Vulnerability and status of marine fishes
for the Australian State of Environment
report 2011 – temperate species
DECEMBER 2011
PRODUCED BY Craig Syms, University of Technology, Sydney
FOR the Department of Sustainability, Environment, Water, Population and Communities
ON BEHALF OF the State of the Environment 2011 Committee
Citation
Syms C. Vulnerability and status of marine fishes for the Australian State of the Environment
report 2011—temperate species. Report prepared for the Australian Government Department
of Sustainability, Environment, Water, Population and Communities on behalf of the State of
the Environment 2011 Committee. Canberra: DSEWPaC, 2011.
© Commonwealth of Australia 2011.
This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no
part may be reproduced by any process without prior written permission from the
Commonwealth. Requests and enquiries concerning reproduction and rights should be
addressed to Department of Sustainability, Environment, Water, Populations and
Communities, Public Affairs, GPO Box 787 Canberra ACT 2601 or email
public.affairs@environment.gov.au
Disclaimer
The views and opinions expressed in this publication are those of the author and do not
necessarily reflect those of the Australian Government or the Minister for Sustainability,
Environment, Water, Population and Communities.
While reasonable efforts have been made to ensure that the contents of this publication are
factually correct, the Commonwealth does not accept responsibility for the accuracy or
completeness of the contents, and shall not be liable for any loss or damage that may be
occasioned directly or indirectly through the use of, or reliance on, the contents of this
publication.
Cover image
Shark Bay, WA
Photo by Nick Rains
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Preface
This report was commissioned by the Department of Sustainability, Environment, Water,
Population and Communities to help inform the Australia State of the Environment (SoE)
2011 report. As part of ensuring its scientific credibility, this report has been independently
peer reviewed.
The Minister for Environment is required, under the Environment Protection and Biodiversity
Conservation Act 1999, to table a report in Parliament every five years on the State of the
Environment.
The Australia State of the Environment (SoE) 2011 report is a substantive, hardcopy report
compiled by an independent committee appointed by the Minister for Environment. The
report is an assessment of the current condition of the Australian environment, the pressures
on it and the drivers of those pressures. It details management initiatives in place to address
environmental concerns and the effectiveness of those initiatives.
The main purpose of SoE 2011 is to provide relevant and useful information on
environmental issues to the public and decision-makers, in order to raise awareness and
support more informed environmental management decisions that lead to more sustainable
use and effective conservation of environmental assets.
The 2011 SoE report, commissioned technical reports and other supplementary products are
available online at www.environment.gov.au/soe.
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
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Executive Summary

This report examines the assessment of vulnerability and population status of Australian marine
fishes using i) Fisheries model population growth parameters; ii) Intrinsic vulnerability based on
ecological and life history generalizations; iii) The IUCN combination of intrinsic vulnerability with
model parameters and temporal population variability. With careful application, the IUCN
framework is considered to be the most robust contemporary approach for assessment of fish
population health.

The temporal changes in abundance of a key habitat type was examined to illustrate cautions
about integrating and interpreting temporal changes

Two key stressors are considered, following the key points highlighted in the SoE 2006: i) Climate
change impacts; ii) Fishing pressure

Vulnerability assessments were carried out for two temperate nearshore marine fishes

An assessment of vulnerability was carried out for the red morwong, Cheilodactylus fuscus. This
species, although locally abundant with high numbers of reproductive individuals, was classed as
‘Vulnerable’ because of its restricted spatial distribution and hence sensitivity to climate change
effects, and its susceptibility to local recreational fishing. However, this species responded
rapidly to closure to fishing.

An assessment of vulnerability was carried out for the southern Maori wrasse Ophthalmolepis
lineolata. This species is locally abundant, with high numbers of reproductive individuals, but its
range extends longitudinally to Western Australia. Despite being landed in commercial numbers
as bycatch, as well as landed locally by recreational fishers its vulnerability is considered to be
low
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1. Background
1.1 Australian State of the Environment Reporting – Marine Ecosystems and Fish
population health
Three Australian State of the Environment (SoE) reports have been prepared since 1996 as
independent national stocktakes of the Australian environment. Marine and coastal environments
have featured in each report, identifying key issues, pressures and responses to pressures. The 2006
report considered no new issues that had not already been raised in previous reports (Beeton et al.
2006 p49), and identified a continuing and pressing need to act to mitigate pressures that marine
ecosystems face. The most significant pressures identified were urban development, agriculture,
fishing, aquaculture, coastal and marine pollution and introduced marine species. In particular,
fisheries decline and climate variation were identified as key points of interest. The Beeton et al.
(2006) report concluded that there was no nationally consistent system for measuring conditions and
trends of coast and ocean ecosystems; suggested planning for adaptation to climate change;
suggested action on ship ballast water flushing; advised fisheries management should be improved;
and generally lamented that the problems identified in 1996 were still as important in 2006.
In this report we address issues in developing metrics of fish population health, and apply these
concepts to two species of nearshore marine fishes. We consider the characteristics of the Australian
marine environment; characteristics of marine fish population structure and dynamics; and identify
the importance of two key pressures: fisheries extraction and management, and climate change.
1.2 The Australian marine environment
The Australian marine environment is unique for a continental-sized maritime land mass. Both east
and west coasts are strongly influenced by south (poleward flowing) warm tropical currents. The East
Australia Current (EAC) originates in the Coral Sea and flows southwards where it separates
northeast and eastwards at the subtropical convergence, and may generate eddies that provide
episodic influxes of warm waters as far south as Tasmania. The extent of the mean EAC southern
intrusion is consequently temporally variable, and in the presence of climate change the mean effect
may alter (Ridgway 2007, Ridgway and Godfrey 1997, Ridgway and Dunn 2003). On the west coast,
the Leeuwin current flows southward from the Indian Ocean, and intrudes into the Great Australian
Bight as far as Tasmania. To the south, the continent is bounded by the cooler waters of the
Southern Ocean exerting a cool water influence on the south coast. In general however, Australian
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waters are largely tropical and subtropical in origin and oligotrophic (nutrient poor) (Hobday et al.
2006). Australian marine ecosystems are strongly influenced by large scale oceanographic and
atmospheric processes such as the El Nino Southern oscillation (ENSO), weather effects, terrestrial
inputs from runoff, upwelling changes, cyclonic disturbance in the tropical regions, coastal current
dynamics amongst other things.
