Tag Archives: ancient

What Happened to all the IRL Horseshoe Crabs? SLR/IRL

Young horseshoe crabs, public photo, 2017

When I was a kid, I often walked to the Indian River Lagoon and just stood there in amazement watching the hundreds, if not thousands, of baby horseshoe crabs winding their way through the sands. They left circular trails, crossing over and over again…

Where were they going? What were they doing? Why were there so many?

Photo by Anthony J. Martin

Every once in a while, I would pick one up and place it carefully in the palm of my hand. Its sharp tail and prickly feet pushed against me. I watched in wonder at its strength as it bent in half. Once returned to the sand, the little crab went back to work immediately as if nothing had happened at all.

My mother had told me the horseshoe crabs were more ancient than the dinosaurs and had been here “forever.” “They are living fossils” she would say. “And they can live over 20 years and take 10 years just to mature.”

Although I picked them up with such care, today, forty years later, when I try to find them, they’re gone.

What happened to the horseshoe crabs of the Indian River Lagoon? How did a creature so ancient, resilient, and prevalent almost “disappear?”

Although there is quite a bit of literature on the Central Indian River Lagoon, I could not find much on the Southern Lagoon. Some of the best documentation came from Gretchen S. Ehlinger and Richard A. Tankersley. On line, they are cited multiple times for their paper “Reproductive Ecology of the American Horseshoe Crab, Limulus Polyphemus, in the Indian River Lagoon: An Overview.”  I was also able to read “Evaluation of the Horseshoe Crab Fishery in the Indian River Lagoon Using Catch Data From Two Power Plants,” and a September 2014 “FPL Cape Canaveral Energy Center Horseshoe Crab Deterrent Fence Specifications” publication.

All of these lead to the following observations: decline of the species has been noted  for around three decades. There  have been UME’s or “Unexplained Mortality Events” where up to a 100,000 have died in the same area around the same time.

Factors that are related to their overall decline in the lagoon include intense coastal development, shoreline breeding grounds destruction, and unbridled  human population growth; expansion of agriculture drainage watersheds into the IRL; deteriorating water quality; power plants sucking up as many as 100,000 a year into their intake canals; and over-fishing. The crabs are used as bait, collected for marine purposes, and more recently captured live and bled for their “blue-blood”that is invaluable to human health.

Unfortunately, for many years, the value and importance of the horseshoe crab was not recognized. For instance, Ehlinger and Tankersley note  a one year study in the early 2000s at two Indian River Lagoon power plants that recorded a total of 39,097 crabs trapped on the intake screens at Cape Canaveral, and 53,121 at the Orland Utilities Plant. The scientists also mention a previous study from 1975 that estimated 69,662 at the Canaveral Plant, and 104,000 trapped annually at the Orlando Utilitility’s Indian River plant. “This alone could easily account for a decline in the Indian River population.” (Ehlinger and Tankersley 2007)

The St Lucie Power Plant  located here in the southern lagoon did not agree to be part of the study and there is very little research one can now find on the subject.

In any case, the good news is that just recently the Cape Canaveral plant has installed a wall to protect the horseshoe crabs and science’s recognition of the species has people wanting them to come back.

The Florida Wildlife Commission notes:

“Horseshoe crabs are extremely important to the biomedical industry because their unique, copper-based blue blood contains a substance called “Limulus Amebocyte Lysate”, or “LAL”.This compound coagulates in the presence of small amounts of bacterial toxins and is used to test for sterility of medical equipment and virtually all injectable drugs.  Anyone who has had an injection, vaccination, or surgery has benefitted from horseshoe crabs!”

…”in March 2000, a series of management measures for horseshoe crabs went into effect in Florida. The regulations required a license to harvest and set a limit on the number of animals each licensee could harvest per day (25 to 100 animals allowed per day per person depending on the permit). In 2002, a biomedical permitting rule created a mechanism to allow for biomedical collection.”

Yikes!

Horseshoe crabs being bled. Image as shared by FWC in 2017, first published in Popular Science.

Personally, looking at these photos of the horseshoe crabs being bled is like a science fiction movie to me. Never as a kid would I have imagined my little friends with needles in their heads being milked for their blood.

….But if this is what is going to save them… I must say, if they could talk, I bet now is the strangest part of their 450 million year journey. In my mind, they will always be free and drawing circles in the sand.

Ancient horseshoe crab fossil. CREDIT CARBON NYC / FLICKR CREATIVE COMMONS

 

Horseshoe crabs gather under a full moon to procreate. Photo, National Park Service.

Links:

Horseshoe crab eye, JTL.

