Though diverse and widespread, sharks and rays need our help now more than ever.
Why Should We Care About Sharks and Rays?
Sharks and rays are partly responsible for the well-being of our home here on Earth. They are ecosystem heroes! Many sharks are apex predators at the top of the food chain. They keep prey populations in check and eat the weak, diseased and sick so that the oceans stay healthy and balanced. The food chain maintenance that sharks provide keeps ocean vegetation from being over-grazed by animals such as sea turtles and prey fish. This matters to the whole planet because seagrass stores carbon which keeps carbon dioxide from entering our atmosphere which in turn maintains the planet’s climate. Mobula rays (Manta and Devil Rays) play their part as well. Because of their tendency to feed on offshore plankton at night, they circulate nutrients from elsewhere in the ocean to coral. Like seagrass, coral can store carbon that would otherwise be in our atmosphere. Along with their crucial roles, the world of sharks and rays is extremely diverse and fascinating. They differ in behavior and appearance from species to species and can live anywhere from coastal to arctic seas. Let us dive deeper by taking a look at ten sharks and rays who need our help.
1. Atlantic Shortfin Mako
2. Scalloped Hammerhead
3. Angelshark
4. Oceanic Whitetip
5. Sand Tiger Shark
6. Daggernose
7. Blue Shark
8. Porbeagle
9. Giant/Oceanic Manta Ray
10. Devil Ray
1. Atlantic Shortfin Mako (Isurus oxyrinchus)
Why Are Shortfin Makos So Cool?
If there was a shark who could participate in a wild planet Olympics, the Atlantic Shortfin Mako might be the one. The 12 foot/3.7 meters, 300 pound/136kg predator is the fastest shark with speeds of 45 miles per hour (72.4 km/h) and can leap to impressive heights when hunting. These sharks, like others in the Lamnidae family of sharks, are warm-blooded (endothermic). This means that shortfin makos have a special blood vessel structure which can store the heat their muscles create to stay warm in colder waters. They rule the open ocean and can be found worldwide from tropical to temperate latitudes.
Population Level of Shortfin Makos
Atlantic Shortfin Mako sharks were last assessed in 2004 by the IUCN Red List* and found to be vulnerable and decreasing in population. It is said that this species of shark is caught the most often among sharks. They are threatened by pelagic longline fisheries.
Where To Dive With Atlantic Shortfin Makos
Because they live in the open ocean, Shortfin Makos are hard to find without bait. During summer months in San Diego, California, there is a high probability of seeing one. From July to October, they can be seen off the coast of Rhode Island as well as Pico Island in Portugal. In Simon’s Town, South Africa, a charter can bring you to encounter Makos from October to July.By March, they will be more prevalent in Cancun, Mexico and Baja’s Los Cabos.
2. Scalloped Hammerhead (Sphyrna lewini)
Why Are Scalloped Hammerheads So Cool?
Like other hammerheads, the Scalloped Hammerhead has the characteristic head of a hammer. This species is further named for notches which can be seen on the front edge of their head. Found in coastal pelagic waters, the Scalloped Hammerhead has a worldwide range along the tropical to warm temperate latitudes. These sharks owe a lot to their heads, being known to have a more accurate sense of electric fields of its prey, often found buried in the ocean floor. Using it as a tool, they can pin sting rays to the sandy bottom while hunting! Mainly a shy, solitary shark, Scalloped Hammerheads spend a part of the year socially gathered in large groups. Scientists are not sure why they do this. Scalloped Hammerheads are a rather large shark and can grow up to 13 feet/4 meters long! Their lifespan gives them about 24 years to thrive in the ocean.
Population Level of Scalloped Hammerheads
Because of their large gatherings, they are easy targets for fishing. Threatened by this as well as being victims of bycatch, they are listed as endangered by the NOAA and assessed as critically endangered by IUCN in 2018.
Where To Dive With Scalloped Hammerheads
Scalloped Hammerheads can be found worldwide. You can dive with them in Australia, Papua New Guinea, the Philippines, Malaysia, Indonesia, Japan, the Maldives, Egypt, and Mexico. Other places they can be spotted are the Galapagos Islands, Columbia’s Malpelo Island, and the Cocos Islands off Costa Rica.
3. Angelshark (genus Squatina)
Why Are Angelsharks So Cool?
There are many species of Angelsharks; up to 26 of them! As ambush predators, Angelsharks are most comfortable living in kelp forests, rocky reefs and on soft bottoms of the ocean where they can use their camouflage to blend in with the sand and avoid being eaten. Speaking of eating, this shark uses a rather alien method to feed. It extends its jaws and suctions in its prey whole! Living up to 15 years, they mature slowly, unable to reproduce until they are 13 years of age.
Population Level of Angelsharks
Due to threats like targeted fishing, bycatch, set nets and more, eight of 26 known species of Angelshark are endangered. Many were last evaluated by Red List in the late 2010’s as critically endangered.