Due to its size, its latitudinal range from tropical to temperate regions, and longitudinal breadth, the
Australian marine environment is far from homogenous. As a consequence, the Australian
Government Department of Sustainability, Environment, Water, Population and Communities has
developed a marine regionalisation program – the Integrated Marine and Coastal Regionalisation of
Australia (IMCRA v. 4) to provide a spatial framework for natural resource management. Additionally,
the Department of the Environment and Heritage has produced a National Marine Bioregionalisation
of Australia.
Figure 1. Marine bioregionalisation of demersal fish assemblages for continental shelf fishes
(http://www.environment.gov.au/coasts/mbp/publications/general/pubs/aspd-bio-19.pdf,
Commonwealth of Australia, Department of the Environment and Heritage, 2005)
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In addition to being a management tool, the marine regionalisations provide the framework for
Australia's National Representative System of Marine Protected Areas (NRSMPA) by identifying
ecologically meaningful breaks in species distributions that are important to consider when
identifying the effects of different pressures on marine assemblages.
1.3 Climate change as a present threat to marine environments
Beeton et al (2006) singled out climate change and fishing pressure as key threats in the 2006 SoE
report. Climates have and will change in geological time with important consequences for marine
ecosystems. Observable changes in sea surface temperature are evident from reconstructed
temperature series, with all Australian regions changing at similar rates (Fig. 2a). It is important to
note however that different regions still have very distinct temperature ranges, but as discussed
below this may still have important consequences for Australian fish populations.
All current model projections, including the latest CSIRO Mk3.5 model, indicate that climate warming
will have strong effects on key oceanic processes, notably the greatest warming is likely to occur in
the Tasman Sea, resulting in an increased strength of the East Australia current (Hobday et al. 2006,
Ridgway 2007, Ridgway and Godfrey 2007). The vulnerability of marine life to these and other
stressors will affect Australian bioregions to different extents. The most vulnerable region extends
from the southern end of the Great Barrier Reef (GBR) south, and west to Kangaroo Island in South
Australia. All bioregions within the eastern-central and south-east domains are likely to be strongly
affected by climate change (Hobday et al. 2006, Fig. 4-1).
Sea surface temperature change itself can bring shifts in marine communities. While much focus has
been placed on coral reef communities, and in particular impacts of bleaching due to elevated sea
surface temperatures, temperate waters are also likely to be subject to important, if not greater,
impacts. Latitudinal increases in temperature indicate that climate zones on the east coast of
Australia have shifted southward by 200km (~2° latitude) from 1950-1969, to 1987-2006 (Lough
2008). This has effectively compressed the temperate zone and, as Australia is bounded by deep
waters to the south, reduced the amount of available habitat for cooler water inshore and shelf
species.
Temperature alone is not the only proximate driver of change. Decreases in zonal westerly winds are
likely to inhibit eastern Tasmanian upwelling, which in combination with strengthening of the
oligotrophic tropical East Australian current will reduce nutrient supply to south-eastern Australian
temperate communities. This will particularly impact kelp forest assemblages. The continued
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decrease in zonal westerly winds are also likely to contribute to fish stock decline by resulting in
decreased fish recruitment, which in combination with high fishing pressure is likely to further stress
fish populations in the south-east province (Hobday et al. 2006)
b) Sea surface temperature
1.0
30
0.8
28
0.6
Northern tropics,
Northwest region,
and Coral Sea
26
0.4
Temperature (°C)
Temperature anomaly (°C)
a) Sea surface temperature anomaly
0.2
0.0
-0.2
-0.4
-0.6
24
22
20
Tasman Sea and
Southwest region
18
16
-0.8
Southern region
-1.0
14
-1.2
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
12
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Year
Year
Figure 2. a) Sea surface temperate anomaly; and b) Raw sea surface temperature for Australian
Northern Tropics, Northwest Region, Coral Sea, Tasman Sea, and Southern Region (Data source:
http://www.bom.gov.au/climate/change/)
1.4 Fishing pressure
Fishing pressure has the potential to strongly decrease fish population size. While compared with
some other countries Australia has a relatively limited commercial fishery impact, the concentration
of human populations along the coast may cause locally high demand for commercial fish, in addition
to high concentrations of recreational fishers. Of the 101 stocks managed by the Australian
Government and assessed in 2009, 12 were deemed to be overfished, for 30 stocks it was not clear if
they were overfished and the remaining 58 stocks were assessed as not overfished.
At the State level, in the 2008-2009 assessment by the New South Wales Government (for example)
assessed 108 fished species, and listed 6 species as ‘Overfished’ or ‘Recruitment overfished’ (ie.
fishing pressure is sufficient to significantly reduce the input of juveniles into the population). Five
species were listed as ‘Growth overfished’, in which the fish biomass being removed was less than
optimal for the fishery, and approximately 47 species were considered as ‘Fully fished or less’, in
which fishing levels were < half the estimated natural mortality. Interestingly around 50% of the
species listed were defined as ‘Uncertain’ or ‘Undefined’ (Rowling et al. 2010). The lack of knowledge
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of fishing levels of many species is of concern. While commercial landings are generally accounted
for, there is a lack of information about recreational fish catch (with some exceptions e.g. Steffe et al.
1996, Stewart and Hughes 2008), which in some cases has been estimated to be higher than
commercial catch for some species.
2. Establishing metrics and benchmarks to assess fish population health
In the best of all possible situations, measuring fish population health requires knowledge of the
population size, age, size-structure, reproductive output, recruitment, survivorship of recruits,
sources of mortality, and how these measures vary across the spatial extent of the population, and
vary over enough generations so that multidecadal environmental changes in these measures could
be observed and modelled.
2.1 Population resilience
The resilience or ability of a fish population to rebound from decreases in abundance is central to
predicting whether a stressed population will persist in time, or be pushed to a stable minimal
population level, or to extinction. Resilience has been generally considered in one of two ways,
reflecting either a fisheries or ecological perspective. First, the theoretical capacity for a population
to increase in size can be derived from classical models of population growth, which are used to
estimate the maximum population growth rate. These are often expressed as population doubling
time, a conceptual notion of the duration taken for a population at a very depressed size to double in
size. Classical fisheries approaches are strongly dependent on good estimation of (key variables such
as) age-specific growth rates and size at maturity, in combination with sound modelling of the
population growth rates. In combination, this can provide a limited measure of resilience of a fish
population to decreases in abundance, assuming the physical and population growth parameters
remain constant (Musick 1999). These approaches are widely using in fisheries modelling, albeit with
strong caveats regarding the precision of the model parameter estimates. Their wide use is assisted
by the availability of generic parameter estimates in the literature and in Fishbase
(www.fishbase.org).
