Chapter 11: Environmental Stewardship
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| Sunset in the Sapelo Island National Estuarine Research Reserve. |
Surviving Thriving on the ICW
11. Environmental Stewardship on the ICW
One of the primary reasons people go cruising is to experience nature; healthy, untrammeled nature. When cruising on the ICW, your floating home gets to spend time in some of the most spectacular coastal wetlands on the planet. Our boats give us access to incredible places that our land-bound friends never get to see, or at least not from such an up-close vantage point. The wild and scenic places that can be accessed by cruising the Atlantic portion of the ICW include four national seashores; five national estuarine research reserves; and 14 national wildlife refuges. And these preserves represent just a small fraction of the natural habitats that you will encounter along the Atlantic ICW. There are countless more coastal preserves, state parks, state and national forests, wildlife management areas, and privately owned conservation areas. The AICW is the gateway to the last great coastal wilderness areas on the East Coast.
Most cruisers are keen to protect the special places that they visit in their boats. Here are some tips on how cruisers can protect the habitats of the Atlantic ICW, which can be applied to just about any body of water.
Don’t discharge your wastewater overboard
In the U.S., it is illegal to dump untreated sewage waste (AKA “blackwater”) in inland waters, which includes the entirety of the ICW. In many areas, designated as “No Discharge Zones,” it is even illegal to discharge treated waste (such as that from a Type I or II Marine Sanitation Device). So what is a conscientious boater to do? Go to a pumpout dock. Pumpout facilities are common along the ICW. Many of the marinas and mooring fields on the ICW even have mobile pumpout boats, so you don’t even need to go to the pumpout facility; they’ll come to you! What could be easier?
Figure: photo of a pumpout facility or pumpout boat
So now that you know what’s legal, what’s illegal, and how to stay on the right side of the law, let’s take a deep dive into sewage and find out why this is such an important issue. Come with us to the diving board alongside the cesspool…
Everyone knows that sewage wastewater or “blackwater” is bad for the environment. But not everyone understands completely why it’s so bad. Most people know untreated sewage that gets into the water spreads disease pathogens, such as hepatitis. If a person with hepatitis (a lot of people who have it don’t realize it) pumps their holding tank overboard, other people can catch their disease by swimming in the water or by eating seafood harvested from the local waters. There are all kinds of waterborne illnesses that can be spread this way, besides hepatitis.
But besides the public health threat of discharging blackwater, there are also tremendous environmental conservation concerns, stemming from the nutrients that it contains. The important nutrient to consider in coastal waters is nitrogen. Both our feces and urine contain high concentrations of nitrogen-containing compounds. Well, you might ask, aren’t nutrients necessary to support the food web? Yes, indeed they are. But the ecosystem already has its natural sources of nutrients, which get recycled continually in the food web.
When humans add their nutrients to an aquatic ecosystem that already has its own natural sources of nutrients, bad things can happen. These nutrients are literally fertilizer that promote the growth of algae. The algae uses the nutrients, along with sunlight, to create its “food” (sugars) through the process of photosynthesis. Excess nutrients can cause algal blooms, or explosive growth of algae.
There are three basic environmental problems that these algal blooms can cause. The first is harmful algal blooms (HABs), which include "red tides." This happens when the type of algae that blooms is toxic. These toxic HABs, or red tides, can cause large-scale fish kills, as well as die-offs of dolphins, manatees, sea turtles, and seabirds. They can also have serious health consequences for humans, including causing respiratory distress and neurotoxic shellfish poisoning.
The second problem caused by the introduction of excess nutrients happens when the individual algal organisms complete their life cycle and die. Microalgae, which are tiny, single-celled organisms, have very short lifespans. When they die, they tend to sink to the bottom, where bacteria consume them. The process of bacteria “scavenging” on dead organisms is known as decomposition and is a natural phenomenon. An algal bloom, where the abundance of algae explodes rapidly, is always accompanied by a bloom of bacteria. The bacteria provide a valuable service. By decomposing the dead algae, they make the energy and nutrients in the dead algae available to the other organisms in the food web. But those bacteria also consume oxygen, just like us. When the amount of bacteria explodes in response to an algal bloom, their consumption of oxygen also explodes, resulting in large areas where the water contains little or no oxygen. Fish and aquatic invertebrates all require oxygen; without it, they die. These areas that are devoid of oxygen are sometimes called “dead zones” because of the massive die-offs of fish and other creatures that they cause. One of the most famous dead zones is in the Gulf of Mexico. Every summer, an area the size of Rhode Island in the northern Gulf of Mexico turns into a dead zone, due mostly to excess nutrient runoff coming from the Mississippi River that triggers an algal bloom. But there are other dead zones, including ones along the AICW such as in Chesapeake Bay, Pamlico Sound, Mosquito Lagoon, and Indian River Lagoon.
