Category: Fish

by Nicole Porter and David Wheeler

Many of New Jersey’s streams have been manipulated by being impounded with dams or weirs, or otherwise redirected over time – decreasing their ecological habitat diversity and blocking fish passage for native brook trout and other species. Restoring these streams to a more natural state can greatly benefit wildlife. 

The Land Conservancy of New Jersey, along with assistance from Conserve Wildlife Foundation, Natural Resources Conservation Service, and Urbani Fisheries, worked on a stream restoration project on a highly modified part of stream flowing through the West Brook Preserve in West Milford this summer. This vital 170-acre preserve holds the headwaters of the West Brook, one of the primary sources of water for the Wanaque Reservoir, which provides drinking water for two million New Jerseyans. 

It appears that sometime in the 1950s, part of the West Brook was taken out of the original stream channel and redirected to a channelized ditch that ran alongside it. There were also several culverts installed in the stream (including one that was the size of a small grain silo) which restricted flow and acted as a blockade to fish passage. In addition, one of the unnamed tributaries leading to the mainstream channel had a pond where water was being held back by a weir, resulting in elevated water temperatures. The original channel and tributaries also needed an enhancement of a thalweg, the line of lowest elevation that the stream follows as well as the addition of pools, riffles and runs.

A healthy stream should have an established thalweg – a connected floodplain – as well as pools, riffles, and runs. All of these features are important in the function of the stream.  For example, pools provide areas for various aquatic species to seek refuge, while riffles aid in the reoxygenation of the water. 

The ultimate goals of the West Brook project included restoring the native fish habitat, improving the overall water quality, and rejuvenating the macroinvertebrate population. 

The work done to accomplish this included:

• Restoring the river back to the original stream channel. 
• Enhancing features along the whole length of the stream.
• Creating wetland pools out of the old ditch and within the riparian zone. 
• Removing five culverts and the small weir. 

After the restoration, it appeared some of the site is now suitable for native brook trout, and the project has greatly improved habitat diversity in a stream that flows into a Category One trout production stream. New Jersey Fish & Wildlife and The Land Conservancy will continue to monitor the project.

Nicole Porter is a biologist with Conserve Wildlife Foundation.

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Learn more about New Jersey’s Brook Trout here.

Latest Podcast explores climate change threats to this ‘living fossil’  

by Milena Bimpong

A ‘living fossil’ today swims the Delaware River, having survived eons from the days of the dinosaurs through the caviar craze a century ago that nearly wiped it out for its roe, or valuable eggs.

However, as explored in the latest episode of State of Change – Conserve Wildlife Foundation’s regular podcast exploring climate change impacts on New Jersey wildlife –the Atlantic sturgeon faces an abundance of modern threats.

From a historic population of 360,000 adults, “Based on our best estimates, there’s less than 300 in the river. There’s less than 1 tenth of 1% that was there historically,” says Dewayne Fox, a professor of fisheries at Delaware State University. “The loss of one or two adults is a significant loss of spawning potential in the Delaware River.”

Among the largest river fishes in North America, the Atlantic sturgeon can grow up to 14 feet and weigh up to 800 pounds. One sturgeon from New Jersey is believed to have been over 1,000 pounds. The Atlantic sturgeon’s features indicate that their existence can be traced back to millions of years.

Yet that lengthy run was in jeopardy after facing ensuing perils of caviar harvesting and pollution.

Continue reading “Swam with Dinosaurs and Famed for Caviar, Atlantic Sturgeon at risk in New Jersey”

Insight Into Important (Bio)Indicators: Ospreys

by Ben Wurst, Habitat Program Manager

Mid-summer marks the nestling period of nesting ospreys, a coastal raptor, whose diet consists mainly of fish. As a state that’s heavily influenced by its location along the Atlantic Ocean, they play a critical role in our coastal ecosystem. Ospreys are important bioindicators of the health of our coastal waters, through the lens of their prey, where pollutants are biomagnified through the food chain. As we consume many of the same fish, they show the effects of these pollutants long before humans, so the health of their population has implications for our coastal waters and us! Continue reading “2018 Osprey Outlook”

PLASTICS MAY THREATEN WILDLIFE FOR MANY YEARS

by Corrine Henn, Communication Coordinator

For those of us who call New Jersey home, we’ve all likely witnessed the impact human activities have on our environment and the species who thrive here. Although habitat loss, illegal poaching and invasive species can be equally devastating to an ecosystem, the presence of plastic pollution around our state is a threat that almost every individual can be found personally culpable.

Although many forms of pollution impact our native species, the summer months at the Jersey Shore often result in a surge of plastic debris that are left behind or improperly disposed of. Plastic pollution impacts millions of wildlife species globally, and the diverse number of species in New Jersey are no exception.

The plastic pollution that accumulates in our waterways and elsewhere around New Jersey poses a serious threat to native species. Single-use plastic products like plastic bags, bottles, bottle caps, wrappers, straws, and even balloons are not only unsustainable, but particularly dangerous for the animals that may become entangled in them or accidentally ingest them.

A few years ago, CWF’s Habitat Program Manager Ben Wurst and his dedicated group of volunteers who monitor the osprey nests along the coast began to hold onto the trash and debris collected in and around the nests. While it may not be the most visually appealing educational resource, it made the growing problem of plastic pollution personal for Ben, in a way that words aren’t always able to convey.

Plastic bags, one of the most common single-use plastic products, were overwhelmingly prevalent in many of the nests. And osprey aren’t the only wildlife species facing this threat. Seals, terrapins, shorebirds, fish, whales, sharks and dolphins can also be impacted by plastic debris.

The presence of plastic in our daily lives is interminable and difficult to eliminate completely, but there are a number of things we can do to minimize the impact our habits may have on our wildlife!

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Clean up after yourself:
Whether you’re spending the day at the beach, having a picnic by a lake, or tubing down a river, make sure you take any trash with you before leaving and recycle what you can.

Be mindful of your surroundings:
If you’re out and about and notice that someone left some trash behind, take a moment to throw it away.

Reduce your consumption:
A number of small changes from millions of people can make a big difference. For starters, invest in reusable shopping bags and water bottles. And cut down on the number of miscellaneous throw away plastics you use, including straws and plastic wrappers.

Donate:
Consider donating to CWF to support our conservation projects and ensure our biologists and our volunteers are able to continue surveying and aiding species in need.

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LEARN MORE

• Marine Debris Post Sandy
• Ospreys, Plastics and Marine Debris Fact-sheet 2016

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

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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.

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

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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.

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

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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.

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

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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.

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

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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.

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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.

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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.

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