Fisheries-type approaches have a long history of setting clear measurable benchmarks or biological
reference points. These reference points can be viewed either as targets (particularly for exploitation
purposes) or thresholds beyond which the population could be considered threatened (often known
as a limit reference point). In fisheries applications these thresholds are expressed either as target or
limit levels of fishing mortality, or biomass levels - usually as a function of virgin or pre-exploitation
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biomass. Three kinds of analyses are typically used to establish these reference points: Yield per
recruit, Stock-Recruitment, and Spawning stock biomass per recruit. While the terminology may
indicate an exploitation intent, the principles are broadly applicable to establishing the viability of
any population and can be phrased as “For a given population size with a certain spawning level, and
survivorship – will the population persist, be severely affected, or go extinct?”. There is an
unfortunate schism between fisheries and more classical ecologists in the way different disciplines
approach the same question. The models behind these analyses have been established for several
decades and both the models and their reference points are being continually refined (eg. Ricker
1954, Beverton and Holt 1957, Gulland and Boerema 1973, Hilborn and Walters 1992, Myers et al.
1994). A perception among many ecologists is that classical fisheries approaches have failed to
conserve many fisheries, but this is in part due to model uncertainty – a failure of the models to fully
represent the uncertainty that exists in the populations and ecosystems, and to effectively represent
the effects of specific management decisions and the consequent risks to fished populations and
their ecosystems. Successful fisheries analyses generally require long time series of fisheryindependent stock and ecosystem assessments; but the particular charge of fisheries scientists is to
optimise extraction (ie. increase mortality) of the fish population.
Population resilience can also be evaluated by examining time series of population numbers, and
measuring time taken to return to some level following perturbation. While time series data are
essential for deriving fisheries models (above), they have also been used (with some debate) to
measure density-dependent processes (eg. Wolda 1989, Solow, 1990; Holyoak 1993; Wolda and
Dennis 1993;). More recently, fish population time series have been used to measure declines in fish
population sizes. However, developing a baseline population size that represents a pre-exploitation
level is problematic. Observational judgements may be subject to a ‘sliding baseline’ syndrome (Pauly
1995) in which the population size at the beginning of observation is deemed to be the baseline
which, in the face of true decline in a fishery becomes lower with each generation of fisheries
biologist. Attempts to back-calculate what the population would have been in the absence of
fisheries (Virtual Population Analysis), while subject to their own methodological limitations, are also
stuck with the same problem that the strength and importance of density-dependent population
regulation processes will differ between present day and ‘true’ pre-exploitation populations and
communities. Equally, the ecosystems and population interactions that existed at the time of preexploitation may have changed markedly, because of the combination of natural system changes and
the cumulative impacts of fishing on many other species.
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Notwithstanding the difficulties in interpretation of time series of population numbers, few fish
population data sets are available. While many commercial species have long series of catch data,
these cannot be readily viewed as unbiased estimates of populations through time as catch effort will
change through time, and even if catch data are standardized for changes in effort, substantial biases
may still occur (eg. serial depletion). Fisheries-independent time series are more reliable, but are not
available for many Australian fish species. The most notable exception is the Long-Term Monitoring
Project conducted by the Australian Institute of Marine Science on the Great Barrier Reef (GBR) since
1986. Unfortunately, few fisheries-independent time series of fish abundance in Australian waters
exist outside the GBR.
2.2 Intrinsic vulnerability
In marine fishes, an important set of criteria are being increasingly applied to evaluate the intrinsic
vulnerability of a fish population to extinction, where extinction may refer to extinction from a
fishery or ecological extinction in which the species no longer fulfils an ecological function. This
classification system has been developed from a range of sources (Jennings et al., 1998, 1999a,b;
Reynolds et al., 2001; Cheung et al. 2005; Cheung et al. 2007) and is based on general relationships
between life history and ecological traits, and how these contribute to increasing vulnerability of
fishes to increased mortality. This mortality is assumed to be due to fishing, but could also result
from other sources such as chronic changes to environmental conditions. The system is predicated
on the correlation between key life history traits such as maximum rate of population growth (which
is a measure of the maximum rate a population can respond to an acute reduction in size) and
ecological characteristics Adams, 1980; Roff, 1984; Kirkwood et al., 1994; Dulvy et al., 2003).
An example of an application of this framework was developed by Cheung et al. (2005). A range of
life history and ecological characteristics (maximum body length, age at first maturity, von
Bertalanffy growth parameter, natural mortality, maximum age geographic range, annual fecundity,
and aggregation behaviour) were divided into overlapping (‘fuzzy’) groups of vulnerability classes
(Fig.3), and a fuzzy clustering method applied to grade species on a vulnerability index of 0-100.
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Figure 3. Classification of intrinsic vulnerability of fishes based on life history and ecological
characteristics from Cheung et al. 2005. (Reprinted from Biological Conservation, 124, Cheung,
W. W. L., T. J. Pitcher, and D. Pauly, A fuzzy logic expert system to estimate intrinsic extinction
vulnerabilities of marine fishes to fishing, 97-111, 2005, with permission from Elsevier).
From a resource manager’s point of view, this intrinsic vulnerability classification scheme has the
advantage that it provides a readily available numerical value. Indeed, this scheme is applied to
species in the widely used Fishbase webpage (www.fishbase.org), and can provide at a glance
vulnerabilities of individual species or, for example, species classed by habitat type (Fig. 4).
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Figure 4. Classification of intrinsic vulnerability of fishes based on IUCN Red List classification, and
habitat type from Cheung et al. 2007. (Cheung, W. W. L., R. A. Watson, T. Morato, T. J. Pitcher,
and D. Pauly. 2007. Intrinsic vulnerability in the global fish catch. Marine Ecology Progress Series
333:1-12. Reprinted with permission from Inter-Research Science Center)
However there are some cautions that should be exercised when interpreting these values. First, the
index itself might not be immediately intuitive and should not be interpreted as a probability of
extinction. Consequently, a formal benchmark of what constitutes a ‘healthy’ fish population is not
easy to define, however reference to the average Intrinsic vulnerability index of IUCN Red List species
would suggest that an index value of 60% or greater would indicate significant cause for concern.
Second, many of the variables included in the classification scheme may be approximations, derived
from other proxies, or not well-estimated – especially the life-history based estimates such as von
Bertalanffy growth parameters, mortality rate, and fecundity. While the ‘fuzzy-classification’ scheme
might reduce some of these sensitivities, the application of the method detailed in Cheung et al.
