Adapted from Kuleana Coral Restoration SITE RECON lesson

1. Aggregate reef: Hard-bottom substrate with corals, also referred to as continuous of consolidated reef. Most reefs that do not fall in other types are recorded as aggregate reef. 

2. Pavement: Flat, low-relief, solid rock in broad areas often with partial coverage of sand, algae, hard coral, gorgonians, zooanthids, or other sessile invertebrates that are dense enough to begin to obscure the underlying surface. 

3. Spur and groove: habitat with alternating sand and coral formations that are oriented roughly perpendicular to the shore, bank, or shelf.

4. Rock/boulder: Large, irregularly shaped carbonate blocks or boulders or volcanic rock often extending offshore from the island bedrock or headlands.

5. Reef rubble: Unconsolidated small (<10cm) fragments of coral skeletons or reef rock often colonized with filamentous or other macroalgae.

6. Aggregate patch reefs: Coral formations that are isolated from other coral reefs formations by sand or other habitats and that have no organized structural axis relative to the shore or shelf edge covering > 10% of the survey.

7. Pavement with patch reefs: Areas of pavement with occasional patch reefs formations that make up less than 10% of the general area.

8. Pavement with sand channels: Habitats of pavement with alternating sand/surge channel formations that are perpendicular to the shore, bank, or shelf.

9. Sand with scattered coral/rock: Sand bottom with scattered rocks or small, isolated coral heads that make up <10% of the total area.

Reef Rubble

Aggregate Reef

Aggregate Patch Reefs

Pavement with patch reefs/rubble

Spur and groove

Some pavement (harder to find)

1. The reefs of South Maui are much younger than the reefs on Oʻahu. The island of Oʻahu is 2-3 million years older than Haleakalā, the summit above South Maui’s reefs. The reefs on Oʻahu, therefore, have had millions of years more to develop and grow than Maui’s reefs, providing older, larger, and more abundant pavement-type habitats for restoration. 

2. Work in South Maui was proposed due to the existing work occurring mauka in Kula moku: fencing for ungulate control, sediment removal from flood-prone gulches, wetland restoration, and reef-friendly landscaping. While many shallow reefs in Kula Kai (North Kīhei) are declining due to sedimentation, many resilient reefs still exist at depths around 30-35 feet, indicating that restoration could be a useful tool for the area.

   1. Māʻalaea Bay as a whole, for example, has seen reduced turbidity since the creation of Keālia Pond National Wildlife Refuge and the areas along the pond have some of the best water quality recorded by Hui O Ka Wai Ola. Water quality seems to be improving moving from Kīhei towards Māʻalaea. Additionally, some pavement substrate exists between 18 and 24 feet in Māʻalaea Bay, along Sugar Beach.

3. Shallower habitat substrate in Kula Kai/North Kīhei consists of reef rubble, aggregate reef, and aggregate patch reefs. 

4. The pavement habitat type is ideal for restoration activities utilizing large rescued colonies (LRC) and module outplanting. While some of it exists in South Maui, it is less common in Kula Kai/Kula moku. 

5. While sedimentation is common in Kula Kai, some offshore areas are outside the usually turbid zones and show high coral cover and species diversity. These areas are accessible by boat, around 30-35 feet in depth, and have restoration potential. 

6. One of the most helpful parts of learning about site selection and habitat types was diving with Kuleana Coral on Oʻahu and training in their restoration techniques. In-person training and visuals are highly effective in understanding what to look for in terms of habitat and reef type, rather than relying on maps or bathymetric data. Diving with existing coral restoration organizations is highly recommended to see the “live” substrates required for different restoration activities.