Food + a cozy home = algae blooms (https://chinalakeassociation.org/alum-faq-glossary#algae-bloom)that degrade water quality. To expand: One of algae’(https://chinalakeassociation.org/alum-faq-glossary#algae)s main food sources – phosphorus (https://chinalakeassociation.org/alum-faq-glossary#phosphorus)– has entered the lake from stormwater runoff on developed land, leaking septic systems, timber harvesting, poorly maintained dirt/gravel/paved roads, fertilizers and other sources of soil erosion. Phosphorus is also present due to the internal recycling/loading (https://chinalakeassociation.org/alum-faq-glossary#internal)from stored phosphorus in lakebed sediments. Warmer summertime water temperature and a longer growing season encourage algae to grow quickly and stay in the lake longer. When algae grow quickly, an algae bloom can occur – this degrades water quality because the algae bloom reduces water clarity. Water can even become toxic to people and animals if the algae is a toxin-producing species. When algae die, decomposition consumes the dissolved oxygen (https://chinalakeassociation.org/alum-faq-glossary#dissolved-oxygen)that fish and other aquatic wildlife depend on to survive; further degrading water quality.

China Lake’s water quality has been degrading since the early 1980’s. The lake has been extensively researched since then, with multiple studies recommending aluminum treatments (although none have been performed). Left untreated, China Lake’s phosphorus p(https://chinalakeassociation.org/alum-faq-glossary#phosphorus)roblem means ongoing, persistent algae blooms (https://chinalakeassociation.org/alum-faq-glossary#algae-bloom)that will adversely impact water quality, wildlife, recreational opportunities, drinking water, the community, and the local economy.

This is an important concept to understand. It’s the process of phosphorus b(https://chinalakeassociation.org/alum-faq-glossary#phosphorus)eing released from the lake’s bottom sediments into the water column (https://chinalakeassociation.org/alum-faq-glossary#water-column)when levels of dissolved oxygen (https://chinalakeassociation.org/alum-faq-glossary#dissolved-oxygen)are low in the water column (this can also happen during periods of ice cover). To expand: when dissolved oxygen is plentiful, it binds – at the molecular level – to phosphorus and iron. This iron-bound phosphorus remains “trapped” in the sediment… so long as there’s enough oxygen. When dissolved oxygen is depleted; however, the phosphorus – again, at the molecular level – breaks free from the iron. This “breakup” is called a redox (reduction of oxygen) reaction. The more phosphorus that gets released, the greater the chance an algae bloom (https://chinalakeassociation.org/alum-faq-glossary#algae-bloom)will occur and degrade water quality.

This is an important concept to understand. In summary: when dissolved oxygen (https://chinalakeassociation.org/alum-faq-glossary#dissolved-oxygen)is plentiful, phosphorus ((https://chinalakeassociation.org/alum-faq-glossary#phosphorus)which is negatively charged) remains bound – at the molecular level – to iron and aluminum (both positively charged). The aluminum-bound phosphorus remains bound to the aluminum, however, iron-bound phosphorus only remains bound as long as there’s enough oxygen. When dissolved oxygen is depleted; however, the iron-bound phosphorus breaks free. This “breakup” is called a redox (reduction of oxygen) reaction. The more phosphorus that gets released, the greater the chance an algae bloom (https://chinalakeassociation.org/alum-faq-glossary#algae-bloom)will occur (because algae e(https://chinalakeassociation.org/alum-faq-glossary#algae)at phosphorus) and result in poor water quality. How do oxygen levels get low enough to even cause all of this? Read on! 1. Warm water doesn’t contain as much dissolved oxygen as cool water. This low solubility occurs because of the water molecules’ high kinetic energy, i.e. they’re moving too quickly to “trap” more oxygen as in cooler temperatures. 2. Warmer water also “sits” on top of colder water due to differences in density. These layers (stratification)(https://chinalakeassociation.org/alum-faq-glossary#stratification) result in a temperature barrier (thermocline)(https://chinalakeassociation.org/alum-faq-glossary#thermocline) that prevents the circulation of dissolved oxygen from the upper to the lower layers of the lake. 3. Meanwhile, microbes at the bottom of the lake consume dissolved oxygen as they decompose algae, plants and animal matter. 4. Since the stratification/thermocline prevents new dissolved oxygen from reaching the bottom to replenish what’s been consumed by the microbes, the amount of dissolved oxygen continues to lower. (Low-oxygen conditions are referred to as anoxia/anoxic). 5. This causes phosphorus to be released from sediment into the water column,(https://chinalakeassociation.org/alum-faq-glossary#water-column) where it feeds algae and can result in an algae bloom.

No. Watershed remediation isn’t – by itself – enough to meet the water quality goals in WBMP. While addressing runoff and shoreline erosion is critical to improving water quality within China Lake, in order to meet the water quality goals outlined the WBMP the internal recycling/loading must be addressed.

While it is well know that certain types of algae (Cyanobacteria) can produce toxins that are harmful to people and animals, it is extremely rare to find concentrations of these toxins in Maine Lakes that pose a threat. It is not completely understood what specific conditions lead this algae that produce toxins, however they are more commonly found when a Harmful Algae Bloom is occurring. Thus, by reducing the potential for an algae bloom we are reducing the risk of toxins in China Lake. More information on this subject can be found on the Maine DEP’s cyanobacteria and cyanotoxins page.