Conserve Wildlife Blog

Posts Tagged ‘horseshoe crab’

The Importance of water temperatures, windstorms and shoals on the Delaware Bay

Friday, May 19th, 2017

By Dr. Larry Niles, LJ Niles Associates LLC

As we begin our field work on Delaware Bay shorebirds, our 21st season, oddly enough we are once again faced with extraordinary circumstances. As usual, the birds, after various flight of up to 6 days of nonstop flying, arrive in emaciated conditions. For example, in one catch this week we caught several red knots at around 86 grams far lower than normal weight of 130 grams. Putting that into perspective, a woman of 145 pounds would tip the scale at 93 pounds while a male of 175 pounds at 113 pounds! In other words, these birds are desperate to feed on the only prey on which they can build weight fast, the eggs of Delaware Bay horseshoe crabs.

But the various impacts of climate change and destructive forces of sea level rise, storm surge and out of normal weather patterns can wreak havoc on the timing of the horseshoe crab spawn. It messes with the heating and cooling of the bay and when combined with the normal variation one expects in an estuarine system, it creates almost unpredictable consequences.

Adding more uncertainty to this mix is the ongoing harvest of crabs for bait and the irresponsible bleeding by international medical companies. Both kill hundreds of thousands of crabs every year while doing nothing to create new crabs. Their combined impact has put the brakes on any recovery of the population after they both nearly mortally wounded the Bay population in the 1990’s and early 2000’s. Higher numbers of crabs would overcome a lot of early season uncertainty; lower numbers exacerbate them.

And thus, the story of this early part of the shorebird stopover. It starts with the odd weather this April and May. Can everyone remember how warm the weather of this winter? The map below is a reminder that it was one of the warmest on record. The figure below that shows how the Bay’s water warmed early reaching the threshold temperature for horseshoe crab breeding by early May. We trapped sanderling in the first week and were surprised to see a truly great crab spawn on May 4. Thank God for that.

The bays water temperature as measured at the Lewis DE buoy, increased earlier than normal until the first week of May. By that time it reached the threshold for horseshoe crab spawning. But by the second week it plunged as a consequence of the cooler than normal weather.

By the second week of May and yesterday (May 16) temperatures plunged in horseshoe crab world. We generally consider water temperature of near 59 degrees necessary for crabs to spawn in great numbers. We reached 62 degrees on May 4, then it went down to 58 degrees, lingering there for five crucial days.

At the same time, we suffered brutal westerly winds. Wind from this direction gins up waves on Delaware Bay that crash against many of the important crab spawning beaches. Crabs don’t spawn in waves.

Westerly winds turn the Delaware Bay into a tumult of breaking waves because of its relative shallow depth. Horseshoe crabs won’t breed in breaking waves

And just as the first flush of shorebirds came to the Bay, over 5,000 red knots on the New Jersey side, all the spawning shut down. All tried desperately to find enough horseshoe crab eggs to regain lost weight and begin the process of doubling their body weight.

Fortunately, breaking waves and cold water will prevent crabs from spawning on the beaches but not in the intertidal creeks. One of the key features of the New Jersey bayshore are its abundant tidal creeks. Most drain only tidal watersheds, draining and filling marshes twice every day. Naturally they build sand shoals because sand moves around the Bay generally in a south to north direction along the Cape May peninsula. When sand encounters the currents of the creeks, it settles forming shoals.

A small creek just north of Dennis Creek on Delaware Bay. The tidal creek mostly drain tidal marsh, the daily ebb and flow warming the waters making crab spawning possible when the bay waters are too cold

These shoals support most shorebirds during these early days. This is so because the intertidal flow of water into the marsh and out again warms the water that flows over the shoals. The shoals themselves are practically paradise for breeding crabs because of the loosely consolidated and large grain sand. They breed with abandon laying eggs in the shifting sands that brings many of the eggs to the surface where shorebirds can prey upon them. And they do.

