Tag: sharks

This story marks the final of six blog stories spotlighting New Jersey’s shark species.

THE “GREAT” WHITE  SHARK: MISTAKENLY BLAMED FOR THE NJ SHARKS ATTACKS OF 1916?

By Michael Davenport, Wildlife Biologist & GIS Manager

The New Jersey shark attacks of 1916, during which four people were attacked and killed and one injured along the New Jersey shore by one or more sharks, are usually blamed on the great white shark. The great white is definitely a dangerous shark and has been responsible for more fatal shark attacks on people than any other species. However, since one of the attacks occurred upstream within the Matawan Creek, another species (the bull shark) has recently received some scrutiny as being, if not the culprit in all the attacks, at least responsible for some. The bull shark, unlike the great white, is known for frequently entering freshwater, traveling far upstream in some rivers.

However, Matawan Creek is actually a saltwater tidal creek and is certainly deep enough for a white shark. Eyewitness accounts of individuals who witnessed a shark within the creek in 1916 also describe a shark which is more similar to a white rather than a bull shark. The white shark (either multiple individuals or one shark) remains the chief suspect for at least some, if not all, of the 1916 attacks.

Regardless of whether this is the species which terrorized the East Coast during the summer of 1916, this can be a deadly species due to their size, power, and sharp serrated teeth. This species specializes in preying on large marine mammals, primarily seals and sea lions. Even a “nibble” or “taste” can be fatal to a human.

To learn more about this shark species which occurs in New Jersey waters, visit our Field Guide page.

This story marks the fifth of six blog stories spotlighting New Jersey’s shark species.

THE NURSE SHARK: A SHELLFISH-EATING BOTTOM-DWELLER

By Michael Davenport, Wildlife Biologist & GIS Manager

The nurse shark isn’t your typical-looking shark. It doesn’t have the torpedo-shaped body of the fast swimming mako or great white, nor the large mouth in front. Instead, it has a somewhat flattened body with a small mouth located under it’s head. This species is specialized for feeding on the bottom of the seabed, primarily on shellfish. It’s teeth are not intended for tearing flesh, but for grinding hard prey, such as crabs.

The nurse shark is a relatively docile species which is not generally considered dangerous to humans. They are easily approached and popular with SCUBA divers. However, if they are provoked (grabbed by a diver) they will bite in defense. Their mouth has a powerful suction for catching prey and they have been known to hold on after biting, so it’s best to leave them alone.

To learn more about this shark species which occurs in New Jersey waters, visit our Field Guide page.

This story marks the fourth of six blog stories spotlighting New Jersey’s shark species.

THE DUSKY SHARK: LATE TO MATURE & SLOW TO REPRODUCE

By Michael Davenport, Wildlife Biologist & GIS Manager

The dusky shark provides a good example of why shark species and shark populations around the world are in trouble. Dusky sharks have been known to live up to 40 years. Females aren’t ready to start breeding until they’re about 21 years old. Within that 21-year time, they face dangers from other predators, such as larger sharks. In a natural setting, free of human interference, enough sharks survive to be able to reproduce fast enough to compensate for those sharks which don’t reach adulthood.

Due to overfishing, dusky shark populations are only a small fraction of what they once were. They are often hunted for their fins or they are caught as by-catch when commercial fishermen are targeting other species. Due to their slow growth, late maturity, and low rate of reproduction, the species simply cannot replace its numbers fast enough. Because of this, the dusky shark is classified by NOAA Fisheries as a Species of Concern throughout its range and the species has been prohibited in both commercial and recreational fisheries since 2000. Though it has no legal conservation status in New Jersey, it is still illegal to take, possess, land, purchase, or sell them.

To learn more about this shark species which occurs in New Jersey waters, visit our Field Guide page.

This story marks the third of six blog stories spotlighting New Jersey’s shark species.

