Coral reefs are some of the most diverse ecosystems in the world; thousands of species of corals have been discovered. Their diversity means that some can live in warm, shallow, tropical seas while others can thrive in the cold, dark depths of the ocean. Because of the diversity of life found in the habitats created by corals, reefs are often called the "rainforests of the sea." About 25% of the ocean's fish depend on healthy coral reefs, as fish and other organisms shelter, find food, reproduce, and rear their young in the many nooks and crannies formed by corals. Coral reefs are also able to help the environment, greater world ecosystem, and community; they protect coastlines from storms and erosion, are a source of food and new medicines, and are a tourist attraction for local businesses.

Unfortunately, the world's coral reefs are severely threatened and becoming extinct. Though some threats are natural (like diseases, predators, and storms), most of the factors are human-induced: pollution, sedimentation, unsustainable fishing practices, urbanization in coastal areas (which places tremendous stress on marine life) and climate change and global warming (which raises ocean temperatures and causes ocean acidification). These stressors cause damage to the corals, and can often lead to their death, which has a ripple effect on the many species that rely on them– including us humans.

With the rapid decline of coral reefs increasing, there is a strong need for exploring interdisciplinary methods for reef restoration. Examining how to conserve the biodiversity of coral reefs is a key issue, but there is also an urgent need to invest in technology that can improve the coral ecosystem and our understanding of the reef environment. This is what led to the joint research project from faculty at Bar Ilan University, the Technion, the University of Haifa, and Tel Aviv University.

Professors and Ph.D. students from these institutions published a paper in the journal Science of the Total Environment, highlighting a 3D printing method they developed to preserve coral reefs. Their innovation is based on the natural structure of coral reefs off the southern coastal Israeli city of Eilat, but their model is adaptable to other marine environments and may help curb reef devastation plaguing coral ecosystems around the world.

How it works: combining 3D scanning algorithms with environmental DNA sampling

The 3D process begins by scanning underwater photographs of coral reefs. From this visual information, a three-dimensional model of the reef is assembled with maximum accuracy. Thousands of images are photographed and sent to the laboratory to calculate the complex form of the reef and how that form encourages the evolution of reef species diversity. Then, the researchers use a molecular method of collecting environmental genetic information which provides accurate data on the reef’s organisms. This data is incorporated with other parameters and is fed into a 3D technology algorithm, making it possible to build a parametric interactive model of the reef. The three-dimensional model can be designed to precisely fit the designated reef environment. With all this information, they are able to produce a ceramic reef using 3D printing. The reefs are made of a unique ceramic that is naturally porous underwater and provides the most ideal construction and restoration needs to the affected area, or for the establishment of a new reef structure as a foundation for the continuation of life. As says Prof. Ezri Tarazi concluded, “Three-dimensional printing with natural material facilitates the production of highly complex and diverse units that is not possible with the usual means of mold production."

Credit: Natalie Levy and Ofer Berman

The joint research was led by Prof. Oren Levy and Ph.D. student Natalie Levy (Bar-Ilan University), Prof. Ezri Tarazi and Ph.D. student Ofer Berman (Technion), Prof. Tali Treibitz and Ph.D. student Matan Yuval (University of Haifa), and Prof. Yossi Loya (Tel Aviv University). The researchers are thrilled to have accomplished a study that meets the needs to facilitate large-scale restoration that can be adapted to support coral reefs worldwide while also being able to recreate the natural complexity of the coral reef, both in size and design, that will attract reef species such as corals, fish, and invertebrates that support the regrowth of natural coral reefs.