Under-Ice Algae Bloom: A Model of Arctic Ecology |…

What is an Under-Ice Algae Bloom?

Under-ice algae blooms are significant events in polar aquatic environments, particularly in the Arctic. These blooms occur when light penetrates through snow-covered ice and reaches the water below, stimulating photosynthesis by microscopic algae. The process is crucial for the marine food web as it provides primary production that supports higher trophic levels.

The model simulates this phenomenon using a 2D cross-section approach, which helps in understanding how varying conditions such as snow depth, ice thickness, and sunlight angle influence algal growth.

How Does Light Affect Algae Growth?

Light is the primary energy source for photosynthesis in algae. The Beer-Lambert law describes how light intensity decreases as it passes through a medium, such as ice and snow. In polar regions, this effect is critical because the light must penetrate several meters of ice and snow to reach the water column.

The Steele-curve model used in the simulation represents the growth rate of algae based on available light. This curve illustrates how algae growth increases with increasing light intensity up to a certain point before leveling off or even decreasing due to other limiting factors.

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Role of Grazers

Grazers, such as copepods, play a vital role in the ecosystem by consuming algae. In the model, grazing pressure is adjustable, allowing users to observe how predation affects algal biomass and distribution.

The interaction between algae growth and grazing can lead to dynamic changes in population dynamics, which are crucial for understanding the overall health of polar marine ecosystems.

Why Does This Model Matter?

Understanding under-ice algal blooms is essential for predicting how climate change might affect polar ecosystems. As ice cover decreases and light penetration increases, there could be significant changes in primary production rates, which would have cascading effects on the entire food web.

The model also helps researchers and policymakers assess the impact of human activities such as shipping and oil exploration on these delicate ecosystems.

Frequently asked questions

How does snow depth affect algal growth?

Snow depth affects light penetration, with thicker snow reducing the amount of light reaching the water. This can limit algae growth by decreasing available photosynthetic energy.

What is the Steele-curve model used for in this simulation?

The Steele-curve model describes how algal growth rates vary with light intensity, providing a realistic representation of how changes in light conditions can impact algae populations.

Why are copepods important in this model?

Copepods act as grazers that control algal biomass. Their presence and activity levels influence the balance between algal growth and consumption, which is crucial for maintaining ecosystem health.

How can changes in light affect the entire food web?

Changes in light availability due to variations in snow depth or ice thickness can alter primary production rates. This affects the entire food web by impacting the amount of organic matter available to higher trophic levels.

Try it live

Everything above runs in your browser — open Under-Ice Algae Bloom: 2D Cross-Section Model and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

▶ Open Under-Ice Algae Bloom: 2D Cross-Section Model simulation