**A SEASCAPE PERSPECTIVE FOR MANAGING DEEP-SEA HABITATS**

A. Williams, R. Kloser, B. Barker, N. Bax and A. Butler

CSIRO Marine Research

PO Box 1538, Hobart, Tasmania, Australia, 7001

\<alan.Williams@csiro.au\>

**\
1. INTRODUCTION**

Sustainable use of the deep seabed off southeastern Australia is
presently a focus for marine planning agencies, conservation groups,
fishery managers and user groups including the offshore fishing
industry. An important stimulus for this focus is Australia's Oceans
Policy (Commonwealth of Australia 1998) which is being implemented
through Regional Marine Plans (RMPs) (NOO 2003) that include a National
Representative System of marine protected areas (ANZECC 1999) so as to
encompass many areas of continental shelf and slope seabed. In addition,
and largely independently, an expanded control of the offshore fisheries
of the region's South East Fishery (SEF) through spatial management is
signalled by a range of fishery-specific management planning by the
Australian Fisheries Management Authority through bycatch action plans,
strategic fishery assessments and ecological risk assessments.
Ecologically sustainable development in the SEF, including spatially
based management concepts, is also the focus of conservation NGOs (e.g.
Ward and Hegerl 2002), and ecologically-sound fishing practices are
supported by the strategic plans of peak industry associations,
including the trawl sector.

At present, however, the information needs of this spatial policy focus
considerably exceed our existing knowledge of the large offshore seabed
areas. This is particularly the case for the outer continental shelf and
continental slope that support a considerable and expanding fishing
effort, but which are largely unseen and their ecosystems poorly
understood. In the vast area to be managed by the first RMP (\> 2 000
000 km^2^), the two exceptions are a group of cinder cones (now the
Tasmanian Seamounts Reserve) and an area of continental shelf (the
Twofold Shelf bioregion) studied by Koslow et al. (2001) and Bax and
Williams (2001) respectively. Nonetheless, those studies, in common with
those undertaken elsewhere (e.g. Langton, Auster and Scheider 1995),
demonstrated the multiple spatial scales at which seabed habitats and
biodiversity exist, and therefore the multiple scales at which
structures and functions of marine benthic ecosystems are organized.
Understanding these patterns at the landscape scale is now recognized as
essential to successfully managing natural resources for objectives such
as biodiversity conservation and ecologically sustainable development
(Simberloff 1998; Roff and Taylor 2000, ANZECC and BDAC 2001).
Therefore, one of the needs for effective and integrated spatial
planning on the deep seascape off SE Australia is that of identifying
the spatial scales at which information is required.

**\
2. METHODS AND DATA SOURCES FOR HABITAT CLASSIFICATION**

Here we provide a multi-spatial scale perspective for habitat
distribution on the upper continental slope -- the seabed region bounded
approximately by the 200 and 700 m isobaths -- and review briefly the
relevance of each scale to scientific survey (especially mapping),
habitat use, and habitat management. We do this by describing a variety
of seabed habitats that make up 150 km^2^ of a large terrace at the SE
margin of the Big Horseshoe Canyon (the Big Horseshoe Canyon SE terrace)
collected as part of a larger habitat mapping survey (Kloser, Williams
and Butler 2001a, b). Summary details of habitats come from Williams *et
al.* (2004). A framework for our multi-spatial scale classification of
habitats is provided by a hierarchical scheme being adopted for spatial
planning by the Regional Marine Plans (NOO 2003; Williams and Bax
2003a). A hierarchal classification of "habitats" is effectively used as
a surrogate for the hierarchy of ecological units and processes. The
scheme applied to the SER recognizes a series of nested, pseudo-spatial
'Levels' for the structure of habitats, each reflecting the influence of
characteristics and processes acting at different scales (Table 1). It
is mainly under development by V. Lyne and P. Last of CSIRO Marine
Research,

**Table 1 (separate file)**

Hobart. In addition, explicit spatial scales for habitats are defined
according to the scheme of Greene *et al.* (1999).