Ehlinger and Tankersley: http://www.horseshoecrab.org/research/sites/default/files/DONE%20Ehlinger%20and%20Tankersley.pdf

http://articles.orlandosentinel.com/1999-08-22/sports/9908220099_1_crabs-mosquito-lagoon-titusville

FPL wall to protect marine life, central lagoon:
http://www.nexteraenergy.com/energynow/2015/0915/0915_marinelife.shtml

St Lucie Power Plant effects on IRL and environment: https://www.nrc.gov/docs/ML0214/ML021430397.pdf

Changing Global Perspectives on Horseshoe Crab Biology and Conservation Management: https://www.kobo.com/at/en/ebook/changing-global-perspectives-on-horseshoe-crab-biology-conservation-and-management

Bleeding Horseshoe Crabs for Human Health: http://www.americanpharmaceuticalreview.com/Featured-Articles/167236-The-Incredible-Horseshoe-Crab-Modern-Medicine-s-Unlikely-Dependence-on-a-Living-Fossil/

FWS: https://www.fws.gov/northeast/pdf/horseshoe.fs.pdf

FWC:
http://myfwc.com/research/saltwater/crustaceans/horseshoe-crabs/fishery/

http://myfwc.com/research/saltwater/crustaceans/horseshoe-crabs/facts/

continued….

Me with horseshoe crab on my head, Spoil Island family boat outing, IRL, 1980. Photo Sandra Thurlow.

Ehlinger and Tankersley Links:

Addendum to FPL CCEC Horseshoe Crab Fence ERP Application

Ehlinger and Tankersley 2007 Fla Sci

Power Plant Study

Chasing Tarpon! SLR/IRL

Chase with a tarpon he recently caught and released, St Lucie River/Indian River Lagoon region. Photos courtesy of  Chase’s iPhone, 5-24-17.

Happy 17th Birthday to Chase! If you don’t already know him, Chase is one of Stuart’s leading sports fishermen, in any age category. This photo is of a recent catch of my favorite fish, the beautiful and unforgettable, “Silver King Tarpon.”

Since Chase was thirteen years old, when we ran into each other, he would share photos of his fishing expeditions. I always stood there, mouth wide open…”Are you kidding me?” I would ask. He would just smile with his wide, blue eyes saying it all:” THIS IS NO FISH STORY…

In 2015, Chase and I,  together with many others tried to save a pigmy whale that had beached at Stuart. Chase loves the outdoors and has respect for all of the water’s creatures.

Yesterday,  in Jensen, I ran into Chase celebrating his 17th birthday with family and friends.

Perhaps it is his mother’s wonderful name, “Cobia,”  that inspires her son! 🙂

If you are a reader of my blog you know, the ancient, acrobatic, and historic tarpon is my favorite fish as it was the original sports fish of the St Lucie River/Indian River Lagoon, until its numbers were destroyed by canals, C-44, C-23, C-25 and C-25. Had these canals not been allowed to decimate our river, Tarpon would still be King, not the famous off-shore Sailfish….

Thank you Chase for sharing and inspiring us all! We know you have a great future ahead of you!!!! I can’t wait ’til you have your own show!!!!!!

Chase w/Tarpon . What a beautiful fish!
Chase w/Tarpon!
Tarpon Fishing in the St Lucie River/S. Indian River Lagoon ~ by famed artist or the time, Kent Hagerman, 1893-1978. Image courtesy, Sandra Henderson Thurlow archives.

Former Blog post explaining the story of  Stuart’s focus from “Tarpon to Sailfish: “He Shall Be King Again! The Silver King of the St Lucie River/Indian River Lagoon, by Jacqui Thurlow-Lippisch: https://jacquithurlowlippisch.com/tag/st-lucie-river-tarpon-club/

Tarpon Links:

Fishing Stuart,Tarpon: http://www.fishingstuart.com/floridafish/tarpon.php

FWC, Tarpon:http://myfwc.com/research/saltwater/tarpon/information/facts/

Tarpon Facts:Tarpon:https://www.tarponfish.com/tarpon-facts/

Florida Museum, Tarpon: https://www.floridamuseum.ufl.edu/fish/discover/species-profiles/megalops-atlanticus/

Bonefish/Tarpon Trust: https://www.bonefishtarpontrust.org

CANALS:

Canals in Martin and St Lucie Co.: C-23, C-24, C-25 constructed in the 50s and 60s. C-44 connected to Lake Okeechobee, the worst,  constructed in the 1920s. These canals, assisting agriculture and development, destroyed the “fishing grounds of presidents” from the early 1900s, the famed St Lucie River. In the 30s and 40s the offshore Sailfish was marketed and Stuart became known as the “Sailfish Capital of the World” as so many of the tarpon and other fish of the river had declined. The tarpon was forgotten as the original main game fish of the St Lucie River. May he rise again! JTL