(2005) suggests that certain parameters may ‘trigger’ classifications in a conservative manner.
However, in the absence of other information this is a scheme that is readily available and based on
what most fish and fisheries ecologists would consider to be intuitive rules-of-thumb.
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2.3 The IUCN Red List
The IUCN have produced probably the most comprehensive set of guidelines for evaluating fish
population health and extinction, culminating in the Red List of levels of threats to species (IUCN
2001, 2010, 2011). This measure combines intrinsic vulnerability based on life history characteristics,
range size and population fragmentation with past, present, and projected temporal changes, and
modelling approaches such as Population Viability Analyses. In broad terms the criteria are: a)
Declining population (past, present and/or projected); b) Geographic range size, and fragmentation,
decline or fluctuations; c) Small population size and fragmentation, decline, or fluctuations; d) Very
small population or very restricted distribution; e) Quantitative analysis of extinction risk (e.g.,
Population Viability Analysis).
An important component of this framework is that it combines the intrinsic vulnerability of Cheung
and others, with model-based estimates of potential for populations to recover or fail to recover
from population decrease. It also includes temporal change in abundance as an explicit criterion. The
inclusion of temporal change in abundance as a measure of population health is important. Generally
(with the exception of extreme decreases in abundance) the population decline criteria are based on
the longer of 10 years or 3 generations. However, for many marine fishes which may be long lived,
and/or first mature at greater ages, 10 years is likely to be too short to evaluate changes in numbers
and, in combination with the time scales of environmental fluctuations, population changes could be
potentially either under or overestimated (with unknown uncertainty) using this specific form of the
criteria.
The overall classification scheme however is balanced by several caveats and conditions, presented
in summary form (from the original document) in Table 1. Full guidelines can be found in the full
IUCN (2010) 85 page document. At present, careful application of the IUCN criteria would be a
preferred approach to a broad evaluation of fish population health, with appropriate adjustments to
account for species-specific features that fall outside the generic IUCN model.
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Table 1. The five criteria used by the IUCN red list to evaluate species vulnerability. Note the
(abbreviated) conditions imposed on each criterion. Table 2.1 from: IUCN. 2010. Guidelines for
using the IUCN Red List Categories and Criteria. Version 8.1. Prepared by the Standards and
Petitions Subcommittee in March 2010.
(http://intranet.iucn.org/webfiles/doc/SSC/RedList/RedListGuidelines.pdf)
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2.4 Temporal changes in population size
Temporal trends in population abundance and size-structure are one of the most important
indicators of the health and future of a population. In addition to being a primary data requirement
for fisheries models, they are also the basis of performance indicators for management actions.
However in marine fish communities (and marine communities in general) measuring and
interpreting temporal patterns in populations is subject to several difficulties that should be
considered when interpreting population change or lack thereof. One of the most comprehensive
time series of marine community structure in Australia is the Australian Institute of Marine Science
Long-Term Monitoring Project (LTMP). The LTMP has been surveying 47 reefs since 1986, using a
combination of 15x50m transects to count fish and measure benthic cover on the north-east flanks
of reefs distributed alongshore and within different latitudinal sectors of the GBR (Fig. 5), and mantatows of Crown-of-thorn starfish numbers and supplementary coral cover estimates around the
circumference of each reef.
The problems associated with interpreting temporal patterns of marine organisms can be illustrated
by the temporal trajectories of hard corals from the LTMP. There has been widespread concern
about total coral cover loss on the GBR (e.g. Bellwood et al. 2004; Bruno and Selig 2007). Coral cover
is an indicator of reef ecosystem health, and many fish species are dependent on coral cover to some
extent so net loss is of great concern. However, the spatial and temporal dynamics of variability
should also be taken into account and placed into perspective. Across the 47 reefs surveyed there
has been a (statistically significant) hard coral decrease across reefs of 0.21% per year. However, the
spatial and temporal variability of coral cover relative to this decrease is quite marked (Fig. 5), with
considerable non-linear fluctuations. Importantly, these fluctuations are not coordinated in time or
space across the entire GBR (Fig. 5). While some sector-shelf combinations of reefs undergo the
same fluctuations in time – usually due to being subject to similar disturbances such as cyclones,
crown-of-thorns starfish, and coral bleaching – there is considerable decoupling of the temporal
dynamics across the entire reef and within some sector-shelf combinations (Sweatman et al. 2011,
Sweatman and Syms 2011).
This has important implications for fish populations that are associated with these habitats. First,
there are episodic habitat changes which many fishes are initially resistant to or at least have a
temporally lagged response to. Indeed the ability of fishes to endure environmental fluctuations is
largely responsible for population persistence in the face of competition, and is known as the storage
effect (Chesson 1981, Warner and Chesson 1985, Chesson and Huntly 1997). Marine bony fishes
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(with one notable exception) also have a bipartite life history with a dispersive larval phase. So if local
conditions are made unsuitable for a species by, for example, local disturbance or fishing pressure, if
there are refugia from the unsuitable conditions then the species is unlikely to go extinct. However, if
the unsuitable conditions occur at or near the spatial scale of the population extent, or temporal
fluctuations are linked at the scale of the population then the fish population becomes vulnerable.
This is why geographic extent is so prominent in both the intrinsic vulnerability and IUCN criteria.
The Australian marine ecosystem is strongly linked to oceanographic processes that operate at long
time scales. ENSO events (La Nina, El Nino) occur on time scales of 3-10 years, and may be correlated
with recruitment success or failure of different species for example (Carr and Syms 2006).
Multidecadal shifts such as the Pacific Decadal Oscillation can also contribute to generate ocean-wide
oscillations and regime shifts (Chavez et al 2003). While measuring fish population size over three
generations is difficult enough, making simple linear projections or forecasts of population trends has
only limited accuracy in the context of a temporally variable environment.
2.5 Summary
There are common elements to each measure of population health. First, certain life history and
ecological traits intrinsically predispose fishes to different degrees of vulnerability to various forms of
pressure. Widely dispersed species that are locally abundant, grow and mature rapidly, and are very
fecund are less vulnerable than species that are geographically restricted, uncommon when present,
slow growing, and produce few young. The general correlation between these sets of life history and
ecological characteristics are implicitly included in classical fisheries models, intrinsic vulnerability,
and the IUCN classification schemes, and as such all three can provide an initial insight into
evaluating the health of a population. Temporal data on population size and size-structure provide
the best possible means of monitoring population health, but these data sets are very few for
nearshore Australia fish species. Even the best temporal data set available – the AIMS LTMP data set
– only just incorporates the recommended 3 generation time span recommended by IUCN for
determining less-than-extreme population declines. The example used from the AIMS data set also
illustrates that three generations is still likely to be too short because of concurrent temporal
changes in habitat structure, and potential differences in ocean conditions due to short-term (eg.
