Conservation Moorings

November 2017
By:
M. Conor McManus and Eric G. Schneider, Rhode Island Department of Environmental Management and Lisa N. Havel and Chris Powell, Atlantic Coastal Fish Habitat Partnership
Local Action to Help Preserve and Restore Marine Ecosystems

seagrass, scuba diver, seagrass bed

When mooring your boat, you may not think much about the sea floor beneath you, but it supports several critical habitats, including seagrasses. Seagrass is found in the shallow coastal waters of most continents and the health of these seagrass beds has wide ranging impacts. For many fish and invertebrates, it provides spawning and nursery habitat, areas of refuge, and forage grounds.

Seagrass also serves an important role as the base of many marine food webs. Like other plants, seagrass converts energy from the sun into food for larger, predatory organisms in coastal marine ecosystems. Many endangered species rely on seagrass for food, including sea turtles and manatees.

Seagrass not only provides nourishment and protection for sea creatures, it also improves water quality by stabilizing sediments on the seafloor, producing oxygen for aquatic animals, and removing excess nutrients. Seagrass also helps mitigate climate change by removing carbon dioxide from ecosystems at a rate ten times faster than tropical rainforests.

Yet seagrass beds have been disappearing from the planet at an alarming rate since 1980, and the loss has been accelerating in recent years. They are considered one of the most threatened ecosystems in the world, in part due to the one billion-plus people that reside within 50 kilometers of them. Coastal development, nutrient runoff, chemical pollution, dredging, and boating impacts have all greatly reduced the expanse and quality of seagrass beds. However, if proper attention is given, these negative impacts can be mitigated.

mooring, conservation, seagrass bed

One way to reduce the impact from boats is with conservation moorings. Traditional moorings, the ones we typically think of in harbors and waterfronts around the world, rely on long heavy chains at least twice the depth of the water that connects a mooring ball to an anchor of some sort. Conservation moorings, on the other hand, use a buoyant bungee-like cord or floating, flexible rode to minimize contact with the seafloor. This reduces the “halo-effect” in seagrass beds caused by traditional chain moorings dragging along the bottom.

The drag with traditional moorings can scour the seafloor and create a scar, or halo, of bare sand where seagrass has been damaged or destroyed, particularly as moored boats move with the wind and tides. Instead of a traditional cement block mooring or mushroom weight, conservation moorings employ a helix anchor, which is installed with minimal impact and has a much smaller footprint on the seafloor.

seagrass, seagrass bed, halo, damage, moorings

The success of conservation moorings has been documented via aerial and SCUBA survey programs. Pilot projects in Massachusetts and Rhode Island implementing conservation moorings have shown a decrease in sea floor scouring and seagrass degradation when these moorings have been properly installed and maintained. From underwater, the rode appears to float above the seagrass, preserving the benthic habitat.

For boaters, conservation moorings have benefits as well. A properly installed conservation mooring may exceed the holding power of a traditional mooring. Conservation moorings can have financial benefits as well. While they may be more expensive upfront to install, manufacturers claim that routine inspection and maintenance costs are less expensive compared to traditional moorings.

While these projects use conservation moorings to preserve seagrass in mooring fields, other structured, stationary marine habitats could also benefit from this innovative technology, such as coral reefs. Damage from moorings may take years or decades to recover, depending on the habitat and damage inflicted. Thus, installing conservation moorings in popular anchoring sites with coral reefs and seagrass beds may reduce impacts from anchoring.

moorings, seagrass

These efforts highlight the impacts that small actions, such as mooring reconfigurations, can have in trying to preserve these valuable ecosystems that serve so many ecological and economic roles in coastal areas around the globe. 

Take Action

You can make a difference. Follow these steps to create a positive future for the ocean.

Take Action
  • Where to get your conservation mooring: Multiple brands of conservation moorings are available. Hazelett, StormSoft, and Eco-Mooring systems have been installed along the Massachusetts coast at Gloucester, Manchester-by-the-Sea, Boston, Wareham, and Falmouth; and Hazelett and StormSoft systems have also been installed in Jamestown, Rhode Island. While these moorings are more expensive than traditional moorings, maintenance can be considerably less than traditional moorings and replacement may be less frequent.

  • Know your mooring site: Consider the depth and tidal range when fitting the mooring. Fitting at a low-low tide has been most successful. Some sites might be too shallow for certain models to work effectively, as the top-side hardware can hit the seafloor. Different designs or shorter rodes should be considered if there is any contact with the bottom.

  • Keep up with maintenance: Seasonal maintenance with a scrub brush and gloved hand is recommended, as heavy fouling has been observed when moorings are not cleaned at least once per season. These fouling loads can weigh the equipment down to the bottom and reduce the benefits to the seafloor. 

  • Be cognizant of mooring placement: Grouping conservation moorings in one place can have greater benefits to seagrass regrowth than if they are dispersed among traditional moorings. Conservation moorings should also not be placed too close together – though the system allows for more moorings in a given area, extra boats can shade the seagrass, reducing photosynthesis and recovery rates. Conservation moorings should not be placed in seagrass beds where there are currently no moorings, but instead should be used to retrofit traditional moorings. Healthy, undisturbed seagrasses should be left undeveloped.

  • Talk with your managers. Boater and harbor manager confidence is essential. This new technology needs support from the boating community and harbor masters to become more common. If interested in conservation moorings, speak with your local harbor master and marine authorities on how to effectively make a difference in your community, and promote its growth.