NOPR Collection:

Bathymetry retrieval from landsat thematic mapper

Thu, 01 Jun 1989 00:00:00 GMT

Title: Bathymetry retrieval from landsat thematic mapper Authors: Sridhar, P N; Mishra, A K; Prasad, K S Abstract: A hand held radiometer with landsat thematic mapper (TM) compatible band (band 2 pertaining to wavelength 520 to 600 nm) was used for developing an algorithm for bathymetry retrieval from nearshore waters. The noise due to suspended sediments is discussed. The proposed algorithm can be used to retrieve bathymetry (up to 30 m contour) from atmospherically corrected remotely sensed satellite data. Page(s): 147-148

Boring activity of littoral isopod, Sphaeroma annandalei Stebbing and its interspecific relationship with Cirolana willeyi Stebbing

Thu, 01 Jun 1989 00:00:00 GMT

Title: Boring activity of littoral isopod, Sphaeroma annandalei Stebbing and its interspecific relationship with Cirolana willeyi Stebbing Authors: Nair, G Achuthan; Nair, N Balakrishnan; Vijayamohanan, T G Abstract: Sphaeroma annandalei showed maximum boring activity in salinities 10.5-17.5 x 10 ^-3 (seawater). An inverse relationship existed between the size of the animal and the burrows it excavated in laterite slabs. Observations made on the interspecific competition between S.annandalei and Cirolana willeyi in occupying the boreholes showed that the latter was always successful in its attempt when compared with the slow-moving S.annandalei. Page(s): 145-146

Short-term movements of the penaeid prawn Penaeus indicus H. Milne Edwards in a tropical estuary

Thu, 01 Jun 1989 00:00:00 GMT

Title: Short-term movements of the penaeid prawn Penaeus indicus H. Milne Edwards in a tropical estuary Authors: Babu, K Surendra; Babu, K Sasira Abstract: Short-term movements of Penaeus indicus were investigated through mark-recapture studies in the Upputeru estuary, along the central east coast of India. The passive movements observed were mainly along the axis of the estuary. There was a progressive downward movement towards the mouth of the estuary as they grew in size. Page(s): 143-144

Circadian respiratory biorhythm of marine gastropods Natica maculosa, Umbonium vestiarum and Polynices didyma

Thu, 01 Jun 1989 00:00:00 GMT

Title: Circadian respiratory biorhythm of marine gastropods Natica maculosa, Umbonium vestiarum and Polynices didyma Authors: Sivalingam, P M Abstract: Circadian respiratory biorhythm of the three gastropods was investigated and compared with that of bivalves under conditions identical to their tropical niche. The three marine gastropods conformed extremely well to the diurnal tidal rhythm similar to suspended sedentary bivalve, Perna viridis L. However, the maxima and minima were shifted by approximately 4 h respectively against the maximal high and minimal low tides. The shift by 4 h in maximal and minimal circadian respiratory activities corresponded to the receding and incoming tides, respectively. Comparison of maximal nocturnal respiratory activity against that of daylight maximal respiratory activity demonstrated the former to be greater by 39 and 48 % for N. maculosa and U. vestiarum, respectively, and for P. didyma by 25,22 and 26 % with increase in size (2.2, 2.8 and 3.2 cm). Page(s): 141-142