**3. HABITAT SCALES AND LINKS TO SURVEY, USE AND MANAGEMENT (TABLE 1)**

**3.1 Provincial scales**

Provinces are the first level in the classification scheme, and they
divide Australia's SE Region of more than 2 000 000 km^2^ into large
areas based on regional patterns in fauna (CSIRO Marine Research 2001)
and physiography. Our study area falls within the easternmost Province 3
off the SE Australian continental margin. It is a *Level 1* habitat of
some 500 000 km^2^. Within the province, *Biomes* defined by major
community types and physiography separate the continental slope from the
adjacent continental shelf and continental rise at *Level 2* in the
classification scheme (Table 1). Off SE Australia, the upper continental
slope is a 3 000 km long sinuous ribbon of seabed that averages only 7.2
km in width as it winds around the continental margin immediately
seaward of the shelf break between depths of about 200 and 700 m.

Depth is the strongest environmental correlate of fish community
structure in the deep temperate Australian marine environment (see
references in Williams and Bax 2001b), and the southeastern upper slope
is defined biologically as a *Sub-biome* at *Level 2b* (Table 1). It has
a distinct demersal fish community that differs markedly to those at the
adjacent shelf-break and the mid-slope (CSIRO Marine Research 2001, Last
et al. 2005).

At the largest habitat scales, biogeographic provinces, biomes and
sub-biomes provide the context to view the habitats of the Big Horseshoe
Canyon SE terrace. Their attributes are the large scale environmental
variables of latitude, depth and hydrology (at several scales) that
correlate with the distributions of marine communities (biodiversity)
and fishery resources (Bax and Williams 2001 and references therein).
The Big Horseshoe Canyon SE terrace can therefore be visualized as
making up part of a habitat restricted to the approximately 300--600 m
depth zone on the upper slope in the eastern province of the SE region.
Its communities include a suite of large benthic and benthopelagic
fishes, including the commercially-exploited pink ling where it occurs
at its peak population abundance, and is targeted by the offshore
fishing fleet made up by trawlers and 'non-trawl' boats fishing with
hook and line, gillnets and traps. As a result of the narrowness of this
depth zone it has a relatively small area overall (11 250 km^2^), and a
correspondingly small fraction of the South East Fishery (SEF) region,
i.e. 5 percent of the 227 340 km^2^ of the area used for fishing outside
coastal waters defined as from 3 nm from shore to 1 300 m depth.

**3.2 Megahabitat scales (km to 10s of km and larger)**

Geomorphic features at large megahabitat spatial scales and the
biological communities they support are represented at *Level 3*, the
next level in the habitat classification scheme as Major
Biogeomorphological Units. The study area represents one of these units:
the terrace being the western extent of sediment plain that extends
eastwards. Additional *Level 3* habitat units are represented by the
other regions that bound the study area: the main arm of the Big
Horseshoe Canyon that extends rapidly to 850 m depth to the west, the
shelf break escarpment characterized by a series of slumps, scarps and
steep slopes in the approximately 200--300 m depth range to the north,
and the mid-slope (\> 700 m depth) to the south. While submarine canyons
are prominent features of the continental slope seabed off SE Australia
(NOO 2003, p. 54), with over 100 primary or tributary canyons estimated
to intersect the 300--600 m depth zone in the South East Fishery region,
Big Horseshoe Canyon is distinctive in forming one major arm of Bass
Canyon, the region's largest canyon. Within the restricted upper slope
habitat, the Big Horseshoe SE terrace is therefore an example of a
habitat of 150 km^2^ existing in a location that is unique with respect
to its topography and hydrodynamic climate.

This scale represents the largest units of the continental shelf and
slope that can be mapped cost-effectively by swath acoustics and
'ground-truth' sampling (i.e. over a period of days) (Kloser *et al.*
2002). Swath acoustics provide complete mapping coverage of the seabed
(Exon and Hill 1999) and enables visualization at scales of 10 km^2^, as
well as production of maps based on detailed bathymetry and seabed
textures. This allows scientific sampling to be targeted at particular
seabed features or textures (Kloser *et al.* 2002). Habitats at this
scale may correspond to locally distinct ecosystems such as canyons that
are defined by topography and, or, locally defined circulation, and may
support enhanced productivity and biological aggregations e.g. Big
Horseshoe Canyon (Bax and Williams 2001). As such, habitats at this
scale are correlated with the general distribution of fishing grounds
and the study area is an example of a large multi-sector fishing ground.
Vulnerability may be assessable at this level based on knowledge of
geological properties of habitats and impact studies made at finer
scales. Collectively, these factors identify major geomorphological
units at large megahabitat scales as the largest operational scale for
managing anthopogenic habitat use.