ENSO) and longer-term (eg. multidecadal oceanographic changes). While there is a glaring need for
temporal monitoring of fish populations at many locations, over many years, their main benefits will
only become apparent at the decadal scale. At this time, application of the IUCN framework adapted
for species-specific characters and interpreted in the context of temporal variability in environment
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(habitat and/or water quality) appears to be the most robust approach to assessment of Australian
fish population health/status.
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a) Spatial distribution of AIMS coral/fish
monitoring
c) Cross-shelf and along-shelf variability in
coral cover
b) GBR-wide temporal variability and linear
trends in coral cover
Figure 5. Spatio-temporal coral cover from Long-term Monitoring program on the Great Barrier
Reef. a) Spatial distribution of samples alongshore and cross-shelf; b) GBR-wide trends in hard
coral cover. Dark points are mean values, dotted line is a linear change of 0.21%/year (95% CI: 0.36 to -0.16) estimated from a linear mixed effects model; c) Changes in coral cover per reef in
each sector and shelf combination. (With kind permission from Springer Science+Business
Media: Coral Reefs, Assessing loss of coral cover on Australia’s Great Barrier Reef over two
decades, with implications for longer-term trends, Volume 30, 2011, pages 521–531, H.
Sweatman, S. Delean and C. Syms, Figures 1, 2, and 4)
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
3. Species-specific assessments
For the purpose of this report, we focus here on two species in the south-east corner of Australia:
the red Morwong (Cheilodactylus fuscus), and the southern Maori wrasse (Ophthalomolepis
lineolata). Both species are predatory generalists, with trophic levels of 2.80±0.26 and 3.5±0.37
respectively. The higher trophic level of Maori wrasse is attributable to occasional feeding on small
fishes. Both species are similar in that they are temperate rocky reef habitat generalists. Although
there are habitat types in which they are more abundant, they have no obligate relationship with
habitat types as do, for example, tropical butterflyfishes. They both have long larval lives, and hence
high dispersal potential. As with most subtropical/temperate fishes they are fished to some degree.
It is difficult to find temperate carnivores that are not fished to any significant extent, but these two
species differ in susceptibility to fishing.
The morwongs (family: Cheilodactylidae) worldwide comprise 18 species from 5 genera, of which 16
species from 3 genera occur in Australian waters. Although primarily temperate, some
representatives of the family are also found in tropical waters. The genus Cheilodactylus is the most
diverse (7 species). Two Cheilodactylid species (Nemadactylus macropterus and N. douglasi) are
commercially fished, and in NSW are classed as overfished.
The wrasses (family: Labridae) are a very diverse group of about 500 species in approximately 60
genera, of which about half are represented in Australia (Gomon et al. 2008). They are especially
diverse in tropical regions, but also very diverse in temperate regions too. While only a few species
are (or have been) individually targeted in Australia (eg. Achoerodus spp.), they frequently form a
large part of bycatch from other fisheries and are generally sold under the name “wrasse”.
These two species differ in important ways. Red morwong are gonochoristic (female and male sexes
are separate and remain so after maturity), whereas Maori wrasses are, as with most other wrasses,
protogynous hermaphrodites (fish mature as females, then later change sex to males).
3.1 Data sources
Two primary data sources were available for this report. In contrast with monitoring programs such
as the AIMS LTMP which contains a 20 year time spatio-temporal time series for a wide range of GBR
fish species, few equivalent data sets are available for temperate species. However, a developing
spatial and temporal data set is available for both of these species. Dr Graham Edgar at the
University of Tasmania has been establishing an Australia-wide spatial and, eventually, temporal
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
monitoring program of subtidal reef communities (Edgar, unpubl.). To evaluate temporal patterns, in
combination with closure to fishing, the second data source used here is from the Jervis Bay Marine
Park Monitoring program (Barrett et al. 2006). Data consist of 50m transect counts at several sites
inside and outside areas closed to fishing. The lack of temporal monitoring data from multiple sites is
a serious limitation in evaluating temporal patterns in temperate fish populations, and the Jervis Bay
data was important to provide the temporal context for this report. Data from both sources were
kindly provided for the purposes of this report by Dr Graham Edgar (UTAS).
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
Red Morwong (Cheilodactylus fuscus)
Red morwong are primarily confined to the southeast coast of Australia (1500 linear km), and are
occasionally found as vagrants in New Zealand waters. They are large (up to 65cm), generally found
on rocky reefs <30m deep, in boulder habitats (Lowry and Suthers 2004) and, as with other members
of the family, they are generalist carnivores feeding on a wide range of invertebrates. They appear
from tagging experiments to be home ranging, and form loose aggregations which may persist in the
same location over years (Lowry and Suthers 1998). They grow and mature relatively rapidly,
reaching 30cm in about 5 years. It appears that juveniles recruit into shallow water and estuarine
habitats, and undergo an ontogenetic shift to adult habitats (Lowry and Suthers 2004). Recruitment
to shallow waters and intertidal rock pools has also been noted for the closely related banded
morwong Cheilodactylus spectabilis). There is some indication of depth differences, with females and
smaller fish occurring in shallower water than males (Lowry and Suthers 2004). In contrast with the
AIMS LTMP data set, there are no long-term temporal estimates of red morwong populations, with a
few exceptions, primarily restricted to limited sets of locations.
Figure 6. Red morwong (Cheilodactylus fuscus). Photo courtesy of Dave Harasti,
www.daveharasti.com
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
There is no official listing for red morwong on the IUCN red list (“Not evaluated”). However, given
their criteria, if this species had been evaluated the listing would be “Vulnerable” primarily on the
basis of their geographic extent, and occupancy. Red Morwong are largely confined to NSW, along a
1500km linear stretch of coast which, assuming an approximate distribution 1km offshore to the 30m
isobath, would be slightly below the IUCN value of 20,000km2. However, they occur in low numbers
in north-eastern New Zealand (Paulin et al. 1989), indicating potential for long-range larval transport
from eddies of the East Australian Current, to the East Auckland Current. If the IUCN red list were to
include the NZ occurrences into the geographic extent, it is likely red Morwong would drop to the
“Least concern” category. However under the ‘exclusion of vagrants’ provision under IUCN rules,
“Vulnerable” seems a reasonable classification. The NZ population could not be considered a refuge
for the species in the face of local extinction of the Australian population, as it is probably not selfsustaining, and would not be able to repopulate the Australian mainland due to lack of east-west
larval transport. The “vulnerability” based on Cheung et al. 2005 of red morwong has been classed as
“High”, with a score of 58/100, although under Cheung et al.’s original scale 58/100 places red
morwong at the cusp of Medium-High. This is likely due to the combination of large body size and
restricted spatial range.
