In August of 2006 in Stark Strait (in the Peter the Great Bay) Foraminifera and Nematoda communities were investigated at two stations: in bottom under a red alga Ahnfeltia tobuchiensis bed and on a site located outside of the bed. Bottom sediments at the stations are represented by sands of various silting extent. Foraminifera dominated at both stations, the second place by abundance was occupied by Nematoda. Extremely high population density of meiobenthos, 14278.9 ± 4623.1 thousand sp./m2, was observed under the Ahnfeltia bed. The foraminifera percentage was 98.1%, which was probably connected with the mass development of diatom algae on Ahnfeltia. A high degree of domination of one Foraminifera species was recorded—Cribroelphidium frigidum. Nematoda constituted 1.5% with the prevalence of Comesomatidae family representatives. At the station situated outside of Ahnfeltia field mean population density of meiobenthos was an order lower—1731.8 ± 621.3 thousand sp./m2. Foraminifera constituted 63.8% of the total meiobenthos density with Eggerella advena as the dominating species. Among Nematoda (12.5%) Paracanthonchus macrodon, Axonolaimus seticaudatus and Monoposthia latiannulata were dominant. Foraminifera and Nematoda community under Ahnfeltia bed, where bottom sediments are more silted, had low indices of species diversity and a high degree of domination.