GIZMO 4. Investigate four ponds. For each pond, measure the dissolved oxygen concentration at 6:00 am. Fish for six hours and record how many catfish and trout you catch in each pond. Hint: To find a pond with relatively high levels of dissolved oxygen (above 5 ppm), select No farms. To find a pond with low levels of oxygen (below 4 ppm), uncheck No farms.

The graph shows the amount of global warming happening in different ecosystems. which populations of organisms will likely decline the most as a result of climate change, and why? a. coral reefs because of the loss of the symbiotic algae living within their bodies b. penguin populations because the fish they eat will move into warmer waters c. mountain-dwelling birds because rising sea levels will relocate their food sources d. large cats in the rainforest because of decreased habitat loss for their prey