Lab 3 Assignment

Author

Maya Frey

#load packages
library(tidyverse)
── Attaching packages ─────────────────────────────────────── tidyverse 1.3.2 ──
✔ ggplot2 3.4.0      ✔ purrr   1.0.1 
✔ tibble  3.1.8      ✔ dplyr   1.0.10
✔ tidyr   1.3.0      ✔ stringr 1.5.0 
✔ readr   2.1.3      ✔ forcats 0.5.2 
── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
library(lubridate)

Attaching package: 'lubridate'

The following objects are masked from 'package:base':

    date, intersect, setdiff, union
library(palmerpenguins)

Essentials:

1.) Read in https://raw.githubusercontent.com/rfordatascience/tidytuesday/master/data/2021/2021-05-04/water.csv check the format of the date column and change it using lubridate so it is correct

#read in the water data
water<-read_csv('https://raw.githubusercontent.com/rfordatascience/tidytuesday/master/data/2021/2021-05-04/water.csv')
Rows: 473293 Columns: 13
── Column specification ────────────────────────────────────────────────────────
Delimiter: ","
chr (9): report_date, status_id, water_source, water_tech, facility_type, co...
dbl (4): row_id, lat_deg, lon_deg, install_year

ℹ Use `spec()` to retrieve the full column specification for this data.
ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.
head(water)
# A tibble: 6 × 13
  row_id lat_deg lon_deg repor…¹ statu…² water…³ water…⁴ facil…⁵ count…⁶ insta…⁷
   <dbl>   <dbl>   <dbl> <chr>   <chr>   <chr>   <chr>   <chr>   <chr>     <dbl>
1   3957   8.07     38.6 04/06/… y       <NA>    <NA>    <NA>    Ethiop…      NA
2  33512   7.37     40.5 08/04/… y       Protec… <NA>    Improv… Ethiop…    2019
3  35125   0.773    34.9 03/18/… y       Protec… <NA>    Improv… Kenya        NA
4  37760   0.781    35.0 03/18/… y       Boreho… <NA>    Improv… Kenya        NA
5  38118   0.779    35.0 03/18/… y       Protec… <NA>    Improv… Kenya        NA
6  38501   0.308    34.1 03/19/… y       Boreho… <NA>    Improv… Kenya        NA
# … with 3 more variables: installer <chr>, pay <chr>, status <chr>, and
#   abbreviated variable names ¹​report_date, ²​status_id, ³​water_source,
#   ⁴​water_tech, ⁵​facility_type, ⁶​country_name, ⁷​install_year
# Change format of date column with lubridate
water$report_date <- mdy(water$report_date)
str(water)
spc_tbl_ [473,293 × 13] (S3: spec_tbl_df/tbl_df/tbl/data.frame)
 $ row_id       : num [1:473293] 3957 33512 35125 37760 38118 ...
 $ lat_deg      : num [1:473293] 8.073 7.374 0.773 0.781 0.779 ...
 $ lon_deg      : num [1:473293] 38.6 40.5 34.9 35 35 ...
 $ report_date  : Date[1:473293], format: "2017-04-06" "2020-08-04" ...
 $ status_id    : chr [1:473293] "y" "y" "y" "y" ...
 $ water_source : chr [1:473293] NA "Protected Spring" "Protected Shallow Well" "Borehole" ...
 $ water_tech   : chr [1:473293] NA NA NA NA ...
 $ facility_type: chr [1:473293] NA "Improved" "Improved" "Improved" ...
 $ country_name : chr [1:473293] "Ethiopia" "Ethiopia" "Kenya" "Kenya" ...
 $ install_year : num [1:473293] NA 2019 NA NA NA ...
 $ installer    : chr [1:473293] "Private-CRS" "WaterAid" NA NA ...
 $ pay          : chr [1:473293] NA NA NA NA ...
 $ status       : chr [1:473293] NA NA NA NA ...
 - attr(*, "spec")=
  .. cols(
  ..   row_id = col_double(),
  ..   lat_deg = col_double(),
  ..   lon_deg = col_double(),
  ..   report_date = col_character(),
  ..   status_id = col_character(),
  ..   water_source = col_character(),
  ..   water_tech = col_character(),
  ..   facility_type = col_character(),
  ..   country_name = col_character(),
  ..   install_year = col_double(),
  ..   installer = col_character(),
  ..   pay = col_character(),
  ..   status = col_character()
  .. )
 - attr(*, "problems")=<externalptr> 

