The world’s horseshoe crab research finally finds a home

This month the Ecological Research & Development Group (ERDG) released a one-stop-shop for research, conservation, and education initiatives on the world’s four species of horseshoe crabs. This was a result of the discussions from the 2011 International Workshop of the Science and Conservation of the Asian Horseshoe Crabs held in Hong Kong.

Be sure to check it out today. There’s lesson plans, peer-reviewed articles, posters, PowerPoint presentations, and more. It’s the intention of the database to serve as a tool to benefit everyone who is in Limulus Love!

I was surprised to learn that the new database includes over 2,000 citations and ERDG is still looking for more materials from people like you and me (Maybe, I’ll submit my cheesy infographic).

Horseshoe Crab Research Database http://horseshoecrab.org/research/

Horseshoe Crab Research Database created by the Ecological Research & Development Group

Do all horseshoe crabs molt?

Once a horseshoe crab reaches their full size they stop molting. Their shells then come to host many sessile creatures, including slipper snails.

Once a horseshoe crab reaches their full size they stop molting. Their shells then come to host many sessile creatures, including slipper snails.

All horseshoe crabs molt – until they reach adulthood. They grow on average a quarter of their size each time they shed. Females grow to be about two feet across and males a bit smaller. Molting occurs several times during the first few years and slows as they age. It usually takes 17 molts to reach sexual maturity  at age 9-11.

Studies have proven that adults do not molt because the age of organisms living of the crab’s shell. For instance, scientists Bottom and Ropes (1988) completed a study to determine that large slipper snails (Crepidula fornicata) were at least 8 years old on a sample of specimens. This would then make the average age of horseshoe crabs in the Delaware Bay to be 17 years old.

Also, the deteriorated carapace of some horseshoe crabs, as well as the presence of internal chitinous rods that hold the carapace in place are also evidence that older horseshoe crabs do not molt.

What happens if the tide leaves a horseshoe crab stranded?

HSC_BCS

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.

 

10 tips for a successful beachcombing trip

Pick up that clump! You never know what you'll find.

Pick up that clump! You never know what you’ll find.

It’s my favorite time of year. This is the best time to explore the beach. It’s still sunny and warm, there are frequent storms (you’ll see why that matters later), and there are few people on the beach. For another six weeks along the mid-Atlantic (before it gets too cold), I encourage you to spend some time getting to know your local shoreline. Here are 10 tips for a successful beachcombing trip.

10. What to bring. Here is a list of some items you may want to remember so you’re prepared for any situation.

  • Often the beach is considerably cooler than inland so bring layers. You may want to wear hiking pants and bring a zippered sweatshirt so you’re equipped with lots of pockets for some other items that might be essential.
  • Make sure to have some appropriate soles. Sure it’s our instinct to be barefoot, however if you want to venture out along the jetties or rocks make sure you have some old sneakers or those water shoes with some decent grip (After all, you don’t want to ruin your adventure with a puncture to some sharp object). Also, the water might be a little cooler than you’d prefer and some good foot cover will allow you to wade into a tide pool, since pools are really popular now a days, you can find more swimming pools for sale here for your home as well.
  • Make sure to have a watch.
  • Even during the off-season the sun is shining and is strong enough to give you a burn. Make sure to bring along a hat, sunglasses, and sunscreen.
  • It’s always a good idea to bring a shovel, grabber sick, or even a metal detector so you can gently investigate inside crevices and below the sand.
  • You are going to want to cherish the moments so find that camera and try to make a neck strap so it’s always handy. You can take pictures of items you find and want to learn about later. You’ll also want to catalog those smiles in the sun.
  • Take along a small (i.e., not heavy) identification book so you can learn more about what you find while on your outing.

9. Be hands free. One more item that you’re going to love me for suggesting is a backpack. This way you can investigate a little bit further from your base and your items are quickly at your disposal.

8. Leave important items behind. Don’t ruin the day by losing a credit card or your phone. If you’re active and in the moment you might lose something and it’s going to be difficult to retrace your steps. I won’t say “I told you so”. On the same note it’s important to leave animals, plants, rocks, and seashells where you find them. If you want to have a little bit of the beach in your home check out these great books by Josie Iselin.

