The Aquaculture Environment Review Series is an independent literature review series relating to marine farming interactions with the environment in Tasmania and beyond. The aim of the series is to support the sustainable planning and regulation of marine farming in Tasmania, as well as providing a reference source for people with an interest in aquaculture, including proponents of aquaculture developments, resource managers, and the general public.
The Aquaculture Environment Review Series was developed to provide an accessible, evidence-based resource that supports informed management, regulation, and research across the sector.
The first release of the series is presented in four parts:
Together, these reviews synthesise research on what is known, where knowledge gaps remain, and how monitoring and management can continue to evolve to support sustainable aquaculture.
Click one of the interaction tiles to the right to read about each of the habitat types in the series, or click on the hyperlinks above.
You can also find more of our team’s research on the Publications page.
The development of this series was supported by the Sustainable Marine Research Collaboration Agreement between the University of Tasmania and the State Government of Tasmania.
Aquaculture is one of many human activities that interacts with the environment, with positive, negative or neutral all possible. Aquaculture is one of the fastest growing primary industries worldwide and is a major contributor to regional economies. It is crucial that this industry grows sustainably, minimising its impact on the marine environment while providing economic benefit to local communities. This will ensure the ongoing health of our coastal and marine environments and the wide range of environmental, social and economic values and services they provide.
Aquaculture interactions with the environment are broad and vary depending on the type of species farmed, farming practices and local environmental conditions. Feed-additive aquaculture sectors (e.g. finfish, crustaceans) often carry greater environmental risk than extractive aquaculture sectors (e.g. seaweed, shellfish), as they involve adding extra nutrients through feeds into the environment. In addition, there can be cumulative and synergistic effects between aquaculture and other pressures like climate change, fishing and run-off from coastal development.
To find out more about aquaculture environment interactions, the Tasmanian aquaculture industry and the legislative framework that guides marine farming, read the Aquaculture Environment Review Series: General Introduction.
Soft sediment communities have a natural ability to process organic matter, which makes them resilient yet sensitive to additional inputs from aquaculture.
Most aquaculture in Tasmania occurs over soft sediment habitats. In the case of finfish aquaculture, uneaten salmon feed, salmon faeces and biofouling debris can be released to the seafloor. This may result in organic enrichment and sedimentation/smothering.
Animals in the sediments break down this excess organic matter and consume oxygen in the process. Organic enrichment can cause community changes in the fauna, with small amounts of enrichment stimulating biodiversity and abundance, but sustained organic inputs will favour opportunistic species that can rapidly breakdown organic material. If the ability of these animals to break down this matter is exceeded, oxygen levels may decline, there will be a loss of infauna from the sediments, and hydrogen sulphide gas may be released as organic matter break-down is left to microbes.
Typically, these interactions are greatest immediately below actively farmed salmon cages, decreasing with distance from the farm. The magnitude of interactions depends on the intensity and management practices of farming, environmental conditions at the farm site (e.g. depth of water below cages, water movement in the area) and the sensitivity of the soft sediment ecosystem.
To find out more about how aquaculture interacts with soft sediment habitats, read part one of the Aquaculture Environment Review Series: Ecological effects of finfish aquaculture on soft sediments.
Primary producers in the water column, such as phytoplankton, take-up water column nutrients and make them available across the pelagic food web and into other habitats. Nutrients are essential for marine life and increased nutrients can generally be assimilated by the water column ecosystem without negative effects. However, high nutrient levels can lead to nutrient enrichment, which can cause excessive growth of algae (a process known as eutrophication). Over time, this can disrupt the balance of local ecosystems, reducing water quality and affecting marine food webs.
Finfish aquaculture provides nutrient inputs directly into the water column via the release of dissolved and particulate waste products such as uneaten feed, fish waste, and metabolic by-products. The interactions between finfish aquaculture and the water column can vary considerably depending upon farming practices and the environment in which aquaculture occurs. More exposed environments with greater water movement experience greater dilution of nutrients, whereas sheltered environments are more prone to adverse effects.
Understanding how farm-derived nutrients influence the water column is crucial for understanding maintaining water quality and ecological health. Monitoring regularly combines field sampling and modelling, with advanced sensor networks, satellite data and eDNA techniques now provide near-real-time insights into water quality trends.
To find out more about how aquaculture interacts with the water column, read part three of the Aquaculture Environment Review Series: Ecological effects of finfish aquaculture on the water column.
In Tasmania, shallow temperate rocky reefs habitats are largely dominated by kelp forests that support diverse fish and invertebrate communities. These reefs are vital for coastal productivity and habitat complexity, but are exposed to many sources of nutrients, including agricultural runoff, freshwater flows, urban activity and marine finfish aquaculture.
Finfish aquaculture influences shallow reef ecosystems through nutrient enrichment from dissolved and particulate waste. Excess nutrients can lead to the growth of opportunistic algae (characterised by rapid growth and reproduction) and epiphytic algae (algae that grows on the surface of other algae). Although this is the environment’s mechanism for adjusting to increased nutrients, sustained growth of opportunistic and epiphytic algae can smother other species and reduce light penetration, causing shifts in the reef ecosystem.
Site selection is a key strategy for managing interactions between finfish aquaculture and shallow reefs, with more dispersive sites reducing local impact. Regular monitoring is also a key part of this framework.
To find out more about how aquaculture interacts with shallow reef habitats, read part four of the Aquaculture Environment Review Series: Ecological effects of finfish aquaculture on shallow temperate reef ecosystems.
Along with understanding aquaculture environment interactions, in recent years, our team has been involved in several research projects aimed at improving our understanding of the broader social and economic interactions of aquaculture and their interplay with environmental interactions and other marine resource-based industries.
Understanding how the community values our marine and coastal ecosystems helps industry, managers and local communities better appreciate how changes to aquaculture management might impact these values.
Although societal interactions are a more minor focus for our team, some of the outputs of our work in this space include:
For a deeper exploration of how aquaculture interacts with other industries, community values and the environment, see the following resources:
