A presentation by: Christine Adams, Louise Tunnah, Jen Dwyer, Steven Sutcliffe, Jenn O’Blenes, and Jill Briand

 The intertidal is broken up into three different zones:  supralittoral zone  midlittoral zone  infralittoral zone  Factors affecting zonation

 Species commonly found Ascophyllum nodosumMytilus edulis Fucus vesiculosusSemibalanus balanoides

 Wave Stress creates disturbance events  Organisms adaptation  Wave stress interacts with substrate

 Not all substrate equal for organisms  Larger rocks such as boulders preferred  Medium rocks balance between disturbance and competition/predation (high diversity)

 100 Meter transect at each point  50 meter transect on the other side of Greens Point  Samples taken every 10 meters using a meter by meter quadrat

 The meter by meter quadrat was divided into four sections, for time purposes, only one quarter of the quadrat was sampled  Rocks within the quarter quadrat were measured and recorded as specific rock type based on the Wentworth Scale

 Rocks were classified as:  Sand – Less than 4mm  Pebble - 4mm and 64mm  Cobble - 64mm to 256mm  Boulder - greater than 256mm  Bedrock

 Invertebrates were then identified and counted on each rock measured  For identification purposes, some species were bagged and brought back to the lab

 Simpsons Diversity Index was calculated for each individual quadrat as well as each entire sampling site  One way ANOVAs were then performed to determine the percent cover at each site and the difference between the sampling sites  A regression analysis was then done to compare rock type and species diversity at each sampling site

 To determine the percent coverage of rock in each quadrat:  pictures were taken of each quadrat  analyzed on the computer program ImageJ.

 For each image, a scale meter was set using the markings on the quadrat  Different sized substrate were measured to determine the Wentworth classification of each  Each different substrate was traced and the area was measured.  These measurement were used to find the percent cover of each substrate type for each quadrat.

 Figure 1: Taxonomic distribution of all organisms sampled at Indian Point, Green’s Point 1, Green’s Point 2 and Barr Road. (n=3784).

 Figure 2: Mean Rock Composition and relative cover at all four sample sites.

 Figure 3: Simpson’s Diversity Indices for each of the four sample sites with a non-significant p-value of

 Figure 4: Regression Correlation between diversity and rock type at Green’s Point Sites 1 and 2.  a) %Pebble at Greens Point 1 compared to diversity had a significance value of p=

 Figure 4: Regression Correlation between diversity and rock type at Green’s Point Sites 1 and 2.  b) %Bedrock at Green’s Point 1 compared to diversity had a significance value of p=

 Figure 4: Regression Correlation between diversity and rock type at Green’s Point Sites 1 and 2.  c) % Boulder at Green’s Point 2 compared to diversity had a significance value of p=

 Wide variation in substrate type however no significant difference in diversity  Does this relate to exposure?  Potential impact on species found?

 Reasons for relatively low species diversity:  Temperature  Dissolved oxygen content  Exposure  Salinity  Food supply  Stability

 Green’s Point 1  Bedrock low diversity ▪ high exposure  Pebble high diversity ▪ protection  Green’s Point 2  Boulder low diversity  stability and competition Diversity vs. Substrate

 Why there was no significant difference found in diversity between all the sites?  All within the mid-intertidal zone  Low and high wave exposure sites  Slope and substrate size

 QUESTIONS?