Chapter 30: The status determination process
R Noriega, H Patterson, S Nicol and R Curtotti
30.1 Legislation and policy
Fisheries Management Act 1991
The Fishery status reports assess the performance of Commonwealth fisheries against the objectives of the Fisheries Management Act 1991 (FM Act); in particular:
- ensuring that the exploitation of fisheries resources and the carrying on of any related activities are conducted in a manner consistent with the principles of ecologically sustainable development (which include the exercise of the precautionary principle), in particular the need to have regard to the impact of fishing activities on non-target species and the long term sustainability of the marine environment; and
- maximising the net economic returns to the Australian community from the management of Australian fisheries; and
- ensuring accountability to the fishing industry and to the Australian community in AFMA’s management of fisheries resources.
Commonwealth Fisheries Harvest Strategy Policy
The Commonwealth Fisheries Harvest Strategy Policy (HSP; DAFF 2007) was developed to support the implementation of the objectives of the FM Act. The objective of the HSP is ‘the sustainable and profitable utilisation of Australia’s Commonwealth fisheries in perpetuity, through the implementation of harvest strategies that maintain key commercial stocks at ecologically sustainable levels and, within this context, maximise the economic returns to the Australian community’.
The HSP and associated guidelines provide a framework for an evidence-based approach to the management of Commonwealth fish stocks. The HSP makes the following observations on what constitutes good fisheries management:
- Fisheries are more efficient, profitable, stable and sustainable when stocks are larger than the stock size (biomass) that produces maximum sustainable yield (MSY), referred to as BMSY.
- Future productivity is at greater risk when stocks are reduced to a level at which the recruitment of young fish, relative to the portion of the stock subject to fishing, declines precipitously (referred to as ‘recruitment failure’).
- Fisheries should be managed on a whole-stock basis, and in a way that takes species’ life history characteristics (such as longevity, fecundity and recruitment variability) into account.
- Economic returns can be maximised and, in general, overcapitalisation can be avoided when fish stocks are maintained, on average, at a target adult biomass level that produces maximum economic yield (MEY), referred to as BMEY.
The HSP requires that harvest strategies are developed that pursue MEY and ensure that stocks remain above levels at which risk becomes unacceptably high. Specifically, harvest strategies need to have the following aims:
- Seek to maintain fish stocks, on average, at a target biomass (BTARG) equal to BMEY. Where BMEY is unknown, a proxy of 1.2BMSY (or a level 20 per cent higher than a given proxy for BMSY) is to be used for a single-species fishery. For a multispecies fishery, judgement needs to be exercised in setting targets to optimise multispecies MEY. An alternative proxy for BMEY may be used if it can be demonstrated that it is more appropriate.
- Ensure that fish stocks remain above a biomass level below which the risk to the stock is regarded as too high—referred to as the limit biomass level (BLIM).
- Ensure that the stock stays above BLIM at least 90 per cent of the time. For highly variable species that may naturally breach BLIM in the absence of fishing, the harvest strategy for the species must remain consistent with the intent of the policy.
A harvest strategy sets out the management actions necessary to achieve defined biological and economic objectives in a given fishery. Harvest strategies must include:
- a process for monitoring and conducting assessments of the biological and economic conditions of the fishery
- rules (referred to as control rules) that control the intensity of fishing activity according to the biological and economic conditions of the fishery (as defined by the assessment).
The HSP requires harvest strategies to be developed for all Commonwealth fisheries, except for those that are managed under the joint authority of the Australian Government and another Australian jurisdiction, or under an international management body or arrangement. However, the HSP also notes that the Australian Government will advocate the principles of the policy within jointly managed fisheries.
In March 2012, the then Minister for Agriculture, Fisheries and Forestry announced a review of the HSP. The review found that the policy is widely regarded as a very successful initiative for improving the management of Commonwealth fisheries and that it remains a strong foundation for Commonwealth fisheries management. The results of this review (Penney et al. 2013; Vieira & Pascoe 2013; Ward et al. 2013) are being used to revise and update the HSP. A revised policy is currently being developed by the Department of Agriculture and Water Resources, in consultation with the Australian Fisheries Management Authority (AFMA) and other stakeholders.