Within their geographic range, numbers of red morwong are reasonably high (Fig. 7), with no strong
indication of overfishing. Although the largest reported size is 65cm, most fish from 5 to 35 years of
age will be between 30-45cm long (Lowry 2003). It appears that across the geographic range,
numbers of reproductive individuals are not immediately threatened and, given the long larval life of
the species, replenishment of local population reductions should be possible from other coastal
areas.
While commercial fisheries of red morwong are “Undefined” (Rowling et al 2010), approximately 3t
are caught as bycatch in the NSW Ocean Line and Trap fishery. Recreational fisheries probably
contribute a greater, but unknown (estimated at <10t, Rowling et al. 2010, which could be
approximated to 5,000 individuals), levels of threat to the population. Currently the only effort
control of recreational fishing in NSW is a minimum size limit of 25cm, or fish approximately 5 years
old and entering first year of maturity, and a bag limit of 5 per day. The primary recreational catch is
taken by spearfishermen, and it is here that red morwong are particularly vulnerable. As they are
large, relatively diver-neutral, and found in aggregations in shallow water they are particularly
susceptible to spearing. This has been recognised for red morwong (Lowry and Suthers 2004), and
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
the ecologically similar banded morwong (Cole 1994, Cole et al. 1990). Indeed concern about
vulnerability of banded morwong has even been expressed within the spearfishing community itself
(eg. Leachman et al 1978). If the spearfishing pressure was to increase, it is likely that this would
disproportionately affect female fishes, as males tend to occur in deeper waters (Lowry and Suthers
2004).
While the “resilience” based on estimate of von Bertalanffy growth functions is “Low”, with a
minimum population doubling time of 4.5-14 years (Fishbase), examination of the fitted models of
the original growth parameter estimates (Lowry 1993) indicate this might not be the best estimate,
so this should be treated with caution. In addition, this resilience measure is only ecologically
relevant at a large scale when the population can be effectively treated as closed. It is clear that
protection from fishing can result in rapid changes in local fish numbers and size structure. Following
closure to fishing in the Jervis Bay (NSW) sanctuaries, the numbers of red morwong almost doubled
(Fig. 8), and importantly the number of larger fishes increased (Fig. 9). This is within the time frame
of the estimated growth rates of this species, and probably indicates that while local populations can
be depleted by spearfishing, across the biological population this effect can be compensated by larval
production from individuals in other parts of the range.
Although evidence is preliminary, the apparent ontogenetic habitat shift of red morwong from
shallow and estuarine habitats to deeper exposed reefs creates a potential vulnerability. First, coastal
development of estuarine areas might reduce juvenile habitat availability. This would have important
implications for population maintenance and rebuilding. Second, water quality and pollution effects
on juvenile habitats could be important (Lincoln-Smith and Mann 1989). Organochlorine compounds
can accumulate in red morwong near sewage outfalls, and these may have effects on growth,
development, and maternal transmission of toxicity to offspring (Johnston et al. 2005).
Most immediate vulnerabilities appear to be manageable for this species. However, the restricted
geographic range of red morwong would likely make it sensitive to climate change effects. Red
morwong are at their northern limit at Cape Byron (28°S, Fig. 7), and at their southern limit of 38°S.
They are rare in the Bass Strait and Tasmanian demersal fish provinces, and the most westerly record
is Queenscliff, Victoria (Gomon et al. 2008). This northern limit may already have been contracted by
an estimated 200km (~2° latitude) from 1950-1969, to 1987-2006 (Lough 2008), and the population
could be under pressure of further northward contraction. Despite its long larval life, and relatively
broad habitat requirements, red morwong appear to be strongly bounded to the west at the Bass
Strait province, and although their larvae obviously can cross the Tasman Sea, they appear to have
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
some dispersal restriction and are relatively rare in Tasmania. It is possible that Tasmania might not
provide a refuge from range contraction. However, additional consequences of climate change on
oceanic current changes are harder to predict. The predicted strengthening of the East Australian
current, and weakening of zonal westerly winds (Hobday et al. 2006, Ridgway 2007, Ridgway and
Godfrey 2007), could combine to result in more larval fish being advected offshore, and decrease the
ability of larvae to establish themselves west of Bass Strait.
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
a) Numbers of fish per 500m2
b) Size frequencies (numbers per 5000m2)
1
2
3 4 5
10 15 2025
160
140
120
100
80
60
40
20
0
50 75100
3 5 8 10 13 15 20 25 30 35 40 50
1
2
3 4 5
10 15 2025
160
140
120
100
80
60
40
20
0
50 75100
3 5 8 10 13 15 20 25 30 35 40 50
1
2
3 4 5
10 15 2025
50 75100
160
140
120
100
80
60
40
20
0
50 75100
160
140
120
100
80
60
40
20
0
3 5 8 10 13 15 20 25 30 35 40 50
1
2
3 4 5
10 15 2025
3 5 8 10 13 15 20 25 30 35 40 50
160
140
120
100
80
60
40
20
0
1
2
3 4 5
10 15 2025
50 75100
3 5 8 10 13 15 20 25 30 35 40 50
160
140
120
100
80
60
40
20
0
160
140
120
100
80
60
40
20
0
1
2
3 4 5
10 15 2025
50 75100
1
2
3 4 5
10 15 2025
50 75100
3 5 8 10 13 15 20 25 30 35 40 50
3 5 8 10 13 15 20 25 30 35 40 50
Figure 7. Numbers of red morwong per transect; and size frequency in 2 degree sections of the
south-east Australian coast. Circles represent sections in which fish transects were sampled. Red
circles are sections in which fish were recorded, black circles are sections in which sites were
sampled, but no fish were recorded. a) Boxplots of fish abundance per 500m2 transect. Note the log
scale on the x axis. b) Size-frequency distributions. The grey bars are the size at which fish enter the
fishery, and black bars represent fish that are clearly of fishable size. Frequencies are scaled to
5000m2 areas to correct for different levels of sampling effort.
