Horseshoe Crab Die Off?

[SHELLFISH]

Around the Norwalk Islands in CT. I have seen fairly large numbers of dead horseshoe crabs. I was diving in about fifteen feet of water and the carcasses were piled up on top of each other in a band about 30' from shore, was about 8' wide and continued around the island. I didn't follow it too far though so I don't know if it wrapped around the entire island. There are also numerous carcasses washed up on shore. I was just curious if anyone has seen this phenomenon elsewhere on the east coast? The jellyfish are in pretty strong right now up here. The red jobs up to 12". Got tagged by one; they just leave red dots on the skin where the nematocysts have hit you. Sting and itch last about one hour; not too bad!

[crabologist]

I remember fishing in Bower's Beach , Del. a couple years back and seeing the same thing . Hundreds of them washed up on shore . Never did find out why though.........

[Tuarus]

HEY BOG LAST TIME I WENT FISHIN IN NEW LONDON I SAW A FEW OF THEM BUT THEY  WERE ACTUALLY MATING.  DIDNT SEE ANY OF THEM DEAD.  THATS STRANGE.

[ohiocrab]

i have seen that before and thought , wow look how many dead there are . I was told that it is actually them molting and shedding the shell . Alot of the times you will see them floating on the surface ,too . Only happens certian times of the year . I fyou pick them up you can tell because they look like dead ones but the shell is intact but alot lighter

[SHELLFISH]

Just got the word from the PhD expert who studies the Horseshoe crab in the sound. The answer: Hypoxia (low 02 levels) in the western sound.

[Tuarus]

SO THEY ARE NOT SHELLS.  THEY ACTUALLY DEAD BUT WHY ARE THEY DIEING IN THE SAME SPOT?

[SHELLFISH]

They probably didn't all die there. Wave action deposited the carcasses, as all debris, according to weight. Hence the equidistant (from shore) band around the island and probably all islnds in the area.
Found this interesting: A Horseshoe crab marked in Brooklyn NY was located off Rhode Island! Quite the walk.

[Tuarus]

I FORGOT ABOUT THE WAVES.

[SHELLFISH]

Below is a picture of a Horseshoe crab with a telemetry unit attached. One crab marked and released off Brooklyn NY was next found off Rhode Island. Quite an impressive walk for a slow moving critter!

[SpunkyCrab]

Last year I went crabbing at Captree in Long Island and caught a horseshoe crab in my cage! (hence the profile pic) That thing was HUUUUUUGE.   

[Tuarus]

for those that where unable to see the pic here you go. hope it works.

[Islander]

Tuarus,

What is that thing attched to the Horseshoe Crab ?

[Beth01]

We usually see about 2 or 3 dead ones when we are at the Wye.  Now my question  WHat is their purpose?  I mean I really never understood them.

[Tuarus]

Below is a picture of a Horseshoe crab with a telemetry unit attached. One crab marked and released off Brooklyn NY was next found off Rhode Island. Quite an impressive walk for a slow moving critter!

  THATS THE PIC BOG HAD ATTACHED.

[Frank]

I see a lot of dead ones down at Lewes Delaware when i go down there fishing. I thought they died after mating, thats what i was told but i dont think that is the reason. Frank

[SHELLFISH]

Thanks Taurus for posting the picture. This photo I got from the lady (PhD) who is studying the crabs in Long Island Sound. The yellow marker is just that; a marker. The cylindrical device on its back she calls a sonar. It must be some kind of telemetry unit. I would think that those hanging wires ( I believe them to be antennae) would get caught up in the aquatic vegetation. I don't know how long a crab lives! Good question; I'll find out. I've seen some pretty big ones though covered with barnacles. I don't believe they die after reproduction.

[HSC@Dowling]

The Horseshoe crab life span is known to be over 25 years.
A horseshoe crab does not become sexually mature till it's 10th year.
the way to determin the sex is by looking at the first claw if it is not any diffrent from the rest it is a female or has not reached sexual maturity, if it is shaped like a hook it is a male.
A diagram can be found at this site
http://www.dowling.edu/school-arts-science/earthmarine/HSC.shtm

[Da Princess]

I live on the banks of the Delaware river in Cape May County.  I can't even describe to you how many horseshoe crabs come up on our beaches every year.  Thousands and thousands of them.  They come up to lay their eggs in the sand.  We walk our dogs on the beach and often times see live ones laying on their back, not able to make it back into the water.  We'll pick them up and put them back into the water, usually when their turned over like that they usually die.  I was wondering what makes them flip over like that?  It can't be the tides because we don't get any hard waves.  The water kinda rolls in.  I was never able to figure out why they just don't lay their eggs and go back into the water.

Also, if you ever have the chance to look at horseshoe crab eggs they are pretty cool to look at.  They are transparent and you can actually see the embryos floating inside.  They look like small spiders.  I'm always careful not to touch the eggs because we see the seagulls snacking on the eggs all the time. 

[Larry_D]

Tuarus,

What is that thing attched to the Horseshoe Crab ?

It's an explosive device.  They are religious fanatic crabs!   

Do horseshoe crabs taste good?

[HSC@Dowling]

even if you don't have waves the rollers can flip the crabs over seagulls will also flip them over but they usually attack them quickly after that.
Russ

PS the device is most likely a locater beacon of some sort. It is used to track migration