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| Red tide harmful algal bloom on the Gulf Coast of Florida (Photo credit: NOAA) |
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| Fish killed in a "dead zone" resulting from an algal bloom. |
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| A large fish kill in Sarasota, FL, related to a “red tide” harmful algal bloom. |
The third problem caused by algal blooms is that they shade out aquatic vegetation and smoother bottom-dwelling creatures. Those single-celled microalgae that we mentioned previously drift around in the water. During a bloom, their concentrations become so high that they make the water cloudy. This reduces the amount of sunlight reaching the bottom, and can kill ecologically important seagrass. This shading out of seagrass gets worse the deeper the water is, to the point where the seagrass becomes limited to just the extreme edges of the estuary, where the water is extremely shallow.
The other general class of algae that we have yet to discuss is called macroalgae, which also "blooms" due to excess nutrients. It is larger and attaches itself to structures on the bottom, such as the blades of seagrass and the shells of oysters. This blocks the sunlight from reaching the seagrass and prevents water from flowing freely to the oyster’s gills, causing death in both cases. Algae grow much faster than seagrass (or coral). When excess nutrients from sewage (either from boats or from land) are dumped into the water, the resulting algae bloom will smother the seagrass (and coral).
This section has been pretty dense with scientific details. But we think it is important to understand the range of impacts that nutrient pollution can have. The important thing to remember is that all of the problems described above are caused by, or exacerbated by, the addition of excess nutrients to the ecosystem, the type of nutrients that are in the wastewater in your holding tank.At this point, people often pipe up and say, “What about fish, dolphins, and whales? They poop in the water all the time, and there are a lot more of them than there are cruisers living on boats.” And, of course, there is a nugget of truth in this. But there is one major difference between a dolphin pooping in the water and one of us humans doing the same thing (or pumping our holding tank overboard). When a dolphin does its business in the water, it is just returning nutrients that originally came from that food web back to that food web. There is no addition of new nutrients; it’s just recycling nutrients obtained from the local food web. On the other hand, when we pump our waste overboard, we are adding new nutrients to this particular aquatic food web. Putting our waste in the water adds nutrients from the apple that was grown in Washington State, the tomato from California, the wine grapes from France, the avocado from Mexico, and the beef from Texas. The addition of all those “new” nutrients make it more likely that an algal bloom will occur.
“What about all those dirt-dwellers, flushing their toilets? There are a lot more people living on land than on boats, and their waste eventually ends up in the water. Cruisers are just scapegoats.” Again, there is that nugget of truth. But let’s look at the whole picture. There are standards for wastewater treatment and disposal. Modern municipal wastewater treatment facilities disinfect the waste AND remove over 90% of the nitrogen. That means that a person on a boat disposing of waste directly in the water has an impact on the environment equal to about 10 people living on shore whose toilet is connected to a municipal treatment system. And the discharge for treated effluent from a municipal sewage treatment plant is sited in a location where it will become diluted rapidly and/or where the local ecosystem is less sensitive to added nutrients. Cruisers, on the other hand, spend a lot of time moored in areas that are sensitive to excess nutrients. By injecting their waste directly into these sensitive habitats (i.e., illegally discharging their waste into inland waters), they have a disproportionate impact.
“Does it really matter if I pump out my waste? It’s all going to end up back in the water, anyway.” Probably so. But if you properly dispose of your wastewater at a pumpout facility, it will go into the municipal wastewater treatment system. As mentioned above these treatment systems disinfect AND “de-nitrify” the waste. Using pumpout facilities drastically reduces your impact on the local habitat.
*Figure: photo of a wastewater treatment plant
“What about those wastewater treatment plants that routinely and “accidentally” spew millions of gallons of sewage into the water?” Raw sewage spills get a lot of publicity but they are relatively rare. Most of the spills are caused by the municipal sewage treatment plants being overwhelmed by too much waste. More and more people are moving to the coast, particularly in Florida, and sewage treatment plants are treating a greater amount of sewage than they were designed to handle. Public investments in municipal wastewater treatment capacity have not been keeping pace with increases in the populations of coastal communities. The problem of increasing coastal populations is compounded by the increasing occurrence of severe rainfall events. In many systems, rainwater from the roadways is directed to the treatment plants before being returned to the coastal waters. This is good because contaminants picked up in urban roads by the water can be removed before the water is discharged into the bay. The problem is that severe weather events are occurring more frequently. The amount of rainfall dumped on the land in short bursts overwhelms the treatment plants. The point here is that sewage treatment plants are being asked to treat a greater volume of wastewater in an environment that makes it more likely for spills to occur. As the population in our coastal communities balloons, we need to invest more in sewage treatment plants to keep up with the rising demand. And regardless of the causes and magnitudes of raw sewage releases from treatment plants, they shouldn’t be used as an excuse to spread our own personal waste everywhere. Even if the wastewater generated by cruisers is a drop in the bucket compared to what comes from land, why would we ever want to be part of the problem? It’s all cumulative.