This diagram by Joe Smith shows how the creeks of Delaware Bay create superior spawning and shorebird foraging habitat. Sand movement on the Cape May section of the bay moves northward because of tidal currents. This moves sand from south to north. When the American Littoral Society and CWF placed sand on Pierces, Kimbles and Cooks beaches, some part moved northward to the adjacent beaches. Ultimately it ended up on south Reeds making it a great spawning site. But on the way the sand falls out of the current and settles on the creek shoals. These shoals are large grain sand, loosely consolidated, making them perfect for crab spawning. At the same time the shoals shift exposing eggs to the sea, thus making them available to the birds. This is why the shoals are among the most important habitat on the bay.

This is what happens in the early days of this season. It was nip and tuck for most of the scientists, not knowing if the shoal resources would hold up to an ever-growing number of shorebirds arriving in desperate condition.

But today (May 19) we enjoyed warmth with the promise of the season back on track.

In the last 5 days, we were able capture enough knots, turnstones and sanderlings to track conditions and add new flags to the population for a later determination of population size. Despite adversity, so far so good. The data for each species is below.

Dr. Larry Niles has led efforts to protect red knots and horseshoe crabs for over 30 years.


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20 Years of Shorebird Conservation and Research on Delaware Bay

Wednesday, May 17th, 2017

By Dr. Larry Niles, LJ Niles Associates LLC

A Monumental Work of Conservation

This year marks the 21st year of the Delaware Bay Shorebird Project. As one of the longest running shorebird projects in the world, the only one of its kind in the US, we wanted to memorialize this monumental work. To do so we convened a daylong series of presentations by scientists and managers from all over the world who have worked on the bay. Here are the abstracts. They are worth a look by nearly anyone interested in shorebirds and Delaware Bay.

The participants of the workshop on 20 years of conservation and research on Delaware Bay.

The presentations ranged widely. We heard talks diving deep into the science of shorebird ecology, like Phil Atkinson’s talk on the use of isotopes of carbon and nitrogen locked in feather samples and what they tell us about where knots spend the winter. Or Paul Smith’s talk on how modeled estimates of shorebird numbers compare to numbers counted from an airplane. On the other side of our scientific work were talks like Laura Chamberlin’s describing the role volunteers play in saving stranded horseshoe crabs rolled over by heavy seas or impinged in concrete rubble and derelict wooden bulkheads. In between were talks like those by David Stallneckt on the role of shorebirds in the transmission of flu viruses and how that knowledge might prevent the next pandemic of flu in people.

I liked Joe Smith’s talk on the restoration of Delaware Bay beaches and Ron Porter’s talk on the movement of shorebird tracked by tiny devices called geolocators.

Altogether they spoke loudly of the 20 years of intense study and conservation by our devoted team of scientists, managers and volunteers. In those 20 years of conservation of Delaware Bay we learned basics of protecting any place loved by people who love wildlife.

Dollars on the Beach

As with many places in this divided country of ours, and in many places in the world, we have witnessed on Delaware Bay a sad and wholly preventable natural resource tragedy. It’s now 20 years since the Atlantic Coast fishing industry nearly decimated the horseshoe crabs of Delaware Bay. They didn’t aim to do this of course, but as with any tragedy of the commons, once the crabs gained value as a bait, everyone wanted their share before it was lost. They hauled away millions of crabs, no one really caring about the consequence to the bay or the wildlife that depended on the crabs. It was a race to the bottom, that would not have been stopped if it weren’t for the scientists and managers that stood up to the industry, many of which gave presentations in our workshop.

Shorebirds feeding on eggs while crabs spawn.

The battle gave us several important lessons.

The first revolves around the value of the bay, the crabs and the shorebirds. We biologists, managers and public outreach people often see the natural value of this ecosystem in terms of its meaning to us. We are inspired by the knot’s magnificent journey covering 10,000 miles, often flying 6 days continuously.  We are awed by the natural system that responds to change much as our own body fights for life against all the many abuses we cause or suffer.  But we often miss the real value. During my time on the bay we have defended this valuable natural resource from many assaults, the winner take all crab harvest, the greedy exploitation of crab blood by medical companies, the overreach of aquaculturists plotting out the use of intertidal zones without regard to impact. Underpinning each of these threats is not esoteric value, but real wealth.

