Background Information

Enabling policy for responding to climate change impacts and opportunities for Australia’s oceans

Climate Change and Marine Policy

As detailed in physical and biological chapters of the 2012 Marine Report Card, climate change is predicted to have a range of impacts on marine environments, habitats, and biodiversity and on a range of dependent industries, including fisheries and aquaculture. Marine management and policy will also need to adapt to cope with the impacts of climate change. Without appropriate change in management and policy, impacts may be intensified and opportunities constrained. This emphasises the need for rigorous science-based decision making and multi-objective policy development in all matters relating marine resource use and management.

Further Information

Useful links

Extreme events and climate change

Recent extreme events in ocean climate provide a glimpse of how future climate change could impact biodiversity, and human goods and services that our oceans provide.

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Colin Creighton, Chair, Climate Change Adaptation, Marine Biodiversity, Resources and Fisheries
Fisheries Research & Development Corporation



Management of marine systems, for both biodiversity conservation and for resource management, is not static. Both day-to-day operational changes, as well as legislated changes, are used to respond to historical events, or in anticipation of future events. Climate change is an additional consideration in shaping the tools available for management, and must be considered holistically with other non-climate drivers. In this brief review, a focus is on four key climate impacts and the potential implications for policy and decision-making, specifically; increasing climate variability, increasing frequency of extreme events, changing ocean temperatures and currents, and increasing sea level and impacts on estuaries and wetlands.

i) Increasing climate variability – our climate is becoming more variable and model projections for the future suggest that there will be more climate extremes; more heatwaves and cool periods, more droughts and floods. We also know that many Australian fish stocks and their abundance are strongly linked to Australia’s variable climate. For coastal species, cycles of wet and dry periods also impact on estuarine and coastal species, especially in the tropics. These signals are most obvious in species with short lifespan, such as prawns, where catch is typically composed of a single year class of adults. For example a run of wet seasons typically results in strong recruitment and adult stocks of virtually all prawn species, whereas a run of drier years will reduce the annual populations available to catch. Fish species have similar fluctuations correlated to wet and dry years but the influence of variable climate is somewhat dampened because species such as mullet, bream, whiting and barramundi enter the commercial and recreational fisheries at older year classes, generally age 3+. Thus, environmental effects on recruitment may take several years before affecting harvest levels. Nevertheless, overall affects on population abundance and therefore fisheries management require similar responses.

Scientific methods have been used to predict the size of populations available for catch, following which fishery managers fine tune the fishing effort (e.g. through modifying the number of boats or days allowed on the fishery) such that sustainable economic yield is achieved. A good example of the interaction between science, monitoring annual biomass and population changes, and fisheries management is the northern prawn fishery.

Re-thinking fisheries policy to allow for more flexible arrangements for effort management closely linked to stock assessment is essential across all Australian fisheries. Likewise, variations and flexibility to use and zonings within Marine Parks, including for commercial and recreational fishing, tourist visitation, charter and research permits requires a policy rethink.

Issues do not stop at fishing effort and marine use. There are a series of implications for policy and management. For example, if stock availability is high, without consideration of the total value chain and how best to take profitable advantage of high catch, the return to fishers per volume caught will be reduced, as the market may not be able to handle the extra volume. Science will be needed to cope with the extra environmental variability, and will help with underpinning smart processing and marketing arrangements within the context of industry profitability and food security.

ii) Increasing frequency of extreme events – a good example of the need for changed management arrangements and enabling policy is cyclones and the impact on the live coral trout fishery. Whole sections of the Great Barrier Reef saw reduced populations of coral trout following the recent run of cyclones over the period 2009 – 2011. This led to displacement of both commercial and recreational effort. Under such fluctuations, spatial entitlements and management of ecosystems for conservation based just on spatial considerations are sub-optimum. This refers to both total closures for marine conservation objectives and any partitioning of fishery effort based on fixed boundaries. Again, through real-time predictive stock assessment, smarter management arrangements are needed. Science is required to predict stocks and their fluctuations due to extreme events, evaluate more flexible fishing entitlements and effort management arrangements within the context of sustainable economic yield, and torethink how best to ensure meeting marine conservation and fishing objectives. The current system of fixed permanent closures may not be the most effective policy instrument in a marine setting under climate change, especially when many fish and other biodiversity are moving south as waters warms.

iii) Changing ocean temperatures and currents – an excellent example is the Leeuwin Current and lobster peruleus settlement along the Western Australian coast. Research shows that recruitment of rock lobster has historically been strongly correlated with Leeuwin Current strength, and has been used to set effort within the spatial entitlements of the industry. However, this historical relationship has broken down over recent years, and this could be because of changing ocean climate. For example, the recent onset of extremely warm ocean temperatures there has seen mass kills of sessile species such as Roe’s abalone, necessitating at least temporary closure of the northern sector of this fishery. Another example is the recent pattern of warm eddies extending further south than normal along Australia’s east coast. This leads to aggregation of pelagic fish stocks and therefore increases the opportunities for profitable fishing. Ongoing science investment to monitor biophysical conditions of our oceans and their currents, to predict populations and thus sustainable economic yield is essential and needs to be matched by changes in marine policy to modify and make more flexible management arrangements for all marine uses. There will be new fishing opportunities in the future as the ocean climate changes, and research will help Australian fishing industries take best advantage.