THE SAND TIGER SHARK: PREDATORS EVEN BEFORE THEY’RE BORN

By Michael Davenport, Wildlife Biologist & GIS Manager

Sand tiger sharks look ferocious. With a mouth agape with rows of outward-pointing needle-sharp teeth, they are often regarded as deadly man-eaters. However, their appearance doesn’t tell the whole story. Although they have been known to attack humans, they are not man-eaters. Those needle-sharp pointed teeth are very poor tools for cutting through mammal flesh (unlike the great white’s serrated triangular teeth which are perfect for cutting through mammal flesh). Sand tigers are primarily fish eaters and attacks on humans are often made either when the shark is approached to closely or if a diver happens to be spear fishing and the shark is attempting to catch the speared fish.

Sand tigers are very ferocious when it comes to eating fish. So ferocious, in fact, that they are known to feed on their siblings even before they are born. Sand tigers give birth to live young. The mother sand tiger has two uterine sections within her body in which up to 50 young sand tigers will develop. As they grow, the larger, stronger sand tiger pups will nourish themselves by feeding on the others. Eventually, only the two young will then be born, already born killers.

To learn more about this shark species which occurs in New Jersey waters, visit our Field Guide page.

This story marks the second of six blog stories spotlighting New Jersey’s shark species.

THE BASKING SHARK: A GENTLE GIANT

By Michael Davenport, Wildlife Biologist & GIS Manager

Just as the largest whales are filter feeders, so are the two largest fish in the world. The basking shark, the second largest fish in the world after the whale shark, grows to a length of up to 33 feet long but feeds on organisms smaller than your fingernail. It swims through the ocean with its mouth open while tons of sea water and the small organisms with in it, enter the mouth and get filtered by the shark’s enormous gills. If you’ve used a pool net to skim leaves and insects off the top of a swimming pool, you have an idea of how the basking shark feeds.

Despite their enormous size, basking sharks are harmless to humans. Unfortunately, like many shark species, they are a species in decline. Basking sharks have been hunted as a source of food, fins, and liver oil for many years. They reproduce slowly, so if they are to recover, they will require protection throughout their range for many years.

To learn more about this shark species which occurs in New Jersey waters, visit our Field Guide page.

This story marks the first of six blog stories spotlighting New Jersey’s shark species – and educating people about why shark populations are in danger throughout the world.

CONSERVE WILDLIFE FOUNDATION IS INITIATING CONSERVATION EFFORTS DIRECTED AT THE SHARKS, RAYS, AND SKATES WHICH OCCUR IN NEW JERSEY WATERS.

By Michael Davenport, Wildlife Biologist & GIS Manager

Sharks, rays, and skates are cartilaginous fish within the subclass Elasmobranchii. Elasmobranchs predate the dinosaurs by hundreds of millions years, having first appeared in the fossil record during the Devonian Period approximately 400 million years ago. They are a very diverse group, with over 350 species of sharks and over 500 species of rays and skates currently existing worldwide.

Sharks and rays are highly specialized and occupy a wide variety of habitats. Some species are slow-moving bottom feeders which prey on crustaceans while others are fast-swimming predators of marine mammals. Many shark and ray species are apex predators, at the top of many food chains. They play a critical function within the marine (and occasionally freshwater) ecosystem preying on the weak, sick, or injured and maintaining a balance within their environment.

Sharks and rays are frequently misunderstood and feared as a result. Sharks have been portrayed in movies as man-eating monsters which target humans as a meal. Rays are also feared due to their appearance and because many species do, in fact, carry defensive barbs on their tail which have been known to injure or even kill people.

Because of their bad reputation, sharks are often targeted by recreational fishermen as trophy catches. However, the greatest threat to sharks and rays comes from commercial fishing for several reasons: (1) directed fishing for sharks, especially for their fins; (2) capture as bycatch during other fishing activities; and (3) overfishing of prey species.

Degradation of habitat is another threat to sharks and rays. Many species give birth within inshore coastal waters and those same areas are a nursery for the young. Pollution and/or development of those areas represent a threat to those species during a critical stage of their life. Climate change and its impact on food resources of sharks and rays is another potential major threat to sharks and rays which is poorly understood at this time.

Due to the biology of sharks and rays, these many threats are worsened by the fact that fewer individuals are replaced than are killed. Sharks and rays are generally long-lived species which don’t reach sexual maturity often until they’re in their teens or older. Then, they may give birth to as few as two young every two or three years.

Follow our blog posts throughout the week to learn more about some of the shark species which occur in New Jersey waters.