5.2 Seagrass genetics

Description

This study was the first of its kind to examine the patterns of genetic diversity in seagrasses in the Pilbara region of WA. Three species were assessed: Halophila ovalis (6 populations), Halodule uninervis (8 populations) andThalassia hemprichii (3 populations) at a range of spatial scales, within a meadow (centimetres−metres), among meadows at a local scale (2−60 km) and among meadows at a regional scale (up to 500 km). Due to the varied distribution of species all species across the same spatial scale and range of environments could not be sampled, so a nested approach was designed, with sites replicated at a distance of 2−5 km, and then different species at varied larger spatial scales.

Aims

• To establish fundamental knowledge on the genetic diversity of seagrass meadows in the northwest of Western Australia; and if this varies among sites and with different environmental conditions, particularly clear and turbid water;
• To understand the gene flow among populations; and
• To inform the design of mesocosm and laboratory experiments on seagrass resilience (see Dredging Science Projects 5.5.1 – 5.5.4).