Underwater science and research with ROVs: monitoring the quagga mussel and invasive species in Swiss lakes
Swiss lakes have for years been the subject of study by institutes such as Eawag (the Swiss Federal Institute of Aquatic Science and Technology) and universities, which monitor temperature, water quality, submerged vegetation and aquatic wildlife. In recent years, alongside these established research areas, a topic of growing relevance has emerged: the spread of the quagga mussel and other invasive species, which is altering the ecological balance of several of the country's lakes.
The quagga mussel: a growing problem
The quagga mussel (Dreissena rostriformis bugensis), a bivalve mollusc native to the Black Sea region, was first detected in Switzerland in 2014 in the Rhine near Basel. Since then it has spread to Lake Geneva, Lake Constance, Lake Neuchâtel, Lake Biel, Lake Hongrin and Lake Murten. In pre-alpine lakes the species finds favourable conditions and few natural predators, allowing it to reproduce and spread rapidly.
The impacts are documented on several fronts: the mussels filter large quantities of phytoplankton, reducing the base of the food chain and altering the balance of the lake ecosystem; they colonise submerged surfaces en masse, including water-intake screens and the interior of pipes at water and cooling plants, causing blockages and damage running into millions of francs. According to Eawag's projections, over the next 22 years the biomass of quagga mussel per square metre in Lake Constance, Lake Geneva and Lake Biel could increase by a factor of between 9 and 20.
The limits of traditional monitoring
Until now, checking the colonisation of submerged infrastructure — such as water-intake screens — has mainly been entrusted to divers, who periodically dive to inspect and manually clean the intake baskets. It is an effective but costly method: it requires organising a dive, limits the frequency of checks, and covers only the area directly reached by the operator, making it difficult to build a continuous, comparable picture of the species' spread over time.
The ROV as a scientific research tool
A professional ROV makes it possible to systematically and repeatably document the colonisation of submerged surfaces, without requiring a dive every time. The 4K camera with electronic image stabilisation, combined with LED lighting of up to 4000 lumens, captures detailed footage of mussel density on screens, pipes, dam walls, jetties and other submerged substrates, even in low-visibility conditions or at depths that would make direct visual inspection more difficult. The 360° omnidirectional movement, provided by the 8 vectored-thruster layout of models such as the CHASING M2 PRO, allows a precise, consistent survey path to be followed, so the same monitoring can be repeated at the same location weeks or months later and produce genuinely comparable images — a fundamental requirement for scientific studies tracking the progression of the species.
Because the operation requires just one operator and no diving, surveys can be carried out more frequently and at lower cost, allowing research institutes to expand both the number of monitored sites and the frequency of observations.
Concrete applications on Swiss lakes
Monitoring quagga mussel colonisation — periodic documentation of mussel density on water-intake screens, pipes, dam walls and other submerged infrastructure, to plan targeted cleaning interventions before blockages occur.
Early detection in new lakes — inspection of lakes not yet colonised to detect the first individuals promptly, a key factor in containing the species' spread to new water bodies.
Support for scientific research — collection of geo-referenced video documentation to support studies by institutes such as Eawag and universities on the biomass, distribution and evolution of invasive species populations.
Broader monitoring of lake ecosystems — observation of submerged vegetation, fish populations and other aquatic invasive species, as well as general surveys of the health of alpine and pre-alpine lakes.
An ally for research and water management in Switzerland
For research institutes, water utility operators and cantonal environmental authorities, a professional ROV represents a concrete tool for addressing a topic of growing relevance: monitoring the spread of the quagga mussel and other invasive species requires frequent, systematic, low-impact observation — exactly what a tethered underwater inspection can offer compared with traditional methods based solely on divers.