Manta Rays

Posted on December 26, 2024December 26, 2024 by Annabel Thomas

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Manta Rays: Their Life Cycle and Why They are Vulnerable

by Fahmi, AMD-B’s 2024 Divemaster Intern

Manta rays have a unique but slow reproductive process. Female manta rays give birth to live pups after a pregnancy lasting about a year. What makes them vulnerable is that they typically produce only one pup at a time and may take two to five years before reproducing again. Once born, the pup is left to survive on its own and spends nearly a decade growing and maturing. This slow reproduction rate means manta populations struggle to recover when their numbers are reduced.

Manta rays are highly migratory creatures, travelling vast distances in search of food and suitable habitats. While this behaviour is essential for their survival, it increases their exposure to various threats. Overfishing, entanglement in fishing gear, and habitat destruction—such as the loss of coral reefs that serve as feeding or cleaning stations—pose significant risks. Climate change and pollution also impact the plankton populations that mantas depend on for food, making their survival even more challenging.

Why Manta Rays Matter

Although manta rays do not have a massive ecological role compared to species like sharks or corals, they contribute to marine tourism in a significant way. Destinations like Nusa Penida and Raja Ampat attract divers and snorkellers eager to witness these majestic animals. The revenue from manta ray tourism supports local economies and often funds conservation projects, creating a positive cycle of benefits for both humans and the environment.

The Importance of Protecting Manta Rays

Manta rays are not just symbols of marine biodiversity; they are also indicators of ocean health. Their vulnerability reminds us of the delicate balance in marine ecosystems. Protecting manta rays is not only about saving a species—it’s about safeguarding the health of our oceans, promoting sustainable tourism, and respecting the interconnectedness of life underwater.

Microplastics Inside the Coral Tissue

Posted on November 15, 2024November 19, 2024 by Annabel Thomas

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Microplastics – How do They End Up in the Ocean

by Fahmi, AMD-B’s 2024 Divemaster Intern

Microplastic are tiny fragments of plastic, usually less than 5 millimeters in size, that originate from textiles, such as microfiber shedding, personal care products or cosmetics, paint, tires, and the fragmentation of larger plastics we use. Like the plastic we are familiar with, microplastics are not biodegradable. The problem now is that they are resilient and ubiquitous. Microplastics have been found in nearly every environment, including animal digestion, and even humans. Due to their tiny size, microplastics spread through things like rainfall, rivers, and direct waste dumping. These particles make their way into our oceans, spreading across marine environments and impacting ecosystems everywhere.

Why are Corals Found with Microplastics

As filter feeders, corals pull in tiny particles from the water, mistaking microplastics for food. Because of their size, microplastics closely resemble natural food sources for coral, making them easy to ingest. Studies have shown that some types of coral might even prefer these plastic particles. Unfortunately, this means microplastics get lodged in coral tissues, often staying there for a long time.

How do Researchers Study Microplastics in Coral

To investigate, scientists collect coral samples and apply special dyes to make any microplastic particles stand out. They also use methods like spectrometry and fluorescence microscopy to locate and identify plastics at the microscopic level, helping to determine how much plastic is really being taken in by coral. In some cases, researchers use a process called acid digestion, where a mild acid dissolves the calcium carbonate skeleton, leaving behind microplastic particles. This method, used by one of our team members, enables a clear analysis of embedded plastics without damaging them.

What Microplastics Mean for Coral and Marine Life

For corals, microplastics are a big concern. These particles can get trapped in coral tissues or on coral surfaces, affecting their health. When corals absorb microplastics, it can lead to physical damage, reduced feeding efficiency, and even increased vulnerability to diseases. Corals rely on tiny algae called zooxanthellae, which help them get energy through photosynthesis. Microplastics can block light, disturbing this process and possibly contributing to coral bleaching.

Marine life that depends on corals for shelter or food can also suffer. Fish, crustaceans, and other creatures might ingest microplastics, which can lead to internal injuries, malnutrition, or chemical contamination, affecting entire marine ecosystems.

Boosting Marine Life and Conservation Effort

Posted on October 26, 2024October 26, 2024 by Annabel Thomas

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Boosting Marine Life and Conservation Effort

by Fahmi, AMD-B’s 2024 Divemaster Internship

Artificial reefs are man-made structures that help restore marine ecosystems. They provide places for corals to grow, attract fish, and support overall marine biodiversity. By mimicking natural reef environments, these structures help restore areas where coral reefs are damaged or missing.

How Artificial Reef Work

Corals need the right space to grow—they require enough sunlight, suitable temperatures, and the proper minerals to thrive. Naturally, corals will spread to open spaces, but this process takes a long time and relies on perfect conditions.

Coral reproduction happens in two main ways: sexually and asexually. In sexual reproduction, fertilized coral eggs (or larvae) drift and settle in open spaces, but they need ideal conditions—plenty of sunlight and no obstructions—for this to happen. Asexual reproduction occurs through fragmentation, where pieces of coral break off and grow independently. This is where artificial reefs come into play.

By planting coral fragments on artificial structures, we give corals a “jump-start” in their growth, reducing their vulnerability in the early stages. The rough surfaces of artificial reefs also provide excellent places for sexually reproduced corals to attach and grow, offering a stable environment for both types of coral reproduction. This helps speed up the recovery process and supports the overall health of the reef ecosystem.

What Happens After Installation

The impact of artificial reefs can be seen quickly. Fish are often attracted to the new structures within hours, swimming around and using the spaces for shelter. After a few weeks, you’ll notice algae, sponges, coralline algae, and even anemones starting to grow on the surfaces. Fish may also begin to protect the area as their territory.

Over time, the artificial reef becomes more complex, offering shelter, feeding grounds, and even breeding spaces for different species. This encourages a diverse range of marine life to thrive, making artificial reefs an important part of marine conservation efforts.

Artificial Reef in Bali

Artificial reefs in Bali are planned and developed by various groups, including NGOs, the government, local villages, and businesses. These structures come in all shapes and sizes, with some specifically designed to support coral restoration, while others serve as tourist attractions.

For example, in Amed, you’ll find pyramid-shaped artificial reefs alongside unique designs like the “Post Office” and “Temple.” Padangbai features hexagonal structures, small boats, and cube-like formations that enhance marine habitats.

In Tulamben, the USAT Liberty Shipwreck, though not intentionally planned as an artificial reef, has transformed into a thriving ecosystem, attracting divers from around the world. In Nusa Penida, a technique known as the “rope method” involves hanging corals on ropes, providing protection from predators and promoting faster growth.