30.2 Assessing biological status
Fish stock definitions
Where feasible, statusis reported for the biological stock, defined as discrete populations of the same species that are typically reproductively isolated from each other in space or time, resulting in detectable genetic, biological or morphological differences in fish from different populations. Fishing is assumed to affect the entire stock, but not adjacent stocks. This independence between populations of the same species means that separate assessments and management arrangements are often required for each, and is why status is reported separately for each defined stock. The true structure and boundaries of biological stocks are often not well understood, or a stock may straddle the jurisdictional boundaries of several management agencies. In such circumstances, the stock may be treated as a series of convenient geographic components or ‘management units' that are managed separately by different jurisdictions. For each species reported on, available information on biological stock structure is summarised, and definitions are provided for the biological stocks or management units being assessed.
The Commonwealth generally manages fish resources from 3 nautical miles (nm) from the coast out to the 200 nm Exclusive Economic Zone (EEZ) limit, while states or territories manage fish resources within 3 nm. The Australian Government has negotiated Offshore Constitutional Settlement arrangements with states and territories that provide for the shared, cooperative or transferred management of some stocks that straddle this state–Commonwealth boundary. Fish stocks that occur within Torres Strait are managed cooperatively by Australia and Papua New Guinea under the 1985 Torres Strait Treaty, which provides for joint management of the shared resources in the Torres Strait Protected Zone. In the Australian area of this zone, traditional fishing and commercial fisheries are collaboratively managed by the Torres Strait Protected Zone Joint Authority, established under the Torres Strait Fisheries Act 1984.
Several fishery resources of commercial importance to Australia have ranges extending outside the Australian Fishing Zone into the high seas and the EEZs of other countries, particularly the highly migratory tunas. Under the United Nations Fish Stocks Agreement (1995), the high-seas components of these straddling stocks are required to be collaboratively managed by regional fisheries management organisations (RFMOs). Australia is an active member of a number of RFMOs, including the Western and Central Pacific Fisheries Commission (WCPFC), the Commission for the Conservation of Southern Bluefin Tuna, the Indian Ocean Tuna Commission (IOTC), the South Pacific Regional Fisheries Management Organisation and the Southern Indian Ocean Fisheries Agreement. In managing its domestic fisheries, Australia implements measures agreed by each relevant RFMO. In some cases, Australia's domestic standards exceed those agreed internationally, in which case Australia attempts to obtain international agreement to implement measures consistent with Australian standards.
Reference points and indicators
The biological status of a stock depends on its current stock size (biomass) and the rate of catches (fishing mortality). Two independent aspects of stock status are classified: the stock’s biomass level and its fishing mortality status (Table 30.1). In cases where reference points or estimates of current biomass or fishing mortality have not been determined, other indicators are used to inform stock status. The HSP defines target and limit reference points for Commonwealth fisheries in terms of biomass (BTARG and BLIM, respectively) and fishing mortality (FTARG and FLIM, respectively).
In terms of biomass status, stocks are classified as one of the following:
- not overfished, where the biomass is above BLIM and likely to be adequate to sustain the stock in the long term. This indicates that the biomass (or biomass proxy) is at a level sufficient to ensure that the risk to future levels of recruitment is not excessive (that is, the stock is not recruitment overfished)
- overfished, where the biomass is below BLIM and unlikely to be adequate to sustain the stock in the long term. The BLIM threshold reflects the point at which the risk to future levels of recruitment is unacceptable. The HSP requires that fish stocks remain above a biomass level at which the risk to the stock is regarded as too high (BLIM or a proxy) at least 90 per cent of the time. Two common proxies for that limit are half the biomass required for MSY (0.5BMSY) and 20 per cent of the unfished biomass (0.2B0)
- uncertain, where there is inadequate information to determine the state of a stock’s biomass and the risk to future recruitment.
The guidelines of the HSP do not define if BLIM relates to spawning biomass, exploitable biomass or total biomass. This flexibility allows for reference points to be consistent with the types of data available for stock assessments. For example, stock assessments that rely mainly on catch-per-unit-effort estimate depletion levels related to the exploitable biomass. Alternatively, stock assessments that use catch age analysis with auxiliary biological information allow estimates of depletion levels related to spawning biomass and overall biomass. As a result, depletion-level estimates of all assessed stocks may not necessarily refer to the same portion of the biomass.
