Dunes: a demonstration on the importance of stability

In case you didn’t pick up on this via Instagram or Twitter I’ve recently relocated to Chicago. It’s a far cry from my Mid-Atlantic roots but actually much closer to lots of beautiful beaches and plenty of new inspiration. In fact, one place I cannot wait to visit is the Indiana Dunes National Lakeshore. Here’s why:

Dunes are important (and you should never walk on them!) and should be rebuilt to maintain stability after any natural disaster. I mean … we don’t want to erode the beaches away. Dunes are dynamic and lend themselves as a main cause for a beaches unique features. They’re also such an indicator of the power of the ocean and wind. But, where would they be without stabilizers such as dunes grasses?

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Here’s a quick demonstration I’ve used in a high school class to illustrate 1) how wind carries materials (i.e., sand) to build dunes and 2) why we should protect grasses that stabilize dunes.

Materials: Dry, fine sand, blow dryer, twigs or branches (I have a bunch of strange fairy house trees and shrubs that make for cute miniatures), a cereal box with one side removed, eye glasses (definitely one for each student)

Prep: I create a dune without any stabilization in the center of the box. I think it’s good to make it fairly large (about six inches or so high so that something noticeable can occur.

Discussion/demo: Ask students to draw a picture of what will happen to the dune once the wind (i.e., created from the blow dryer) blows on the dune. In particular ask them what if they can predict if one side might get steeper and one side might increase its slope. I also introduce terms such as “windward” and “leeward” noting how the sand will basically blow over the leeward side of the dune. Once the demonstration is complete, and I’ve used the blow dryer on a low setting for about ten seconds about one feet away, I follow-up and ask them if the migration of the sand was the same as their prediction.

Next, I set it up again and ask them the same questions but I use the stabilizers. For the stabilizers you want to make sure that they are in firmly and won’t blow away (It’s one of those things I learned the hard way).

Outcome: The outcome should be that the students notice a difference with a dune that is stable verse one that doesn’t have vegetation. You can even mention that some dunes can be stabilized with artificial means such as rocks. Dunes that are stable can greatly improve beach erosion which is especially timely given the coastlines aren’t what they used to be. Thanks, climate change (that’s an entirely different discussion).

Note: I generally use quick introductions like this as a journal exercise to get the students thinking and warmed up. I typically ask them to break out a vocabulary section in their notes and copy down and words I might use (e.g., windward, erosion, leeward) and then set up a journal entry for the introduction to class.

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10 best in the past nine years

Sometimes it’s nice to look at the past and see what’s worked. From the past nine years of posts on Beach Chair Scientist, it seems that one post has been the “most valuable player”. 100 ocean quotes is a surefire “make you stop by BCS for the first time and join the mailing list” kinda post. It’s the Wayne Gretzky, Babe Ruth, or Micheal Jordan in terms of stats. All other posts just fall short. But in the ethos of sportsmanship, here are ten posts that also bring some well deserved worth to this little blog. Which one are you rooting for?

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What gives a beach its unique features?

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Tides. Winds. Waves. You might think of those right away when you ask yourself “Why are beaches so different from one another?” The story of how and why beaches are unique is more than what we witness while lying in a beach chair watching the tide go out hour by hour. The personality of a beach actually started long before … depending on what type of activity occurs near it.

If a beach is on a coast with a lot of earthquakes and volcanoes than it means that coast is active. Active coasts are going to be rocky, jagged, and edgy. Think “lots of cliffs”. This is easily seen along the West coast of the U.S. On the other hand, a beach might have a gentle slope with dunes leading to the sea. Think “the picture above”. There may be earthquakes but they’re rare and no volcanoes. This would mean the coast is passive. Being an active or passive coast is the foundation of a beach. Almost like its genetics or DNA.

active_passiveSo what gives a beach its true character is what it relates with on a daily basis. Just like the people and media we interact with on a daily basis shape our true character. For instance, does a beach have an expansive estuary nearby? Does a beach have an energetic or dormant volcano nearby? If this is the case the coast would also be considered primary. Primary coasts have been created by land based factors such as drowned river valleys, glaciers, or volcanoes. On the other hand, the ocean can play an important role in shaping a coast as well. Maybe there is considerable wave erosion lapping the shore? Are coral reefs, barrier islands, or other marine depositions nearby that helped to form a shoreline? These coasts are called secondary.

Beaches are either on a passive or active foundation and each have prevailing short term factors of primary (land based erosion) or secondary (ocean based erosion). The combination of characteristics give each beach a distinctive quality. Just like each one of us each beach is valuable and precious.

One Big Wave, and Millions of Lost Legos

Lego dragons Bigbury

Photos courtesy of Tracey Williams

On Feb. 13, 1997, about 20 miles off the coast of England, a massive wave hit the freighter Tokio Express, toppling 62 giant containers into the rough north Atlantic seas.

