The Cause:
Horseshoe crab populations are threatened globally due to human exploitation and are considered endangered in New England. They are a fascinating species that has been around for over 400 million years. Their survival has a significant impact on other species in their ecosystems, especially red knot birds and humans actually. In fact, horseshoe crabs have unique sky blue-colored blood that clots when it comes into contact with bacterial toxins. Therefore, their blood is used to help sterilize vaccines, drugs and medical devices before they are administered to humans.
The Maritime Aquarium in Norwalk, CT is passionate about leading conservation efforts for the local horseshoe crab population. In 2018 the aquarium received a donation from Richard and Kim Alexander as well as the Ballard Foundation to update and expand their dated horseshoe crab exhibit. At the time, the Main Tank’s chiller was not able to maintain the optimal temperature for the adult horseshoe crabs inside.


My Role:
I was adamant about helping the Maritime Aquarium for my University of Connecticut (UConn) engineering senior design project along with my fellow classmates Kaihla Tomassi, Ewelina Bucior and Caylin Cyr as well as our faculty advisor, Dr. Kristina Wagstrom (the only all-female senior design team in UConn’s 2019 Chemical Engineering class). We helped re-design the aquatic life support system for the adult main tank. For the conservation effort, we also validated the design of two new rack systems being implemented to host horseshoe crab babies at various stages of life from eggs to infants to adolescence until they are ready to be released to the ocean. One rack system was going to be on display for aquarium visitors to see and the second one, referred to as the “Grow-Out Tank”, got located behind the scenes for adolescent horseshoe crabs as they get larger to reduce overcrowding in the first Rack System. I also designed educational visuals for the client-facing side of the exhibit. A big thank you is owed to the Maritime Aquarium staff, especially their Associate Director of Life Support, Erik Holmberg, for teaching us so much and giving us the opportunity for some real hands-on experience.​
The Process:
First, I worked to understand why the current life support system was not satisfactory and did some research on what kinds of heat exchangers would be a more effective replacement for the chiller. Then, the team modeled the Main Tank system and Rack System in the Aspen Plus process simulator as well as carried out heat transfer calculations to validate that the chosen AquaLogic heat exchanger would maintain the proper temperature for both. We also did fluid mechanics equations to validate the sizing of the systems’ pumps. I evaluated how the Main Tank’s mechanical filter functions and we analyzed the effectiveness of the filtration sumps in the Rack System and Grow-Out Tank to ensure the ammonia concentration would be kept beneath the required levels to support baby horseshoe crab health.


For the Grow-Out Tank, we learned from other breeding systems at the aquarium to plan out the system’s process flow and order PVC parts. As a team, we regularly traveled across the state to visit the aquarium and build the Grow-Out Tank by hand. We screwed the stand together, installed the tanks, sump and pump, hand cut and glued all the piping and valves together, etc. The team also modeled the Grow-Out Tank system in Aspen Plus to validate the pump and so I could make recommendations about temperature regulation which were later implemented by the aquarium via the installation of a chiller.

All system design updates have been made and conservation efforts are in full swing. Some adolescent horseshoe crabs have already been released to the Long Island Sound!
More Information:
I also created some digital drawings about horseshoe crabs for the aquarium and one of them is now a formal part of the updated educational display at the exhibit: