The Government of the Azores, through the Regional Secretariat for the Environment and the Sea (SRAM) is carrying out interventions in Furnas Crater Lake throughout the year in order to remove the excess of macrophytes and clean the lake bed and shores, hence contributing to the improvement of water quality.

At this time of the year, and given the development of aquatic vegetation, this type of works will be reinforced in some crater lakes in the Azores, including the Furnas Crater Lake. 

The recent “boom” of microalgae has reinforced the need for this intervention as most part of the mass of dead algae accumulated in the shores, the area with the highest concentration of vegetation (macrophytes).

Taking into account the excess Given the excess of nutrients in the mass of water, the dominant macrophytes, commonly known as whorled water milfoil, had the ideal conditions to proliferate vertiginously, covering almost all areas of certain margin submerged, preventing the growth of native species and favouring the accumulation of waste.

If not removed, the death and accumulation of vegetation turns into organic matter that will contribute to the increase of nutrients in the water, and thus to the degradation of its quality. In the most degraded areas, subject to interventions during the year (in the area north of the hot springs, west and southwest), it is essential to clean and remove organic matter from the lake shores on a regular basis.

Over the past three weeks, and whenever the weather conditions were favourable, this work has been performed using manual removal methods that minimise the destabilisation of beds in the areas of intervention, requiring a greater effort from the SRAM operational services. The organic matter removed will be used in the fertilisation of the soils of the hydrographic basin that do not drain directly into the crater lake. As in previous years, this work will continue during the month of September until the beginning of the rain season.

In addition to these works, the SPRAçores continues to develop actions to implement the land management plan of the hydrographic basin which focus on the recovery of the lake’s ecosystems by reducing the level of nutrients in the water and increasing biodiversity.

The measures to reduce the flow of waste to the crater were the first to be implemented. In order to increase biodiversity, several interventions have been carried out in the water and erosion lines as well as the creation of buffer-strips, afforestation actions and the recovery of the lake shores.