iv) Increasing sea level and impacts on estuaries and wetlands – Australia’s estuaries and wetlands are in varied condition, from pristine to severely damaged and sometimes destroyed [National Land and Water Resources Audit, 2002]. Much can be done to repair these powerhouses of marine biodiversity. As just one example, there are over 1500 barriers to fish passage just in the Burdekin floodplain {GBRMPA Outlook Reports]. These are areas that were essential nursery habitat for fish, prawns and birdlife. Similar levels of habitat alteration exist along the eastern, southern and south-western Australian coast. Yet in excess of 75% of Australia’s commercial and recreational fish and prawn species spend part of their life cycles within these habitats. Clearly, Australia has greatly reduced its potential to have abundant fish stocks through a host of past decisions.

Increasing areas under marine park reservation will not totally redress this issue. What is required is strategic habitat repair. Equally importantly, estuaries and wetlands are at the forefront of any impacts of rising sea level, so that without a major initiative to repair and retain habitat, Australia’s potential to produce fish and prawns, to retain coastal biodiversity, to buffer marine systems from land sourced water quality problems, and to protect our coastal infrastructure from storms will be severely impeded. Fortunately with climate change and Australia’s efforts to sequester greenhouse gases, potential solutions are at hand. Estuaries and wetlands are the most productive of the world’s ecosystems, so it is no surprise that per hectare, these same estuaries and wetlands sequester the most carbon and do so with unparalleled long term certainty and is being promoted internationally by UNEP and others as “blue carbon”. Compare for example the certainty of carbon sequestered into Australian coastal sediments to carbon sequestered in forests and the ongoing threat of bushfire. Repair can be as simple as increasing the size of causeways and road culverts, so that tidal flows are restored, or removing unnecessary barrages to fish passage such as bunds and ponded pasture levees.

Unfortunately Australia’s National Carbon Accounting System does not yet account for sequestration within estuaries and wetlands. Internationally “blue carbon” is a major policy area and is seen as a large part of the mitigation opportunities globally to reduce the impact of greenhouse gases.

Climate change therefore provides Australia with a substantial opportunity to increase its fish stocks through habitat repair, while simultaneously increasing coastal biodiversity, water quality and carbon sequestration. Science and policy is needed to underpin such an initiative so that the carbon sequestered is accounted for, the repair works are done with minimal impact on surrounding high value land uses, and fish habitat value is maximised. The first step required is for the Australian Government policy to be changed so that the carbon sequestered from estuary and wetland repair works is included within the National Carbon Accounts.

Additional factors for marine resource policy

The Climate Change Clean Energy Future policy also has implications for climate adaptation approaches. Research sponsored by FRDC is underway to analyse how the Clean Energy Future policies impact on both commercial and recreational fishing (Mick Keogh, Australian Farming Institute). In brief, diesel is a large part of the input costs of most fishing enterprises – up to about 40% for ocean going trawlers. Likewise, energy costs for aquaculture such as prawn farms are high and energy of course plays a large part of any downstream processing and transport of product. Fishers are keen to play their part in reducing energy use. Science coupled with policy and incentives for improved practices have a key role to play – for example in ensuring 100% adoption of reduced drag and more ecologically benign trawling arrays, reduced reliance on electricity from the grid for aquaculture, and smarter storage, processing and refrigeration systems.

Climate change will initially be experienced through climate variability, which will have major repercussions for fishing industry, including altered weather patterns and fluctuations in fish population. Climate change is just one stressor, or opportunity, for any business. Other factors businesses must include in their profitability analysis include:
• comparative value of Australian $ - applying differently but with impact to both those exporting product and to those where their product has an imported substitution
• labour availability, cost and skills – with many regional variations across Australia, often as a function of other industries in the region such as mining going through boom and bust phases
• changes to regulations and zonings – such as declaration of marine parks, changed management arrangements and entitlements
• input costs, especially such as fuel price rises for such as trawlers or electricity charges for aquaculture
• changes to community demand and therefore price paid for product
For many in the wild fisheries and aquaculture sector, these factors are often of far more immediate concern than long-term climate change. Industry must by virtue of its needs for profitability work on timeframes of seasons to at most 10 years, different to the 20+ year timeframe for Australia’s oceans to experience much of the impact of the predicted average changes that will accompany a changing climate. Climate variability and extreme events will of course happen on much shorter time scales, and will require tactical responses.