Where To Dive With Angelsharks
The best place to dive with Angelsharks is in the Canary Islands. It is here in Lanzarote that they can be found all year round.
4. Oceanic Whitetip (Carcharhinus longimanus)
Why Are Oceanic Whitetip Sharks So Cool?
Known for its white tipped fins, this shark is a locomotive wonder: It can never stop swimming because it cannot pump water through its gills. Because of its unusually broad fins, it can do this continuous swimming with ease. The Oceanic Whitetip swims with its mouth slightly open to filter in oxygen from the water! Oceanic Whitetips also bear live pups, 1-14 of them, after 10-12 months of gestation. Females can have pups after reaching 6-9 years of age and are on an every other year cycle. This means pups can be born every two years. Additionally, these creatures are top predators, preferring a pelagic, or open ocean, lifestyle where they can feed on bony fishes, squid or even marine mammals. They have been found to live up to 25 years!
Population Level of Oceanic Whitetip Sharks
NOAA lists these sharks as threatened while the IUCN red list has assessed them as critically endangered as of 2018. It is thought that, along with being retained for their fins in international trade and struggling with bycatch, Oceanic Whitetips are behaviorally inquisitive. This makes them an easier catch for targeted fishing.
Where To Dive With Oceanic Whitetip Sharks
You can dive with these sharks in the Elphinstone Reef and The Brothers Islands in Egypt’s Red Sea. If you are hoping to dive with them in April and May, they can be found in the Bahamas at Red Cat Island.
5. Sand Tiger (Carcharias taurus)
Why Are Sand Tiger Sharks So Cool?
The Sand Tiger Shark is incredibly common in aquariums, their intimidating visage covering up for their gentle nature. They actually survive very well in captivity which is not common in sharks. Sand Tigers can hunt cooperatively with one another in groups by herding fish. Adults have no predators in the wild. Their low reproductive rate complicates their survival as a species. As far as habitat, they spend their lives worldwide throughout the ocean, preferring subtropical to warm temperate waters. Sand Tiger Sharks can also be seen “gulping” air. If they fill their stomachs with air, they can easily maintain their buoyancy in the water rather than sinking.
Population Level of Sand Tiger Sharks
Listed as endangered by IUCN from their last assessment in 2020, they are often targeted in fishing and caught in bycatch. Not only do they face these threats common to other sharks, but they are also threatened by habitat loss and pollution degradation because they live in coastal waters.
Where To Dive With Sand Tiger Sharks
To dive with Sand Tigers in the US head to North Carolina during the summer months June-September. You can also see them in Fiji in Beqa Lagoon year round. Australia’s Sydney Harbor January through April and South Africa’s Sodwana Bay May through November.
6. Daggernose (Isogomphodon oxyrhynchus)
Why Are Daggernose Sharks So Cool?
A shark of unusual shape and named for its snout, the dagger nose can grow up to five feet long and live to 20 years of age. It is thought to rely on sensory organs in its notable snout due to living in turbid waters where it cannot rely upon eyesight as much to hunt. These sharks can live in freshwater, estuaries and ocean waters and are specific in their locale. Daggernoses are only found from Venezuela to northern Brazil. A year of gestation for this shark produces 3-8 pups.
Population Level of Daggernose Sharks
Last assessed by the IUCN as of 2019, Daggernose sharks are critically endangered. NOAA fisheries has listed them as endangered since 2017. They can fall victim to unregulated gill net fishing which is an artisanal fishing threat.
7. Blue Shark (Prionace glauca)
Why Are Blue Sharks So Cool?
Like to the Shortfin Mako, Blue Sharks are massively athletic fish! They are one of the fastest sharks in the world. They can grow 12.5 feet/3.81 meters long and live up to 10.5 years. The Blue Shark spends its time in the open ocean, meaning it is a pelagic shark. Their name comes from their blue tint, which allows them to be camouflaged with the ocean. Most interestingly, this shark exhibits social behaviors! Juveniles are known to gather in gender-specific schools for no known reason (yet) and adults use body language to demonstrate aggression to one another. Blue shark nurseries are in the sub-Arctic. It is here that they birth between 25-50 pups at a time.
Population Level of Blue Sharks
The Red List assessed Blue Sharks as near threatened in 2018. Threats to this shark include targeted fishing for fins and meat as well as bycatch. It is a victim to catch and release fishing as well due to its appeal to big-game fishers.
Where To Dive with Blue Sharks
Like Shortfin Makos, the only way to dive with Blue Sharks is to bait the water since they live in the open ocean. From October through July, they can be encountered via charter in Cape Town, South Africa. Later in the year, July through October, they can be found off Pico Island in the Azores, in San Diego, California, and in Rhode Island. During the summer, from June through August, you can dive with Blue Sharks in Newquay, Cornwall.
