program

Responses of the seagrass Posidonia sinuosa to light availability - Summary

Researchers: Collier, Catherine (Owner) ,  Collier, Catherine, Dr (Owner)

Brief description Data on Posidonia sinuosa characteristics across a depth related gradient in long-term light availability were collected from Warnbro and Cockburn Sound, W.A. from 2002 to 2004. Also data from an in situ experiment to test for responses to short-term light reduction; and data from experimental investigations into the role of translocation to cope with reduced light availability was collected.

Lineage Maintenance and Update Frequency: notPlanned

Lineage Statement: The study was conducted in Cockburn Sound (CS) and Warnbro Sound (WS). At these locations mostly monospecific stands of P. sinuosa grow on steep sub-tidal depth gradients ranging from 1 to 9 m depth. The CS sites were located at north-east Garden Island. Sampling was carried out at six depths; 1.6, 4.0, 5.7, 6.5, 8.3 and 9.0 m (lowest astronomical tide). Sampling effort was concentrated nearer to the depth limit where it was expected that the greatest differences would be observed due to the rapid approach to compensating light levels. The five deepest sites were located within close proximity to each other on a steep slope leading to a basin (32° 09' 37.0'' S 115° 40' 47.3'' E) while the shallowest site was located closer to the island shore approximately 800 m away (32° 09' 35.6'' S 115° 40' 16.4'' E). WS was sampled in the north-east of the Sound at the same six depths as CS. Again, the five deepest sites were located within close proximity (32° 18' 57.4'' S 115° 42' 51.5'' E) while the shallowest site was located approximately 150 m away, closer to the mainland shore (32° 18' 53.7'' S 115° 42' 50.3''E).

Notes Credit
Strategic Research Fund for the Marine Environment (SRFME)

Notes Purpose
- Test whether the responses to light reduction observed in a number of other seagrass species are important features that enable the long-term survival of P. sinuosa in conditions of reduced light availability (Chapters 3 and 4); - Measure the responses of P. sinuosa to a range of imposed intensities of light reduction and identify the importance of colonisation depth on these responses (Chapter 5) ; - Identify the importance of morphological versus physiological responses for the tolerance of P. sinuosa to periods of light reduction (Chapters 3 - 5); - Identify the role of clonal integration in terms of carbohydrate storage and translocation of nutrients in the shade response mechanisms of P. sinuosa (Chapters 4 - 6); - Measure recovery rate from imposed light reduction and identify the responses that occur following a return from shaded to ambient light levels; and - Identify and make recommendations on the responses of P. sinuosa that may be applied as indicators of light reduction.

Data time period: 2002-06-01 to 2004-08-31

115.75,-32.05 115.75,-32.4 115.6,-32.4 115.6,-32.05 115.75,-32.05

115.675,-32.225

text: westlimit=115.6; southlimit=-32.4; eastlimit=115.75; northlimit=-32.05

text: uplimit=9; downlimit=1

Identifiers
  • global : 67c19c30-2444-11dc-95fb-00188b4c0af8
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