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
25
a) Habitat protection
20
15
Abundance per 500m 2
10
5
0
1996
25
1998
2000
2002
2004
2006
2008
2010
2002
2004
2006
2008
2010
b) Sanctuary
20
15
10
5
0
1996
1998
2000
Year
Figure 8. Boxplots of red morwong abundance per 500m2 in Jervis Bay Marine Park. a) Habitat
protection zones (open to fishing); b) Sanctuary zones (closed to fishing). Trend lines are Generalized
Additive models of juvenile-adult fishes with natural temporal splines, selected by generalized crossvalidation, with quasipoisson distributions, and log-link. The dashed lines are the standard errors of
the fit. Vertical line indicates the time of Sanctuary establishment.
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
Abundance per 5000m2
1996-2003
a) Habitat protection
2004-2009
140
140
120
120
100
100
80
80
60
60
40
40
20
20
0
0
7.5 10 12.5 15 20 25 30 35 40 50 70
7.5 10 12.5 15 20 25 30 35 40 50 70
b) Sanctuary
140
140
120
120
100
100
80
80
60
60
40
40
20
20
0
0
7.5 10 12.5 15 20 25 30 35 40 50 70
7.5 10 12.5 15 20 25 30 35 40 50 70
Size class (cm)
Figure 9. Size frequency distributions of red morwong in Jervis Bay Marine Park before (left column)
and after (right column) establishment of reserves. a) Habitat protection zones (open to fishing); b)
Sanctuary zones (closed to fishing). Grey bars are the size at which fishes approach harvestable size;
black bars are sizes at which fishes have clearly reached legal minimum retention size. Abundances
have been scaled to numbers per 5000m2 to correct for different levels of sampling effort.
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
Southern Maori wrasse (Ophthalmolepis lineolata)
Southern Maori wrasse are small (to 40cm) temperate wrasses that are endemic to Australia, and
occur from approximately 28°S on the East coast, along the southern coast, albeit in low numbers
particularly in the Bass Strait, though to the Houtman Abrolhos Islands in West Australia (Gomon et
al. 2008). They are found on rocky coastal reefs with adults increasing in abundance with depth to
20m, and in habitats that are often more sponge-dominated than macroalgal or urchin barren
dominated (Rowling et al. 2010). Maori wrasse are generalist carnivores, feeding primarily on small
invertebrates (Morton et al. 2008). They are fast growing protogynous hermaphrodites, and mature
as females at about 19cm (2 years old), then change sex to male at 27-34cm at around 5 years old
(Stewart and Hughes 2008).
Figure 10. Southern Maori wrasse (Ophthalmolepis lineolata). Photo courtesy of Dave Harasti,
www.daveharasti.com
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
Southern Maori wrasse are officially listed on the IUCN red list as “Least concern”. Despite being a
monotypic genus, endemic to Australia and with no records of vagrants to New Zealand, Maori
wrasse are found on both east and west Australian coasts, with a geographic extent of 6170 linear
km, or approximately 61,700km2. The “vulnerability” based on Cheung et al. 2005 of Maori wrasse
has been classed as “Moderate”, with a score of 44/100.
Within their geographic range, numbers of Maori wrasse are fairly high (Fig. 11), with reasonable
densities of both mature females and males across its range. Although it is less common in the Bass
Strait province, semi-quantitative timed counts in Western Australia have found Maori wrasse to be
frequent or abundant on the mid-west coast from Port Denison (Dongara, 29°S, 115°E) southwards
and eastwards to Esperance (34°S, 122°E). It appears that across the geographic range, numbers of
reproductive individuals are not immediately threatened and, given the long larval life of the species,
replenishment of local population reductions should be possible from other coastal areas.
Southern Maori wrasse are not a commercially targeted species. In 2008 they were considered
“Undefined” as a NSW fishery. However they are caught and sold as bycatch in the NSW Ocean Line
and Trap fishery at low levels (<10t annually) and have been more recently reassessed as
“Moderately fished” (Rowling et al 2010). Recreational catch is larger than commercial landings. They
are the 10th most common species caught by recreational fishers in NSW with an estimated catch of
20-30t annually (Steffe et al. 1996). There are no size or bag limits on southern Maori wrasse, and it
appears from age distributions of commercial catches that most individuals are large females or
males between 5 and 7 years old (Stewart and Hughes 2008). It should be noted that the assessment
as ”Moderately fished” is likely based on an estimated fishing mortality of approximately half that of
natural mortality rates of fish older than 4 years (Rowling et al 2010). This is possibly a liberal
estimate, based on the lowest estimated natural mortality and highest estimated fishing mortality,
and likely to have a large random error component, as the regression of the data on which these
rates are based was probably affected by extremes of the age-range (Steffe et al. 1996, page 102),
and it is possible that this is therefore not robust as a stock-wide estimate (see below).
The “resilience” based on estimate of von Bertalanffy growth functions is “Medium”, with a
minimum population doubling time of 1.4-4.4 years (www.Fishbase.org). The parameter estimates
on which this is based is likely to be sound as the von Bertalanffy fit is quite good (Stewart and
Hughes 2008, page 100). This resilience measure is only ecologically relevant at a large scale when
the population can be effectively treated as closed. Protection from fishing in Jervis Bay Sanctuaries
resulted in no difference in abundance (Fig. 12). However there was a small increase in the number
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
of fishes in the 35cm size class in the Sanctuaries (Fig. 13). This relative lack of effect is unlikely to be
due to poaching, as there was a sizeable increase in red morwong numbers and size (Fig. 12, 13) in
the same reserves. This probably reflects either a lack of line fishing pressure in the Jervis Bay area,
or fishers returning Maori wrasse, as many recreational fishers return fish <30cm to the water
(Stewart and Hughes 2008).
The IUCN evaluation of “Least concern” appears to be sound. The northern limit of Maori wrasse
distributions might be contracted by climate change effects, particularly on the east coast with
strengthening of the East Australian Current. Predictions of changes in the Leeuwin current on the
west coast indicate that the West Australian populations are less likely to be affected (Hobday et al.