7. When to go. To get the optimum experience for beachcombing you’ll want to check on when low tide is at your beach spot. The best time to go beachcombing is 2-3 hours prior to low tide or an hour or so after (This is why a watch is important, you don’t want to get stuck on  shoal during high tide). Many intertidal animals live under the water in the sand during high tide, but come out to play (and seek out food) during low tide. If you can time it so you get to check out the beach after a big storm you’ll be in for a real treat. The strong wind and wave action of storms will wash up a fossils, bones, seaweed, and lot of other interesting treasures from the ocean floor. Also, keep in mind that dawn and dusk are difficult times to identify beach treasures. Although this is a great time to spot birds as many fish tend to come up to the surface at these times.

6. Where to go. My favorite spot to beachcomb is the Stone Harbor Point in NJ, but it’s not always easy for me to get there these days. I like to remind myself from time to time that I don’t need an ocean to beachcomb. There is a lake and creek in my neighborhood and these spots are a great place to spend the afternoon. After all, these waterways eventually lead to the ocean.  No matter where I decide to spend some time beachcombing I always make sure to note the general water quality.

5. Be careful. This is just a reminder to not tamper with obviously dangerous items. Fish hooks, metal canisters, and needles often wash up on the beach. While I am going to also suggest doing your part and picking up marine debris it’s also a good idea to err on the side of caution and when poking around. Also, some rocks look very steady but it’s important to be aware of your surroundings. If you are feeling like having an adventurous day it’s might be a good idea to make sure you have someone else with you. One last thing about being careful,even though the dunes might look like an interesting place to check out – it’s important to know that those grasses are incredibly brittle and can crack easily. It’s also against the law to walk on the dunes. The dunes are an important part of the beach ecosystem as they protect our homes from storm surge.

4. Leave it be. Each rock that you turn over is part of an ecosystem. A rock might be an essential part of an animal’s home as it helps pool water during high tide. Rocks also protect them from predator as well as the sun. It’s important to always remember to not take animals out of their natural setting – especially if you see them in a tide pool. Many animals are naturally attached to rocks for survival and you could be risking their survival.

3. Play. You might not want to go home, but you also might be in the company of some people that just don’t have a very long attention span. Even more frustrating is repeating the phrase, “No, you cannot go in the water today” over and over again. Build a sandcastle. Surf fish with your best saltwater spinning reel under 100. Look to the horizon for dolphins or porpoises. Make a sand angel. Look up to the sky for cloud animals. Check out my ebook for other beachcombing adventures.

2. Bag it and track it. It’s always nice to be prepared to be able to do your part. I prefer to take along a hefty canvas bag that can fit in a backpack so I can tote marine debris back to a garbage can. You might even try to acquire one of these nifty bags with holes for sand to percolate through from the Green Bag Lady. When you head back to the car you can even do some citizen science and log your marine debris on the Marine Debris Tracker.

1. Don’t expect too much. It’s important to remember to relax and respect the area you are exploring. All of the ideas above are simply suggestions and ideas to ensure you get the most out of  a beachcombing adventure. Please don’t hesitate to share your favorite stories, spots, and other ideas for a great day. You can comment below of email me at info@beachchairscientist.com.

How to track a horseshoe crab

Today I am excited to bring a new video produced by Coastal Kingdom TV, a television series dedicated to sharing the unique and diverse habitats of the South Carolina lowcountry. Host Tony Mills demonstrates the best way to track horseshoe crabs in the tidal flats of South Carolina and does a superb job enlightening us on some of the animal’s unique characteristics.

What they’re into … with Braddock Spear (Sustainable Fisheries Partnership)

It’s Tuesday and so I am sure you know by now, but this is a series I have been featuring each Tuesday this summer to get a special sneak peek at the different personalities behind the scientists, activists, and educators (including bloggers) who play an integral role in the marine science conservation field. It’s essentially an extension of the overwhelmingly popular and well done Tumblr blog, This Is What A Scientist Looks Like, (BCS was featured in April!) which sets out to illustrate that scientists are not just crazy haired nerds in lab coats. I’ve sent a list of 15 random questions to some folks I know and asked that each person share at least their answers to 5 of them. Here you find the weird preferred smells among other things of Braddock Spear from the Sustainable Fisheries Partnership.