'Acoustic facies' (Kloser *et al.* 2002) form mosaics at smaller
megahabitat scales (1 km--10s of km), and are the equivalent of *Primary
Biotopes*, or *Level 4* units, in the proposed Australian scheme (Table
1). Three types of acoustic facies form the Big Horseshoe Canyon SE
terrace: (a) large areas of homogeneous flat seabed characterized by low
multibeam reflectivity which make up the majority of the area
(approximately 101^2^ of the 150 km^2^) and are interpreted *a priori*
as 'Soft' substratum -- sediments; (b) smaller interspersed
heterogeneous areas characterized by relatively high reflectivity (six
patches making up approximately 43^2^ of 150 km^2^): interpreted *a
priori* as 'Hard' substratum -- i.e. consolidated material; and (c) a
patch found on the western margin of the terrace of high acoustic
reflectivity that occurs on a steep (to 15^o^) slope (\~6 km^2^ of the
150 km^2^): interpreted a priori as 'Rough' substratum -- consolidated
material exposed on steeply sloping seabed.

During sampling with a video camera to observe these acoustic facies
(see below), a total of 85 individuals of adult pink ling were observed;
they were strongly associated with structured microhabitats provided by
the rough habitat (microhabitats detailed below) and had approximately
30 times higher density of individuals on this primary biotope than the
other two.

*Primary biotopes*, existing at megahabitat scales, make up the *major
geomorphological units* and are the appropriate scale at which to
understand habitat values, the interaction of users with the seascape,
e.g. fishing effort and catch, and for scientists to direct scientific
sampling of habitats (Bax and Williams 2001). Of particular importance
is that photography and physical sampling confirmed that habitats at
this level were successfully differentiated by multi-beam acoustics as
their general distributions corresponded well to the a priori
designation of 'Soft', 'Hard' and 'Rough' substrata in backscatter maps.
Because these data can be mapped at sea, targeted sampling at finer
scales can be planned and implemented in 'real-time'.

Such information allows interactions of fishers with fishery habitat to
be understood at the level of primary biotopes, for example, the two
types of fishing grounds that make up the Big Horseshoe Canyon SE
terrace. The first of these is a mosaic of sediment and consolidated
material that makes up most of the terrace that slopes gently between
300 and 600 m depth over a horizontal distance of about 9 km. This area,
being clear of rough rocky 'reefs', provides good access for trawlers to
catch a suite of upper slope species including pink ling. At the western
margin of the terrace at the same depth range, the upper edge of a
relatively steep slope forms the second ground type. This habitat
descends to the base of the canyon at 850 m depth and is composed of
patches of rough rocky bottom that emerges from surrounding sediments.
It can be fished by static gears targeting a range of species,
particularly pink ling, but does allow limited access to trawls.
Although the extact boundaries of fishery habitats occurring at this
level may be ill-defined -- often representing transition zones between
sediments and areas of rock reef -- they provide the basis for
estimating percentage areas of habitats at a scale relevant to spatial
management planning. For example, management goals that specify target
areas of habitat types to be contained within fishery closed areas or
biodiversity conservation reserves.

**3.3 Mesohabitat scales (10 m to 1 km)**

Adding 'ground-truth' sampling to acoustic facies provides habitat
resolution at the next level -- *Secondary Biotopes at Level 5*.
Ground-truthing includes observing the predominant elements of physical
substrata and geomorphology and their fine-scale distribution using
video and evaluating the composition of substrata from physical
collections. Six *Secondary Biotopes* were identified at the Big
Horseshoe Canyon SE terrace (Table 1). Sediments consisted of
homogeneous calcareous muddy sands that form large unrippled patches to
approximately 1 300 m in length at the shallower terrace sites and
irregular (bioturbated) patches to approximately 900 m in length at the
deeper sites. Rubble and debris of extensively burrowed claystones,
mostly composed of gravel and pebble sized clasts, but some of cobble or
boulder size, formed mosaics of numerous smaller patches to
approximately 660 m in length. These were interspersed with sediments
mainly around the southern perimeter of the terrace. Exposed sedimentary
claystone rock on steep slopes at the western margin of the terrace
forms relatively small patches (to 243 m in length) of subcrop and
outcrop in distinct elongate horizontal ridges interspersed with patches
of sediment and rubble or debris.

