© Background image: Tracey Jennings
Here, each species – from the iconic thresher sharks to the endangered green sea turtles, and the rare, endemic Banggai cardinalfish—plays a vital role in maintaining the ecological balance and health of their habitats. Unfortunately, many of these marine creatures face significant threats such as overfishing, habitat destruction, and the broader impacts of climate change. Recognising the interconnectedness of marine life and the benefits of intact marine ecosystems is crucial. We showcase the critical roles of a wide array of marine species in our Marine Protected Areas and beyond, the pressures they face, and the conservation efforts needed to protect these species and ensure the resilience and recovery of coral reefs worldwide.
These species fulfill essential functions in sustaining the balance and health of their ecosystems. Whether they are serving as important predators or prey, or enhancing the structural integrity or functionality of the habitat, their contributions are vital for the resilience and productivity of the ecosystem.
Iconic species, well-known or holding symbolic value, captivate public interest and boost awareness about marine conservation. They often act as powerful ambassadors for their environments.
These species are at a significant risk of disappearing from the wild soon due to threats such as habitat destruction, pollution, climate change, overfishing, and the illegal wildlife trade. Protecting these species and their environments is essential to prevent their extinction and preserve biodiversity.
The IUCN Red List is a system used to classify the conservation status and extinction risk of species. It is recognised as the most authoritative guide to the status of biological diversity. The list is divided into nine categories, each indicating the level of extinction risk faced by different species.
The IUCN Red List is crucial for identifying species needing targeted recovery efforts and focusing the conservation agenda.
The Banggai cardinalfish is one of the rarest and most striking fish found in Indonesia’s Banggai Archipelago. Characterised by a silver body with black stripes and white spots, this small fish has become iconic among aquarium enthusiasts. Its popularity has led to overexploitation, and its restricted range makes it particularly vulnerable to extinction. Conservation efforts – including more sustainable aquarium trade practices and habitat protection – are imperative to ensure the survival of this species.
Parrotfish play a pivotal role in coral reef ecosystems, where they feed on algae, coral, and other invertebrates. Using their beak-like teeth, they scrape the algae off the coral, and in the process, they end up eating some coral as well, which they grind and digest. They then excrete the undigested coral as sand, which helps to create and maintain sandy beaches. By grazing on algae that compete with coral, they promote reef health and regeneration. However, parrotfish face threats from overfishing and habitat destruction, which in turn threatens the resilience and recovery of coral reefs around the world.
Green sea turtles are the second largest sea turtle species, with their name being derived from the greenish colour of their cartilage and fat. This is due to their diet consisting predominantly of seagrasses – in fact, they are the only herbivorous species of sea turtle. They are known to migrate over vast distances, and are vital to the diversity and productivity of marine ecosystems due to their contribution to the health of seagrass beds and coral reefs. Throughout their global range, they face threats from poaching, habitat loss, and climate change, and are often caught as bycatch in fisheries operations.
Hawksbill sea turtles, with their distinctive hawk-like beaks and beautifully patterned shells, are found on tropical reefs worldwide. They help to maintain the health of coral reefs by controlling sponge populations. However, this ancient marine species faces severe threats from the illegal wildlife trade and accidental capture in fishing nets. Habitat loss from coastal development and climate change also endangers them by reducing nesting sites and killing coral reefs they rely on for food. International cooperation is crucial for the conservation of hawksbill turtles. Advocates work to establish marine sanctuaries, while researchers collect data to raise local awareness and improve conservation strategies.
The Napoleon or humphead wrasse is a regal presence on coral reefs thanks to its striking appearance and imposing size. Found throughout the Indo-Pacific region, from the Red Sea to the central Pacific, this species preys on invertebrates that could otherwise harm coral formations. Their ability to eat toxic species such as crown-of-thorns starfish speaks to their ecological importance. Due to overfishing and habitat destruction, their numbers are declining – highlighting the need for international, collaborative conservation efforts.
Green humphead parrotfish act as coral reef architects – by consuming dead coral and excreting it as sand, they contribute to the creation of sandy beaches and the dispersal of coral larvae, thereby aiding in reef regeneration. Their large size and unique appearance make them an iconic species within our Marine Protected Areas and beyond. However, due to overfishing and habitat loss, their numbers are dwindling.
