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.
A dusky shark. Photo by NOAA.
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.
A sand tiger shark. Photo courtesy of Gerald Walters & Jenkinson’s Aquarium.
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.
A basking shark feeding. Photo courtesy of Flickr user jidanchaomian.
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.
A sand tiger shark. Photo courtesy of Gerald Walters & Jenkinson’s Aquarium.
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.
At 8:00 PM on October 29th, 2012, Hurricane Sandy made landfall in Brigantine, New Jersey, only about 30 miles from New Jersey’s Hidden Coast – the Delaware Bayshore. The storm was devastating for the people of the area, many of whom lost their homes and livelihoods. It was equally hard on the area’s wildlife, bringing many species, including the famous horseshoe crab and red knot, perilously close to extinction.
A new episode of our video series “New Jersey’s Hidden Coast” will air every two weeks throughout the summer! Catch a glimpse of the bay, the horseshoe crab at the center of the bay’s system, and the incredible relationship between horseshoe crabs and migratory birds, like the red knot. We will reveal the real value of horseshoe crabs, the challenges to the ecosystem, and the potential for a thriving regional economy along the Bayshore. We will show Hurricane Sandy as a catalyst for decisive action and the work being done to rebuild the area for both people and wildlife.
Over the next several weeks, we will explore the use of “living shorelines” instead of bulkheads and the central importance of marshes to the marine ecosystem. We will discover the on-the-ground, grassroots efforts of the community to build oyster reefs alongside veterans. And we will examine the future of the Bay and the work that needs to be done to preserve our conservation successes thus far.
Matt Tribulski places a young osprey back in its nest.
It’s osprey season. Osprey Survey Season, that is. However, we never like to start the season off with these types of emergency surveys, but with the increase of strong storms and extreme straight line wind events, they are becoming an annual event. Ospreys nest on platforms in open areas near water, so their young can easily become victims during these types of storms. After receiving a text message from my colleague Kathy Clark yesterday evening about the intensity of the storms, she said we should try to do a survey of the affected areas. I had other plans but I knew that those could wait. Continue reading “Emergency Osprey Nest Surveys in Cape May, Wildwood and Stone Harbor”
Boaters urged to not approach active osprey nest inside Barnegat Inlet
by Ben Wurst, Habitat Program Manager
Osprey Nest #3591
Yesterday, while working on Barnegat Bay, we visited this natural nest that is behind the dyke inside Barnegat Lighthouse State Park. This is the third time we’ve passed by to monitor their success. So far, so good and it looks like they now have young in the nest. As you can see the nest is built in a precarious location on a sandbar. When the sandbar is exposed people can walk right up to the nest. Last year the pair did not raise young but people did still walk up to the nest. With young, the adults will be more defensive of their nest to protect their young.
Technology has proven to be vital to Conserve Wildlife Foundation’s work protecting rare wildlife species over the years. Our biologists depend greatly on modern technologies to band, track, and share online the journeys of wildlife. Our webcams broadcast the most intimate behaviors of nesting birds and bats across the web. And we seek out ever-evolving communications technologies to spread the word about the inspiring stories of wildlife, from social media and infographs to e-books and Story Maps. These technologies offer newfound abilities to share complex data on multiple levels, while still incorporating the awe-inspiring photography and videos that bring wildlife’s stories to life.
Conserve Wildlife Foundation of New Jersey is excited to offer our 2015 Annual Report in a unique format that utilizes one of those technologies – Story Maps. In the past year, we have explored the lives of seals, eagles, and freshwater mussels with Story Maps – and the annual report allows all of our projects to be highlighted in this interactive format as well.
Visit the multiple pages within this Story Map to learn about Conserve Wildlife Foundation’s many projects and partnerships in 2015, and the imperiled wildlife species in need of our help. Find examples of the innovative and dedicated leadership of our biologists and volunteers. And take an online journey across the state to learn how our projects made a difference in all corners of New Jersey in 2015 – a great year for wildlife in the Garden State!
Horseshoe crabs may be one of the most unusual animals in the world, but they’re also one of the most extraordinary. They’ve been around for hundreds of millions of years, and we’re only now starting to understand just how important they are – not just to the natural world, but also to the world of medicine. Discover the real value of horseshoe crabs, found throughout New Jersey’s Hidden Coast – the Delaware Bayshore.
A new episode of our video series “New Jersey’s Hidden Coast” will air every two weeks throughout the summer! Catch a glimpse of the bay, the horseshoe crab at the center of the bay’s system, and the incredible relationship between horseshoe crabs and migratory birds, like the red knot. We will reveal the real value of horseshoe crabs, the challenges to the ecosystem, and the potential for a thriving regional economy along the Bayshore. We will show Hurricane Sandy as a catalyst for decisive action and the work being done to rebuild the area for both people and wildlife.
Over the next several weeks, we will explore the use of “living shorelines” instead of bulkheads and the central importance of marshes to the marine ecosystem. We will discover the on-the-ground, grassroots efforts of the community to build oyster reefs alongside veterans. And we will examine the future of the Bay and the work that needs to be done to preserve our conservation successes thus far.
One in a Series of Updates on the 20th Year of the Delaware Bay Shorebird Project
by Dr. Larry Niles, LJ Niles Associates LLC
On our final effort to trap shorebirds on Delaware Bay, we had the remarkable opportunity to watch sanderling and ruddy turnstones lift off for the Arctic. We first saw them feeding on the wave-tossed shoreline within the protected area in Villas; 1500 birds weaving as a single thread 5 deep with the contours of the wave, acting like a flying flock on the ground. Then a disturbance, a crow flying low down the shoreline and 2000 birds fill the sky. Most settled again but one group of about 300 flew more with greater determination than the rest. Still low but gaining altitude the flock wavered, and a mutinous band peeled away deciding against the departure returned to the safety and abundant crab eggs on the shore just north of us. The other 150 grew more determined, more structured and rose slowly as they powered their way north. Then they disappeared into the Northern sky.
