Hypotheses (motivate these in your introduction, discuss them in your discussion in the context of the results) There are patterns of association between species presence and substrate type There will be differences in the associations among species (why is this an important question – think about maintenance of diversity) There are patterns of association between species presence and relief There will be differences among species in these relationships.

General Methods Transects sampled: 60, 70, 80…150 Offshore and onshore sampling 2 samplers per transect Point interval: .5 meters Sampled species directly under point

Offshore Onshore

Offshore Onshore

Some notes For the written report Each person will write their own paper The paper will be based on the group data and your methods and results should cover the group project Use the guidelines to help craft your paper

Some notes For the graphs “Preference Index” is a standardized measure of the association from that expected by chance For example if 40% of the substrate is boulder habitat then the expected abundance of leafy red algae on boulders is 40%. A positive deviation means more than expected, a negative deviation means less than expected There are 3 categories of strength of association. >.66 or <-.66 are considered Strong .66> PI>.33, -.66< PI <-.33 are considered moderate All other Deviations are considered weak

Preference Index Observed number = the number of observations made for a species Expected number = the expected number of observations for species given NO pattern of association For example: if bedrock was 50% of all substrate then the expected percentage of observations on bedrock is 50% for all species Assume that there were 120 observations of crustose coralline algae. Here the expected number on bedrock would be 50% x 120 observations = 60

Preference Index continued Preference Index can be calculated as: PI = (O-E)/(O+E) Where O= observed and E = expected PI scales between -1 (strong negative association) and 1 (strong positive association) PI = 0 indicates no pattern of association (O=E)

Example: Crustose coralline algae Substrate Substrate Percent Observed number (CCA) Expected number PI (O-E)/(O+E) Association Bedrock 50 60 none Boulder 20 24 0.35 positive Cobble 10 -0.41 negative Sand 12 -1 strongly negative Total 100% 120 Values >.66 or less than -.66 show strong associations Values >.33 and <.66 or >-.66 and <-.33 show an association Values <.33 and >-.33 show no important association

2015 2015 2014 2014

Note dashed and dotted lines indicate levels of association: Strong, Moderate

Note dashed and dotted lines indicate levels of association: Strong, Moderate