Conclusion

Just as commercial, recreational and indigenous fishers, aquaculturalists and non-extractive resource users such as divers and whale watchers must consider impacts of climate change, so to must Australia’s marine managers and policy makers. Particularly desirable are the win-win policy changes: those that provide both short-term opportunities and long-term benefit. The challenge for science and policy is to develop multi-objective policy that meets the needs of all Australia’s marine users, while simultaneously meeting multiple demands and stresses on our marine environment, including climate variability and change as one of these stresses. The 2012 Report Card synthesises our current knowledge of observed impacts of climate change and provides an insight into potential futures changes in the marine environment. The knowledge and data streams contained here will underpin our multi-objective policy responses.

Extreme events also help us develop and test adaptation responses and preparedness. The intense La Niña event in the summer of 2010/2011 led to two events in Australia that are likely to intensify in the future. One event was the extreme rainfall and floods in Queensland. These led to declines in seagrass beds, particularly for shallow sub-tidal species, because of increased nutrient loads and reduced light availability associated with sediment transport down rivers. Many green turtles died because of malnutrition, unable to find sufficient seagrass to meet their dietary requirements. Ongoing monitoring of turtle populations has shown these mortalities declined as water quality and seagrass beds recovered, but also as animals moved away from affected areas This event highlighted some of the impacts that can be expected from heavy rainfall events in the future. See 2012 Reports on El Niño-Southern Oscillation and Marine Reptiles for further information.

The second noteworthy event of 2010/2011 was the marine heatwave in Western Australia. The strong La Niña conditions contributed to an acceleration of the southward-flowing, warm-water Leeuwin Current, coupled with atmospheric conditions that transferred heat to the ocean. Coinciding with a period of calm weather in late February and early March 2011, caused extremely warm water temperatures, reaching 5°C above normal along the central west coast, Abrolhos Islands and Shark Bay. The hot water temperatures killed fish and invertebrates (e.g. Roei abalone) and temporary range extensions of many tropical species down the west coast and eastwards towards the Great Australian Bight, including whale sharks and manta rays that were sighted off Albany. Several fisheries and livelihoods were negatively impacted, but adaptation responses were put in place to maximize recovery. The abalone fishery in the northern region was shut, and a research trial started on the translocation of abalone from nearby unaffected areas into the depleted areas. This has been successful. The recruitment of juvenile scallops and crabs in Shark Bay was improving by the end of 2011, and the management focus is now is on the long-term recovery of the population. This event may also have longer-term implications for some marine stocks, as effects of the warm temperatures during their spawning and larval phases will take several years to manifest. Fisheries management already has approaches in place to deal with variability in the size of fish stocks, but modification of existing approaches and development of innovative new ones will be necessary in the future. It is likely that Australia will encounter such ocean heatwave conditions and extreme rainfall events much more frequently in the future (Fig. 1). See 2012 Reports on Leeuwin Current, Temperature, Macroalgae, Pelagic fish, and Seabirds for further information.

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Figure 1. The effect of changes in temperature distribution on extremes. Different changes in temperature distributions between present and future climate and their effects on extreme values of the distributions:
(a) effects of a simple shift of the entire distribution toward a warmer climate;
(b) effects of an increase in temperature variability with no shift in the mean;
(c) effects of an altered shape of the distribution, in this example a change in asymmetry toward the hotter part of the distribution.
(Reproduced from Special Report of the IPCC: Managing the risks of extreme events and disasters to advance climate adaptation. Summary for Policy Makers).

Gretta Pecl, Institute for Marine and Antarctic Studies, Taroona, Tasmania, Australia.
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Redmap (Range Extension Database and Mapping project) is a citizen science program hosted by the Institute for Marine and Antarctic Studies( IMAS), in collaboration with a range of organisations around Australia, which collects data to help identify changes in distribution of marine life (primarily fishes, but also invertebrates, reptiles and algae).

The project highlights species which are thought to be changing distribution or are likely to be influenced by changing climatic conditions and indicates areas where, if seen, they should be reported (via the interactive website; www.redmap.org.au). However, participants can submit sightings of any species they know or suspect to be unusual for a particular area.

Community members (divers, fishers and boaters) send in photos and map where they sight these species, recording additional information at the same time. Submitted photographs are sent to members of a large scientific panel for confirmation of species identity, and geo-referencing information is extracted from photographs where possible, ensuring high quality data.

The data recorded include photographic identification, and a range of variables including location, date, time, size and weight estimates. In addition to direct display of individual and summarised data on the Redmap website, metadata are publicly available through the Institute for Marine and Antarctic Studies GeoNetwork (University of Tasmania) and through Australian National Data Service (ANDS) via Research Data Australia (RDA) and the Australian Ocean Data Network (AODN). Data dissemination and availability will occur via the website (RDA and AODN once published). Initially this project focussed in temperate Tasmanian waters, but is currently undergoing expansion and will soon be reporting on species on an Australia-wide scale (from November 2012).