*Level 5* is the minimum resolution level necessary for resolving
habitat boundaries and patch structure for monitoring, and therefore
mapping, during surveys because the high spatial variability encompassed
at larger scales will obscure identification of impacts on habitat
resulting from its use, as well as any benefits such as restoration
resulting from management intervention. This is the basis for
establishing animal--habitat associations at lower levels of habitat
description and provides a resolution at which to understand the
significance of habitat types, such as what defines 'essential fish
habitat' (i.e. what limits populations in any way, *sensu* Steneck *et
al.* 1997 and references therein). Optimizing the 'ground-truth' --
targeted physical sampling of acoustic facies -- is important for the
execution of cost-effective surveys (Kloser *et al.* 2002).

Mesohabitat scale is also the size of seabed features that experienced
fishers are familiar with and operate on. Their knowledge at this level
is the basis for successfully targeting their fishing effort at features
that result in aggregation of certain species in commercial
concentrations (Bax and Williams 2001). Knowledge of habitat variability
at this scale is therefore necessary for management areas to be defined
without unnecessarily excluding fishers from important parts of larger
fishing grounds. Sector-specific (gear-specific) fishery management
intervention at this scale could correspond to clearly delineating
claystone-based habitats at the western edge of the Big Horseshoe Canyon
SE terrace.

**3.4 Macrohabitat scales (1m to 10s of m)**

*Biological Facies,* *Level 6* in the scheme, at the macrohabitat scale
are described by the conjunction of information on the dominant fauna
with that on the physical seabed structure. Fifteen predominant
biological facies were observed on the terrace. These included a
sedentary fauna composed mostly of low (\< 10 cm) encrusting sponges,
anemones and sand-dwelling sponges that were the primary epifaunal
inhabitants of unrippled muddy sands. Infaunal bioturbators -- including
ranellid gastropods and *Latreillopsis petterdi* -- appeared to be
abundant on the highly irregular (bioturbated) muddy sands. A mobile
fauna including hermit crabs was also frequently observed. Small
encrustors and erect epifauna were the most commonly observed biological
facie associated with claystone debris or rubble. Beds of small sponges
were also attached to this substratum where it was present on the
steeply sloping seabed, and to debris or rubble composed of larger
cobble and boulder sized clasts. The facies representing the greatest
density of epifauna, the largest-sized individuals, and possibly the
greatest biodiversity, were beds of small and large sponges associated
with subcropping and outcropping claystone rock on the steeply sloping
seabed.

Spatial management in the marine environment is ultimately directed at
the biological inhabitants of habitats -- to conserve biological
diversity and local ecosystems or protect particular species (often
commercial fishes for fishery management). Understanding animal-habitat
associations will therefore require surveying at macrohabitat (and
microhabitat) scales because these are the scales at which animal
distributions vary, impacts can be recognised and quantified, and at
which monitoring must occur.

**3.5 Microhabitat scales (\< 1 m)**

*Microhabitats, Level* 7, represent the lowest level in the hierarchy.
Those observed by video during the study are crevices, cracks edges and
ledges associated with rocky outcrops and subcrops, irregular features
such as pits and mounds associated with bioturbated sediments, and erect
epifauna -- mostly sponges -- also associated with rocky outcrops and
subcrops. The abundance of crevices, cracks, edges and ledges results
from the combination of high seabed slope (to 15^o^) that exposes
claystone, which is buried in sediment on flatter bottoms, and the
pronounced up-slope dip, or tilt, in the rock that results in the
down-slope rock faces being slightly elevated. These are the structured
microhabitats with which high densities of pink ling were associated.
Much of the claystone exists as detached flat boulders; those visible
(not embedded in sediment) averaged 144 cm by 78 cm in size with the
largest being 220 cm by 150 cm (n = 25).

