteries, halogen lightbulbs and sprays. We do leave a smoke trail behind the boat, not only form the incinerator but from the diesel engines that propel us through the ever changing ocean surface.
Every day our trash devourer gets fired up to eliminate our waste
We have a water treatment plant that crunches all waste and then zaps it with electricity before releasing the waste to the ocean. The process kills all living organisms without the use of chemicals. The process is stopped 30 minutes before we get to a sampling station.
We do use some chemicals in our labs that are collected for their later disposal when we are done with them. We empty the small containers, like the one below, into 50 gallon metal drums.
Jugs like this ones are found on the labs to collect unwanted chemicals for their disposal.
The drums will make their way at the end of the cruise to Palmer Station on the Antarctic Peninsula. They will be stored with the station's chemical waste and waste from other cruises. Every two years a large shipment is sent to the US from Palmer Station for its proper recycling or disposal.
It is a human reality to dispose of our waste. The best we can do is to limit the amount of waste we as individuals generate with our every day choices, reuse and recycle. We all end up juggling our trash like Sam on the Palmer.
Sam juggles even when the seas are bad, like humans juggle with their waste.