Reef-Friendly Landscapes
World Ocean Day is June 8th, and we want to make sure we, as responsible landscapers, are doing our part to protect our oceans and reefs! Sadly, the landscaping and land maintenance industry can cause great harm to our oceans, and it’s up to us to educate ourselves and our customers to protect our fragile reefs and ocean ecosystem.
Impacts of Common Landscape Applications
Pesticide, herbicide, and fertilizer applications on properties near our oceans can run off into the water during heavy rains or over time by leaching through the ground. These products can cause an immense amount of damage to our reefs, ocean wildlife, and the natural ecosystems surrounding our islands. Here’s how:
Synthetic Pesticides
Cause coral bleaching
Synthetic pesticides cause corals to expel the symbiotic algae living in their tissues due to environmental stress, causing them to turn white and become vulnerable to disease and death.
Cause birth and developmental defects in aquatic life
Contamination from synthetic pesticides can reduce biodiversity by killing sensitive species, disrupting food webs, and impairing ecosystem services.
Synthetic Herbicides
Inhibit photosynthesis in Zooxanthellae and Phytoplankton
Zooxanthellae are photosynthetic single-celled organisms capable of symbiosis with marine invertebrates, including corals, jellyfish, demosponges, and nudibranchs.
During the day, Zooxanthellae provide their host with organic products of photosynthesis, often providing up to 90% of the host's energy needs for metabolism, growth, and reproduction.
Phytoplankton are photosynthetic, microscopic organisms that live in the upper sunlit layers of the ocean.
Phytoplankton play a vital role as primary producers in the aquatic ecosystem, converting carbon dioxide into organic compounds through photosynthesis.
They form the base of the aquatic food web and support a diverse range of marine life, and are essential for nutrient cycling and oxygen production in aquatic environments.
Fertilizers
Synthetic water-soluble fertilizers dissolve and release nitrogen, which enters the groundwater and then makes its way into the ocean. Nitrogen pollution in the ocean causes:
Eutrophication
The process by which water bodies become enriched with nutrients, which can lead to excessive plant and algae growth, often resulting in oxygen depletion and ecosystem degradation.
Algal blooms
Nutrient runoff helps promote the growth of algae and invasive seaweeds, disrupting the ecosystem and pushing out native seaweeds.
Tumor growth in sea turtles
Sea turtles eat the invasive algae and seaweeds that are nutrient-polluted with high levels of nitrogen, causing chronic tumors that can be deadly.
There is a direct link between the tumors found in our native Green Sea Turtles and Eutrophication- coastal waters being polluted by fertilizer runoff causes invasive seaweeds and algae to grow at an accelerated rate, taking over shallow waters where sea turtles graze. The turtles eat the seaweed that now has high levels of arginine, which causes chronic tumors. This is one of the leading causes of death in Green Sea Turtles and further threatens our ocean’s ecosystem.
“To prevent them from consuming superweeds that promote these tumors—their greatest known source of mortality, we need to manage aggressively all land-based sources of nutrient pollution and to restore the turtle's native diet.” -UH Mānoa Marine Biology Professor Celia Smith
What is the Solution?
The main issue with these synthetic and chemical products that leach into our oceans is that they cause an addictive cycle. They are applied frequently and dissolve quickly. The salt in these products is also harsh on soil microbes, which are important for nutrient cycling, plant growth, and soil structure and stability. If soil stability is compromised, more runoff of nutrients and chemicals is likely. But there are ways to combat these issues with mindful landscaping and maintenance practices.
Go Organic
The best way to prevent runoff is to build a healthy microbial soil.
Microbes feed on natural materials in the soil and release nitrogen naturally for the plants to use- no need to over-fertilize.
Feed the soil without synthetics
Try using a compost tea
Compost tea is a nutrient-rich liquid fertilizer made by brewing compost in water. It is packed with beneficial microbes that improve soil and plant health.
This tea can also treat White Fly!
Incorporate Biochar
Biochar is a product made from biomass waste that can be used as an amendment to the soil.
It is primarily composed of carbon and ash, and is highly porous. Its large surface area can help retain water and nutrients, and support microbial life in the soil.
Switch to water-insoluble fertilizers
WIFs are fertilizers that break down slowly due to their low solubility in water, making them ideal for long-term nutrient availability and responsible agricultural and landscaping practices.
Conserve energy and protect the reefs
Opt for battery-operated equipment in your landscaping to prevent any fuel spills and help to conserve energy.
Create mindful landscape designs that utilize plants as shade and naturally cool your landscape.
Dry, depleted soils are much more susceptible to runoff.