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Explore how substrate composition influences organism diversity in intertidal zones. Study aims to analyze the effects of different substrates on species richness and distribution along stress gradients.
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The Effects of Substrate Composition on Intertidal Organism Diversity Hala Nader, Alyson Pickard, Sam Shaw, & Jenna Thebeau
Background - Terms • Diversity • Probability that two randomly selected organisms from a community will belong to a different species
Background - Terms • Diversity • Probability that two randomly selected organisms from a community will belong to a different species • Richness • Number of species in a community
Background - Terms • 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
Introduction • What effects diversity? • Vertical & horizontal stress gradients • Wave exposure • Temperature • Desiccation • Shelter availability
Types of Stress • Limitation Stress • Lack of available resources
Types of Stress • Limitation Stress • Lack of available resources • Disruptive Stress • Causes cellular damage
Vertical Stress Gradients • 3 categories: • Supralittoral • Midlittoral • Infralittoral
Vertical Stress Gradients • 3 categories: • Supralittoral • Midlittoral • Infralittoral • Depends on elevationand exposure
Horizontal Stress Gradients • Depend on ice scour intensity and wave exposure
Horizontal Stress Gradients • Depend on ice scour intensity and wave exposure • Wave exposure determines what type of substrate is foundalong horizontal gradient
Wave Exposure & Substrate • High wave exposure • Washes away small debris • Leaves large rocks & cobble • Low predation
Wave Exposure & Substrate • High wave exposure • Washes away small debris • Leaves large rocks & cobble • Low predation • Moderate wave exposure • Bedrock & cobble • Stable habitat
Wave Exposure & Substrate • 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
Aim of The Study • Effect of substrate type on organism diversity and individual species preference
Aim of The Study • Effect of substrate type on organism diversity and individual species preference • Hypothesis • Diversity will change with respect to substrate type
Methods • 3 sites were sampled • Green’s Point • High wave exposure, large rock & cobble
Methods • 3 sites were sampled • Green’s Point • High wave exposure, large rock & cobble • Indian Point • Moderate wave exposure, bedrock & cobble
Methods • 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
Methods • 10 samples along a 50 m transect line within midlittoral zone at each site
Methods • 10 samples along a 50 m transect line within midlittoral zone at each site • 1x1 m quadrat placed every 5 m
Methods • 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
Methods • 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
Results • A. nodosum • C. crispus • Corraline sp. • Dictyosiphon sp. • Elachistaflaccida • F. vesiculosus • Lithothamnion sp. • U. lactuca • Acmaetestudinaris • Asteriasforbesii • B. balanus • L. littorea • L. obtusata • N. lapillus • S. balanoides • S. droebachiensis Plant Species Animal Species
Results Figure 1: The diversity of the 3 substrates based on the Shannon-Wiener diversity index
Results Figure 2: Species Richness and the 3 locations
Results • A. nodosum • C. crispus • Corraline sp. • Dictyosiphon sp. • Elachistaflaccida • F. vesiculosus • Lithothamnion sp. • U. lactuca • Acmaetestudinaris • Asteriasforbesii • B. balanus • L. littorea • L. obtusata • N. lapillus • S. balanoides • S. droebachiensis Plant Species Animal Species
Results • A. nodosum • C. crispus • Corraline sp. • Dictyosiphon sp. • Elachistaflaccida • F. vesiculosus • Lithothamnion sp. • U. lactuca • Acmaetestudinaris • Asteriasforbesii • B. balanus • L. littorea • L. obtusata • N. lapillus • S. balanoides • S. droebachiensis Plant Species Animal Species
Results Figure 3: Percent coverage per m2 (mean ±SEM) for 3 different substrates
Results Figure 4: Number of Nucella lapillus found per m2(mean±SEM)
Results Figure 5: Number of Littorinalittorea(mean ±SEM)
Results Figure 6: Number of Fucusvesiculosus(mean±SEM)
Discussion • Rocky substrate – Greens Point • Ascophyllumnodosum(common brown algae) • Found it in exposed areas • Could be due to ability to attach to substrate
Discussion • Rocky substrate – Greens Point • Ascophyllumnodosum(common brown algae) • Found it in exposed areas • Could be due to ability to attach to substrate • Coralline spp.(red algae) and Elachistaflaccide(brown algae) • Sheltered due to canopy
Discussion • Rocky substrate – Greens Point • Ascophyllumnodosum(common brown algae) • Found it in exposed areas • Could be due to ability to attach to substrate • Coralline spp.(red algae) and Elachistaflaccide(brown algae) • Sheltered due to canopy • Nucella lapillus(whelk) • Found due to coverage of plants
Discussion • Bedrock substrate – Indian Point • Fucusvesiculosus(bladder wrack) • Only grow if fucusspiralis is removed
Discussion • Bedrock substrate – Indian Point • Fucusvesiculosus(bladder wrack) • Only grow if fucusspiralis is removed • Lithothamnion spp. (calcareous algae) • Fucus could have provided shelter • Rock provides suitable place to grow • Larvae can settle due lower wave exposure
Discussion • Bedrock substrate – Indian Point • Littorinalittorea(periwinkle) • Fucus provided shelter from wave exposure and protection from desiccation • Feed on green & brown algae
Discussion • Bedrock substrate – Indian Point • Littorinalittorea(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
Discussion • Muddy Substrate – Bar Road • Semibalanus balanoides(barnacle) • Littorinalittorea(periwinkle) • Acmaeatestudinalis(limpet)
Discussion • Muddy Substrate – Bar Road • Semibalanus balanoides(barnacle) • Littorinalittorea(periwinkle) • Acmaeatestudinalis(limpet) • Possibility of burrowed organisms
Conclusions • Species are not evenly distributed in environments • Acorn barnacles are the dominant species • Plant species provide protection for animal species
Conclusions • 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
Conclusions • 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
Limitations • Estimation of species numbers rather than an actual count of the species.
Limitations • Estimation of species numbers rather than an actual count of the species. • Sample Size
Limitations • Estimation of species numbers rather than an actual count of the species. • Sample Size • Some species not seen but present
Future Direction • Greater variety of substrates
Future Direction • Greater variety of substrates • Monitoring physical and biological factors
Thanks! Questions?