I once had a conversation with Rob Winkle, before he retired as Chief of Law Enforcement for NJ Division of Fish and Wildlife. He said “Larry you’ll never be able to protect these crabs, because to many people, they are dollars on the beach”.  In other words, natural wealth is wealth, pure and simple. The question is – do we protect this wealth for our children and grandchildren to make up their own minds about how to spend it?

Protection Requires a Relationship

The real value of natural resources speaks to the second lesson. Protection is not only an action composed research, monitoring and management, it is also a long-term relationship with a place. Those of us working on the bay for 20 years know this very well. The abstracts speak to the relationship and our continuing efforts to understand and improve, to rebuild what was lost, to anticipate what comes next. If in 1997 we started work in the bay to publish a few papers and move on to the next interesting place, the battle to save this vital shorebird stopover and horseshoe crab spawning area would have been lost. The dollars crawling up on the bay beaches means protection doesn’t end with fighting one short-sighted greedy use, because there will be an inevitable successor. It takes a long-term relationship to develop protection and keep it vital and active.

I learned this many times in my career, most recently from my good friend David Santos now a professor at the University of Belem in northern Brazil. We have been doing work in the northern coast, a major wintering areas for Arctic nesting shorebirds. After a passionate discussion on how to best bring greater protection of the area he said “you come here for a few weeks and think you can save this place”. He was right, the truth is we can only help if we commit to work in northern Brazil for enough time to get it right.

And this is my final lesson. There is no easy way to develop a long-term effort to prevent the inevitable series of short sighted use of a natural resource without the help of the people who care.

Clive Minton on Delaware Bay.

When Clive Minton and Humphrey Sitters first came to the bay to start the project that is now 20 years old, I was awed by their experience, skill and knowledge. I thought why are they doing this? Neither were being paid only supported to do the work. I was employed as the Chief of NJ Fish and Wildlife’s Endangered Species Program. Now I know, it is only because they care. They are fascinated by the bird’s natural history, they publish scientific papers on the subject but they come year after year because they care.

There’s more to this than just tree-hugging emotionalism. In the US, we have gradually professionalized conservation, ensuring only paid staff do the work with only minor roles for users. It’s an entirely credible position in times of flush budgets. Its pitfall becomes obvious in the age of Trump, years of budget cuts and increasing influence of resource industries dismantle that achieved in the good years. Overall it ends with natural resources declining in nearly every section of the country.

Clive and Humphrey, come from England and Australia where conservation depends heavily on volunteers. It’s a pastime to research, monitor and conserve birds, not necessarily something that pays. For example, the Royal Society for the Protection of Birds (RSPB) has over a million members, but over 18000 volunteers working at 200 preserves and only 1300 staff. Remember this is in a country that has a population of 53 million. By contrast in the US with a population of over 300 million National Audubon Society half the number of members and staff and nearly the same budget.

In our experience these numbers don’t speak to the reality of how people actually feel in the US, or at least hear on the bay. We can say without reservation that the research, monitoring and conservation on the bay depends on the dedication of many volunteers taking part in our work. We literally could not do the work without their help.

John, upper right in red shirt, is a volunteer steward protecting beach important to Delaware Bay shorebirds. This is he first year. Next to him is Humphrey Sitters, the editor of Wader Study, an international technical journal on shorebirds and a highly trained expert on shorebirds. He has worked on Delaware Bay as a volunteer scientist for 20 years. It is the work of these two and many others that makes the protection of Delaware Bay a success.