“But I have a Type I Marine Sanitation Device. It treats the wastewater so it’s ok to discharge it.” Actually, Type I MSDs are primarily designed to just disinfect the waste. There is no government standard for nutrient removal in Type I MSDs, so these devices are not very effective at removing nitrogen. Although you can discharge your Type I MSD legally in a lot of coastal waters, you will be contributing to that problem of excess nutrients and algal blooms. You should also note that there are many “No Discharge Zones” along the ICW, where it is even illegal to discharge treated wastewater from a Type I MSD. And, as a reminder, most marinas are designated as No Discharge Zones.
One thing to remember about nutrient pollution is that there are many different sources of it, and it’s all cumulative. The way to tackle it is for each of us to take responsibility for our waste. We each need to start by removing as much of our waste as possible from the total amount.
Minimize the Nutrients in Your Graywater/Food Waste
Graywater is the water that runs off your deck when you are washing your boat, and that which comes from your sinks, showers, washing machines, and anything else that discharges water (besides your blackwater MSDs). Similar to blackwater, graywater contains nutrients. So it is important to minimize the concentrations of these nutrients in your graywater. The sources of nutrients in graywater on a cruising boat are primarily soaps, shampoos, detergents, and food wastes. In addition to containing algal bloom-inducing nutrients, many soaps and detergents contain toxic chemicals. You can minimize the impact of your graywater by
- Finding boat soaps, dish detergents, laundry detergents, and shampoos that are nontoxic, biodegradable, low in nitrogen-containing nutrients.
- Reducing the amount of cleaners used when scrubbing your boat. Try a water-only washing. Usually just a hose-down will do the trick.
- Using a sink strainer in your galley sink to prevent food waste from going down the drain.
- Not throwing your food scraps overboard. Besides being unsightly, it adds nutrients to the ecosystem. Just like when you’re camping, remember the phrase “Pack it in, pack it out.”
Photo: less toxic boat soap. Vinegar. Sink strainer.
Reduce Your Fuel Consumption
If your boat has a full displacement hull (monohull sailboat or non-planing trawler yacht), the closer you get to your maximum hull speed the more fuel you need to burn for each additional tenth of a knot. Once you are at 80 or 90% of hull speed, it takes a lot of additional fuel to get to hull speed. Is that last half of a knot worth all the extra fuel (and money)? And if you are at hull speed, there is absolutely no sense in trying to go any faster. If you push your engine harder to try to go faster than hull speed, you’ll just burn more fuel and make a bigger wake, but you won’t go any faster. If you normally cruise at hull speed, you could potentially save a lot of money on fuel by slowing down just a little bit. It is not uncommon for full displacement boats to be able to save about 20% on their fuel consumption simply by reducing their speed by about 10% from hull speed. For example, if your boat has a maximum theoretical hull speed of 7.5 knots (STW) then you could potentially save about 20% on your fuel costs by reducing your speed to 6.75 knots. For planing hulls, the most fuel efficient speed for cruising is usually just fast enough to keep the boat on a plane.
- Know how much fuel your tank or portable jug will safely take, given the amount of fuel that may already be in it.
- Before you start fueling, place oil absorbent pads next to the fill port and under the vent to catch any accidental spills.
- Fill the tank slowly. Listen to the sound of the fuel in the inlet hose and vent; you can hear it backing up before it overflows. Stop before the fuel overflows. Because fuel tanks on boats vent directly to the atmosphere, fuel will usually come out the vent before it backs up in the fill hose. Therefore, the automatic shut-off feature on fuel pumps won’t work, as it does for your car’s fuel tank. Stop filling before the tank is completely full. For gasoline, fill the tank to no more than 90% of its capacity to allow for expansion.
- Mud-dauber wasps love to make nests in vent hoses. A clogged vent hose will make the fuel burp up from the fill hose, long before the tank is full. Evict those pesky wasps and keep the vent clear. If burping is a problem, fill the tank slowly (and, perhaps, eat fewer onions).