8. Porbeagle (Lamna nasus)
Why Are Porbeagle Sharks So Cool?
Sometimes mistaken for baby Great White Sharks, the Porbeagle is an active predator from coastal waters to the open ocean. Like the Atlantic Shortfin Mako, the Porbeagle is endothermic, regulating its body temperature to stay warmer than the surrounding ocean. Found worldwide in temperate to cold temperate ocean, this apex predator measures up to 12 feet/3.7 meters long as an adult and can weigh up to 500 pounds/226.8 kg! Porbeagles give birth to live pups; up to four at once. As far as food, they can feed on mostly anything but have not been known to dine on mammals.
Population Level of Porbeagle Sharks
Porbeagle sharks were last assessed by IUCN in 2018 and found to be vulnerable. Their populations are decreasing because of threats such as bycatch which is used for meat and fins. Like blue sharks, they are a target in big-game fishing.
Where To Dive with Porbeagle Sharks
Though they prefer the cold waters of the North Atlantic and southern hemisphere, Porbeagles gather in large numbers for their summer migration off Brittany in northwestern France.
9. Giant/Oceanic Manta Ray (Mobula birostris)
Why Are Manta Rays So Cool?
Welcome to the largest ray in the world! Living up to 45 years, Oceanic Manta Rays have wingspans of up to 26 feet/7.9 meters and weigh up to 4,400 pounds/2000kg. This impressive wingspan is on full display when they filter feed by doing backward barrel rolls in the ocean. They have the largest brain of any fish and love to visit wrasse fish cleaning stations, sometimes every day; this is a fish who enjoys a good ocean spa! Like their relatives, the Giant Devil Ray, they reproduce slowly, having one pup every two to three years (very occasionally two). These rays are creatures of the open ocean.
Population Level of Manta Rays
The Red List assessed Oceanic Mantas as endangered in 2019. They are threatened not only by bycatch and overfishing, but are harvested for international trade because their gills are used in Chinese medicine. Conservation efforts in the past few years are focused on replacing the income from selling gills into ecotourism; the same populations making income from hunting can lead diving or snorkeling tours instead.
Where To Dive with Manta Rays
There are many places to go diving with Manta Rays. They can be encountered in Indonesia; off Komodo from November to May, and in Raja Ampat from October until May. In the winter, from February through May, they abound in Mexico’s Socorro Island. Manta Rays can be seen year round in the Maldives and Kona, Hawaii.
10. Devil Rays (genus Mobula)
Why Are Devil Rays So Cool?
Mobula Rays, including the Giant Devil Ray and multiple species of Pygmy Devil Rays, are a large family of beautiful rays. Devil Rays form large groups called cyclones and are most known for their displays of leaping from the ocean. Flapping their wings, they appear to take off into the sky. Though their reason for leaping is unknown, they seem to make their jumps as high as they can or perform flips! Like Oceanic Mantas, they are filter feeders, and slow in gestation. One egg will develop in the female Devil Ray for a year before a live pup is born.They are worldwide and prefer coastal habitats and open ocean waters.
Population Level of Devil Rays
These rays are overfished for their gill plates, like the Manta Ray. As well as their coveted gills, Mobula Rays are threatened by pollution to their nurseries. The Red List last assessed them as endangered in 2018 and cited bycatch and net entanglement as other reasons for their population status. Ecotourism is also being used with Devil Rays to increase the living value of these wonderful creatures.
Where To Dive with Devil Rays
Diving with Devil Rays can be done year round in the Azores, specifically off Sao Miguel. In Madagascar, they can be encountered from August to December in Sainte Marie and Nosy-Bé.
Fascinated With Sharks & Rays?
Fascinated yet? Sharks and rays are incredible creatures who need so much more time to be studied and discovered. One can see why humans need to do all we can to help them survive when so many are threatened. If you enjoy learning about sharks, subscribe to our newsletter and join our shiver. Every month you will get to learn about a new shark species with our Monthly Chomp program. Then you can take our After Bites Quiz to check out how much you learned.
*The IUCN Red List is the International Union for Conservation of Nature and Natural Resources. They keep an incredible database of endangered animals throughout the planet. As far as sharks, they plan to reassess populations by 2030. NOAA is the National Oceanic and Atmospheric Administration. NOAA also keeps a database of fishery populations which can be searched for threatened species.
Written by Medea Ramnath-Christiansen, University of Alaska Fairbanks, College of Fisheries and Ocean Sciences and Shark Angels intern.
References
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Convention on International Trade in Endangered Species of Wild Fauna and Flora. (2024, May 25). Appendices I, II and III. CITES/UNEP. https://cites.org/eng/app/appendices.php
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Nicolas, A. (n.d.). Sharks are Key to the Health of our Oceans and Climate. World Wildlife Foundation. https://www.worldwildlife.org/stories/sharks-are-key-to-the-health-of-our-oceans-and-climate
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