In terms of fishing mortality, stocks are classified as one of the following:
- not subject to overfishing, where the fishing mortality does not exceed the limit reference point (FLIM). In this case, the stock is not subject to a level of fishing mortality that would move the stock to an overfished state
- subject to overfishing, where the fishing mortality exceeds FLIM. The stock is subject to a level of fishing that would move the stock to an overfished state, or prevent it from rebuilding to a not overfished state. The HSP indicates that an overfished stock should not be subject to any directed (targeted) fishing. Also
- when stock levels are at or above BMSY, FMSY will be the default level for FLIM
- fishing mortality exceeding FLIM will not be defined as overfishing if the stock is above the target level (BTARG) and a formal ‘fish-down’ or similar strategy has been implemented
- when the stock is less than BMSY but greater than BLIM, FLIM will decrease in proportion to the level of biomass relative to BMSY
- any fishing mortality will be defined as overfishing if the stock level is below BLIM, unless that fishing mortality is below the level that will allow the stock to recover (to or above BLIM) within a biologically meaningful time frame. The HSP gives a period of 10 years plus one mean generation time, or three times the mean generation time (whichever is less) as examples of typical recovery time frames
- uncertain, where there is inadequate information to determine whether the level of fishing mortality represents overfishing.
Some RFMOs report against reference points for biomass and fishing mortality when providing advice on stock status, although these reference points may be defined differently from those in the HSP. The limit reference points adopted by the WCPFC and the IOTC are the same as those prescribed in the HSP. However, the IOTC determines stock status relative to target reference points, not limit reference points. For jointly managed stocks, ABARES determines stock status using the limit reference points described in the HSP and considers the impacts of fishing mortality from all fleets on the stocks. Consequently, the status of some jointly managed stocks reported by RFMOs may differ from that reported by Australia.
Changes to the stock status classification system
The classification system for stock status has been modified several times since the first Fishery status reports (1992). In 2004, the ‘underfished' and ‘fully fished' categories were replaced by a combined category of ‘not overfished'. This change was made partly because of potential confusion about the meaning of ‘fully fished'. It was also difficult to classify a stock as ‘underfished' because data were often lacking for stocks likely to fall into this category.
Another change in 2004 was inclusion of a distinction between a stock's biomass status and its fishing mortality status. Before 2004, each stock was given a single status classification, based on the worst-case scenario. For example, if a stock was considered ‘subject to overfishing', it was classified as ‘overfished', and there was no separate determination of the stock's biomass status. Also, stocks were only classified as ‘not overfished' if overfishing was also not occurring. In 2007, this classification system was aligned with the reference points defined in the HSP (Table 30.1).
TABLE 30.1: Reference points for fishing mortality and biomass, with associated status implications and actions in line with the HSP
|Biomass (B)||F < FTARG|
(fishing mortality is below the target)
|FTARG < F < FLIM|
(fishing mortality is between the limit and the target)
|F > FLIM|
(fishing mortality is above the limit)
|B>BTARG (biomass is greater than or equal to the target)||Not overfished|
Overfishing is not occurring
Overfishing is not occurring
Overfishing is occurring: note possible planned fish-down where overfishing would not be occurring|
|BTARG > B > BLIM (biomass is between the limit and the target)||Not overfished: rebuild to BTARG|
Overfishing is not occurring
|Not overfished: rebuild to BTARG
Overfishing may not be occurring, provided that fishing mortality will allow rebuilding towards target
|Not overfished: rebuild to BTARG
Overfishing is occurring
|B < BLIM (biomass is below the limit)||Overfished: adopt and follow a rebuilding strategy to rebuild biomass above BLIM within a required time frame
Overfishing may not be occurring: no targeted fishing permitted
|Overfished: adopt and follow a rebuilding strategy to rebuild biomass above BLIM within a required time frame
Overfishing may not be occurring, provided that fishing mortality will allow rebuilding towards target within a required time frame; no targeted fishing permitted
|Overfished: adopt a rebuilding strategy to rebuild biomass above BLIM within a required time frame
Overfishing is occurring: reduce fishing mortality; no targeted fishing permitted
High risk to stock
Note: Colours show how these reference points relate to stock status classifications used for each stock.
