For Summer 2023, two interns in the UMES Research Experience for Undergraduates in Marine and Estuarine Sciences program will be working on this project, and we will focus our efforts on two topics: 

1. Will horseshoe crabs spawn inside of the canal if given some appropriate spawning habitat?

   • In June 2023, we built a platform (Figure 1) filled with sand and placed it in the canal. We are observing the platform to answer the following questions: 

     • Can crabs locate the platform? Answer: Yes! We have observed many crabs climbing up the ramp (Figure 1). We are continuing to monitor the crab behavior on and around the platform. 

     • Will crabs nest and lay eggs on the platform? Maybe. We have seen female horseshoe crabs with attached males sit in the box for several hours. We have not yet located eggs on the platform, but we will continue to look. 

2. How do crabs enter and exit the canals?

   • In July 2023, we began tagging horseshoe crabs using Passive Integrated Transponder tags. These tags are placed inside the body of the crab, and can be detected using an electronic detector.  This is very similar to the "microchips" used in pets. We will use this technology to attempt to answer the following questions:

     • Do live crabs stay in the canal all summer?  To answer this, we've tagged 60 live crabs at the end of the canal. We will be back periodically with the detector to see if those same crabs are remaining inside of the canal. If dead crabs appear in the canal, we will scan those too to determine if they are the ones that we tagged.  This will help us to understand whether the dead crabs come from those that entered the canal alive or whether they are dying outside and drifting in. 

     • Do crabs from spawning areas outside of the canal enter the canal? We will tag an additional group of crabs near the spawning habitat at Swan Point near the mouth of the canal. We will monitor the canal to see if we detect any of them inside the canal.