effects of tide pool volume on pool diversity lindsay grant, anna mairs, charlotte martin, natalie...

Effects of tide pool volume on pool

diversityLindsay Grant, Anna Mairs, Charlotte Martin, Natalie Rideout and Gillian

Tetlow

The Rocky Intertidal – Tide Pools

• The coastal area that is exposed during low tide and submerged during high tide

• Contains a high biodiversity of species

• A receding tide leaves an accumulation of pools

Tide pools

• Allow organisms to escape high temperatures and desiccation

• Acts as breeding and nursing grounds, provides protection and a feeding habitat

• Can also be stressful environments • Changing ocean salinity, temperature and pH

Goal of Study

• To determine if the tide pool size affects the species diversity

• Hypothesis - Species abundance will increase with increased size and depth

of tide pools - However, species distribution will not be significantly different

between varying tide pool dimensions

Methods

• Sampled 10 random tide pools of different sizes• Measured dimensions

• Used a quadrat (1m x 1m) for larger pools

• Collected samples of all plants and animals present• Plant coverage estimated

• Identified all species in the lab http://vitalsignsme.org/sites/default/files/climatechange12012/049.jpg

Methods – Calculations

• Simpson’s Diversity Index: n = total number of organisms of a particular speciesN = total number of organisms of all species

Methods – Calculations

• Shannon-Wiener Diversity Index:

pi = proportion of total sample represented by species i

• H’max:

S = number of species

Results

• Plant average – 4.3

• 12 species total

• Animal average – 4.9

• 18 species total

Results

Results

Results

• No significant patterns found for plant or animal diversity

• More sparse species of animals found than plants

Discussion

Plants:

• 3 outliers

• Constant diversity irrespective of tide pool size

• Failed to support hypothesis

http://www.clarku.edu/departments/biology/biol201/2002/EMachala/Gallery.htm

Discussion

Animals:• Similar to plants, 2 outliers

• Richness vs Abundance

• Failed to support hypothesis

https://www.clarku.edu/departments/biology/biol201/2002/JDubois/Marine%20Gastropods.htm

Discussion

Confounding variables:

• Ambient conditions

• Elevation

• Uneven distribution of pool volumeshttp://www.acurite.com/7-5-thermometer-00338.html

Discussion

Supporting studies:• Cullity (2012)• Found no significant relationship

Biological relevance:• Metaxas and Scheibling (1993)• Refuge area from stressful conditions

Questions?