Status determination framework
A weight-of-evidence decision-making framework for biological status determination was a key output of the Reducing Uncertainty in Stock Status (RUSS) project, undertaken from 2009 to 2012 (Larcombe et al. 2015). Application of the framework requires the assembly of an evidence base to support status determination and is analogous to a review of fisheries indicators. The framework provides a structure for the assembly and review of indicators of biomass and fishing mortality status, which has been applied in the compilation of the Fishery status reports since 2009. The framework provides guidance on interpreting these indicators, and aims to provide a transparent and repeatable process for status determination. It requires a description of attributes of the stock and the fishery, documentation of lines of evidence for status, and presentation of the key information used to support the status classification. Expert judgement plays an important role in status determination, with an emphasis on documenting the key evidence and rationale for the decision. The decision-making process is undertaken separately for biomass and fishing mortality.
30.3 Assessing economic status
The economic status of each Commonwealth fishery (excluding jointly managed Torres Strait fisheries) is determined by assessing management performance against the economic objective of the FM Act, which is to maximise net economic returns (NER) to the Australian community from the management of Australian fisheries. Performance against this objective is evaluated using three criteria: key economic trends, management arrangements, and performance against the HSP's economic objective.
The economic status of Torres Strait fisheries is also evaluated. However, as these fisheries are managed under the Torres Strait Fisheries Act 1984, the HSP and its economic objective do not apply. Therefore, performance of these fisheries is assessed against fishery-specific objectives, as well as those of the Torres Strait Fisheries Act 1984. These are:
- to acknowledge and protect the traditional way of life and livelihood of Traditional Inhabitants, including their rights in relation to traditional fishing
- to manage commercial fisheries for optimum utilisation
- to have regard, in developing and implementing licensing policy, to the desirability of promoting economic development in the Torres Strait area and employment opportunities for Traditional Inhabitants.
Key economic trends
NER are a major indicator of a fishery's economic performance. NER measure the difference between the revenue a fishery earns in a given year and the economic costs it incurred earning those revenues. These include costs associated with fuel, crew, repairs, fishery management, depreciation, and the opportunity cost of capital and owner operator labour.
Survey estimates of NER calculated by ABARES are available for some the most valuable Commonwealth fisheries. For other fisheries, indicators of fishery revenue and costs are analysed to evaluate likely changes in profitability. Although estimates of a fishery's gross value of production are readily available and provide an indicator of revenue, information on costs is more difficult to obtain. Measures of fishing effort and fuel prices are used for some fisheries to provide an indication of total fishery costs. For data-poor fisheries, the level of unused fishing rights (‘latency') can provide an indication of NER. High latency suggests that the fishery is operating at or above a point equivalent to its theoretical open-access equilibrium—at this point, average NER are zero, and all potential resource rents from using the resource are likely to be lost.
Changes in a fishery's NER reflect changes in factors that are both external and internal to the control of fishers and fishery managers. External factors include fish prices and fuel prices, while internal factors include catch and fishing effort. The evaluation of a fishery's economic status primarily focuses on factors that are under the control of fishery managers. However, external factors can be highly variable and complicate the determination of economic status. Therefore, a fishery's NER should be interpreted over time (that is, in terms of its NER trend), and use other fishery information and performance indicators. For example, if a fishery generates positive NER, this does not necessarily mean a positive economic status in the context of maximising NER from the resource. Management arrangements may be impeding the generation of additional NER. Similarly, the catches generating these positive NER may be associated with overfishing. In these cases, economic status could be improved by reducing management constraints or rebuilding stock status.
Economic productivity measures support the interpretation of a fishery's trend in NER and its overall economic status. Productivity measures indicate how effectively a fishery's inputs (such as fuel, labour, capital and the fish stock) are converted into output (catch). At given output prices, an improvement in fishery productivity will be associated with an improvement in NER. Productivity growth in a fishery over time will reflect some combination of improved production decisions by fishers and improvements in fishery management.
Management arrangements can be a key influence on whether a fishery achieves its full economic potential. The assessment of economic status therefore considers whether a fishery's NER could be improved under alternative arrangements. An informed assessment requires an understanding of a fishery's characteristics, which can vary considerably across fisheries. This allows evaluation of the relative advantages and disadvantages of alternative management arrangements for that fishery.
