Question

thursday
an invasive species is an organism that causes harm to a new environment where it is not native. some invasive species can feed on native species to extinction because the invasive species has no predator. the graph shows the number of invasive trout in a lake per year. using the dates from the graph, describe how the number of invasive trout changes over time.

number of invasive trout in spring lake vs. year

brainstorm different reasons why the trout numbers declined in the later years.

Explanation:

Part 1: Describe how the number of invasive trout changes over time

1. First, observe the trend before the peak: From around 2001 to the peak year (let's assume around 2008 - 2010 based on the graph's shape), the number of invasive trout shows an increasing trend. This is likely because the invasive species had access to sufficient resources (like food from native species) and no natural predators initially, allowing their population to grow rapidly (exponential growth phase in population dynamics).
2. Then, after the peak: From the peak year onwards (towards 2014), the number of invasive trout decreases. This could be due to various factors like resource depletion, introduction of predators, or changes in the environment that limit their survival and reproduction.

1. Resource Depletion: The invasive trout may have over - consumed their food source (e.g., native fish, aquatic plants). As the food supply became scarce, the trout population could not be sustained, leading to a decline.
2. Introduction of Predators: Humans or natural processes might have introduced a predator species to the lake that preys on the invasive trout. This new predator would then reduce the trout population.
3. Environmental Changes: Changes in water quality (e.g., pollution, changes in pH, temperature) could have made the lake less suitable for the invasive trout. For example, if there was an increase in water temperature beyond their tolerance range, it could lead to higher mortality rates.
4. Disease Outbreak: A disease could have affected the invasive trout population. If a pathogen spread through the trout population, it would cause a significant decline in their numbers as many individuals get sick or die.
5. Competition from Other Species: Maybe another species (either native or another invasive species) started competing with the trout for the same resources (food, space). This increased competition could have led to a decrease in the trout population as they were out - competed.

Answer:

From approximately 2001 to a peak year (around 2008 - 2010), the number of invasive trout in Spring Lake increases (likely due to abundant resources and lack of predators). After reaching the peak, from the peak year to 2014, the number of invasive trout decreases (possibly due to resource limitations, new predators, or environmental changes).

Part 2: Brainstorm reasons why trout numbers declined in later years