2 Read in some data from Justin’s PhD!

bzcoral<-read.csv('https://raw.githubusercontent.com/jbaumann3/BIOL234_Biostats_MHC/main/coralcover.csv')
head(bzcoral)
  site       type lat transect diver cc_percent
1    1  Back Reef   3        1     4  5.8435758
2    1  Back Reef   3        2     4  0.9505263
3    1  Back Reef   3        3     4  5.2423389
4    1  Back Reef   3        4     5  5.0040475
5    1  Back Reef   3        5     5  5.8954916
6    2 Patch Reef   3        1     4  5.2826190

3 Look at the data and generate a hypothesis to test (X, Y, and/or Z has no effect on coral cover (cc_percent), for example). cc_percent is the only numerical variable we care about here! Everything else is categorical. Write your hypothesis in BOLD below.

Null hypothesis: Reef type has no effect on coral cover. Alternative hypothesis: Reef type has an effect on coral cover.

4 Filter out the columns that you are not using for your hypothesis test

bzcoral_sel <- select(bzcoral, type, cc_percent)
head(bzcoral_sel)
        type cc_percent
1  Back Reef  5.8435758
2  Back Reef  0.9505263
3  Back Reef  5.2423389
4  Back Reef  5.0040475
5  Back Reef  5.8954916
6 Patch Reef  5.2826190

5 Using the pipe, %>%, group your data and calculate the mean(s) you need for your visual hypothesis test

bzcoral_mean <- bzcoral_sel %>%
  group_by(type) %>%
  summarise(meancc_percent = mean(cc_percent), sd = sd(cc_percent), n = n(), se = sd/sqrt(n))

6 Graph your results! Means + errorbars required :) Make a nice, easy to see graph with clear labels and text

ggplot(data = bzcoral_mean, aes(x = type, y = meancc_percent, color = type)) + geom_point() + geom_errorbar(data = bzcoral_mean, aes(x = type, ymin = meancc_percent - se, ymax = meancc_percent + se)) + theme_classic() + labs(x='Reef Type', y = 'Mean Coral Cover Percent', title = 'Mean coral cover percent by reef type', color = 'Type')

7 Assess your hypothesis! What does your graph show (Note: We did not do stats, so please do not say ‘significant’)

Mean coral cover percent is smaller in nearshore reefs compared to back reefs and patch reefs. From looking at my graph, the data seem to support my alternative hypothesis that reef type has an effect on coral cover. # Depth

1: Read in intertidal transect data. View it, identify the columns that contain species/cover items and pivot from wide to long format!

op<-read.csv('https://raw.githubusercontent.com/jbaumann3/BIOL234_Biostats_MHC/main/Ocean_Point_Data%202018.csv')
head(op)
  Number  trans_description year tidal_ht_m tidal_ht_cat_num bare_rock calothr
1      0 a_cobble_protected 2017      -0.13                1         0       0
2      0 a_cobble_protected 2017      -0.13                1         5       0
3      0 a_cobble_protected 2017      -0.13                1         5       0
4      0 a_cobble_protected 2018       0.38                2        10      12
5      0 a_cobble_protected 2018       0.38                2         0      93
6      0 a_cobble_protected 2018       0.78                2         0      65
  semibal mytilus Halichondria Spongomorpha chaetomo ulva_lac ascophyl lamin_di
1       0       0            0            0        0        0        0        0
2       0       0            0            0        0        5        0        0
3       0       0            0            0        0        0        0        0
4       8       0            0            0        0        0       10        0
5       7       0            0            0        0        0        0        0
6      30       0            0            0        0        0        0        0
  lamin_sa fucus_spir fucus_vesic fucus_dist fucus_sp chondrus mastocar
1        0          0           0          0        0        0       40
2        0          0           5          0        0        0       20
3        0          0           5          0        0        0       20
4        0          0          60          0        0        0        0
5        0          0           0          0        0        0        0
6        0          0           5          0        0        0        0
  petrocel corralina ceramium lithothamn Enteromorpha tectura litt_sax litt_lit
1        0         2        0         58            0       0        0       64
2        0         5        0         60            0       0        0        0
3        0        15        0         55            0       0        0        0
4        0         0        0          0            0       0        0      112
5        0         0        0          0            0       0        0      112
6        0         0        0          0            0       0        0        0
  litt_obt nucella carcinus Cancer.crabs
1        0       0        0            0
2        0       0        0            0
3       16       0        0            0
4       80       0        0            0
5       16       0        0            0
6        0       0        0            0
# All of the columns from bare_rock over are species/cover items
op_long <- op %>%
  pivot_longer(bare_rock : Cancer.crabs, names_to = 'species', values_to = 'abundance')
head(op_long) # Column you want to start pivoting at : Column you want to end pivoting at
# A tibble: 6 × 7
  Number trans_description   year tidal_ht_m tidal_ht_cat_num species    abund…¹
   <int> <chr>              <int>      <dbl>            <int> <chr>        <dbl>
1      0 a_cobble_protected  2017      -0.13                1 bare_rock        0
2      0 a_cobble_protected  2017      -0.13                1 calothr          0
3      0 a_cobble_protected  2017      -0.13                1 semibal          0
4      0 a_cobble_protected  2017      -0.13                1 mytilus          0
5      0 a_cobble_protected  2017      -0.13                1 Halichond…       0
6      0 a_cobble_protected  2017      -0.13                1 Spongomor…       0
# … with abbreviated variable name ¹​abundance

