A sedimentation scanner was used to measure daily sediment height at 10 sites associated with a 14 million cubic metre dredging project in Port Hedland harbour, Western Australia, between July 2011 and May 2012. Data were collected from seven potential impact sites, where up to 35 mm of additional sedimentation was predicted via modelling to result from dredging and at three reference sites, where background variation was monitored. A variety of mangrove habitat health indices from each site (including leaf area and health, pneumatophore and faunal burrow density) were collected before, during and after dredging. Despite predictions, most impact sites received between 0 and 10 mm over the dredging period, with one site experiencing a gain of 28 mm. Reference sites received between 2 and 28 mm which was attributed to natural processes. It was concluded that the health of Avicennia marina (Forssk.) Vierh. and Rhizophora stylosa Griff., the most common mangroves, were neither affected by a net sedimentation up to 28 mm of over a period of 11 months (i.e. 30.5 mm y) nor rapid changes over shorter time periods such as 14 mm over two days. This technology could be deployed in any tidally influenced sedimentary environment where short-term processes were of interest.

April 2014 marked the four-year anniversary of the BP Deepwater Horizon Disaster; a rig explosion in the Gulf of Mexico that killed 11 workers and led to the worst offshore oil spill in US history. Oil gushed from the sea floor for 87 days before the well was capped an estimated 5 million BBL spilled into the Gulf, inflicting untold environmental damage. The event highlighted how little the industry knows about containing deep-water oil spills or about how oil spreads. Oil washed up hundreds of miles away on coastlines in Louisiana, Alabama, Mississippi and Florida, but scientists struggled to determine where all of the oil had gone. Had some of it evaporated or was it hiding below the surface? Had it been carried by currents to the Gulf’s deep waters or perhaps even further? No one can say for sure. The resulting science highlighted that oil drifts along the surface of ocean water at 97% of current speed, but at only a fraction of the wind speed. During the Deepwater Horizon Disaster, the tracking buoys sat too proud and were driven the wrong way by the wind. It is essential to track the currents, since they account for at least 95%–98% of the ultimate oil spill trajectory. WorleyParsons designed, developed and deployed an oil spill tracking buoy (OSTB) to provide a scientific instrument for capturing only the surface currents. The specific gravity of each buoy is such that it tracks surface currents. Material selection and manufacture, ocean validation and telecommunication engineers came together to produce such a device, which is largely underwater but can continue to communicate with satellites.