Coral Cam Web Site


OBJECTIVE: 1.Students will be able to construct a pyramid of numbers using data
                               from a Bermudian coral reef.
Skills                  Science and mathematics

AGE GROUP:   13 – 15 years


It is important that students have already constructed a food chain and web of a coral reef. To do this they will also have become familiar with the Bermuda Coral website. 
In any community there will always be a vast number of producers that form the basis for a web consisting of a large number of herbivores, fewer carnivores and finally a small number of top carnivores. The food web that students have constructed will not be totally realistic because it does not take into account the numbers of the animals and plants that live on the reef. This activity uses fictional data that can be used to build the food web into a pyramid of numbers.It is important that students are aware that this is very simplified and does not take into account other feeding relationships such as scavengers, filter feeders and omnivores

Instructions for Teachers

    1.The following data needs to be downloaded and then photocopied or placed onto an overhead transparency.

Name of organism                  Type of feeding                 Number
Algal turf                                       Producer                            700
Jointed seaweed                            Producer                            500
Phytoplankton                               Producer                            10000
Zooplankton                                  Herbivore                          1000
Finger coral                                   Carnivore                           7500
Common sea fan                            Herbivore                          7000
Brain coral                                     Herbivore                          6000
Sponge                                          Carnivore                          1000
Spotlight parrot fish                        Herbivore                          5
Squid                                             Carnivore                          2
Purple sea urchin                            Herbivore                          6
Nassau grouper                              Carnivore                          24
4 eyed butterfly fish                        Herbivore                          2
Silver porgy                                   Carnivore                           3
Surgeon fish                                   Herbivore                          4
Blue tang                                        Herbivore                         2
Barracuda                                      Carnivore                          1

2.The students need to count all the numbers of producers and record this total.
3.Next the students should count up the number of herbivores and record this.
4.Students then need to count up the carnivores and note the total.
5.The students should then be able to draw a pyramid shape to put the numbers in, starting with
   the producers at the base, then a band of herbivores and finally a top level of carnivores.


6.Some students may like to draw out the pyramid on graph paper and use an appropriate scale
   to produce a ‘pyramid' made of rectangles, each directly proportional to the number of
   organisms in that food level.

For example each square centimetre of graph paper could represent 1000 organisms. If there were 10,000 producers in the section of coral reef being sampled then the rectangle drawn would need to be 10 squared centimetres.
7. Students need to label each of the rectangles with producers, herbivores and carnivores.     

© BBSR and TCOE Coral Web Site Team 1999
Funded by a grant from the Goldman Foundation