Alternative Solutions

Three different tanks have so far been designed based on my current knowledge of what horseshoe crabs need and in what type of environment they thrive in. Each design accomplishes a different goal, and the designs are very basic and undetailed. Whichever design is chosen to move forward with will then be altered to fit with the necessary systems.

The first tank I designed (seen above) was a basic cylindrical tank with an observation window in the front through which the horseshoe crabs could be inspected. I worked in a basic water flow system which ended up not being accurate and was based on very limited knowledge of pumps. This, however, is a small and easily fixable mistake. This tank is good because the cylindrical shape maintains its stability when put under the pressure of many gallons of water. The shape of this tank limits the ability of scientists to evaluate the horseshoe crabs regularly however, because of the depth and radius, the scientists may not be able to easily round up the horseshoe crabs in the tank. If this tank design were to become the final solution, a secondary contraption could then be constructed to make horseshoe crab collection within the tank easier.

This tank was designed with the location of the horseshoe crab breeding ground in mind. Generally the horseshoe crab breeds and lays eggs in the inter-tidal zone, so this design worked in the slope and dry sand area which would be found in the areas in which they live for the first few months of their lives. However, in their youth the dry sand may not be necessary since they generally only leave the water to mate. The shape of the tank, however, allows for tide simulation and better representation of the horseshoe crabs natural environment. One obstacle I am expecting to run into with this tank is the sand. I would like to have the bottom of the tank to be coated in sand from the area, however with the sloped bottom and constant movement of water the sand may settle on the lower part of the slope leaving the top exposed.

The third solution I created was based off of the tanks the NOAA lab already has in place. In the center of the tank is a water drainage pipe which regulates the level of the water. I could then attach this pipe to a water pump and a series of filters to continue using the water rather than wasting resources. I've also worked in the slope which would also be found in the natural habitat and would allow for the crabs to live in slightly deeper water but provides scientists with the shallow water to make accessing the crabs easier.

This last solution was another tank designed off of already existing tanks in the NOAA laboratory, however I modified the style to better fit the needs of the horseshoe crabs. The design of this tank takes into account the natural incline of the shore which the horseshoe crabs would, in nature, live during the time we will be raising them. The design also saves space while also allowing for the necessary scientific observation and separation during their time in the lab. 

Background Information on the Purpose of the Project

Sign in Atlantic Highlands, NJ

Horseshoe crab harvesting has become a common practice to collect the valuable blue blood and also to use as bait for other marine life. The animals are also threatened by habitat destruction caused by climate change. As a result, the population of Limulus polyphemus is declining and quickly becoming a threatened species. With hopes of helping the species thrive, my team along with two other teams has taken on the challenge of creating a simulated habitat for the horseshoe crab. We took this opportunity to expand the population of this very important animal while also presenting the scientific community with the opportunity to study and hopefully better understand the species.

Banking Blue Blood

Production of LAL

Stranded Horseshoe Crabs

Dead Horseshoe Crab in Myrtle Beach

The horseshoe crab is a vital part of the world economy and plays an important role in the medical field as well as in the scientific community. If the population of horseshoe crabs continues to decline, the effects will be felt by everyone including other species of animals. The species is extremely important in the medical community for the special properties of the blue blood the animals produce. Groups like the American Littoral Society and the ERDG are working toward educating the public about the horseshoe crab and also have started programs and campaigns, which highlight horseshoe crab conservation. These groups as well as interested scientists may take the design of our system and apply the design to their needs, whether that is for research or to aid in raising horseshoe crabs to supplement the natural population.

The loggerhead sea turtle has suffered
from reduced numbers of horseshoe crabs

Horseshoe crabs may help with
the development of antibiotics

The red knot bird relies on
the horseshoe crab for food

The horseshoe crab is an ancient
species beginning to die

Just Flip 'Em Program Art Contest Winner

This is a species that has been on Earth for a lot longer than humans have been. Since humans arrived and started changing the ecology of the Earth, habitats and weather patterns are changing and the horseshoe crab cannot keep up. Between over harvesting and habitat loss, their numbers are dwindling and once they are gone they can never come back. Without the horseshoe crab the medical field will lose out on numerous breakthroughs, which could result in furthering the study of horseshoe crabs. If this project works as intended, the scientific community will better understand a species which at the moment is somewhat of an enigma to humans. 

