Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Coral reefs are among the most biodiverse ecosystems on Earth, but they are increasingly threatened by multiple interacting stressors. Changes in ocean temperature, pH, bleaching frequency, and herbivore abundance all influence biodiversity patterns across coral reef systems. Because biodiversity responds to both biotic and abiotic factors, reefs offer a clear real-world example of how mathematical representations can be used to support or revise explanations about population and diversity changes at different scales.
Corals live in a narrow temperature range, and even small increases in ocean temperature cause physiological stress. When temperatures spike, corals expel their symbiotic algae, resulting in bleaching. Bleached corals have reduced growth, lower reproductive success, and higher mortality. As bleaching events become more frequent, coral cover declines. Mathematical datasets show declines from over 40% cover to under 15% within two decades in some regions, correlating with rising temperature anomalies.
Ocean acidification provides another abiotic stressor. As atmospheric CO
Biotic factors also play crucial roles. Herbivorous fish, such as parrotfish and surgeonfish, help control algae that compete with corals for space. When herbivore populations decline - due to overfishing or coastal development - algae grow unchecked. Algal overgrowth prevents coral larvae from settling, slows recovery after bleaching events, and reduces habitat availability for reef fish. In datasets, herbivore density declines align with increased algal cover and reduced fish species richness.
As coral cover declines and algae expand, fish biodiversity falls. Species that rely on branching corals for shelter and feeding lose essential habitat. Larger predators decline as prey fish become less abundant. Diversity indices show strong declines as environmental conditions worsen.
Mathematical models, trend graphs, and long-term monitoring data allow scientists to connect rising temperature anomalies, falling pH, declining herbivore density, and increasing bleaching severity to measurable losses of biodiversity. By examining coral reefs at multiple scales - from small patch reefs to entire reef systems - students can observe how different factors drive changes in species richness and population distribution.
Diagram 1.
Source:
https://www.researchgate.net/figure/The-impacts-of-environmental-and-anthropogenic-stressors-on-coral-reefs
Diagram 2.
Table 1.
Year | Coral Cover % | Temp Anomaly | Fish Species Richness |
|---|---|---|---|
2000 | 42 | 0.3 | 58 |
2005 | 38 | 0.5 | 55 |
2010 | 29 | 0.7 | 47 |
2015 | 21 | 1 | 39 |
2020 | 14 | 1.3 | 32 |
Graph of Information - Figure 1.
Table 2.
Year | Ocean pH | Herbivore Density fish100/m | Bleaching Severity Index |
|---|---|---|---|
2000 | 8.12 | 22 | 1.1 |
2005 | 8.07 | 20 | 1.8 |
2010 | 8.03 | 17 | 2.6 |
2015 | 7.98 | 13 | 3.9 |
2020 | 7.94 | 9 | 5.2 |
Graph of Information - Figure 2.
Using Table 1 and Figure 1, describe the relationship between coral cover, temperature anomalies, and fish species richness from 2000 to 2020.
According to Table 1, in which year did fish species richness first fall below 40 species?
Using Diagram 1 and the reading, explain how both biotic and abiotic limiting factors contribute to coral reef decline.
Based on Table 2, which variable shows the strongest indication of environmental stress on corals between 2000 and 2020?
Using Table 2 and Figure 2, describe how declining pH and herbivore density relate to increasing bleaching severity.
Explain how multiple stressors - temperature anomalies, acidification, herbivore decline, and bleaching - combine to alter energy flow and matter cycling in coral reef ecosystems.
Respond using Claim, Evidence, and Reasoning.