Observing and understanding fishing impact must also occur at these
scales. Video observations showed physical impacts occur when bottom
trawls 'hook-up' on claysone boulders (or 'slabs') by turning and moving
loose pieces. There is evidence of fishing impacting the habitat of the
fish being targeted, that is at least partly irreversible. Understanding
of vulnerability therefore relies on surveying at macrohabitat and
microhabitat scales with extrapolation to primary biotope or geomorphic
unit scales by mapping, or to provincial scales based on knowledge of
regional geology (Bax and Williams 2001). The key attribute for
understanding the impact on rocky claystone habitats is that these rock
types are sedimentary and therefore friable, forming loose claystone
boulders ('slabs'), many of which are only partially embedded in
sediments. They form large, although unquantified, fractions of
mesohabitats and they, together with their attached epifauna, are
movable or removable by trawls.

Targeted harvesting of aggregated pink ling populations on rocky habitat
by static fishing methods is another form of impact and knowledge of
such habitat associations may be necessary for meaningful stock
assessment off southeastern Australia (Thompson in review). Off southern
Africa, the combination of targeted trawl and demersal longlining
resulted in severe depletion of kingklip (the closely related
*Genypterus capensis*) (Punt and Japp 1994). While it is not known
whether the different methods were targeting different habitats, Punt
and Japp reported that reduced trawl catches were attributed by trawl
operators to the systematic removal of the aggregated kingklip spawner
stock by longline fishing. The relevance of information on multi-scale
habitat distributions and species-associations to spatial management in
the SEF is that at present (2003) the fishery is experiencing a large
expansion in longline effort and an areal expansion of trap fishing to
target pink ling at the same time trawl effort is expanding on the upper
slope. The consequence is that all habitat types used by pink ling will
be commercially fished and many of them with increasing effort.

Assessing the success of conservation measures requires repeated
surveying to monitor changes in size and abundance of epifauna, and the
distributions of mobile habitat features -- particularly sediments. In
deepwater, this must be done at microhabitat scales by photography in
conjunction with near-seabed acoustic mapping.

**4. FISHING INDUSTRY'S KNOWLEDGE OF HABITAT DISTRIBUTIONS**

Habitat distributions at 'intermediate' scales -- mega- and mesohabitat
-- are not known for the vast majority of the continental shelf and
slope seabed around southeast Australia. Techniques for using surrogate
variables to reliably predict the distributions of habitats and
components of biodiversity at these scales are under active development
(Kloser *et al.* 2001b) but substantial resources are required before
scientific mapping at intermediate scales can be extrapolated over large
areas.

However, these are the scales at which commercial fishers know the
seabed and their working maps, typically in vessel electronic
trackplotters, in the context of the hierarchical classification
framework being used for the SER (Table 1), are a mix of Levels 3--6 in
the habitat classification scheme. The utility of fishers'mapping data,
if collected in the right form, is as it can possibly provide
interpreted habitat information (distribution, boundaries, sizes,
generalized geology and community types) at megahabitat scale or finer.
As well, fishers collectively have near-complete coverage for the
continental shelf and slope (from about 100 m out to about 1 300 m
depth) at provincial scales.

A project between the CSIRO and the trawl and non-trawl sectors of the
southeast Australian offshore fishing industry (Williams and Bax 2003b)
was started in 2001 with the explicit aim of incorporating fishers'
knowledge of the seascape into strategic management planning. Industry
executives supported the project primarily because they viewed it as a
way to participate directly in the forthcoming, but then unspecified,
spatial management process. It was argued that with their information
systematically collected and rigorously evaluated fishers would be able
to critically evaluate proposed spatial management plans, and push for
management agencies to have clearly defined and measurable aims for
their proposed management options. Equally importantly, these data
provide industry with a synoptic view and a more detailed understanding
of the habitats types that sustain the productivity of their fisheries.
There is support to use these data to contribute to both the initial
identification and subsequent selection of MPA sites. However, although
involvement of industry data in this way has clear potential to enhance
conservation, fishers remain uncertain about the consequences for them
and therefore are uncertain about how, or indeed whether, to contribute
their data.

