Conclusions to Ten-Year Study of Shore Crabs

- Fewer crabs at the High-Tide zone than at the Low and Mid -Tide zones

Students calculate the average number of crabs per sq. meter

-Thenumber of crabs has increased over the decade from 1999 to 2009. The average number in1999 was 28 crabs per sq. meter and the average in 2009 was  36 crabs per sq. meter.

Students collect 10 crabs in a pail and calculate average mass and carapace width

Students set up a race course on the cement walkway.  Crabs are timed to see how long it takes to go two meters.  Students can coach the crabs, but no touching is allowed!

Velocity-

Students have attempted to measure the velocity of the Shore Crabs.  The measurements were taken on thecement walkway using a two meter race track constructed with wooden metersticks on t he wet walk.   Noconclusions can be made as there are too many systematic errors.  However, Crab Races were a fun part ofthe investigation and showed that the crabs can walk quickly from one tidalzone to another.

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