BCSreg (version 1.1.1)

raycatch: Fishing Data from Todos-os-Santos Bay

Description

This dataset contains information on white ray landings using the traditional "grozeira" fishing method in Baía de Todos os Santos, Brazil. Data were collected from January 2012 to January 2013 by Marion (2015). The study aimed to analyze the relationship between catch per unit effort (cpue) and various environmental factors.

Usage

data(raycatch)

Format

A data frame with 186 rows and 8 variables:

period

fishing period, categorized as "Dry" or "Rainy".

location

fishing location, categorized as "Area 1", "Area 2", "Area 3", or "Area 4".

wind_speed

wind speed (m/s).

tide_phase

tide phase, categorized as "Quadrature" or "Spring tide".

max_temp

maximum temperature (°C).

min_temp

minimum temperature (°C).

sunshine_duration

duration of sunshine (hours).

cpue

represents the catch per unit effort, calculated as the productivity (in grams) divided by the product of the number of hooks and the soak time (in hours).

Details

In Brazil, marine fish are harvested through various fishing activities, with artisanal fishing playing a particularly prominent role, especially in the state of Bahia, in the northeastern region of the country. In this region, particularly within the Baía de Todos os Santos, most of the marine production comes from small-scale operations. Among the species landed and sold, rays constitute a significant portion of the catch. The data analyzed in this application were collected by Marion (2015) over a 13-month period (January 2012 to January 2013), based on 231 fishing trips that employed the grozeira (a type of bottom longline) as gear. After eliminating missing data, the data contains information on 186 fish landings. The objective is to identify key factors influencing ray catch levels. The response variable is the catch per unit effort (cpue), defined as \( \text{cpue} = \dfrac{\text{Productivity (g)}}{\text{Nº of hooks} \times \text{Immersion time (hours)}}. \)

References

Marion, C. (2015). Função da Baía de Todos os Santos, Bahia, no ciclo de vida de Dasyatis guttata (Chondrichthyes: Dasyatidae). Doctoral dissertation, University of São Paulo, Institute of Oceanography. Retrieved from https://teses.usp.br/teses/disponiveis/21/21134/tde-22072015-154346/pt-br.php

Paula, G. A., and Kumagaia, G. H. Relatório de análise estatística sobre o projeto: "Variabilidade espaço-temporal da captura da raia branca, Dasyattis guttata, na pesca artesanal da Baía de Todos os Santos, Bahia". São Paulo, IME-USP, 2014.

Examples

data(raycatch)
summary(raycatch)
plot(cpue ~ tide_phase, raycatch,
     xlab = "Tide phase", ylab = "CPUE (kg)",
     main = "Effect of tide phase on CPUE")