Management arrangements in Commonwealth fisheries can be categorised as either input controls (for example, effort limits) or output controls (for example, catch limits). Input controls restrict a fishery's effort—for example, by restricting gear use, fishing time or fishing areas. If a fishery manager is trying to control a fishery's catch, input controls alone provide no guarantee that a catch target will be met. Over time, such controls can lead to overcapacity and lower economic returns, especially if the controls are not frequently adjusted to counteract an increased efficiency of the limited number of fishing effort units. However, input controls are often associated with lower implementation and monitoring costs than output controls (Rose 2002). They can also have advantages where attempts to control catch are complicated by a stock's high variability and unpredictability.
Output controls restrict a fishery's harvest through the setting of total allowable catches (TACs). Individual transferable quotas (ITQs) are the dominant form of output control used in Commonwealth fisheries—a stock's TAC is allocated to holders of ITQs. Each quota entitles its owner to a share of the TAC in a given season, which can then be sold or leased. An advantage of ITQs is that, once fishers have been allocated a TAC share, the incentive to race to fish against other operators may be diminished and replaced with an incentive to maximise profit for their given catch allocation (Grafton 1996). By directly controlling catch, the need to restrict inputs (and operator efficiency) to indirectly limit catch is reduced, and operators are afforded greater flexibility to choose the most efficient mix of fishing units. However, input controls may still be required to meet other management objectives (for example, controlling bycatch). The transferability of ITQs also means that quota can gravitate to the most efficient fishers, improving overall economic performance of the fishery. However, ITQs can have drawbacks, including high set-up and monitoring costs, and incentives to discard and high-grade catch (Copes 1986; Rose 2002).
Another key management consideration for determining economic status is latency. High levels of latency over a long period indicate low levels of NER and suboptimal fishery economic performance. Latency creates additional issues for fisheries managed with tradeable fishing rights (such as ITQs or effort). These mechanisms can capture efficiency gains through having fishing rights traded towards their most efficient use, but, if TAC or effort levels are maintained above economically viable levels so that latency prevails, the value of fishing rights will be low. This reduces the incentive to trade fishing rights and limits the potential efficiency improvements through the movement of rights to more efficient users (Elliston et al. 2004). Interpretation of latency must consider the characteristics of the fishery. For example, if a fishery targets a highly variable stock, fluctuations in fishing rights latency would be expected.
Management in pursuit of other FM Act objectives relating to sustainability, bycatch and the environment can affect a fishery's profitability. Whether these objectives have been met with the lowest possible cost should also be a key consideration when determining economic status. Costs include not only the management costs incurred in meeting these objectives, but also costs associated with any reduction in NER that results from such management.
Performance against economic objective
The HSP supports the implementation of the economic objective of the FM Act by recommending that harvest strategies are designed to achieve a stock's MEY biomass level (BMEY)—the biomass level that is expected to maximise a fishery's NER. The assessment of economic status considers how well a fishery's harvest strategy meets the economic objective of the FM Act.
This assessment first involves evaluating a fishery's harvest strategy target reference points in terms of how well they reflect an MEY target for that fishery. For some fisheries, target reference points are biomass based (that is, BMEY), and the evaluation will focus on whether the adopted target is consistent with MEY, given the biological and economic characteristics of the stock. For other fisheries, alternative targets are used because biomass targets are considered inappropriate (for example, if the fishery is data poor or targets highly variable stocks). Such alternatives include catch-rate targets, catch triggers and effort triggers. In these cases, the evaluation focuses on how well the economic objective of the HSP is being met by these alternative approaches.
If a fishery's harvest strategy targets are consistent with MEY, performance indicators can be compared with targets to assess whether the fishery is achieving MEY. For multispecies fisheries, performance against harvest strategy targets is evaluated across the predominant and most valuable stocks caught in the fishery. Performance indicators that are close to target for these stocks will indicate that management is meeting the HSP's economic objective for the fishery. If the performance indicators are off target but moving towards target, performance against MEY is improving. If neither is occurring, then management settings have resulted in suboptimal outcomes for the stock, and management adjustments may be required. Such evaluation focuses on recent historical performance over a number of years (rather than just one year), given the variability in factors that influence a fishery's MEY. If harvest strategy targets do not exist for a fishery, the evaluation focuses on how well the intent of the HSP is being met under the current harvest strategy.