**\
5. CONCLUSIONS**

We provide examples to illustrate a range of relevant spatial scales at
which information on deep seabed habitats exists (Table 1) and suggest
that it is the *collective* understanding of these scales -- the
seascape perspective -- that enables specific management goals to be
defined and their success to be evaluated. However, our examples are
from one of the few surveys of deep shelf and slope habitats off
Australia and it is unlikely that additional areas will be surveyed over
the range of spatial scales needed in the timeframes (months to a few
years) during which wide-ranging spatial management intervention is
being planned for the Australian Marine Jurisdiction. Another
prospective way of understanding habitat distributions at a regional
scale would be through partnership with the offshore fishing industry.
Fishers' mapping data, if collected in the right form, could provide
interpreted habitat information at useful spatial scales for the
continental shelf and slope (from about 100 m out to about 1 300 m
depth) with 'provincial scale' coverage. Including fishers' knowledge in
spatial management planning for a seascape best known to them is perhaps
the best way to gain their acceptance and understanding of conservation
objectives and for these to deliver fishery benefits through informed
management of fishery habitat.

**6. ACKNOWLEDGEMENTS**

We gratefully acknowledge the research work of several colleagues in
related fields that provides background for this paper, especially
Vincent Lyne and Peter Last of CSIRO Marine Research. The habitat
mapping methodology development survey that generated the example data
used here was funded jointly by Australia's National Oceans Office and
CSIRO Marine Research. The CSIRO-industry mapping project was funded
jointly by CSIRO Marine Research and the Fisheries Research and
Development Corporation.

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Table 1 Benthic habitats from the Big Horseshoe SE terrace classified in
the hierarchical habitat classification scheme proposed for Australia's
marine environment. Spatial scale follows Greene et al. (1999).
Relevance of each level of habitat described in relation to mapping by
scientific survey, use by its biological inhabitants and for commercial
fishing, and the implications of these attributes for marine resource
managers. (Data from Williams et al. in review).