- Fill portable jugs on land rather than on your boat or on a dock (if possible). Put an oil absorbent pad under the jug to catch spills.
- The new “non-spill” spouts on fuel jugs are a nightmare. They require three hands to pour fuel from a full jug and they almost always end up spilling fuel. To safely and easily transfer fuel from a portable jug to your boat’s tank, use a shaker or “jiggler” siphon hose (one of our favorite boat gadgets).
Filling gas jug on shore, with diaper beneath it.
Jiggler hose
Fig: photo pouring oil into recycling.
Fig: photos of solar panels and wind gens.
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| Turtle grass, in Puerto Rico. This species also grows in the waters surrounding the ICW in Florida. Due to increases in nutrient pollution, the abundance of turtle grass in Florida has plummeted in recent years, causing large losses of fish and manatees. During our last ICW cruise, we tried to take photos of seagrass along the ICW in Florida’s Indian River Lagoon but we couldn’t find any to take pictures of. (Photo credit: NOAA) |
Even if you can get your anchor to set, there are other important reasons not to anchor in seagrass. Seagrasses, a group of plant species that live below the low tide line, are incredibly important to ecosystem health. Ecologists classify seagrasses as ecosystem engineers because they create a novel type of habitat, called a seagrass meadow, that provides food and shelter to an enormous variety of organisms. In the absence of seagrass, the habitat would be a barren sandflat or mudflat. Seagrass is eaten by a variety of animals, including manatees, green sea turtles, and pinfish. It clarifies the water; as the water flows through the seagrass meadow, the forest of grass blades slows the current, which results in the particles of suspended sediment being deposited on the bottom.
Seagrass meadows are also referred to as a form of “blue carbon” because they absorb carbon dioxide to perform photosynthesis. The plants use the energy (sugar molecules) created through photosynthesis to grow their tissues, many of which, such as the roots and rhizomes, are hidden below the mud and sand in which they grow. These roots and rhizomes persist for centuries, even after the plant dies, because decomposition occurs at an incredibly slow rate in these underwater sediments. Thus seagrass is one of the most effective natural carbon sinks that extract carbon dioxide from the water and atmosphere and sequester it in the subsea sediments. Having lots of healthy seagrass is important for slowing the buildup of climate-warming carbon dioxide in the atmosphere.
Overall, seagrass health was in sharp decline prior to the implementation of the federal Clean Water Act in the 1970s. Throughout the period from the 1980s to 2000s, following the passage of the Clean Water Act, improvements in water quality sparked recovery of seagrasses throughout the coastal waters of the U.S. This coincided with increasing fish populations in coastal waters. In the past decade, however, the recovery has slowed in some areas, and even reversed drastically. The Indian River Lagoon, in particular, has seen dramatic declines in both the geographic coverage and density of seagrass. As more people move to that region, nutrient pollution increases. As described above, this causes plankton blooms that block out the sunlight. The resulting loss of seagrass has been so drastic in the past few years that it is causing mass starvation of manatees, which rely on seagrass as their primary source of food. Protecting the remaining seagrass and improving water quality is crucial.The problem caused by anchoring on seagrass, or running through it with an outboard motor, is that it causes “scarring” in which the roots, rhizomes (horizontal stems or runners), and grass blades are all damaged. Unlike a divot in the grass on a golf course, which will repair itself quickly, scars in a seagrass meadows can take years to recover. If enough scarring takes place the seagrass meadow reaches a tipping point, where the grass in an entire area may die off.
Fig: Sea grass prop scars (NOAA)
So how do you avoid seagrass? It typically grows in shallow water, beginning at the low tide line. Water clarity determines the depth to which adequate sunlight reaches, thus dictating the maximum depth at which seagrass will grow. In crystal clear water, it can grow at depths of well over 20 feet. Along the ICW, it will typically grow to a depth of about 10 feet. Anchoring in water deeper than this will help you avoid seagrass. In some areas, it is difficult to find deeper water. In that case, avoid anchoring on patches of bottom that are dark in color (dark green, brown, or nearly black). Drop your anchor in the lighter green areas that indicate bare sand or mud. Your anchor chain can also damage the seagrass so make sure the patch of bare bottom on which you drop your anchor is large and drop it in the center of the patch so that your chain won’t tear up the grass as the boat swings with the shifting winds and currents. The patch itself should have a diameter that is at least equal to the length of your boat.