The number of horseshoe crabs is declining

Horseshoe Crab eggs are
very small and vulnerable

Loss of habitat and breeding grounds
threaten the horseshoe crab

Even naturally, horseshoe crabs
find themselves in odd situations

The time has come for the horseshoe crabs to fight back

Overall in this project I hope to provide the scientific and engineering community with the best possible way to go about raising young horseshoe crabs. More than just the marine world will benefit from this project and many people will be effected during the process of creating, finalizing, and utilizing this tank. 




At one year old the horseshoe crab
is about the size of a quarter

In a proper environment, young
horseshoe crabs can thrive

Maintaining a professional mindset is important

Current laboratory tanks

The natural habitat of the horseshoe crab will be mimicked

My team is taking this project seriously and we hope to convey that into our design. The design needs to be sterile for a lab and highly functional and efficient. Wasted space or time is unacceptable and may eventually be harmful to the study. Function comes first in our project, and though I want to make the tank aesthetically pleasing, the project will not fail because of appearance. The tank will end up being very similar to a fish tank, though altered to fit the needs of the specific species of invertebrate while also working to please the needs of those who will use the tank to study the species. This tank will mainly be a combination of technologies already created for other uses and will combine to best recreate the habitat of the horseshoe crab. Many of the pieces which will be incorporated into the design can be found in an average fish tank, though we will be altering some and connecting them to perform functions, which will mimic nature.

Design Brief, Specifications, and Limitations of Designing the Tank

Design Brief: Design, model, develop, and build a simulated habitat housing for future MAST students to house 100 horseshoe crabs from 6 months to 1 year in a climate controlled lab setting and have a survival rate of 20% while also allowing for scientific research to expand human knowledge of the species.

Specifications:

• have space to raise 100 six month to one year old horseshoe crabs (five cubic feet)
• increase the survival rates of horseshoe crabs to 20%
• be beneficial to the study and understanding of the horseshoe crab as a species
• replicate the natural environment of the horseshoe crab by simulating natural nutrients, temperature, and features
• be stable enough to not collapse or leak under the pressure of the water in the tank
• properly connect with the pump and nutrient systems
• have a constant flow of salt water
• be waterproof
• run constantly as an entire system
• be replicateable for others to use

Limitations:

• variability of the size of young horseshoe crabs
• availability of space in the lab
• not all natural processes such as inclement weather can be replicated in a lab setting
• joints and seems are weak points
• ability to filter the water within the system to reuse water instead of constant replacing 
• over filtration causing an imbalance of nutrients
• availability of non-corroding materials (ie: plastic, glass)
• the length of the average human arm (limits depth and width of tank)
• availability of generators for power outages
• design simplicity

Research and Brainstorming

The Atlantic Horseshoe Crab (Limulus polyphemus)

• adult females may lay ~90,000 eggs a year
• about 10 reach adulthood
• eggs hatch in the sand and the babies swim for about a week and then settle to walk on the shore floor
• juveniles generally spend first and second summers in intertidal flats
• the species is on the road to being endangered
• at six months they are appx. the size of a nickel
• by one year they reach about the size of a quarter
• live alone the Atlantic coast of the United States
• Chesapeake Bay
• Sandy Hook, NJ
• sexual maturity is not reached until 9-12 years
• they have a higher survival rate in captivity when the tank contains sand compared to without

additional information at:
http://www.horseshoecrab.org/info/lifecycle.html
http://www.ceoe.udel.edu/horseshoecrab/history/lifestages.html
http://marinebio.org/species.asp?id=281
http://iobis.org/mapper/?taxon=Limulus%20polyphemus

Marking Period 1 Calendar of Work and Due Dates

Due Dates:

9/13 - calendar of dates due

9/16 - background information, design brief, specs, limits, summer research/brainstorming, alternative solutions

