Occurrence patterns of Plecoglossus altivelis altivelis at an artificial sandy beach in Furuhama Park facing a city canal, Ota City, Tokyo

Abstract

To evaluate the habitat function for fish of an artificial sandy beach constructed in the inner Tokyo Bay, occurrence patterns of Plecoglossus altivelis altivelis were examined based on samples collected monthly at both low and high tide from March 2018 to February 2019, using a small seine net in the sandy beach of Furuhama Park, Ota City, Tokyo. The number and mean body length（± SD）of specimens collected were 1,817 and 20.6 mm（5.4 mm）at high tide and 218 and 17.4（3.5 mm）at low tide, respectively. Because these sizes correspond to the phase of growth where fish gain swimming ability, they are considered to migrate positively to and from the sandy beach of Furuhama Park and the canal on the flow and ebb tides, respectively. The results suggest that the sandy beach of Furuhama Park has a habitat function as a nursery ground for P. altivelis altivelis at least.