Concerns are mounting for a juvenile whale that has been stranded inside Western Australia's Peel-Harvey Estuary for more than a week, with fears growing that the animal may be in serious danger.

The young whale's prolonged presence in the estuary has alarmed wildlife observers and authorities, as the shallow, enclosed waterway is far from the open ocean environment the animal would need to survive and thrive.

Estuaries pose significant risks to whales, which can become disoriented and struggle to navigate back to sea. The longer the animal remains, the greater the concern for its health and survival.

Authorities are understood to be monitoring the situation closely as efforts to assess the whale's condition continue.