And so, this is the final lesson. The best way to overcome this cycle caused by the relentless exploitation of the bay’s natural wealth is building a team of people devoted to it study and conservation. This involves the many professionals who care enough to maintain a focus through the ebb and flow and agency prerogatives, a team of retired professionals and young adults seeking experience for their nascent careers and just as importantly as many people who care enough to put time into the yearly care of this valuable natural systems.

Dr. Larry Niles has led efforts to protect red knots and horseshoe crabs for over 30 years.


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Reef dedication, seining to help celebrate Veterans Day on Delaware Bay

Thursday, October 20th, 2016

Oyster reef to be dedicated to New Jersey Veterans at second annual event

By Emily Hofmann, Project Coordinator

a-seine-net-about-75-feet-long-is-dredged-in-the-bay-and-brought-up-on-the-beach-to-collect-the-species-for-study

A seine net about 75 feet long is dredged in the bay and brought up on the beach to collect the species for study. Photo courtesy of Middle Township Gazette.

You and your family are “whelk-come” to join American Littoral Society and Conserve Wildlife Foundation and for our 2nd Annual Veterans Day on the Bay on Saturday, November 12 from 11:00 AM -2:00 PM at Moores Beach on the Delaware Bayshore! In April, we held our 2nd Annual Shell-A-Bration where proud volunteers braved the elements and helped build an oyster reef at Moores Beach.

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The 1st Annual Veterans Day on the Bay was held on November 11, 2015 at South Reeds Beach. The oyster reef was dedicated to all veterans and highlighted veteran involvement in the effort to restore New Jersey’s Delaware Bayshore. Event attendees honored their own military veterans by inscribing that special person’s name on a shell and placing that shell on “Veterans Reef.”

 

This year we’d like to continue to show our appreciation and mark the progress we’ve made by dedicating another reef to a specific military branch.

 

Please join us for the 2nd Annual Veterans Day on the Bay, which will feature:

  • Raw oysters and fare from Spanky’s BBQ
  • Beach Clean-up
  • Seining and marine wildlife study
  • Arts and crafts for children
davidbensonshells1

Photo courtesy of David Benson.

Help us study the wildlife living in this new reef with hands-on, interactive marine science activities like seining and species identification!

 

The highlight of the event will be the dedication of Moores Beach oyster reef in honor of our military veterans. Attendees are invited to honor their own military veterans by inscribing that special person’s name on a shell and placing that shell on the reef.

 

This family fun day and volunteer event will be held from 11:00 AM – 2:00 PM; with the reef dedication ceremony taking place at 12:30 PM. Veterans Day on the Bay is rain or shine. The celebration will be a picnic-style event, so please bring blankets and chairs.

 

Join us at Moores Beach, at the end of Moores Beach Road (which intersects with NJ Route 47 near Delmont United Methodist Church) Maurice River, New Jersey, 08314.

 

RSVP appreciated to Quinn Whitesall, quinn@littoralsociety.org or Emily Hofmann, emily.hofmann@conservewildlifenj.org by November 7.

 


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Emily Hofmann is a Project Coordinator with Conserve Wildlife Foundation.

 

Volunteers and biologists add the next oyster reef to Dyers Cove

Thursday, October 6th, 2016

Team works through threat of downpour to strengthen Delaware Bay’s resiliency and ecology

By Emily Hofmann, Project Coordinator

 

Although the weather was on the brink of being rainy and bleak, that did not stop a team of dedicated biologists and volunteers from building an oyster reef on the Delaware Bayshore this past Saturday. Committed volunteers and young people braved the weather to work alongside American Littoral Society and Conserve Wildlife Foundation to build a near-shore oyster reef at Dyers Cove, at the end of Dyers Creek Road in Newport, Cumberland County, New Jersey.

 

oyster-reef-2

This reef – like the one at South Reeds Beach – was built to protect restoration work done after Hurricane Sandy and provide habitat. Constructed to prevent sand loss from wind-driven waves and create calmer water for spawning horseshoe crabs, this is the third of five such reefs that have been built by the Littoral Society and CWF. The conservation organizations will continue to monitor whether the reef breakwaters help reduce beach erosion and create calmer water for spawning horseshoe crabs.