2006). Despite their endemism, larvae of southern Maori wrasse appear to be able to disperse widely
along the Australian coastline, and they are locally abundant when present. An increase in targeted
fisheries might be a cause for concern. As this species is a protogynous hermaphrodite, and only fish
>30cm are generally retained by fishers, fishing effort is disproportionately applied to males and
large females. This has three important consequences. First, large females are likely to supply most
of the potential recruits to the population. Second, the testis of male Maori wrasse are relatively
small, implying they are pair spawners (Stewart and Hughes 2008) and hence many males may be
required to successfully fertilize all eggs (in contrast with some tropical wrasses). Third, many
wrasses exert social control of sex change. The presence of a male may inhibit sex change in females,
resulting in larger females with higher egg production. Continual removal of large, male fish may
therefore decrease the total population fecundity by inducing females to change sex at younger ages.
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
a) Numbers of fish per 500m2
b) Size frequencies (numbers per 5000m2)
1
2 3 45
10
25
50
100
160
140
120
100
80
60
40
20
0
100
160
140
120
100
80
60
40
20
0
3 5 8 10 13 15 20 25 30 35 40 50
1
2 3 45
10
25
50
3 5 8 10 13 15 20 25 30 35 40 50
1
2 3 45
10
25
50
160
140
120
100
80
60
40
20
0
100
3 5 8 10 13 15 20 25 30 35 40 50
160
140
120
100
80
60
40
20
0
1
2 3 45
10
25
50
100
3 5 8 10 13 15 20 25 30 35 40 50
160
140
120
100
80
60
40
20
0
1
2 3 45
10
25
50
100
1
2 3 45
10
25
50
100
160
140
120
100
80
60
40
20
0
3 5 8 10 13 15 20 25 30 35 40 50
3 5 8 10 13 15 20 25 30 35 40 50
Figure 11. Numbers of southern Maori wrasse per transect, and size frequency along 2 degree
sections of the south-east Australian coast. Circles represent sections in which fish transects were
sampled. Red circles are sections in which fish were recorded, black circles are sections in which sites
were sampled, but no fish were recorded. a) Boxplots of fish abundance per 500m2 transect. Note
the log scale on the x axis. b) Size-frequency distributions. White bars are immature fish; grey bars
are likely to be mature females; black bars are likely to be mature males. Frequencies are scaled to
5000m2 areas to correct for different levels of sampling effort.
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
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30
a) Habitat protection
25
20
15
Abundance per 500m 2
10
5
0
1996
30
1998
2000
2002
2004
2006
2008
2010
2002
2004
2006
2008
2010
b) Sanctuary
25
20
15
10
5
0
1996
1998
2000
Year
Figure 12. Boxplots of southern Maori wrasse abundance per 500m2 in Jervis Bay Marine Park. a)
Open to fishing (Habitat protection zones); b) Reserve or Sanctuary zones (closed to fishing). Trend
lines are Generalized Additive models of juvenile-adult fishes with natural temporal splines, selected
by generalized cross-validation, with quasipoisson distributions, and log-link. The dashed lines are
the standard errors of the fit. Vertical line indicates the time of Reserve establishment.
Australia ■ State of the Environment 2011 Supplementary information
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Abundance per 5000m2
Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
1996-2003
a) Habitat protection
250
2004-2009
250
200
200
150
150
100
100
50
50
0
0
2.5
250
5
7.5 10 12.5 15 20 25 30 35 40
b) Sanctuary
2.5
5
7.5 10 12.5 15 20 25 30 35 40
2.5
5
7.5 10 12.5 15 20 25 30 35 40
250
200
200
150
150
100
100
50
50
0
0
2.5
5
7.5 10 12.5 15 20 25 30 35 40
Size class (cm)
Figure 13. Size frequency distributions of southern Maori wrasse in Jervis Bay Marine Park before
(left column) and after (right column) establishment of reserve protection. a) Open to fishing
(Habitat protection zones); b) Reserve or Sanctuary zones (closed to fishing). White bars are
immature fish; grey bars are the sizes at which females become mature; black bars are sizes at which
females change sex to become reproductively mature males. Abundances have been scaled to
5000m2 to correct for different levels of sampling effort.
Australia ■ State of the Environment 2011 Supplementary information
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Vulnerability and status of marine fishes for the Australian State of the Environment report 2011 – temperate
species
4. Conclusions
Indicator
Red Morwong
Cheilodactylus fuscus
Population trends



Population structure


Extent of threats


Inherent vulnerability



GOOD
Populations fluctuate through
time with no apparent linear
trend
When released from localized
fishing pressure, populations
recover quickly
Available time series too short
to project future trends
GOOD
Where present, are locally
abundant
Individuals distributed across
size classes as expected
POOR
Localized threats due to fishing
pressure, but this probably
affects <30% of the population
Long-term threat due to
climate change, with
contraction of geographic
range
POOR
The size, range, fecundity, and
age structure of his species
indicate it can recover in a
reasonable time from
reduction in population size
Increases in population size are
evident within 5 years of
release from fishing pressure
The large size, moderate
growth rate, and small range
size make this species
vulnerable
Maori Wrasse
Ophthalmolepis lineolata








GOOD
Populations fluctuate through
time with no apparent linear
trend
Available time series too short
to project future trends
GOOD
Where present, are locally
abundant
Individuals distributed across
size classes as expected
GOOD
Despite classification as
“moderately fished”, no
apparent effect of removal of
fishing effort
Wide geographic range should
buffer climate change effects
GOOD
The size, range, fecundity, and
age structure of his species
indicate it can recover
moderately rapidly from
reduction in population size
The small size, rapid growth
rate, and large range size
reduce vulnerability
IUCN evaluation
VULNERABLE
LEAST CONCERN
Overall assessment
POOR-GOOD
GOOD
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species
Acknowledgments
The spatial fish abundance data of Cheilodactylus fuscus and Ophthalmolepis lineolata were kindly
provided by Dr Graham Edgar and Dr Rick Stuart Smith, University of Tasmania. The temporal data of
these species from Jervis Bay were also kindly provided by Dr Graham Edgar and Dr Neville Barrett,
University of Tasmania. We thank Dave Harasti for providing photographs of the two species.
Literature cited
Barrett, N., G. Edgar, A. Polacheck, T. Lynch, and F. Clements. 2006. Ecosystem Monitoring of Subtidal
Reefs in the Jervis Bay Marine Park (1996-2005). Tasmanian Aquaculture and Fisheries
Institute Internal Report.
Beeton R.J.S, Buckley K.I,. Jones G.J., Morgan D., Reichelt R.E., Trewin D (2006) Australia State of the
Environment 2006. Independent report to the Australian Government Minister for the
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