Here we predict oceanographic connectivity among four geographical locations in the south west of Western Australia using hydrodynamic modelling of larval dispersal and test these predictions against genetic descriptions of population structure, population boundaries and estimates of larval migration in two co-distributed sea urchin species. Sea urchins are excellent models for characterising marine population connectivity because of their commonness, diversity of larval life histories, ease of sampling, and ecological importance as grazers in coastal benthic habitats. Our study sampled two species, Heliocidaris erythrogramma and Phylocanthius irregularis. H. erythrogramma spawns predominantly in summer and its lecithrotrophic larvae are free swimming for 3-4 days in laboratory observations. In contrast, little is known about spawning time and larval duration in P. irregularis. The south-west corner of Australia is dominated by the Leeuwin current system, the worlds only poleward-flowing western continental boundary current. The Leeuwin current (LC) is particularly strong in the late autumn and winter months and is weaker in the summer. Strong seasonal contrasts in the LC flow pattern make it possible to generate testable predictions about the predominant direction of larvae-mediated gene flow in H. erythrogramma. Comparison of genetic structure with oceanographic model predictions allowed us to make predictions about the possible larval biology of the less well characterised urchin P. irregularis.

The dynamics of the seasonal evolution of chlorophyll a at the continental shelf break around 32 degrees south has been investigated using a one-dimensional numerical BGC model at shelf and lagoon scales. The results show that a combination of vertical mixing associated with the Leeuwin Current and surface cooling during the winter months is responsible for the wintertime increase in chlorophyll a concentration at the shelf break (Greenwood and Soetaert, 2008). In addition, variation in the timing and magnitude of the winter increase in chlorophyll is shown, for the first time, to relate to the strength of the Leeuwin Current. A nitrogen budget for the southwest WA shelf has been derived by diagnosing the simulated fluxes of particulate and dissolved nitrogen from the 3-D model across the shelf boundaries (across two cross-shelf transects at 27S and 34.5S and across the 100 m isobath) as well as deposition and release of nitrogen at the seafloor.

The Science Plan for WAMSI Node 1 Project 1 characterised the south west Australian marine coastal and shelf ecosystem structure and function. Mooring progam An array of instruments was deployed four times between July2007 and May 2008, recovered after 4-6 weeks each time to download data, and service the instruments. CTD Surveys During the course of the mooring program a ctd survey of the region was completed at approximately monthly intervals using the RV Linnaeus. In the first 2 surveys a grid of 25 stations was occupied after which a further 5 stations were added to the northern end of the grid.

Within this experiment the blue mussel ( Mytilus edulis ) is being used as a proxy indicator to understand rates of secondary production across the continental shelf off Marmion WA. The experiment is being run at 5m depth intervals between 0 and 40 meters. Length and width of valves and wet/dry weights of tissue matter are being measured to compare condition and growth rates of individuals from different depths. Stable isotope values are obtained to compare relative C13 and N15 values, to understand if there is a difference in diet across the shelf. Water sampling is also being carried out and regular intervals whilst the experiment is deployed to investigate differences in Particulate organic matter, Chl-a, HPLC and isotope values of organic matter in the water column, to aid in explaining variation in growth and diet patterns.

A) Rates of primary productivity for reef macroalgal and sediment microalgal communities will be determined from measurements of oxygen release (and/or CO2 consumption) collected from reef (3x) and bare sand/microphytobenthos (3x) communities using benthic chamber incubations. B) Nutrient enrichment experiments - response of macroalgae will be measured in terms of N assimilation in algal tissue, changes to species composition and changes in abundances. The response of consumers (abundance and other aspects of population dynamics, biomass, feeding biology and fecundity) will also be investigated, using video for mobile (fish) grazers, and quadrat sampling for less mobile grazers (eg. gastropods on reefs, urchins in sediments). Variations in the isotopic composition of the algae and consumers will be used to assess nutrient exposure and subsequent energy flow pathways into secondary production.

These data, reported in CSIRO's "Oceanographic Station List" series in 1957, comprise mainly measurements of surface temperature, and salinity (as chlorinity), from sea surface samples collected by the merchant ships MV "Dulverton", MV "Kabbarli" and MV "Duntroon". Sampling was only carried out in one year (1956). The merchant vessel sampling program was carried out at a time when the CSIRO Division of Fisheries had no dedicated ocean-going research vessel, as a means of acquiring information about offshore waters. In the volumes cited, similar data are also reported from the Tasman Sea, Coral Sea, and south-eastern Australian waters and Bass Strait.

Laterals of kelp Ecklonia radiata were cut from healthy individuals, photographed, placed on reefs for 2-3 days, then collected and re-photographed. Area loss was calculated from photographs.