Braddock Spear is Deputy Director of the Improvements Division at the Sustainable Fisheries Partnership (SFP) and has worked there for the last 18 months trying to improve fisheries around the globe. For 8 years before SFP, he worked at the Atlantic States Marine Fisheries Commission ending his tenure as Senior Coordinator for Policy and having coordinated fisheries management of horseshoe crabs, northern shrimp, and Atlantic menhaden. Also before joining SFP, Braddock blogged on the sustainable seafood movement at Sustainable Ocean Project. The site is no longer updated with new content, but all past posts are still there for the reading. Braddock received a BS in Marine Biology from the University of Maryland and a MA in Marine Affairs from the University of Rhode Island.

What is the last thing you bought that you shouldn’t have?
A ticket to Vegas. I’ll be saving my pennies til I go.

What is your favorite fruit flavor?
Mango! I was spoiled in Belize when I got fresh mango from my host family’s tree every morning.

What is your favorite Sunday breakfast?
A coffee and a scone at the Baltimore farmers market.

What is your favorite scent?
Gasoline and cigar smoke are two of my favorites. Though not too much of either and definitely not together.

How superstitious are you?
Not at all. I’ve walked under lots of ladders, broken a few mirrors, and had a black cat. Despite all that, I’d say my luck has been pretty good (hoping that continues in Vegas).

Bonus random fact:
I’ve recently become a big fan of street art. If you’re interested, check out: http://www.streetartnews.net/

Thank you for participating, Braddock! It was great to hear from you (Braddock is an old co-worker on mine). Have a great time in Vegas!

Don’t forget to read the rest of the “What they’re into …” series.

Witness the horseshoe crab molting process

I’d like to share this remarkable two and a half-minute video of a horseshoe crab during the molting process. Produced by the Hong Kong Coast Watch and filmed by Kevin Laurie in May 2011, this film shows a juvenile Tachypleus tridentatus (one of the three species found in the Pacific ocean along the coast of Japan) shedding its outgrown exoskeleton at 16 times real speed. With calming music playing in the background you can witness the horseshoe crab as it burrows in the sand and exerts a tremendous amount of effort pulsing and pushing as it releases itself from its old shell. You can also get a glimpse as to the interesting creatures crawling around on the shores of the Pacific sea. For more information on the morphology differences between the four extant species of horseshoe crabs visit the Ecological Research & Development Group (ERDG), a leading resource for all things horseshoe crab related.

Why is the blood of horseshoe crabs blue?

Horseshoe crabs use hemocyanin to distribute oxygen throughout their bodies. Hemocyanin is copper-based and gives the animal its distinctive blue blood. We use an iron-based hemoglobin to move oxygen around.

The blood of this living fossil has the ability to  clot in an instance when it detects unfamiliar germs, therefore building up protective barriers to prevent potential infection. This adaptation has made the blood of the horseshoe crab quite desirable to the biochemical industry.

Image (c) wired.com

How have horseshoe crabs been able to remain unchanged for centuries?

In case you have not had the opportunity to get your hands on the new book, Horseshoe Crabs and Velvet Worms, about animals that have remained unchanged through time (Richard Fortey) here is a video from the BBC  on how the horseshoe crab has been able to survive through the ages.

I am particularly fond of this clip because the horseshoe crab expert notes that the horseshoe crab, while an opportunistic and a generalist, is not an aggressive animal.

Please feel free to comment if you’re one of the few that has eaten horseshoe crab eggs.

Share your beachcombing adventures!

It’s just about time to get back to reality from a weekend, so why not extend the good times and share your beachcomber adventures?Did you find anything interesting? Did you watch any birds swoop down to the sea for food? What was the sunset like? Share your pictures or any fun stories! Here is a photograph I call ‘Littlest Limulus Love‘ from a visit the the Stone Harbor Point.

Looking forward to hearing all the amusing anecdotes from your times at the sea! To share you can reply to this post or find Beach Chair Scientist on Facebook or Twitter.

The most effective kind of education is that a child should play amongst lovely things.” — Plato (Greek philosopher, 428 – 347 BC)

Find more great nature at play quotes compiled by the “Institute for Nature in Childhood” here.