Exploration of patterns in Deep sea coral and sponge communities in the Mariana Archipelago Multivarite Analysis Goals Use NMDS to explore community structure at different dive stations in the Mariana geological region Characterize the environmental parameters of dive sites to determine which variables contribute most to the pattern of species assemblage at each site Hypotheses Null: There is no difference in species assemblage between dive sites Alternate: Species composition between dive sites is different and organized by depth, temperature, and oxygen

Data Description 36 sample stations (rows) 107 species (columns) Family/Genus/species level identifications Measured in animals per meter traveled 12 Variables Megahabitat (type of feature) Habitat (location on feature) Latitude (decimal degrees) Longitude (decimal degrees) Depth max/min (meters) Temperature max/min (°C) Oxygen max/min ( µl O2 / l seawater) Salinity max/min ( PSU) https://oceanexplorer.noaa.gov

Dataset Processing 63 Species columns Discarded Criteria: taxa present in fewer than 5 sample rows 3 Sample rows Discarded Criteria: stations containing fewer than 2 taxa Transformations Multiplied species by 1000 (animals per km) Log-transformed (species data + 1) Relativizations Species given equal weight by relativization by column totals Environmental variables given equal weight by relativization by column totals Final Sample size for analysis: 33 Stations 44 Species 12 Variables

Dataset Exploration

Dataset analysis

Results interpretation Criteria for axis selection Criterion 1: Decline in Stress with added axis at least 5 Criterion 2: P value < 0.05 Final Stress: 11.27593 Clarke’s rule = thumbs up!

Results interpretation Coefficient of Determination (%Variance Explained) Orthogonality

Results interpretation

Results Interpretation Shallower Warmer Less Salty East Less O2 L3-05 L3-05 More O2 Deeper Colder Saltier West Final Stress: 11.27593

Results Interpretation Shallower Warmer Less Salty East Less O2 More O2 Deeper Colder Saltier Deeper Colder Saltier Shallower Warmer Less Salty West Final Stress: 11.27593

Discussion – the Method Species organized in a 3-dimensional ordination Alternate hypothesis was supported Depth/Temp/Salinity axis Oxygen axis Longitude Some types of megahabitats appear to be closer in ordinal space while others are spread out Not all feature types were well represented in analysis Only one station represented fore-arc habitat Only two stations represented in arc and trench Best Learning outcomes: understand the limitations of my data PC-ORD software limitations for analysis

Discussion – next steps For Reanalysis: Cluster analysis of Species MRPP between habitats For more detailed gradient analysis Cut dive sites into equal length segments for finer gradient resolution Species Indicator Analysis Investigate substrate types and habitat features