Increase maximum economic yield in a patchy environment.

In this work, we study the model of a fish species growing logistically exploited by a fishing fleet in a heterogeneous environment. The environment is made up of a network of fishing patches connected by fish migrations taking place on a fast time scale. We are interested in the maximum economic yield (MEY) which corresponds to the maximum profit made by the fishing fleet.

Connectivity between two fishing sites can lead to an emergence phenomenon related to Maximum Sustainable Yield.

In this study, we examine the effects of connectivity on the total catch of a fishery consisting of two fishing sites when the fish population is a predator of a larger prey-predator system. To this end, we analyze a prey-predator fish community model in a two-site environment and compute catch at Maximum Sustainable Yield (MSY). We exhibit some emergence phenomenon: the total catch can be greater than the sum of the catch at two isolated sites due to connectivity.

The Impact of COVID-19 Health Measures on Adults With Multiple Chemical Sensitivity: Cross-Sectional Study.

Background: Multiple chemical sensitivity (MCS) develops in response to repeated small-level chemical exposures or a major exposure in a subset of people, who then experience symptoms that can range from mild to debilitating when exposed to chemicals. The arrival of the COVID-19 pandemic and the stringent health measures put in place may have increased the burden for those living with MCS, as it became more challenging to avoid chemicals that trigger their condition.

Objective: This study aimed to better understand the lived experience of Canadians living with MCS during the first year of the COVID-19 pandemic.

Sustainable management of predatory fish affected by an Allee effect through marine protected areas and taxation.

Ecological balance and stable economic development are crucial for the fishery. This study proposes a predator-prey system for marine communities, where the growth of predators follows the Allee effect and takes into account the rapid fluctuations in resource prices caused by supply and demand. The system predicts the existence of catastrophic equilibrium, which may lead to the extinction of prey, consequently leading to the extinction of predators, but fishing efforts remain high.