9/20 - first log due

9/23 - rationale report, model

9/27 - testing procedure, weekly log

10/4 - weekly log

10/11 - weekly log

10/18 - weekly log

10/25 - weekly log, developmental work

10/30 - outline for formal presentation

10/31 - presentations begin

Day after presentation - mentor contacts

2 days after presentation - presentation reflection

Working Plan*:

9/13 - finish formatting blog; look over summer work and items due Monday; visit the NOAA lab to learn what technologies they already have in place; finalize calendar

9/14 - delineate specs and limits; create alternate solution based on trip to NOAA; work on background information
9/16 - finalize tank design; begin modeling the tank structure

9/17 - preparation for informal presentation; continue modeling tank structure

9/18 - informal presentation; update blog

9/19 - begin rationale report; begin adding details and connections for Rob's system additions

9/20 - finish model of tank and add Rob's pump and systems

9/23 - research tank materials; update blog

9/24 - find possible weak points of the tank and add supports into the design

9/25 - begin formal drawings of the tank design

9/26 - explain the weeks work in a log; post testing procedure on blog

9/27 - begin looking at requirements for developmental work
9/30 - begin developmental work

10/1 - update mentor contacts; research materials to be used in connecting the systems to the tank

10/2 - continue working on developmental work and formal drawing of design

10/3 - explain the weeks work in a log; update blog

10/4 - collaborate with other horseshoe crab tank groups to see which direction they are working in

10/7 - finish formal drawings
10/8 - continue research on the needs of young horseshoe crabs

10/9 - look into the average cost of materials to be used in design

10/10 - explain the weeks work in a log; update blog

10/11 - update mentor contacts; work on developmental work

10/15 - make sure systems properly connect with tank

10/17 - explain the weeks work in a log; update blog

10/18 - continue developmental work

10/23 - finish developmental work

10/24 - explain the weeks work in a log; update blog

10/25 - begin to outline formal presentation

10/28 - work on permal presentation and ensure everything needed for a presentation is available

10/30 - update mentor contacts

10/31 - formal presentations; update blog

*subject to change

Works Cited

Babin, Perry. "Working With Acrylic." N.p., n.d. Web. 25 Nov. 2013.

Funch, Peter. Stranded Horseshoe Crabs. 2011. Xray-mag.com. Web. 14 Sept 2013.

Gerhard, Dale. Juvenile Horseshoe Crab Crawls in a Tank. 17 August 2012. Wildnewjersey.tv. Web. 28 Sept 2013.

Gonzalez, Mike. Loggerhead Sea Turtle. 2007. Geargia Aquarium. Atlanta, Georgia. Wikipedia.com. Web. 15 Sept 2013.

Habitats of Horseshoe Crabs. 2013. Afcd.gov.hk. Web. 17 Sept 2013.

Hill, Randall. Dead Horseshoe Crab. 2002. Myrtle Beach. Postandcourier.com. Web. 14 Sept 2013.

Horseshoe Crab Harvest for LAL Production. N.d. Nerrs.noaa.gov. Web. 14 Sept 2013.

Horseshoe Crab Landings. N.d. Dnr.state.md.us. Web. 28 Sept 2013.

Kathy. Baby Horseshoe Crab. 4 October 2010. Flickr.com. Web. 28 Sept 2013.

Lauderdale, David. Flipped horseshoe crabs. 2010. Islandpacket.com. Web. 15 Sept 2013.

Matt. Horseshoe Crab Character. 30 May 2010. Mattoonart.blogspot.com. Web. 28 Sept 2013.

Red Knot. 2005. WVTF.org. Web. 15 Sept 2013.

Reynolds, Joe. Atlantic Highlands Sign. 2007. Bayshorewatershed.org. Web. 14 Sept 2013.

Smilowitz. Just Flip 'Em Program. 2006. Horseshoecrab.org. Web. 14 Sept 2013.

Switek, Brian. Horseshoe Crab. 2008. Delaware. Wired.com. Web. 15 Sept 2013.

              

Thiessen, Mark. Banking Blue Blood. 2011. Nationalgeographic.Com. Web. 14 Sept 2013.

Winter, Steve. Horseshoe Crab eggs. Allposters.com. Web. 15 Sept 2013.