+------+------------------+--------+-----------------------------------+
| Cl   | Habitat          | S      | > Relevance to ecology, mapping,  |
| assi | description      | patial | > use, and management             |
| fica |                  | scale  |                                   |
| tion |                  |        |                                   |
| l    |                  |        |                                   |
| evel |                  |        |                                   |
+------+------------------+--------+-----------------------------------+
| 1:   | Eastern province | prov   | > Regional ecosystems delimited   |
| Prov | of south-eastern | incial | > by biogeographic and            |
| ince | large marine     |        | > physiographic features          |
|      | domain           |        |                                   |
+------+------------------+--------+-----------------------------------+
| 2a:  | Continental      | prov   | > Primary division of regional    |
| B    | slope (SEF)      | incial | > ecosystems by physiography      |
| iome |                  |        | > (esp. depth) to broadly define  |
|      | (200-1,500 m     |        | > distinct community types and    |
|      | depth range)     |        | > physical environment            |
+------+------------------+--------+-----------------------------------+
| 2b:  | Upper            | prov   | > Secondary division providing    |
|      | continental      | incial | > depth boundaries for community  |
| S    | slope            |        | > structure, and composition of   |
| ub-b |                  |        | > species and life history stages |
| iome | (200-700 m depth |        | >                                 |
|      | range)           |        | > Suites of species targeted by   |
|      |                  |        | > particular fishing methods/     |
|      |                  |        | > fleets                          |
+------+------------------+--------+-----------------------------------+
| 3:   | Big Horseshoe SE | large  | > Boundaries for local ecosystem  |
| M    | terrace          | megah  | > structures and processes, e.g.  |
| ajor |                  | abitat | > topographic features, enhanced  |
| bio  |                  |        | > productivity, biological        |
| geo- |                  |        | > aggregations                    |
|      |                  |        | >                                 |
| m    |                  |        | > Mapping of entire units may be  |
| orph |                  |        | > cost-effective using swath      |
| olog |                  |        | > acoutics                        |
| ical |                  |        | >                                 |
| u    |                  |        | > Large individual fishing        |
| nits |                  |        | > grounds with multi-sector       |
|      |                  |        | > activity                        |
|      |                  |        | >                                 |
|      |                  |        | > Areas amenable to spatial       |
|      |                  |        | > management based on broadly     |
|      |                  |        | > defined goals                   |
+------+------------------+--------+-----------------------------------+
| 4:   | \* Elongate      | megah  | > Habitat values defined by       |
| Pri  | rocky banks      | abitat | > coarsely resolved physical      |
| mary | interspersed     |        | > attributes and associations     |
| biot | with sediments   |        | > with communities and individual |
| opes | patches (sloping |        | > species                         |
|      | flank of canyon) |        | >                                 |
|      |                  |        | > Spatial extent (approximate     |
|      | \* Patchy mosaic |        | > boundaries) of general bottom   |
|      | of mixed         |        | > types (textures) resolved by    |
|      | substrata:       |        | > swath acoustics (acoustic       |
|      | 'hard' and       |        | > facies)                         |
|      | 'soft' seabed    |        | >                                 |
|      | types (terrace)  |        | > Differentiation of fishing      |
|      |                  |        | > grounds used by specific        |
|      | \* Sediment in   |        | > fishing sectors                 |
|      | large clear      |        | >                                 |
|      | patches          |        | > Areas amenable to specific      |
|      | (terrace)        |        | > management goals, e.g. for      |
|      |                  |        | > fishery habitat                 |
+------+------------------+--------+-----------------------------------+
| 5:   | \* Outcropping   | mesoh  | > Fine scale resolution of        |
| S    | sedimentary      | abitat | > habitat boundaries/ patch       |
| econ | claystones       |        | > structure by 'ground-truth'     |
| dary |                  |        | > targeted physical sampling of   |
| biot | \* Subcropping   |        | > acoustic facies                 |
| opes | sedimentary      |        | >                                 |
|      | claystones       |        | > Associations define essential   |
|      |                  |        | > fish habitat, e.g. for          |
|      | \* Debris /      |        | > spawning, nursery, feeding      |
|      | rubble of        |        | >                                 |
|      | cobble/ boulder  |        | > Features known and targeted by  |
|      | clasts           |        | > individual fishers from         |
|      |                  |        | > particular sectors              |
|      | \* Debris /      |        | >                                 |
|      | rubble of        |        | > Specific management goals set,  |
|      | gravel/ pebble   |        | > and performance criteria        |
|      | clasts           |        | > evaluated, based on monitoring  |
|      |                  |        | > at this level or lower          |
|      | \* Highly        |        |                                   |
|      | irregular        |        |                                   |
|      | calcareous muddy |        |                                   |
|      | sands            |        |                                   |
|      |                  |        |                                   |
|      | \* Unrippled     |        |                                   |
|      | calcareous muddy |        |                                   |
|      | sands            |        |                                   |
+------+------------------+--------+-----------------------------------+
| 6:   | \*15 based on    | macroh | > Community dominants identified  |
| Bi   | video            | abitat | > by targeted biological sampling |
| olog | observations     |        | >                                 |
| ical |                  |        | > Fine scale resolution of        |
| fa   |                  |        | > community boundaries/ habitat   |
| cies |                  |        | > associations                    |
|      |                  |        | >                                 |
|      |                  |        | > Biodiversity distributions      |
|      |                  |        | > mapped                          |
|      |                  |        | >                                 |
|      |                  |        | > Impacts of fishing recognised   |
|      |                  |        | > in photographic images          |
|      |                  |        | >                                 |
|      |                  |        | > Monitoring of fauna for         |
|      |                  |        | > management performance          |
|      |                  |        | > assessment                      |
+------+------------------+--------+-----------------------------------+
| 7:   | \* 7 based on    | microh | > Precise role of habitat         |
| M    | video            | abitat | > detailed                        |
| icro | observations     |        | >                                 |
| habi |                  |        | > Impacts of fishing quantified   |
| tats |                  |        | >                                 |
|      |                  |        | > Monitoring of individual animal |
|      |                  |        | > attributes such as density,     |
|      |                  |        | > size and growth rate            |
+------+------------------+--------+-----------------------------------+