# Calculate biomass and plotting

# Loading libraries and data

```
library(tidyverse)
## Cargamos los datos desde internet
base <- read.csv("https://www.dropbox.com/s/st52i2c7yx3vyki/base_monitoreo.csv?dl=1")
```

# Data Wrangling

We filter by fishes and then calculate the biomass using the formula

```
base <- base %>%
filter(Label == "PEC") %>%
mutate(Biomass = (Quantity * A_ord * (Size^B_pen))/(Area * 100))
```

We then summarize data by region. First we sum by transect (our sampling unit) and then we estimate by calculating the average.

```
grafico <- base %>%
group_by(Year, Region, Reef, Depth, Transect) %>%
summarise(Quantity = sum(Quantity),
Biomass = sum(Biomass)) %>%
group_by(Year, Region) %>%
summarise(Quantity = mean(Quantity),
Biomass = mean(Biomass))
```

# Graph

```
ggplot(grafico, aes(x = Region, y = Biomass)) +
geom_col()
```

Written on February 19, 2021