Swath surveys

Linking Swath to UPC

10 points 10 points 10 points 10 points 10 points 10 points

counts counts counts counts counts counts

Species, Substrate, Relief

Section 1 Section 2 Section 3 Section 4 Section 5 Section 6

ExampleCable distance

Side Section Substrate % Relief % UPC species

% Swath Species

counts

110 Deep 1 Bedrock 20 F 30 BranchyRed

10 Macrocystis 2

110 Deep 1 Boulder 40 S 10 Leafy Red

10 Cystoseira 6

110 Deep 1 Cobble 10 M 30 Cup corals

0 Patiria 5

110 Deep 1 Sand 30 H 30 Sponge 0 Pisaster 2

More

Analytical approach

1. Set up a raw data matrix

Species 1 2 3 4 5 etc.

Transect/SectionS110, 1 54 0 0 5 0S110, 2 37 1 0 4 0S110, 3 68 2 0 2 0S110, 4 60 0 0 0 1S110, 5 47 0 0 2 0S110, 6 60 0 0 0 0etc.

2. Calculate a dissimilarity (Bray-Curtis) matrix

S110,1 S110,2 S110,3 S110,4 S110,5 S110,6 etc.

S110,1 .000

S110,2 .203 .000

S110,3 .666 .652 .000

S110,4 .216 .331 .759 .000

S110,5 .328 .410 .796 .191 .000

S110,6 .336 .432 .796 .183 .054 .000

etc.

Linking biological communities to other communities or environmental variables

• Are differences in species composition related to differences in other communities or to associated environmental variables?

BIO-ENV procedure

Samples

Speciesabundances

Envvariables

Euclidean

Bray-Curtis

Subsets ofvariables

Rank correlation- Spearman- Weighted Spearman

Similarity/Dissimilarity matrix

Swath Matrix

UPC Species Matrix

UPC Habitat Matrix=

110, 1 vs 110, 2

Cable distance, section

SAMPLE1 SAMPLE2 HABITAT UPC Species Swath Species

100Deep1 100Deep2 26.45751311 45.64660208 26.75672112

100Deep1 100Deep3 42.42640687 32.120788 41.53649771

100Deep1 100Deep4 26.45751311 62.83970173 30.77990704

100Deep1 100Deep5 33.1662479 48.09984974 44.91068164

100Deep1 100Deep6 28.28427125 50.15522278 35.84000683

100Deep1 100Shallow1 30 56.1168548 49.60762989

100Deep1 100Shallow2 58.30951895 52.03166864 60.18648399

100Deep1 100Shallow3 26.45751311 71.72398383 43.14766078

100Deep1 100Shallow4 22.36067977 63.27472869 54.24428506

100Deep1 100Shallow5 53.85164807 61.07488731 73.81040148

100Deep1 100Shallow6 42.42640687 57.58597575 54.99411833

Dissimilarity

Habitat dissimilarity

Swath Species Dissimilarity ?

Habitat dissimilarity

Swath Species Dissimilarity

UPC species dissimilarity

Prediction

Habitat dissimilarity

Swath Species Dissimilarity

UPC species dissimilarity

Null Hypothesis

If there is a match

• Look at specific species to determine if associations make sense– For example: is Macrocysitis found in sandy

habitats– Species selected

• Marcrocystis and Cystoseira• Balanus nubilus and Styela• Cryptochiton and Lithopoma• Patiria and Pisaster giganteus

Questions to be addressed

• Is there an association between Swath species composition and (1) UPC species composition and/or (2) habitat attributes?– This needs to be motivated in intro and discussed in discussion. Why

would we be interested in this question? Why is it important? What would you predict?

• Do the associations differ in relative strength?– This needs to be motivated in intro and discussed in discussion. What

is the essential question here? Is there a basis for a prediction? • For select species are there a set of strong associations/dis-

associations and do these make sense?– This needs to be motivated in intro and discussed in discussion. Can

you make predictions? Why would we care about this?