Coral Habitat Rehabilitation and Restoration

coral reef, fish

Coral Habitat Rehabilitation and Restoration

Reviving Underwater Worlds: A Coral Rescue Mission in the Pacific

HDR’s marine biologists and coastal ecosystem restoration specialists recently completed a sophisticated coral habitat restoration venture in the Pacific Ocean, commissioned by a confidential client. The project aimed to revamp and modernize a deepwater port in the Pacific Ocean while ensuring minimal impact on essential fish habitat and endangered species. To achieve this, the team collaborated closely with the United States National Marine Fisheries Service.

The project was meticulously planned and executed, with two primary objectives in mind. First, we aimed to delineate and stabilize a 400-square-meter coral habitat rehabilitation area on an offsite underwater shoal. Second, we planned to relocate healthy coral colonies from the project area to this designated site. The chosen shoal, which lacked natural corals due to human activity, provided an ideal location for rehabilitation. To provide a successful relocation, we targeted an extra 500 coral colonies for transplantation to compensate for potential losses.

Stabilizing the delineated area was crucial to providing a suitable substrate for coral attachment without harming existing habitats. This was achieved by combining limestone boulders, polyethylene mesh mats, and strategically placed concrete structures to enhance stability and habitat complexity.

Given the challenges posed by the COVID-19 pandemic, the project's implementation followed stringent safety protocols, including adapted diving practices aligned with University of Hawaii guidelines and phased implementation to mitigate risks.

The project unfolded in three phases:

  1. Unexploded Ordnance Surveys: Prior to project initiation, both the project area and the rehabilitation site underwent surveys for UXO anomalies. While abundant non-munition debris was found, no explosives were identified, ensuring the safety of divers and project personnel.
  2. Coral Habitat Rehabilitation Area Stabilization: A designated area on the offsite shoal was prepared for coral habitat rehabilitation. Loose coral colonies were removed, anthropogenic debris cleared, and limestone boulders strategically placed to create a stable substrate.
  3. Coral Translocation: Healthy coral colonies identified for relocation were carefully removed from the project area, transported, and attached to the prepared site using a Portland cement mixture. Fragments of fragile species were also retained whenever possible.

Despite the challenges we faced, such as predation by parrotfish during the translocation process, the project yielded positive outcomes. The rehabilitation site saw an increase in rugosity and habitat complexity, promising enhanced ecological functionality. This is a testament to the resilience and determination of our team. Additionally, the area is expected to support a diverse array of native fauna, contributing to the overall health of the marine ecosystem.

Our successful completion of this coral habitat restoration project underscores our expertise in marine conservation and coastal ecosystem restoration while showcasing our commitment to sustainable development in the Pacific Ocean.

coral reef, fish