Asian Shore Crab and European Green Crab Habitat

Asian Shore Crab and European Green Crab Habitat Amy Darbyshire | Conor Clifford | Quinn Coughlin | Stephanos Mitrokostas | Augusta Davis

Hemigrapsus sanguineus Carcinus maenas Asian Shore Crab (Hemigrapsus sanguineus) on the left and European Green Crab (Carcinus maenas) on the right.

Question and Hypothesis Research Question: “How do the hydrophysical properties of the Sandwich Town Beach Estuary affect the distribution of Hemigrapsus sanguineus and Carcinus maenas? ” Hypothesis: Based off of some prior research -- and consultation with Dr. Pete -- we suspect that the Asian Shore Crab (H. sanguineus) will be more common in the turbulent and cooler outer beach waters rather than in the estuary, whereas the European Green Crab (C. maenas) will likely be found in calmer estuary waters, but not necessarily in warmer ones.

Materials and Method Materials: 2 nets and 2 pails (to catch and contain crabs) ham (bait) 3 pieces of string, 2 one meter long and 1 five meter long (one to assist in measuring the quadrats, one to tie the bait, and the third to tie the water bottle to measure current speed) an empty water bottle 2 poles (to measure out quadrats) 2 pairs of waders i. Phone (for taking pictures, stopwatch and a gps) • •

Materials and Methods: Catching the crabs: Tie a pole to each end of the one meter long piece of string and place the poles in the water so the string is stretched out, measuring one meter and record GPS coordinates of the quadrat. Tie the bait to the other meter long piece of string and place it in the water. Use the nets to catch the crabs as they attack the bait. Fill the two pails with water and keep the Asian Shore crabs (H. sanguineus) in one bucket and the European Green crabs (C. maenas) in the other. • •

Materials and Methods: Current Speed: Tie the five meter long string to the water bottle and release it into the water. Use a stopwatch to time how long it takes to travel the five meters. Divide five meters by the amount of seconds it took the bottle to travel five meters to find current speed. Temperature Place thermometer in water at the different sites and record temperature in o. C. We used 2 different thermometers to record an accurate temperature • • •

Raw Data Temperature, Current Speed and Number of Shore Crabs at Sandwich Beach Estuary

Processed Data

Processed Data (cont. )

Conclusion The number of crabs that live in a certain area is affected by current speed and water temperature. As our data shows, the faster the current and the colder the water, the less likely crabs will live in an area. It is also apparent that C. Maenas (European Green Crabs) are far more common than H. sanguineus (Asian Shore Crabs). While C. maenas Crabs were more common, H. sanguineus Crabs were found in colder water with faster current speeds than the water where C. maenas Crabs were found though to little data of H. sanguineus Crabs was collected to draw a complete conclusion of the habitat of the H. sanguineus. In conclusion, C. maenas are very common and tend to live in warmer water (around 17 degrees celsius), and with slower current speeds (below 0. 45 meters per second).

Evaluation Limitations / Advantages Why is this a problem / benefit? How did this affect the lab? The amount of We spent a different amount of time spent at at each location. This may impact each area. the opportunities to catch crabs. It is difficult to determine whether the hydrophysical properties of the Sandwich Town Beach Estuary impacted the number of crabs found or whether it was the amount of time spent at each station. How effectively the group worked together. Good communication and equal effort by team members. Efficient completion of the task. We were also able to collect data in an orderly manner and make sure it was thorough and accurate. Sharing of knowledge and personal ability. The team members had different strengths and abilities. Sharing knowledge between ourselves; our strengths and weaknesses varied and we were able to learn different things from each other.

Pictures!

Online Images Bibliography "Hemigrapsus Sanguineus. " Wikipedia. Wikimedia Foundation, 10 June 2013. Web. 15 Oct. 2013. Bortolus, Alejandro. "Carcinus Maenas | The Exotics Guide. " The Exotics Guide. N. p. , n. d. Web. 15 Oct. 2013.