Adventure in Virginia: Part 2
On Wednesday with fair weather Rachael and I navigated seven miles to the marina. We managed to get around the sandy peninsula of the Grandview nature preserve within a narrow channel marked by red and green visual aids. The markers we were following are connected to the bottom of the ocean by either pilings or poles. Because we were going into the bay, we kept the red buoys to our right and the green to our left.
Dredging is essentially the process of removing silt and debris that accumulate over time due to sedimentation-the natural process of sediments washing downstream. Commonly, dredging is done to maintain or increase the depth of waterways and channels. It’s important for the economy that we dredge waterways because our material goods are mostly imported. It’s also regularly used to help maintain the environment. Environmental dredging is common around populated areas where sediments at the bottom of the ocean are contaminated. Generally, pollutants are released from both point sources (overflow sewer systems, spills, etc) and non-point sources (storm runoff). The NOAA Office of Response and Restoration helps efforts to protect and restore the marine environment when disasters occur. A company called Dredge America dredges intake channels for nuclear and coal power plants to make sure sufficient flow of water is maintained for the plant’s operations. Typically, the US Army Corps of Engineers dredges navigation channels.
For about a mile we followed the narrowly-dredged channel until we arrived at the marina. Docking the boat was a challenge and we are grateful for the wonderful staff who helped us get tied up.
The next day the boat was hauled with a boat hoist and brought up on the hard. It was blocked and put on stilts, ready for us to start the bottom job.
Painting the bottom of a boat begins with sanding, but what I’m really interested in about the bottom job is the paint we used. We bought two gallons for two green coats of CPP Antifouling Ablative paint. A gallon of this paint costs $140 at West Marine – and that’s the cheap stuff.
We pay a high price for this paint because of the copper biocide technology within it. Copper antifouling technology has been around for 100 years and is said to be applied to 90% of the world’s boats’ hulls, according to a ChemQuest Group report. The form of copper that exists commonly in antifouling paints is identified as cuprous oxide, which is a solid inorganic matter that exists as a powder or as a nanoparticle.
A nanoparticle is a particle that ranges between 1-100 nanometers, and most nanoparticles are made up of just a few hundred atoms. Nanoparticles have a very large surface area when compared to bulk materials like powder. Because of their very small size and large surface area, copper nanoparticles have unexpected optical, physical, and chemical properties. Typically, copper is considered a soft material, but when it’s a nanoparticle, copper is incredibly hard with much different malleability and ductility.
Paint with copper inside of it is sold to boat owners and shops as antifouling paint, which inherently helps to prevent organic growth on the underside of the boat. Preventing growth is important to boat owners because it helps ensure the hull’s integrity and it also helps performance of the boat in general: the more growth, the slower the boat, and theoretically more fuel for the boat due to its slower speed and inefficiency. Interlux, an antifouling paint manufacturer, also claims safety is a reason why someone might want to buy antifouling paint: “fouling can also grow unevenly across the bottom, throwing your boat off balance, potentially making it dangerously uncontrollable. This can have serious implications in challenging weather conditions.”
To give you some perspective on how much growth really grows on boats...ours had 25 gallons of stuff on it (see pic)
Antifouling paint, powered with copper biocide technology, works because it slowly erodes itself releasing copper into the water and therefore prevents growth like barnacles from sticking to the side of the boat. Releasing copper into the ocean has effects on the environment, considering most antifouling paints consist of 30-60% copper.
Copper is a naturally occurring micronutrient existing in sediment and other particles dissolved in water. Marine life relies on trace elements of copper to catalyze reactions that they rely on to metabolize energy, respirate, photosynthate, and reproduce. The human body is full of enzymes, and almost all chemical reactions in the body are a byproduct of copper. A healthy amount of copper in waterways and in organisms and different mechanisms for evaluating copper levels are controversial. However, the toxic level of copper in the water does not far surpass the non-toxic level that algae relies on to survive and reproduce. Toxic effects of copper on marine biota occur when the uptake rate of copper exceeds the rate of detoxification and excretion.
Photosynthetic marine biota, like macroalgae, are able to provide a buffer for copper pollution in the form of something called a ligand. A ligand is an An organic molecule attached to a tracer element or a macromolecule. In water with excess copper, some biota will counteract the negative effects of high copper concentrations by transporting the copper-bound ligand molecule into or out of a cell through a plasma membrane for using or detoxifying the metal. This phenomena decreases the available amount of copper in the water because it is apprehended by the ligand.
Macroalgae goes through micro and macroscopic stages in its lifecycle. During the early microalgal phases the algae is particularly sensitive to copper toxicity, therefore impacting successful growth and reproduction of the algae, like kelp.
Copper no doubt has an effect on the reproduction cycle. Offered as non-hormonal birth control, female bodied people utilize copper’s affect on the reproductive cycle as a form of an IUD. A copper IUD seems appealing to many people because it doesn’t introduce synthetic hormones to a body that have the side effect of altering the adrenal gland’s behavior and mess with irregular but necessary cortisol and adrenaline levels. Although it may not explicitly introduce new hormones to the body, copper and estrogen are intimately related. The copper IUD works by releasing small amounts of copper into the uterus to immobilize sperm when it travels to the filopian tubes. Once released, despite popular belief, that copper becomes mobile in the body and bloodstreams. It moves throughout the entire body. High levels of copper can cause serious symptoms in the human body. It can deplete zinc levels, lower iron, can cause an unusual rise in Vitamin A, and can aggravate vitamin B metabolism.
