INBO helps silver eels make their way safely to the sea
Last autumn, INBO travelled to Blankenberge to monitor the annual exodus of silver eels migrating out to sea. Silver eels are the adult, sexually mature stage of the eel. The ‘Blankaal’ project forms part of the refurbishment of the drainage structure at Blankenberge harbour, where temporary pumps are being used to regulate the water level of the Blankenbergse Vaart. However, these pumps are not fish-safe.
Commissioned by Stadsbader Contractors nv, INBO helped the migrating eels to pass safely past the pumps. A total of 150 silver eels were transferred to the Blankenberge marina. From there, they were able to safely continue their long journey to their spawning grounds in the Sargasso Sea.
Monitoring shows that heavy rainfall is a major catalyst for eel migration. It is precisely at these peak times that the temporary pumps operate most frequently, thereby increasing the risk of mortality. INBO therefore recommends investing in eel-safe permanent emergency pumps as part of the new drainage structure.
The research also highlights the importance of adapted sluice management to allow young eels, or glass eels, access to the Blankenbergse Vaart once again. This involves temporarily leaving the sluice gates ajar during high water, so that glass eels can reach inland from the sea.