2 Filter data such that we retain only ‘species’ that are animals. These include: carcinus, Cancer.crabs, nucella, litt_obt, litt_lit, litt_sax, semibal. Everything else is either rock or algae. Please do this filter step AFTER you pivot to long format. Note: It is easier to do this when you are in wide format, but this is good practice! Ask questions if you need help :). Hint: The ‘|’ key is how you say ‘or’ in code :)

op_animals <- op_long %>%
  filter(species == "carcinus" | species == "Cancer.crabs" | species == "nucella" | species == "litt_obt" | species == "litt_lit" | species == "litt_sax" | species == "semibal")
head(op_animals)
# A tibble: 6 × 7
  Number trans_description   year tidal_ht_m tidal_ht_cat_num species  abundance
   <int> <chr>              <int>      <dbl>            <int> <chr>        <dbl>
1      0 a_cobble_protected  2017      -0.13                1 semibal          0
2      0 a_cobble_protected  2017      -0.13                1 litt_sax         0
3      0 a_cobble_protected  2017      -0.13                1 litt_lit        64
4      0 a_cobble_protected  2017      -0.13                1 litt_obt         0
5      0 a_cobble_protected  2017      -0.13                1 nucella          0
6      0 a_cobble_protected  2017      -0.13                1 carcinus         0

2 Using the same data–> rename the factors in the trans_description column based on wave exposure. a_cobble_protected is low, c_flat_profile and d_semi_expos are both moderate, e_exposed is high. Hint: use ifelse(). Justin can help!

op_animals$wave <- ifelse(op_animals$trans_description == "a_cobble_protected", "Low",
                          ifelse(op_animals$trans_description == "e_exposed", "High", "Moderate"))
head(op_animals)
# A tibble: 6 × 8
  Number trans_description   year tidal_ht_m tidal_ht_ca…¹ species abund…² wave 
   <int> <chr>              <int>      <dbl>         <int> <chr>     <dbl> <chr>
1      0 a_cobble_protected  2017      -0.13             1 semibal       0 Low  
2      0 a_cobble_protected  2017      -0.13             1 litt_s…       0 Low  
3      0 a_cobble_protected  2017      -0.13             1 litt_l…      64 Low  
4      0 a_cobble_protected  2017      -0.13             1 litt_o…       0 Low  
5      0 a_cobble_protected  2017      -0.13             1 nucella       0 Low  
6      0 a_cobble_protected  2017      -0.13             1 carcin…       0 Low  
# … with abbreviated variable names ¹​tidal_ht_cat_num, ²​abundance

3 Using the same data, make a simplified tidal height column. We want tidal height cat <4 to be ‘low’, >7 to be m’oderate’high’, and in between to be ‘intermediate’. Hint: You can use if_else for this as well!

