GPS: --° --.---' North
        ---° --.---' East
~39,000 sq. meters
Maximum length:
~330 m
Maximum depth: 30 m
Class: Meromictic

Brief Description
Clear Lake (CLM) is similar to Ongeim'l Tketau (OTM) in depth, size, and its compliment of most obvious metazoans (sponges, mussels, anemones, golden jellyfish, gobies, and apogonids). Clear Lake, however, is oriented north-south rather than east-west, the vertical structure of its water column differs from that of OTM, and the bacterial plate is much more diffuse. Although it remains to be demonstrated, circumstantial evidence suggests these differences influence the population dynamics of the golden jellyfish which, in contrast to the perennial population in OTM, have been recorded only sporadically in CLM since the lake was first studied. In turn, the sporadic appearance of the jellyfish may have influenced the behavior of the anemone Entamaea medusivora which, in CLM, can regularly be seen consuming mussels rather than medusae.

Physical Profile


O, oxygen
S, salinity
T, temperature

Profiles show mean ± one standard error
(4 profiles, Oct. 1979 to Oct. 1998 )

Arrow indicates Secchi disk depth
(mean ± one standard error)

Horizontal shading indicates the approximate position of
the diffuse population of purple-sulphur bacteria.

Species List

Crustacea - Oithona sp., Acrocalanus sp.

- Acentrogobius janthinopterus, Sphaeramia orbicularis, Pranesus sp.

- Entacmaea medusivora
Scyphozoa - Mastigias sp.

Bivalvia - Brachidontes sp.

Sources: CRRF unpubl. data; Fautin & Fitt 1991; Hamner & Hamner 1998; Lipps & Langer 1999; G. Paulay pers. comm.; K. Tilbrook pers. comm.