Hala Nader, Alyson Pickard, Sam Shaw, & Jenna Thebeau

 Diversity ◦ Probability that two randomly selected organisms from a community will belong to a different species

 Diversity ◦ Probability that two randomly selected organisms from a community will belong to a different species  Richness ◦ Number of species in a community

 Diversity ◦ Probability that two randomly selected organisms from a community will belong to a different species  Richness ◦ Number of species in a community  Evenness ◦ The degree of similarity in the distribution of each species within the community

 What effects diversity? ◦ Vertical & horizontal stress gradients ◦ Wave exposure ◦ Temperature ◦ Desiccation ◦ Shelter availability

 Limitation Stress ◦ Lack of available resources

 Limitation Stress ◦ Lack of available resources  Disruptive Stress ◦ Causes cellular damage

 3 categories: ◦ Supralittoral ◦ Midlittoral ◦ Infralittoral

 3 categories: ◦ Supralittoral ◦ Midlittoral ◦ Infralittoral  Depends on elevation and exposure

 Depend on ice scour intensity and wave exposure

 Wave exposure determines what type of substrate is found along horizontal gradient

 High wave exposure ◦ Washes away small debris ◦ Leaves large rocks & cobble ◦ Low predation

 High wave exposure ◦ Washes away small debris ◦ Leaves large rocks & cobble ◦ Low predation  Moderate wave exposure ◦ Bedrock & cobble ◦ Stable habitat

 High wave exposure ◦ Washes away small debris ◦ Leaves large rocks & cobble ◦ Low predation  Moderate wave exposure ◦ Bedrock & cobble ◦ Stable habitat  Low wave exposure ◦ Primarily muddy ◦ Low drainage leading to anoxia

 Effect of substrate type on organism diversity and individual species preference

 Hypothesis ◦ Diversity will change with respect to substrate type

 3 sites were sampled ◦ Green’s Point  High wave exposure, large rock & cobble

 3 sites were sampled ◦ Green’s Point  High wave exposure, large rock & cobble ◦ Indian Point  Moderate wave exposure, bedrock & cobble

 3 sites were sampled ◦ Green’s Point  High wave exposure, large rock & cobble ◦ Indian Point  Moderate wave exposure, bedrock & cobble ◦ Bar Road  Low wave exposure, mud & sand

 10 samples along a 50 m transect line within midlittoral zone at each site

 1x1 m quadrat placed every 5 m

 10 samples along a 50 m transect line within midlittoral zone at each site  1x1 m quadrat placed every 5 m  Estimation of the number of plant and animal species encountered

 10 samples along a 50 m transect line within midlittoral zone at each site  1x1 m quadrat placed every 5 m  Estimation of the number of plant and animal species encountered  Species identified

Plant Species Animal Species  A. nodosum  C. crispus  Corraline sp.  Dictyosiphon sp.  Elachista flaccida  F. vesiculosus  Lithothamnion sp.  U. lactuca  Acmae testudinaris  Asterias forbesii  B. balanus  L. littorea  L. obtusata  N. lapillus  S. balanoides  S. droebachiensis

Figure 1: The diversity of the 3 substrates based on the Shannon-Wiener diversity index

Figure 2: Species Richness and the 3 locations

Plant Species Animal Species  A. nodosum  C. crispus  Corraline sp.  Dictyosiphon sp.  Elachista flaccida  F. vesiculosus  Lithothamnion sp.  U. lactuca  Acmae testudinaris  Asterias forbesii  B. balanus  L. littorea  L. obtusata  N. lapillus  S. balanoides  S. droebachiensis

Plant Species Animal Species  A. nodosum  C. crispus  Corraline sp.  Dictyosiphon sp.  Elachista flaccida  F. vesiculosus  Lithothamnion sp.  U. lactuca  Acmae testudinaris  Asterias forbesii  B. balanus  L. littorea  L. obtusata  N. lapillus  S. balanoides  S. droebachiensis

Figure 3: Percent coverage per m 2 (mean ±SEM) for 3 different substrates

Figure 4: Number of Nucella lapillus found per m 2 (mean±SEM)

Figure 5: Number of Littorina littorea (mean ±SEM)

Figure 6: Number of Fucus vesiculosus (mean±SEM)

 Rocky substrate – Greens Point ◦ Ascophyllum nodosum (common brown algae)  Found it in exposed areas  Could be due to ability to attach to substrate

 Rocky substrate – Greens Point ◦ Ascophyllum nodosum (common brown algae)  Found it in exposed areas  Could be due to ability to attach to substrate ◦ Coralline spp. (red algae) and Elachista flaccide (brown algae)  Sheltered due to canopy

 Rocky substrate – Greens Point ◦ Ascophyllum nodosum (common brown algae)  Found it in exposed areas  Could be due to ability to attach to substrate ◦ Coralline spp. (red algae) and Elachista flaccide (brown algae)  Sheltered due to canopy ◦ Nucella lapillus (whelk)  Found due to coverage of plants

 Bedrock substrate – Indian Point ◦ Fucus vesiculosus (bladder wrack)  Only grow if fucus spiralis is removed

 Bedrock substrate – Indian Point ◦ Fucus vesiculosus (bladder wrack)  Only grow if fucus spiralis is removed ◦ Lithothamnion spp. (calcareous algae)  Fucus could have provided shelter  Rock provides suitable place to grow  Larvae can settle due lower wave exposure

 Bedrock substrate – Indian Point ◦ Littorina littorea (periwinkle)  Fucus provided shelter from wave exposure and protection from desiccation  Feed on green & brown algae

 Bedrock substrate – Indian Point ◦ Littorina littorea (periwinkle)  Fucus provided shelter from wave exposure and protection from desiccation  Feed on green & brown algae ◦ Semibalanus balanoides (barnacle)  Fucus provided shelter from wave exposure and protection from desiccation  Predators and competitors were absent from this sampling site

 Muddy Substrate – Bar Road ◦ Semibalanus balanoides (barnacle) ◦ Littorina littorea (periwinkle) ◦ Acmaea testudinalis (limpet)

 Muddy Substrate – Bar Road ◦ Semibalanus balanoides (barnacle) ◦ Littorina littorea (periwinkle) ◦ Acmaea testudinalis (limpet) ◦ Possibility of burrowed organisms

 Species are not evenly distributed in environments ◦ Acorn barnacles are the dominant species ◦ Plant species provide protection for animal species

 Species are not evenly distributed in environments ◦ Acorn barnacles are the dominant species ◦ Plant species provide protection for animal species  Bedrock substrates have the highest species richness

 Species are not evenly distributed in environments ◦ Acorn barnacles are the dominant species ◦ Plant species provide protection for animal species  Bedrock substrates have the highest species richness  Muddy substrates have the lowest species richness

 Estimation of species numbers rather than an actual count of the species.

 Sample Size

 Estimation of species numbers rather than an actual count of the species.  Sample Size  Some species not seen but present

 Greater variety of substrates

 Monitoring physical and biological factors

Questions?