30.4 Assessing environmental status
The Australian Government's fisheries management objectives recognise the need to consider the broader impacts of fishing on bycatch species (including species protected under the Environment Protection and Biodiversity Conservation Act 1999 [EPBC Act]), marine habitats, communities and ecosystems. Fishery status reports 2017 reports on key bycatch issues in each fishery and information from ecological risk assessments (ERAs) by AFMA.
A species is considered to be a bycatch species if it is (a) incidentally taken in a fishery and returned to the sea because it has no commercial value or regulations preclude it being retained, or (b) incidentally affected by fishing activity, but not landed or retained (DAFF 2000). The FM Act states that fishery management plans must include measures to reduce bycatch to a minimum. The Commonwealth policy on fisheries bycatch (DAFF 2000) recognises that different fisheries will have different ways of addressing bycatch issues. The policy requires fishery-specific bycatch action plans (now referred to as bycatch and discarding workplans) to be developed and implemented. The outcomes of these workplans are considered when the environmental status of fisheries is examined. A review of the Commonwealth policy on fisheries bycatch was completed in 2013. Reports and supporting research are available on the website of the Department of Agriculture and Water Resources. A revised policy is currently being developed by the department, in consultation with AFMA, the Department of the Environment and Energy, and other stakeholders.
Ecological risk assessment
In the early 2000s, AFMA and CSIRO, with funding from the Australian Government, initiated the development of ERAs to assess the impacts of fishing activities on ecological components, such as target, bycatch and byproduct species; protected species; habitats; and communities. The ERA methodology (Hobday et al. 2007) is hierarchical, moving from a low-level, qualitative analysis of risks (level 1) to fully quantitative assessments of the level of fishing mortality (level 3). Low-risk activities and species are screened out at each step in this process. AFMA's responses to the ERA results are detailed in fishery risk management reports, which are linked to the bycatch and discarding workplans for a fishery.
EPBC Act and its interactions with fisheries management
The EPBC Act is the key piece of legislation for conserving the biodiversity of Australian ecosystems and protecting the natural environments that support these ecosystems. Commonwealth marine areas are ‘matters of national significance' under the EPBC Act. The EPBC Act broadly requires that fishing activities do not have a significant negative impact on the Commonwealth marine environment and its biodiversity, including protected species and ecological communities. This is achieved through the requirement for all Commonwealth fisheries to undergo a strategic environmental assessment to determine the extent to which management arrangements will ensure that the fishery is managed in an ecologically sustainable way.
The fishery assessments use Guidelines for the ecologically sustainable management of fisheries (DEWR 2007), which outlines specific principles and objectives to ensure strategic and transparent evaluation of the ecological sustainability of fishery management arrangements. These guidelines have two main principles:
- A fishery must be conducted in a manner that does not lead to overfishing. For stocks that are overfished, the fishery must be conducted such that there is a high probability that the stock(s) will recover.
- Fishing operations should be managed to minimise their impact on the structure, productivity, function and biological diversity of the ecosystem.
The strategic assessments determine whether a fishery should be accredited for the purposes of part 13 (protected species provisions) and part 13A (wildlife trade provisions) of the EPBC Act. Fisheries management also needs to consider the requirements under species recovery plans, wildlife conservation plans and threat abatement plans implemented under the EPBC Act.
If a species is protected under the EPBC Act (with the exception of those listed as conservation dependent), it is an offence to kill, injure, take, trade, keep or move an individual unless the action is covered by a permit issued by the environment minister or is otherwise exempt. In the case of fisheries, interactions with protected species are not offences if they have occurred in a fishery with a fishery management plan or regime accredited under the EPBC Act. This recognises that some level of interaction may be inevitable but that all reasonable steps should be taken to minimise interactions. Fishers are obliged to report any interactions with protected species, and it is an offence under the EPBC Act and the FM Act not to do so.
30.5 Presentation of fisheries data
Data presented in Fishery status reports 2017 were obtained from a number of sources. Most were obtained from AFMA daily fishing logs, AFMA catch disposal records, observer databases and the ABARES commodities database. Other sources include fishery-specific stock assessments, CSIRO, public-domain catch-and-effort data from the WCPFC, the IOTC nominal catch database (public-domain data), the Commission for the Conservation of Southern Bluefin Tuna database, the Commission for the Conservation of Antarctic Marine Living Resources, and the South Pacific Regional Fisheries Management Organisation database.
