Build a canal linking the two ponds that permits free movement of mosquitofish, but not of predators.
Explanation:
On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences.
Inspecting shipments carefully when they arrive ensures that the food was fresh, kept cold and has been properly stored and shipped. It also helps to determine if the food, products or the items have any damage, defects or obvious issues.
In the flask with algae, there would be photosynthesis in the presence of light which uses up the oxygen hence the dissolved oxygen in the flask with algae will be higher in the light but lower in the dark.