While riding in your dinghy, also avoid the dark patches in the shallow water. In very shallow water, you may see the grass blades at the surface. In these areas, shut off your motor, tilt it up, and break out the oars. Row over the grass and take a moment to look down at it and see the diversity of life that it supports. It’s like a tiny rainforest, except that it is actually much better than a rainforest at sequestering carbon. If you see grass blades floating at the surface that have been neatly cut, like lawn mower trimmings, these were cut by the propeller of a boat that ran through a seagrass meadow. If you are an angler, the site of this should anger you; this is fish habitat that has been destroyed by carelessness.
If you buy bottled water to drink on your boat, you could reduce the amount of single-use plastic that you consume simply by drinking the water in your boat’s water tanks. Some people dislike tank water. By keeping your tank and plumbing clean at all times, and using an in-line filter, you can improve the taste of the water. The fiberglass tanks on our 40 year-old boat were in bad shape and the water was undrinkable. So we cleaned and refurbished the tanks, and the improvement in water quality is remarkable. It is so satisfying to be able to drink a glass of sweet-tasting water straight from the tap. This has been one of the best improvements we've made to our boat.
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| Some of the species you can catch in and around the ICW: spotted seatrout, sheepshead, and permit (caught under a scientific collecting permit from Florida FWC). |
Another important thing for anglers to remember is to properly dispose of used fishing line. Monofilament fishing line, which is made of a type of plastic, will persist in the environment for a very long time. It can entangle or be ingested by animals. It may be difficult to imagine but even a large animal, such as an adult bottlenose dolphin, can suffer life-threatening injuries from entanglement in a few yards of fishing line. Many boat ramps and fishing piers along the ICW have collection points where you can bring your used line to be recycled (Look for the large, white PVC pipes).
Photos: Entangled dolphin
PHoto: PVC pipe at a dock for collecting monofilament.
Avoid the Chafe
Most people know about the problems caused by plastics and petroleum in the environment. Your fiberglass boat is made of plastic and contains a lot of petroleum. Derelict boats and wrecks are a major source of pollution along the ICW. Anyone who has spent much time cruising along the coast of Florida will recognize this. So don’t let your boat become pollution. The two most common ways that boats end up being wrecked are by chafing through their anchor rode or snubber and by dragging anchor. Make sure your ground tackle is adequate for your boat and that you know how to deploy it (there's a lot more to it than just tossing the anchor overboard). You don't necessarily need an all-chain rode, but your anchor does need to be attached to a chain that is at least equal to the length of your boat. If you have a combination rope/chain rode, place heavy chafing gear at the fairlead and anywhere else where the rope may contact the edge of a solid object. A 1- to 2-foot tube of thick leather or fire hose works best. If you have an all-chain rode, use a snubber and protect it with chafing gear.
Conclusion
The sheer number and scale of the environmental problems that exist today can seem overwhelming. None of us is perfect and none of us can solve all the world’s problems by ourselves. In this situation, it is tempting to throw up our hands in defeat and just keep going on with business as usual. At the opposite end of the spectrum, the self-righteous among us will insist on strict adherence to perfection; everyone else becomes the target of ridicule. Neither of these attitudes is helpful. Don’t let the perfect be the enemy of the good. We are all on our own personal journeys. Nobody can be perfect. But if we each try to do a little better each day, and we cut ourselves a little bit of slack, together we’ll make a big difference.
In most cases, living on a cruising boat is more environmentally friendly than living in a house on land. Whether it’s on a sailboat or powerboat, living aboard forces you to be conscious of all of the resources that you consume and all of the waste that you generate. And because we generally have to work harder to acquire resources and to dispose of the subsequent waste, we tend to live much more frugally aboard our boats than we do on land. This, in itself, has environmental benefits, and it’s something that just comes naturally to cruisers.
For more ideas on how to reduce your impact on the environment while cruising, check out Sailors for the Sea, an environmental organization created by boaters, for boaters. They have produced a variety of resources to help the boating community, including a Green Boating Guide.
To Learn More
Tools
- Pumpout Nav, a free iOS and Android app, uses a boater’s location information to suggest the nearest public pumpout station on a map or list.
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| Loki watching a bottlenose dolphin that is body surfing in our bow wave. |
- Introduction
- Chapter 1: Tips & Tricks
- Chapter 2: Water Levels
- Chapter 3: Avoiding Obstacles
- Chapter 4: Running Aground
- Chapter 5: Bridges
- Chapter 6: Inlets
- Chapter 7: Docking, Anchoring & Mooring
- Chapter 8: Navigation Electronics
- Chapter 9: Weather Basics
- Chapter 10: Typical Weather
- Chapter 11: Environmental Stewardship
- Chapter 12: The Perfect Boat
- Chapter 13: Maintenance
- Chapter 14: Conclusion
- About the Authors
