• Home
  • Volunteer
  • Volunteer Info
    • Volunteer FAQ
    • Beach Captain Protcols
    • Tagging Pics
    • Where are these beaches?
  • HSC Info
    • Tagging Procedure
    • HSC Videos
    • Reports
Horseshoe Crab Tagging Delaware Bay

background information

Background Information

Picture
Twenty-five years ago, Delaware Bay was the first site of Hemispheric Importance for shorebirds designated by Western Hemisphere Shorebird Reserve Network.   The WHRSN designation recognized the Delaware Bay’s value to thousands of red knots, semipalmated sandpipers, ruddy turnstones and other arctic nesting migratory shorebirds.  Each May, the birds arrive from wintering sites as far away as Tierra del Fuego, Chile to refuel on horseshoe crab eggs before continuing their 10,000 mile odyssey from wintering areas to Arctic breeding sites.  The horseshoe crab underpins this migration and has done so for thousands of years.  

In the mid 90’s the horseshoe crab was overharvested and after 15 years of effort to restore the crabs, populations remain at historic lows.  Shorebird numbers fell as well including the red knot, the arctic breeding shorebird, most dependent on crab eggs.  

Many efforts are underway to restore the horseshoe crab population including large-scale management to restore marginal breeding habitat.  Since the devastation of Superstorm Sandy a consortium of conservation groups and agency staff have worked to restore critical horseshoe crab spawning habitat and foraging grounds for migratory shorebirds on the New jersey side of the Delaware Bayshore. This horseshoe crab tagging program is a monitoring component of this restoration work. More information on the beach restoration work can be found at restorenjbayshore.org.

Throughout the spawning period for crabs, volunteer teams, under the direction of conservation and agency biologists, will follow standardized protocols to tag crabs and conduct a rigorously defined survey of the ratio of tagged and untagged crabs counted on the beach during spawning.  Each team will record the tag number of every resighted crab and additional measurements may be taken at that time.  We envisage this survey to parallel a very successful shorebird band resighting program that underpins the ARM model.

The data from the volunteer teams will be reported to a central database similar to the bird resighting effort called bandedbirds.org.   Coordination with the United States Fish and Wildlife Service will also be part of this project in order to obtain resighting data from the public that is housed at USFWS.  This data will be made available to any scientist with the permission of the principle biologists in charge of collecting the data.  Thus far the data in bandedbirds.org has provided vital data to many scientific analyses including the ARM model.  The same will be possible with this new horseshoe crab tagging and resighting effort. 

Goal:  
To provide valuable data that will inform regulatory decision-making and ongoing science by utilizing volunteers to increase the number of tagged horseshoe crabs and the reporting of resighted tagged horseshoe crabs on Delaware Bay beaches.

Objectives:
  1. Better understand movements and distributions of Delaware Bay breeding horseshoe crab population, to inform and support management decisions including contribution to the Adaptive Resource Management (ARM) model that sets harvest allocations and quotas.
  2. Utilize mark-recapture rates to estimate the population size of horseshoe crabs.
  3. Increase public engagement and stewardship through improved understanding and hands-on interaction with horseshoe crabs.
  4. Improve habitat restoration efforts by identifying restoration techniques that are most attractive to returning horseshoe crabs.
  5. Support the ongoing scientific research of horseshoe crab and shorebird populations by making data available, upon request and approval, to scientists and researchers.

See You on the beach!


Telephone

856-825-2174

Email

quinn@littoralsociety.org
DONATE
  • Home
  • Volunteer
  • Volunteer Info
    • Volunteer FAQ
    • Beach Captain Protcols
    • Tagging Pics
    • Where are these beaches?
  • HSC Info
    • Tagging Procedure
    • HSC Videos
    • Reports