Animals become endangered for a multitude of reasons, whether it be human interference, environmental changes, invasive species, or some other unknown cause. One of the simplest things a person can do to aid these creatures is to simply know about them and spread awareness so that more people will be knowledgeable and, therefore, in a better position to take action.

Everyone knows about the dangers that species such as the turtle face, but there are many marine organisms that are critically endangered, some with populations as low as ten organisms, that aren’t widely recognized. They inhabit places all over the world, belong to various different classes, and live extremely different lifestyles, yet they are all faced with imminent extinction if actions are not taken to ensure their survival.

Cetaceans

The cetacean family consists of whales, dolphins, and porpoises.

Rice’s Whale (Balaenoptera ricei)

Rice’s Whale. Credit: NOAA Fisheries

Rice’s whale (Balaenoptera ricei), also known as the Gulf of Mexico whale due to their year-round inhabitancy of the northeastern portion of the Gulf of Mexico, are members of the Balaenopteridae family. These whales were originally thought to be Bryde’s whales, but after closer examinations, it was determined in 2021 that Rice’s whale was a separate species based on their morphological (form and structure) and genetic differences. Their “common name and species name honors the renowned cetologist Dale W. Rice, who, in 1965, was the first researcher to recognize that Bryde’s whales are present in the Gulf of Mexico,” (“Rice’s Whale”).

However, these whales are among some of the most endangered whales in the world. Estimates of the populations’ size vary, but currently, “the number of mature Rice’s Whales could be as few as 26. The species is geographically and genetically distinct and very likely consists of fewer than 50 mature individuals,” (Rosel et al. 2022). With their small numbers, threats such as vessel strikes, oil spills, entanglement in fishing gear, acoustic disturbances, or ocean debris, are more likely to severely affect the Rice’s whale population.

Hector’s Dolphin/Maui’s Dolphin

Hector’s Dolphin. Credit: NOAA Fisheries

Maui’s dolphin (Cephalorhynchus hectori ssp. maui), also known as the Māui dolphin, is a critically endangered subspecies of Hector’s dolphin (Cephalorhynchus hectori), one of the smallest dolphin species in the world. They are found in New Zealand, with Maui’s dolphin specifically being located in the northwestern waters of the North Island of New Zealand.

The Māui dolphin is “estimated to have a population of only 55,” (“Hector’s Dolphin | Species | WWF”). There are multiple reasons as to why their population is so small, the main being fishing, specifically bycatch in fisheries and the usage of gillnets.

Vaquita

Vaquita. Credit: NOAA Fisheries

The vaquita (Phocoena sinus) is one of the smallest porpoises, growing to be around five feet long, and they reside only in the northern portion of the Gulf of California, making them also have an extremely small geographical range. They are also the most endangered marine mammal, with an estimated population of about 10 individuals.

Gillnets pose the most danger to the vaquita, as once they are caught in them, they are unable to go to the surface, and thereby drown. However, illegal fishing of the totoaba is the most prominent reason for the vaquita’s drastic decline. Totoaba fish are sought after for their swim bladder, which are then sold for their perceived medicinal properties. Despite this trade being illegal, many still use gillnets in order to capture this fish, inadvertently entangling vaquitas as well. Due to the similar sizes of these two species, the gillnets prepared for totoaba fish are the deadliest for the vaquita.

Various conservation efforts have been made over the years, but to no avail.

Elasmobranchii (Chondrichthyes )

Elasmobranchii is a subclass of Chondrichthyes, which refers to cartilaginous fishes, and it consists of sharks, rays, skates, and sawfishes.

Oceanic Whitetip Shark

Oceanic whitetip shark. Credit: NOAA Fisheries

Oceanic whitetip sharks (Carcharhinus longimanus) are pelagic, as they are located in tropical and subtropical open waters all over the world, mainly occupying depths above, or at, 200 meters, despite their ability to dive at depths over 1000 meters. They are also opportunistic feeders, which is when “an animal feeds on a wide variety of prey and is able to adapt to whatever food becomes available,” (Knowlton).

This shark used to be extremely abundant; however, in recent years, its population has declined sharply as a result of being caught as bycatch in gillnet, pelagic longline, and purse seine fisheries. In addition, they are often victim to finning, a process in which a shark is caught, its fins are cut off, and their bodies are then discarded into the ocean, where the shark then meets a slow and painful death. A demand for fins in international trade, especially for the making of shark-fin soup, is the main cause of this. Even though their population was once high, due to “their late age of maturity and low reproductive output, oceanic whitetip sharks are inherently vulnerable to depletions, with low likelihood of recovery,” (“Oceanic Whitetip Shark | NOAA Fisheries”).

Thorny Whipray

In the Eastern Central Atlantic, the Thorny Whipray (Fontitrygon ukpam) can be found anywhere from Guinea-Bissau to the Democratic Republic of the Congo within shallow coastal waters, estuaries, and certain freshwater habitats.

This ray “was considered “extremely abundant” in the rivers around Old Calabar (Nigeria) in the 1800s but has become very rare with relatively few records in the past decades across its known range,” (Jabado et al. 2021). Over the years, it has been caught for its meat, as bycatch in fisheries with gillnets, beach seines, and various other instruments. Its natural habitat has also suffered due to human interference, which has only further decreased its population.

Fish

Red Handfish

Credit: Rick Stuart-Smith

The red handfish (Thymichthys politus) is a benthic fish in south-eastern Tasmania, an island state of Australia, in Frederick Henry Bay. As it is a benthic fish, it dwells on the bottom of the ocean floor, using its ‘hands’ to maneuver itself. There are fourteen species in the handfish family, and three of them are critically endangered: the spotted handfish, the red handfish, and Ziebell’s handfish. However, Ziebell’s handfish have not been spotted since 2005.

Red handfish were once common, however, it is assumed that a major decrease in its population occurred sometime in the 1900s. It is now estimated that there are about 100 adults remaining. Little information is known about this species, but amongst the spotted handfish and Ziebell’s handfish, some of the “principal threats…may include loss of spawning substrate, habitat loss and degradation, water pollution and siltation,
the spread of the invasive Northern Pacific seastar (Asterias amurensis) and the cumulative impacts of boating,” (Commonwealth of Australia 2015).

Coral

Corals are members of the Cnidaria phylum, and are technically considered animals, as they are made up of polyps that, when in a group, make up the colonies that form coral reefs.

Staghorn Coral

Acropora cervicornis staghorn coral. Credit: NOAA Fisheries

Staghorn coral (Acropora cervicornis) is typically found in coral reefs throughout the Bahamas, the Caribbean, and Florida, and it is “one of the most important corals in the Caribbean. It, along with elkhorn coral and star corals (boulder, lobed, and mountainous) built Caribbean coral reefs over the last 5,000 years,” (“Staghorn Coral | NOAA Fisheries”).

One way staghorn corals obtain food is through a symbiotic relationship with zooxanthellae, a type of algae that lives in the coral’s tissue. When coral bleaching occurs, the algae is driven away, leaving the coral more susceptible to diseases, and without its main source of food. Although many other factors, such as ocean acidification, disease, and pollution have contributed to the decline of healthy corals, climate change has proven to be a major threat to many different types of corals, including the staghorn coral. This is because “the leading cause of coral bleaching is climate change… a change in water temperature—as little as 2 degrees Fahrenheit—can cause coral to drive out algae,” (Hancock).

Rice’s whale, Māui dolphins, vaquitas, oceanic whitetip sharks, Thorny Whiprays, red handfish, and staghorn coral have all been declared as critically endangered marine animals. Someone may go their entire life without knowing that these creatures even exist, completely oblivious to the impending doom they face.

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