Trapped inside one of them: nearly 5 million Legos. Many floated to the surface. Carried by currents, they’re still being found on beaches around the world nearly two decades later. Others remain on the ocean floor. It’s not unusual for fishermen trawling the Atlantic to haul up tiny Legos.

The fact that so many of the pieces were nautical themed – sea dragons, pirate swords, sea grass and scuba gear, among others – has turned the Lego spill into one of the most famous and unusual marine debris incidents in recent maritime history.

In Newquay, a seaside town in England, writer and longtime beachcomber Tracey Williams started a Facebook page a few years ago – Legos Lost at Sea – that tracks the whereabouts of the lost Legos as they wash up onto beaches.

Williams recently spoke to the Beach Chair Scientist blog about her work, and you can hear more of what she has to say below. But she hopes to turn the public fascination, much of it generated from a recent BBC story on the spill, into a teaching moment about the harmful environmental impact of marine debris.

Lego octopus Terena

“Clearly, 5 million pieces of Legos spilling into the ocean isn’t good for the environment,” Williams said in a recent phone interview. After the BBC interviewed her about her site a while back, the publicity resulted in people contacting her with stories about beach-bound Legos around the world.

“It has connected beachcombers all around the world, which is fascinating,” Williams said.

She received one report of a Lego flipper found on an Australian beach. She’s also heard from the family of a woman who had scoured the beaches for Lego dragons as a hobby in her 80s, passing her finds along t0 younger generations.

“Obviously, marine debris is a big problem. But I think many children have been captivated by this whole Lego story … I think it reminds people of their childhood. It’s the whole issue of marine debris. Oceanographers are interested in how far it’s spread.”

Meanwhile, she also hears from fishermen who come across Lego pieces in their nets.

“Half of it sinks and half of it floats,” Williams said, referring to the sorts of Legos that fell off the Tokio Express. “So clearly, while we’re finding certain items washed up on our shores like the spear guns and the flippers, fishermen are actually finding other pieces like window frames and car chassis.”

While the lost Legos have made for fun beach combing and treasure hunts, there are bigger questions beneath the surface. If the contents of just one toppled shipping container can spread around the world for decades, what about far bigger and more dangerous spills that go unnoticed because they don’t happen to have Legos in them?

“There were 62 containers that fell off the Tokio Express back in 1997 and we only know about what  was in three of them,” Williams said.

“What’s in all of the others and when will that all wash ashore?”

You can listen to more of Williams and the story of the lost Legos here:

What you need to know about World Shorebirds Day: Saturday, September 6th

world-shorebirds-day1000My husband isn’t happy about this … But, recently, I have found a new love of birds. It’s because we live in the woods and not near the ocean, so those flighted friends have stolen my heart just like fish did back some many years ago. My husband thinks it is hysterical since we grew up in Cape May County, NJ and birders are synonymous with “tourists”, a group to which locals have a love/hate relationship. But, I don’t care … I can hardly contain my excitement for this Saturday – during World Shorebirds Day!

The celebration was proposed and organized by György Szimuly, a well-known bird conservationist based in Milton Keynes, England. Szimuly set out to promote and celebrate shorebirds.

Find out the differences between a seabirds, shorebirds, wading birds here.

“The idea to hold a World Shorebirds Day was inspired by the ongoing conservation issues we have been facing,” Szimuly said. “I think that setting a commemorative day for shorebirds will give conservation bodies and individuals another chance to educate.” He continues that “This is not particularly a citizen science program, but rather an effort to raise awareness for the importance of regular bird monitoring as the core element of bird protection and habitat conservation.”

“I think the global shorebird counts are a good get-together event,” Szimuly said. “I asked birdwatchers to book their site now, where they can go counting shorebirds on the 6th and 7th of September.” There are hundreds of sites and counters already registered for the World Shorebirds Day. The ‘booked’ sites can be seen on the event’s Google Map. https://mapsengine.google.com/map/edit?mid=z3yRwAVo2mAw.k42bDqIRe7a4.

Follow the activities and learn how to submit data of World Shorebirds Day on the website blog and Facebook page.

The short and sweet of horseshoe crab spawning

You may have heard about the phenomena of horseshoe crab spawning … but, do you really know what’s going on? It’s when hundreds of thousands of these ancient arthropods (dating back 400 million years!) make the journey to low-energy sandy beaches along the Atlantic coast, predominately along the Mid-Atlantic region (highest concentration found along the Delaware Bay), around the time of the full and new moons of May and early June to spawn. Here’s the distilled version of the horseshoe crab spawning saga complete with the words you need to know (i.e., “pedipalps” and “satellite” male) if you want to be considered a horseshoe crab expert. Who doesn’t?