Copper commonly finds its place in the liver of our bodies, and when it reaches too high of a level, it inhibits the detoxification of estrogen from the body. This imbalance can lead to estrogen dominance and progesterone deficiency – painful and unwanted endometriosis symptoms. When functioning without birth control, a female body’s adrenal gland sends a signal to the liver to produce something called ceruloplasmin which transports copper around the body. When someone has high estrogen levels and progesterone deficiency, the functioning of the liver and adrenal glands is severely impacted which creates the body to become a victim of copper toxicity. With a snowball effect, copper and estrogen kind of feed off each other and cause unbearable symptoms.
It’s pretty clear that copper, regardless of organism, plays a role in how energy is metabolized. In turn, reproduction cycles are disrupted. The Clean Water Act has changed regulations and rules about copper levels in the water about 20 times since it was first established. The Shelter Island Yacht Basin in San Diego had copper levels that exceeded the Clean Water Act’s regulatory ratio: 3.1mg/L. In an effort to restore to an acceptable level, the state employed best maintenance practice rules when removing debris from the bottom of the boat when hull cleaning and by encouraging testing of antifoul alternatives. The State of California also implemented alternative, but environmentally friendly water quality standards. The state of Washington has implemented paint regulations, however, according to the state, there have not been any antifouling alternatives that promote marine health better than copper-based antifoul. While the state of Washington’s Department of Ecology seeks to reduce copper pollution found in its marinas that state officials have attributed to copper leaching from copper-based antifouling bottom paints, they fear any alternate biocide used in bottom paint as an active ingredient may cause more environmental damage than copper, threatening water quality and damaging Washington’s environment. Therefore, state officials have recommended delaying the ban of copper-based bottom paint, so they may have ample time to study the relative impacts of copper versus non-copper biocides, using models based on Puget Sound marina designs and water quality conditions. (Neal Blossom, American Chemet Corporation, Frank Szafranski, AkzoNobel Yacht, and Aggie Lotz, The ChemQuest Group, Inc)
Protecting boats is critical for the economy to function the way it is now. Thriving marine life is also critical for the economy. It’s all part of a system: the weaknesses for one agent are the strengths for another. The boat hulls are protected, but too much copper can create toxicity for marine life. When algae’s ability to grow or carry out its life and/or reproductive cycle the effects inhibit other natural processes from occurring.
Macroalgae, affected by rising copper levels, provide important services for the rest of the ecosystem. Kelp forests host the greatest variety of different types of animals and plants than almost any other ocean community. Kelp forests provide shelter from predators and storms and exist close to the shore, making them prone to human activity. The buildup of transitional metals, copper, for example impedes the colonization of microbes on the floor of the kelp forest. The impact of decreased bacterial populations are understudied and unknown. This is a place for research.
When we travel back through the Chesapeake Bay to return to the slip for our boat, we will be traveling above and adjacent to different macroalgae in the area. We don’t have sails on our boat yet so the trip will be powered by our engine.
Aft of the engine is a bronze propeller attached to a stainless steel shaft. The shaft has two “zincs” attached to it. The zincs I'm referring to are about 2x3 inches big. In the pictures below you can see our already corroded zincs. Every 4-6 months two zincs are placed on the shaft to prevent the shaft and expensive brass prop from becoming corroded. Corrosion is an electrochemical process of deterioration of metal components when metal is exposed to an aqueous environment, changing the metal from its solid form to an oxide form.
Galvanic corrosion is the result of electrolysis. To understand electrolysis, imagine a steel rod (a prop shaft) underwater. On that steel rod there is a negative side (anodic side) and a positive side (cathodic side). Saltwater conducts electricity more than freshwater, so props and shafts corrode in saltwater faster. In the corrosion process the atoms in the anodic (more negative) side give up electrons to the cathodic (more positive) side. Without the electrons, the remaining positive ions are left to move into the water. The extra electrons move to the cathodic side form negative ions and relocate to the water as well. The negative and positive ions that form end up combining and moving in the opposite direction. The anodic side ends up losing electrons, and thus, experiences corrosion.
The difference between the negative and positive charge of the steel is measured in volts. The higher the voltage is on a metal, the faster corrosion occurs. Voltage multiplied by the square root of current gives us the resistance. The higher the voltage, the higher the resistance. Electricity chooses the path of least resistance. We need to know this in order to understand galvanic corrosion. Galvanic corrosion occurs when two different metals with differentiating voltage are immersed together in the same electrolyte (saltwater). One metal, the more negative one, acts as the anodic metal which corrodes at a faster pace than the cathodic metal. As the anode corrodes, the cathode is protected, because the anodic one attracts the electric current in the water. Our prop and shaft combined are considered to both be considered the cathode on our boat because they have a higher voltage than the zinc pieces attached to the shaft. The zinc has a much lower voltage offering the path of least resistance which then causes the zinc to corrode faster. The zincs eventually deteriorate entirely and need to be replaced to continue protecting the mechanical pieces.
As the zincs deteriorate, so does the integrity of the paint-job we have done. The paint will need to be replaced within the next couple seasons with more antifouling paint. The next step for us is to hoist new rigging and figure out our route...and admire the progress we've made. We still have virtually no idea where we are going so we have to get acquainted with the relevant charts and begin our voyage! As of now, we are heading off the hard and into the soft? Water.
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