The biosphere, our living world, is in crisis. Our hyper-successful species is running out of room and resources on our finite world and humanity faces grave hardship in the near future if we do not achieve a sustainable balance with our home.  Scientists are scrambling to define the limits of comfortable living on our world so that we can better understand what we can and must do to sustain favourable conditions and avert disaster.

A global homogenization of plants and animals has been occurring over the last few centuries as civilizations, societies, cultures, and peoples have increasingly met, mingled, traded, colonized, and migrated. This great biotic exchange brought about by people purposively or accidentally moving plants and animals from one region or continent to another has resulted in great benefits (for example, coffee, chocolate, potatoes, horses, and chili peppers) and also a suite of negative consequences for human societies and natural ecosystems.

The respiratory system is unique such that it is directly linked to the external environment. Because of this, it is particularly susceptible to injury caused by inhaled toxicants including environmental ozone. In the environment, ozone is generated through a series of complex photochemical reactions and perpetuated cyclically by three main reaction mechanisms: photoactivation (solar radiation at wavelengths between 295 and 430 nm), photodecomposition and free radical chain reactions [1].

Those of you who love sushi and love the planet face a gustatory challenge. The oceans are in trouble. Big trouble. Overfishing and habitat degradation have decimated populations of marine species, from whales to sea urchins, from the Arctic to the tropical reefs. When one who is informed about marine conservation issues decides to splurge (it is increasingly expensive) and partake of sushi, one has to navigate a complex set of personal limits of guilt and indirect consequences to marine ecosystems and human societies. For those of you who wish to minimize your impact on threatened marine biodiversity and ecosystems, here are some guidelines to follow, best practices, rules to live by, or suggestions (whatever you are most comfortable with) that may help.