Relative fishing intensity has been mapped where five or more vessels have fished within a certain area. This fishing intensity is mapped using the kernel density function in ArcGIS and an appropriate radius from each fishing operation point, depending on the extent and spacing of fishing operations. The density function results in a smoothing and spreading of estimated fishing effort, and can result in the total area over which fishing operations take place appearing larger than it is. Where necessary, fishing intensity maps have been truncated to limit fishing to management areas.
Fishing intensity is usually mapped as effort, but, in some fisheries (for example, the Bass Strait Central Zone Scallop Fishery), it is mapped as catch. Three levels of fishing intensity are shown, arbitrarily classified as low, medium and high. As far as possible, the same range classes have been used as in previous years. However, if there has been a major shift in effort or catch, this may not be possible. Fishing operations have been mapped for the 2016 calendar year or the 2015–16 financial year.
The total area fished has been mapped for most fisheries, except for those fisheries with a restricted range, such as the Torres Strait fisheries. For these fisheries, the total area fished is mapped at 111 km2 (the equivalent of one degree of latitude squared) and does not show catch or fishing effort. This conforms with AFMA's information disclosure policy (AFMA 2010).
Fishery management area boundaries are shown for reference, but area closures are not shown except for certain major closures. The 200 m isobath (bathymetric contour) is shown on all maps, where relevant. This approximates the edge of the continental shelf. Place names, including ports, capes, islands and seas, have been included for reference and orientation.
In most cases, the maps are in the geographic coordinate system (that is, without being projected). All maps of domestic fisheries use the geocentric datum for Australia (GDA94).
AFMA 2010, Fisheries management paper 12: information disclosure, Australian Fisheries Management Authority, Canberra.
Copes, P 1986, ‘A critical review of the individual quota as a device in fisheries management', Land Economics, vol. 62, no. 3, pp. 278–91.
DAFF 2000, Commonwealth policy on fisheries bycatch, Australian Government Department of Agriculture, Fisheries and Forestry, Canberra.
—— 2007, Commonwealth Fisheries Harvest Strategy: policy and guidelines, DAFF, Canberra.
DEWR 2007, Guidelines for the ecologically sustainable management of fisheries, Australian Government Department of the Environment and Water Resources, Canberra.
Elliston, L, Newton, P, Galeano, D, Gooday, P, Kompas, T & Newby, J 2004, Economic efficiency in the South East Trawl Fishery, ABARE report prepared for the Fisheries Resources Research Fund, Canberra.
Grafton, RQ 1996, ‘Individually transferable quotas: theory and practice', Reviews in Fish Biology and Fisheries, vol. 6, pp. 5–20.
Hobday, A, Smith, A, Webb, H, Daley, R, Wayte, S, Bulman, C, Dowdney, J, Williams, A, Sporcic, M, Dambacher, J, Fuller, M & Walker, T 2007, Ecological risk assessment for effects of fishing: methodology, report R04/1072 for AFMA, Canberra.
Larcombe, J, Noriega, R & Stobutzki, I 2015, Reducing uncertainty in fisheries stock status, ABARES research report, Canberra.
Penney, A, Ward, P & Vieira, S 2013, Technical reviews for the Commonwealth Fisheries Harvest Strategy Policy: technical overview, ABARES technical report to the Fisheries Research and Development Corporation, Canberra, available at http://agriculture.gov.au/fisheries/domestic/harvest_strategy_policy/review.
Rose, R 2002, Efficiency of individual transferable quotas in fisheries management, Australian Bureau of Agricultural and Resource Economics report to the Fisheries Resources Research Fund, Canberra.
Vieira, S & Pascoe, S 2013, Technical reviews for the Commonwealth Fisheries Harvest Strategy Policy: economic issues, ABARES technical report to FRDC, Canberra, available at http://agriculture.gov.au/fisheries/domestic/harvest_strategy_policy/review.
Ward, P, Marton, N, Moore, A, Patterson, H, Penney, A, Sahlqvist, P, Skirtun, M, Stephan, M, Vieira, S & Woodhams, J 2013, Technical reviews for the Commonwealth Fisheries Harvest Strategy Policy: implementation issues, ABARES technical report to FRDC, Canberra, available at http://agriculture.gov.au/fisheries/domestic/harvest_strategy_policy/review.