Tetney - Humberstone Fitties Lagoon
RSPB Tetney Marshes nature reserve is 1,350 ha of intertidal mudflats and saltmarsh.
The saline lagoon is only two hectares, but is nationally important for specialist invertebrates, which include the lagoon shrimp, Gammarus insensibilis - this is the most northerly limit of its word range. Tetney Marsh has nationally important numbers of breeding little terns, Sterna albifrons, and an internationally important wintering/passage assemblage of waterfowl - only a small number of these use the lagoon for feeding.
The lagoon is situated outside the sea-wall and receives water on spring high tides. The main threat to the lagoon is change to the lagoons chemistry and water levels, which over time may affect the invertebrate assemblages.
Actions to address threats
The lagoons are being monitored scientifically to look for evidence of change to its condition; monthly salinity and depth measurements are taken, and surveys are conducted to determine the status of key species.
Rubbish is regularly cleared from the lagoon to keep it free from potential pollutants.