| This study measures the potential biological and economic benefits of using MPAs in the red grouper fishery in Yucatan, Mexico. In addition, MPAs are compared to other regulations including partial area closures, seasonal closures, quotas and minimum sizes. The analysis is completed using an age-structured spatial simulation model, which separates the population into four different areas, selected on the basis of distribution and migration patterns. Previous studies have documented an aggregation of the species in west deep waters during January and February, and a homogeneous distribution from March to December. The model simulates this spatial pattern using one month as a time unit. The results show that MPAs have the potential to increase both the spawning biomass and NPV depending on the location and the timing of the area closures. Permanent MPAs in shallow waters were shown to increase spawning stock biomass; however, they had significant distribution effects. These distribution effects can be addressed by switching to a seasonal MPA; however the biological effectiveness is reduced. Permanent MPAs in deep waters were also shown to increase spawning stock biomass; however, they had significant distribution effects. In this case the distribution effects can not be addressed by switching to a seasonal MPA; hence biological effectiveness is reduced. The results also showed that depending on the length, seasonal closures could produce higher increases in spawning stock and NPV than MPAs. Quotas could produce higher spawning stocks but always resulted in a small decrease in NPV. |
