Decline in crab claws: Danger to biodiversity in our waters!

Decline in crab claws: Danger to biodiversity in our waters!

The beauty of nature is often fragile, which is particularly evident in the example of the crab claws (Stratiotes aloides). This fascinating aquatic plant has experienced a worrying decline in recent decades. Since the 1960s, nature managers in Europe have been drawing attention to the fact that crab claws, which play an important role in the silting up of bog lakes, are increasingly disappearing. This has implications not only for their own survival, but also for the biodiversity they support, particularly for dragonflies. How Nature Today Reportedly, improvements have been observed over the years through measures to combat eutrophication of the water, but recently there has been another worrying decline in the plant.

The situation is particularly dramatic in the Vechtplassen area, where only a few square meters of crab claw vegetation can be found. The species has even completely disappeared in the Naardermeer. In a survey of wildlife managers, 80 percent said they had seen the plant decline in their areas. This decline is evidenced by fewer plants, smaller or discolored specimens, and in some cases even complete absence. A study of 49 sites in 16 nature reserves found that chemical factors such as a lack of carbon dioxide and iron in the water and an overdose of ammonium and sulfur have harmful effects on crab claws.

So what is the reason for this worrying decline? While the researchers see a clear connection between the water values ​​determined and the disappearance of crab claws, it remains uncertain whether these values ​​are the sole cause or whether the plant itself has an influence on its environment. Some animals such as coots and American crayfish, as well as mold infections, may also play a role. The protection and management of the plant species is not as easy as it may seem. Cleaning water bodies too rigidly threatens to endanger the species, while inadequate cleaning can lead to harmful substances accumulating.

The role of eutrophication

Another key issue related to the threat to crab claws is eutrophication. This is caused by excessive nutrient input from agriculture, sewage treatment plants and industry. According to the information from Federal Environment Agency This over-fertilization leads to cloudy water, toxic algae blooms and a lack of oxygen, which results in the loss of biodiversity. Eutrophication is a global problem that now affects 80 percent of marine ecosystems. The resulting increase in phytoplankton not only limits the supply of light to larger aquatic plants, but also leads to a dramatic decline in biodiversity.

Excessive growth of nitrogen and phosphorus is particularly problematic, and the projected increases in fertilizer consumption of 40 to 50 percent by 2050 are alarming. Without adequate measures to reduce these nutrients, the situation will continue to worsen, also affecting crab claws in many waters.

Challenges and perspectives

Precise management strategies are required to protect crab claws and their various habitats. Conservation managers should find a balance that includes both sensible water cleaning and planting crab claws in appropriate locations to promote healthy populations. It is important to take the various ecological factors into account and take targeted measures, as the challenges are diverse and complex.

The crab claw is not just a pretty plant that decorates the water, but an important part of a functioning ecosystem. Their conservation is of great importance because the loss of even one species can have significant consequences for other plant and animal species. Nature needs our active intervention and a good hand in management in order to remain vibrant and diverse in the future.