op_animals$tidal_ht_simp <- ifelse(op_animals$tidal_ht_cat_num < 4, "Low", 
                                   ifelse(op_animals$tidal_ht_cat_num >7, "High", "Intermediate"))
head(op_animals)
# A tibble: 6 × 9
  Number trans_description   year tidal_…¹ tidal…² species abund…³ wave  tidal…⁴
   <int> <chr>              <int>    <dbl>   <int> <chr>     <dbl> <chr> <chr>  
1      0 a_cobble_protected  2017    -0.13       1 semibal       0 Low   Low    
2      0 a_cobble_protected  2017    -0.13       1 litt_s…       0 Low   Low    
3      0 a_cobble_protected  2017    -0.13       1 litt_l…      64 Low   Low    
4      0 a_cobble_protected  2017    -0.13       1 litt_o…       0 Low   Low    
5      0 a_cobble_protected  2017    -0.13       1 nucella       0 Low   Low    
6      0 a_cobble_protected  2017    -0.13       1 carcin…       0 Low   Low    
# … with abbreviated variable names ¹​tidal_ht_m, ²​tidal_ht_cat_num, ³​abundance,
#   ⁴​tidal_ht_simp

4 Using the same dataframe, build 2 new dataframes, one calculating mean and error (standard error) for semibal (barnacle) abundance and one doing the same for nucella (whelk) abundance by tidal height and wave exposure (trans_description)

#New df semibal
semibal <- op_animals %>%
  filter(species == "semibal") %>%
  group_by(wave, tidal_ht_simp) %>%
  summarize(mean = mean(abundance), sd = sd(abundance), n = n(), se = sd/sqrt(n))
`summarise()` has grouped output by 'wave'. You can override using the
`.groups` argument.
semibal$species = "Semibal"
head(semibal)
# A tibble: 6 × 7
# Groups:   wave [2]
  wave  tidal_ht_simp  mean    sd     n    se species
  <chr> <chr>         <dbl> <dbl> <int> <dbl> <chr>  
1 High  High           0     0       12  0    Semibal
2 High  Intermediate  32.4  30.4     18  7.17 Semibal
3 High  Low            6.11  7.82     9  2.61 Semibal
4 Low   High           0     0        9  0    Semibal
5 Low   Intermediate   2.24  5.24    17  1.27 Semibal
6 Low   Low            6.11  9.53     9  3.18 Semibal
#New df nucella
nucella <- op_animals %>%
  filter(species == "nucella") %>%
  group_by(wave, tidal_ht_simp) %>%
  summarize(mean = mean(abundance), sd = sd(abundance), n = n(), se = sd/sqrt(n))
`summarise()` has grouped output by 'wave'. You can override using the
`.groups` argument.
nucella$species = "Nucella"
head(nucella)
# A tibble: 6 × 7
# Groups:   wave [2]
  wave  tidal_ht_simp  mean    sd     n    se species
  <chr> <chr>         <dbl> <dbl> <int> <dbl> <chr>  
1 High  High           0     0       12  0    Nucella
2 High  Intermediate   0     0       18  0    Nucella
3 High  Low            1.78  5.33     9  1.78 Nucella
4 Low   High           0     0        9  0    Nucella
5 Low   Intermediate   0     0       17  0    Nucella
6 Low   Low            0     0        9  0    Nucella

5 Plot barnacle and snail abundance + error across tidal heights & wave exposures. You can plot them both on the same graphs (merging your dataframes could help) or you can make multiple graphs and patchwork them together.

combined <- rbind(nucella, semibal)
head(combined)
# A tibble: 6 × 7
# Groups:   wave [2]
  wave  tidal_ht_simp  mean    sd     n    se species
  <chr> <chr>         <dbl> <dbl> <int> <dbl> <chr>  
1 High  High           0     0       12  0    Nucella
2 High  Intermediate   0     0       18  0    Nucella
3 High  Low            1.78  5.33     9  1.78 Nucella
4 Low   High           0     0        9  0    Nucella
5 Low   Intermediate   0     0       17  0    Nucella
6 Low   Low            0     0        9  0    Nucella
library(patchwork)
ggplot(data = combined, aes(x = wave, y = mean, color = tidal_ht_simp)) + geom_point() + geom_errorbar(data = combined, aes(x = wave, ymin = mean - se, ymax = mean + se)) + theme_classic() + facet_wrap(~species) + labs(x='Wave exposure', y = 'Count', color = 'Tidal height')

6 Write a short interpretative statement. We didn’t run any stats, so avoid the word ‘significant.’ How do snail and whelk abundances appear to vary by tidal height and wave exposure? I do not need you to tell me anything about the ecology of the system, but feel free to do so if you’d like :) I just need you to interpret your graphs.

It appears that neither Semibal or Nucella are found at high tidal heights. The data show Semibals as most abundant where there is both high wave exposure and intermediate tidal height. The data also show Nucella as most abundant when there is both moderate wave exposure and intermediate or low tidal height and high wave exposure and low tidal height.