A flock of shorebirds seen from Reeds Beach venture into the northern horizon for a nonstop flight to the Canadian Arctic.
Shorebirds departing Delaware Bay for their Arctic home, 2500 miles away stand as one of the most awe-inspiring and rewarding parts of our stopover project. They usually start in the early evening under a blue sky drenched with the glow of the setting sun and continue until near dark. They almost always go with a favorable southerly breeze and at least a clear sky in the north. Thousands of all the species after getting fat on the Bay’s bounty of horseshoe crab eggs – red knots, ruddy turnstones, sanderling, semipalmated sandpipers, short-billed dowitchers and dunlin – lift slowly as they fly along the Cape May peninsula coast towards Dennisville and beyond.
Led by Clive Minton, the team counts the number of flocks and flock size from our porch on Reeds Beach. This is only an index, as birds leave after daylight and from other places in the bay.
They are dangerously overloaded with fat. Two birds highlighted the importance of this. On May 30 we caught 97 knots, 168 sanderlings and 75 ruddy turnstones. Among each species were individuals of extraordinary weight. One bird weighed 242 grams, fully 120 grams higher than the fat free weight! They cart this load, like a plane with extra gas tanks, to fly two days to the Arctic islands of Canada. Imagine for a moment – you weigh 150 pounds and gain an extra hundred and fifty, then try to go anywhere, especially for 2000 miles.
In this video one can see all the different body shapes – and weights – of red knots and other species on Cooks Beach shoal. It’s easy to see many birds are ready to leave.
The fact that they can do this is a marvel of flight bio-engineering. While building weight they prepare like weight lifters, increasing muscle mass, heart size, and lung capacity. Close to leaving, they decrease the organs of digestion just to squeeze in the last few grams of fat. Then they wait for good weather, lumber into the sky and go forth into the vast north.
2016 was a good year for the shorebirds stopping over on the New Jersey coast. Most came in better-than-average condition, so they had a head start. The early spawn was strangled by cold water which seemed to hover around the temperature threshold for spawning- 59 degrees F. Tellingly however, the crabs spawned with gusto on the beaches from northern Reeds to Pierce’s Point. There the five inter-tidal creeks and inter-tidal flats warm the water that washes over spawn-inviting shoals and newly restored beaches. Throughout the stopover a majority of the bay’s population foraged on the eggs laid by vigorously spawning horseshoe crabs. On one day we saw a 10,000 red knot flocks on North Reeds Beach happily roosting and feeding on the abundant eggs.
In this iPhone panorama of north reeds beach one could see over 8000 red knots feeding on abundant crab eggs.Spawning crabs on Villas beach
Eventually the spawn accelerated and expanded but the birds still needed to get to the eggs. If constantly disturbed by people, they will move endlessly often to lesser habitat if only to avoid disturbance. In New Jersey we prevent this. Each year for the last 15 years, the New Jersey Division of Fish and Wildlife in collaboration with Conserve Wildlife Foundation of New Jersey, close the beaches important to crabs while leaving small observation areas open to the public. The impact is non-intuitive but positive.
Jim May (first photo) and Niel Olafson (second photo) have been stewarding beaches for over 10 years. Stewards not only defend beaches from the few people determined to breach the rope barriers, but bring their own outreach materials to educate people on the importance of stewardship. They also rescue stranded crabs in tough spots like abandoned bulkheads.
The closed beaches allow shorebirds to gorge on eggs unmolested by people: photographers and birders wanting to get one step closer for the perfect picture, compassionate people wanting to overturn crabs left stranded by the tide, or fishermen wanting to cast for the stripers that run in May. All with good intentions they scatter birds and force them to fly to other less suitable and less accessible beaches losing valuable gained weight in the process. The closures allow the birds to stay in the best places and eat like kings. Paradoxically the bird photographers and watchers end up with even better views because the birds adapt to the settled threat. Even fishermen find enough space to fish from the observation areas.
This person is unaware that her impact has cleared the area of shorebird leaving all the eggs to laughing gulls, who as we all know fear no human.
At the height of the season people could come to one of the five observation areas in the Reeds, Pierce’s Cove and see flocks of nearly 30,000 shorebirds including 14,000 red knots – two thirds of the whole population in the bay this year (as determined by air and ground counts). Photographers, birders and inquisitive people had a wonderful experience and the birds got fat.
Despite the difficulties caused by the unusually cold spring, most birds of the three species we follow reached good departure weights and by May 26th they started to leave. By June 1st most were gone and by June 2nd we advised reopening the beaches, 5 days earlier than the usual June 7th opening.
Our team of scientists, managers, students, volunteers, and stewards deserve praise for all the various projects and research conducted throughout the season, from cannon netting and bird study, resightings of previously banded birds, research on shorebird movement, research on oyster reefs and structural aquaculture, monitoring of horseshoe crabs, monitoring crab egg densities, volunteer efforts to rescue stranded crabs, to steward protected areas and tag crabs. Also, the volunteers of Citizens United to Protect the Maurice River deserve a special thanks for their logistical support for our team, they prepared over 20 dinners for 30 plus people every night of our project. Birds and Scientists all gain weight in May!
They all deserve gratitude, from the birds and horseshoe crabs, the people who love birds and horseshoe crabs and the people who love Delaware Bay.
The 2016 shorebird team
Dr. Larry Niles has led efforts to protect red knots and horseshoe crabs for over 30 years.