Thresher sharks, with their elongated tails that can be as long as the shark’s body itself, are one of the ocean’s most mesmerising species. They use their impressive tails to stun prey, making them effective and efficient hunters. However, they are increasingly vulnerable to threats, including bycatch and targeted fishing for their valuable fins. The loss of thresher sharks could disrupt marine food chains, leading to unforeseen consequences for ocean ecosystems. Protecting them is not only a question of conserving a unique species, but also of maintaining the balance and health of marine environments.
The scalloped hammerhead shark, with its distinctive head (the shape of which is believed to enhance its sensory capabilities) is found in warm waters around the world. Highly migratory, the scalloped hammerhead travels long distances to feed and breed. It is a social species, forming large schools of up to hundreds of individuals. As apex predators, they help maintain the balance of marine life; however, their populations are in decline due to overfishing, particularly for the shark fin trade, and habitat degradation.
The great hammerhead shark is one of the ocean’s most distinctive and misunderstood creatures. With its immediately recognisable head and imposing size, it has a greatly exaggerated reputation for aggression towards humans. These solitary and nomadic tropical water predators play a vital role in controlling prey populations, thereby contributing to the health of marine ecosystems. Great hammerheads are increasingly vulnerable due to overfishing and the shark fin trade.
Blacktip reef sharks, with their distinctive, black-tipped fins, play a vital role in coral reef ecosystems. They keep fish populations healthy by preying on weak and sick individuals, thus preventing the spread of disease and ensuring species diversity. Their relatively small size and curious nature make them a favourite among snorkelers and divers. These sharks face threats from habitat destruction and the fin trade. Efforts to protect their habitats and regulate fishing practices are crucial for their survival and the overall health of reef ecosystems.
Whitetip reef sharks are known for their nocturnal hunting habits which play a key role in controlling the population of nocturnal prey species and ensuring a balanced ecosystem. Unlike other requiem sharks, they can pump water over their gills and lie still on the seafloor. Their slender bodies allow them to navigate through tight spaces in the reef as they hunt for food. However, the decline in their populations due to fishing pressures and habitat loss is alarming.
Grey reef sharks are crucial for the health of coral reefs, acting as apex predators and maintaining the balance of marine life. Despite their modest size, they often dominate over other shark species. Their sleek, powerful form is a common sight in tropical ocean waters, and their presence is a sign of a healthy, thriving ecosystem. Unfortunately, their populations are declining due to overfishing, bycatch, and the degradation of coral reef habitats.
The walking shark, or Raja Ampat epaulette shark, represents one of nature’s most fascinating adaptations. Found primarily in the waters of Indonesia, particularly around the Raja Ampat Islands, this species uses its fins to ‘walk’ along the ocean floor rather than swimming. This unique mode of locomotion allows it to hunt for small fish and invertebrates among coral reefs and tide pools. Found primarily in coastal waters, they prey on small crustaceans and control the populations of other organisms. Habitat degradation due to pollution, coastal development, and unsustainable fishing practices pose severe threats to walking sharks, while their slow rates of reproduction limit their ability to recover from population declines. The aquarium trade further threatens these sharks, making conservation measures, including marine protected areas (MPAs) and sustainable fishing practices, crucial to safeguarding the future of this species.
The pearl bubble coral is a unique species, distinguished by its pearl-like vesicles that inflate during the day to capture sunlight for its symbiotic algae, and retract at night to reveal its feeding tentacles. This fascinating behaviour not only showcases the coral’s adaptability but also its critical role in the nutrient cycles of coral reef ecosystems. The pearl bubble coral provides shelter and nourishment to a variety of marine organisms, contributing to the complex web of life that defines coral reefs. However, it is vulnerable to the effects of climate change, such as coral bleaching, as well as pollution and physical disturbance from human activities.
Galaxea spp. are known for their long, sweeping tentacles and dense clusters of star-like polyps. These hard corals plays a significant role in reef-building, contributing to the structural integrity of coral reefs which provide essential habitats for a diverse range of marine life. They thrive in clear, saltwater environments and are generally found at depths around 15 meters, although they can range from 1 to 30 meters deep. Like many coral species, Galaxea spp. face threats from land-based pollution, unsustainable fishing practices, temperature fluctuations leading to coral bleaching, ocean acidification, and physical damage from human activities. Protecting these corals requires climate change mitigation and the implementation of effective marine conservation strategies.