https://www.flickr.com/photos/beachchairscientist/

https://www.flickr.com/photos/beachchairscientist/

  1. Journeying from intertidal and deeper waters, male horseshoe crabs arrive near the beach waiting for females.
  2. As the females come closer to shore, males attach to the female’s abdomen. The extra claw, or “pedipalps”, is what the male uses to attach itself to the females.
  3. Not just the one … but, many “satellite” males follow the conjoined pair.
  4. The females dig a depression about 5 to 30 centimeters deep in the upper part of the beach and deposit the clusters of eggs.
  5. External fertilization occurs – Allows for a little extra competition from the “satellite” males!
  6. Repeat steps 1 through 5 multiple times per season, laying 3,650 to 4,000 eggs in a cluster (usually an estimated 88,000 eggs annually!).
  7. In 2 to 4 weeks after fertilization, planktonic larvae hatch from the eggs. Some slow moving larvae may even winter within the nests and hatch out the following spring.
  8. After hatching, larvae swim for about six days before they relax in shallow waters to molt into their first juvenile stage in approximately 20 days.
  9. For the first two to three years of life horseshoe crabs molt many times over, growing a quarter of their size each time. Once sexual maturity is reached they slowdown their molting to once per year.
  10. Horseshoe crabs mature around 10 years of age (or 17 molts) and are known to live to be approximately 20 years of age.

For more information on horseshoe crabs and “99 reasons I am in Limulus Love” check out my horseshoe crab page here.

Why you should never walk on dunes

It might seem nonsensical since the dunes look calm and peaceful, but it’s not a good idea to explore dunes. In addition to being illegal in many coastal towns, here are six other reasons why you should stay off the dunes:

1) Dunes store sand that help diminish potential shoreline erosion.
2) Dunes absorb the impact of storm surge and high waves.
3) Dunes prevent water from flooding coastal towns.
4) Dunes provide habitat and crucial nesting area for threatened and endangered species.
5) Dunes create a relaxing backdrop to any beach.
6) Dunes buffer the full force of the ocean and protect property.

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For more on dunes, their importance and role in beach ecology, check out the post “From Sandy, coastal towns learn ‘dune’ diligence. Is it enough?” written immediately after Hurricane Sandy.

17 facts about the wee sea potatoes

In honor of St. Patrick’s Day, and my Irish heritage, here’s a post on the humble and charming sea potato.

  1. The dried shell (also known as the test) of this urchin resembles a potato, hence the common name – sea potato.
  2. The sea potato, Echinocardium cordatum, is a common echinoderm found along beaches on all coasts of Britain and Ireland.
  3. The sea potato is related to sea urchins, heart urchins, and sand dollars.
  4. Most sea urchins live in rocky areas, but the sea potato prefers sand, particularly muddy sand.
  5. The spines of this echinoderm are thin and flattened.
  6. On the underside of the urchin are special spoon-shaped spines that help it to dig.
  7. There are longer spines of the back of the sea potato which aid in helping to breathe while it is burrowing.
  8. The sea potato can survive to depths of 650 feet.
  9. Unlike regular urchins, the sea potato has a distinct front end (i.e., not circular).
  10. The sea potato can grow up to 3 inches.
  11. The sea potato is very fragile and rarely survives collection.
  12. While alive the sea potato is deep yellow in color and covered in fine spines.
  13. The sea potato prefers sub-tidal regions in temperate seas.
  14. The sea potato are a type of heart-shaped urchin.
  15. Sea potato are deposit feeders and tube feet on its underside the sea urchin pick up sediment from the front of its mouth.
  16. The sea potato has no conservation concerns.
  17. The sea potato often has a commensal symbiotic relationship with the bivalve Tellimya feringuosa attached to its anal spines.
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A sea potato, commonly found along the shore of Ireland

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The test of the sea potato

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The underside of the sea potato

Ho, ho, ho! Look who’s coming to town … it’s the bearded seal!

The rather short snout with thick, long, white whiskers gives this true seal it’s appropriate common name. The bearded seal (Erignathus barbatus) can be as long 8 feet and weigh up to 800 pounds. I guess now we know what idiom they use under the sea instead of “the 800 pound gorilla in the room …”. These seals tend not to be seen in packs like their more social counterparts we view along harbors.

Bearded seals spend most of their lives in the Arctic waters, although one was recently found in southeast Florida. They enjoy feasting on arctic cod, shrimp, clams, crabs, and octopus and have been known to live up to 25 years. For more information on the conservation efforts and status of the bearded seal population please check out this page created by the NOAA Fisheries Service Office of Protected Resources.

Adult bearded seal by by wildlife photographer Paul Souders

Adult bearded seal by by wildlife photographer Paul Souders

Image (c)  www.telegraph.co.uk

What happens if the tide leaves a horseshoe crab stranded?

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It’s not often you stumble across this on the beach. I asked horseshoe crab expert Danielle Chesky, Fishery Management Plan Coordinator with the Atlantic States Marine Fisheries Commission, what was happening in this picture and she said that “they’re dug in for the day after spawning until the high tide comes and they can get back out to sea”. For more posts on horseshoe crabs check out the Limulus Love page. Thank you to a colleague’s in-laws for sending along this picture.