BROADSCALE Environmental Monitoring Environmental consultants (Aquenal and Marine Solutions) travel to sites around Tasmania, frequently collecting water and sea floor samples. The purpose is to document broadscale environmental conditions over time. The teams travel to over 40 different sampling stations throughout the state, including the D’Entrecasteaux Channel, Huon Estuary, Mercury Passage, Okehampton Bay, Port Arthur and Tasman Peninsula. There is also an environmental control site in Recherche Bay, which is sampled 15 times each year. The marine scientists collect a range of samples from the ocean, which are then analysed and sent to the Environmental Protection Agency for review. It’s a regulatory requirement Tassal undertakes this farfield monitoring to provide a high level of confidence to ensure we are maintaining a healthy marine environment. Both Aquenal and Marine Solutions employ local marine scientists – it’s great to have such highly qualified personnel assisting us with a range of environmental programs, from water monitoring to reef community and threatened species surveys. Once each month, our scientific consultants survey the same monitoring locations regularly throughout the year. Making sure the survey positions are sampled consistently is key to providing the most reliable data, a GPS is used to ensure each site is sampled in the same location for each survey. Water samples provide a vast amount of information about the health of the ecosystem. Through the Tasmanian Salmonid Growers Association (TSGA), Tassal participates in a Broadscale Environmental Monitoring Program (BEMP) across multiple locations in south-east Tasmania. The monitoring program has a water quality component (surface and bottom water) and a sediment component (sediment biology and chemistry). Water quality sampling is conducted by Aquenal (Environmental Consultants) every two weeks in summer and monthly over winter. 18
WINTER 2018 CURRENT
Mercury Passage
Hobart
Nubeena
Huon
Port Arthur
South and South Eastern Broadscale Monitoring Testing Sites Recherche Bay
From the boat, the team can collect significant data such as water temperature, depth, salinity, pH levels and dissolved oxygen levels using a Water Quality Meter. With ever-improving technology – the quality of sampling equipment is getting better by the year. So much data can now be stored automatically to be taken back to the lab and analysed for environmental trends. Sediment samples are also collected annually from the sea floor. The marine life collected in these samples are a key indicator of ecosystem health. Other tests require further analysis and samples are sent to Analytical Services Tasmania to test for chlorophyll, microalgae (or phytoplankton) and nutrient concentrations. A range of different sampling apparatus are specially designed for collecting a range of different sample types, and at different depths in the water column. The factors measured monthly are key in monitoring any changes in the environment. By developing a more intimate understanding of environmental patterns, we can predict how these changes may affect the health of our salmon, or the ecosystem. After all, we need a healthy, functioning marine ecosystem to produce healthy fish!