 

Due to the heavy rain over the course of the week, the conditions were not ideal. Low-tide never went below waist deep, so it was hard to construct the reef accordingly. But that did not stop the team!oyster-reef-build_5

 

“Every oyster reef we’ve built so far on the Delaware Bay incorporated a different restoration strategy. We have had to adapt new strategies with what has worked best in the past and with what will realistically work based on site conditions. By blending the successes from the previous reefs with innovative approaches, we have been able to construct three reefs to date,” said Capt. Al Modjeski, Habitat Restoration Program Director for the American Littoral Society.

 

The bayshore beaches need restoration and improved resiliency so that horseshoe crabs have proper breeding grounds. Crab eggs feed migratory shorebirds, like the Red Knot, which stops in New Jersey each spring on its long journey from South America to the Arctic Circle. The Red Knot and other shorebirds help bring $11 million in tourist dollars to New Jersey’s Delaware Bayshore region each year.

 

“New Jersey’s Delaware Bayshore hosts an annual wildlife spectacle of global significance – the time-honored migration of Red Knots to reach the eggs of these ancient horseshoe crabs,” said David Wheeler, Conserve Wildlife Foundation of New Jersey Executive Director. “Volunteer projects like this help connect the people of New Jersey with these endangered shorebirds and the largest population of horseshoe crabs in the world.”

 

“Originally, this event was a bare-bones volunteer effort of placing shell bags off the Dyers Cove eastern beach,” said Capt. Al. “But thanks to a donation from Betancourt, Van Hemmen, Greco & Kenyon, we will have a ‘shell-a-bration’ that celebrates the ecology and community of the Delaware Bayshore.”

oyster-reef

In 2015, over 130 volunteers and veterans built an oyster reef at South Reeds Beach in the first annual Shell-a-Bration. That same year, Veterans Day on the Bay dedicated the reef to all veterans and highlighted veteran involvement in the effort to restore New Jersey’s Delaware Bayshore. The second annual Shell-a-Bration, held in April 2016, saw a handful of dedicated volunteers brave a blizzard to build a reef at Moore’s Beach. The third annual Shell-Bration will be held this coming Spring 2017.

 

“There are many strategies to defend our Delaware Bayshore, but one of the best and most productive are these oyster reefs,” stated Dr. Larry Niles, a biologist with the American Littoral Society and Conserve Wildlife Foundation of New Jersey. “They not only replicate a lost but important habitat on Delaware Bay – reefs once covered much of the bayshore – but they provide just enough protection to make a difference in how long our beaches persist against the unrelenting forces of nature. In a way, we are fighting nature with nature.”

oyster-reef-4

The projects are being funded by National Fish and Wildlife Foundation (NFWF) through their Hurricane Sandy Coastal Resiliency Grants Program, and are being developed in partnership with U.S. Fish and Wildlife Service and New Jersey Division of Fish and Wildlife.

 

Emily Hofmann is a project coordinator for Conserve Wildlife Foundation


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New Jersey’s Hidden Coast – Strengthening Bayshore Beaches

Tuesday, July 19th, 2016

NEW JERSEY’S HIDDEN COAST – EPISODE 5

By Emily Hofmann, Assistant Communications Manager

 

Like all ecosystems, Delaware Bay is amazingly complex, and there’s no one way to fix it. Between climate change, sea level rise, and the growing risk of major storms, there’s a lot to consider.

 

We’ve learned that restoring healthy marsh habitat is a key component in rebuilding Delaware Bay beaches; however, we’re also trying to further strengthen bayshore beaches by building reefs – living underwater infrastructure. By creating some reef structures we can keep the sand where we’re putting it.

 

Learn more about strengthening New Jersey’s Hidden Coast – the Delaware Bayshore in our fifth episode to our series.

 

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.

 

Discover Delaware Bay: