Final answer:
The likely effect on Lake Pueblo's ecosystem if zebra mussels spread cannot be contained includes changes to the food web, depletion of food sources for native species, economic damage to man-made structures, and potential extinction of native species.
Step-by-step explanation:
If the spread of zebra mussels cannot be contained in Colorado's Lake Pueblo, the likely effect on the lake's ecosystem would include significant alterations to the food web. Zebra mussels consume large quantities of algae and microscopic organisms that are foundational to the aquatic food chain. Consequently, this can lead to the depletion of food resources for native species, which may cascade into reduced populations of fish and other wildlife that rely on these food sources.
Additionally, zebra mussels can cause economic damage by fouling man-made structures and threatening native mollusk populations through competition for space and resources. Zebra mussels have been inadvertently transported across waterways by human activities, such as the discharge of ballast water from ships or by adhering to recreational boats and equipment.
Their aggressive colonization can lead to the extinction of native species, disruption of food chains, introduction of disease, and direct predation. While they have certain benefits, like improved water clarity in some instances, the overall impact of zebra mussel invasion is typically negative for native ecosystems and can incur substantial ecological and economic costs.