The development of management options for the Central Fladen
potential area for an MPA
1
Purpose of document
The purpose of this document is to provide an overview of work to date on the development
of management advice for the Central Fladen potential area for an MPA. The overview
shows the process and information that has been used and, where relevant and possible,
identifies options for management.
This document has been produced as a case study for the 5th national MPA stakeholder
workshop in June 2012. It may not cover all features or all activities/developments. At the
workshop the focus will be on discussing the process, information used and how this has
been presented. We want to make sure that this paper is a useful starting point for more
detailed discussions on management. Discussions at the workshop will not be focussed on
the detail of any future management that may be required.
Following the workshop, this document will be revised to take account of feedback and used
to support more detailed discussion with stakeholders who are likely to be directly involved
with the Central Fladen potential area for an MPA. The aim will be to use the information
presented in this paper to get a better understanding of current and possible future activities
and the interactions these may have with different features. Through discussion, the options
presented below will be reviewed and recommendations on preferred management will be
produced.
2
Background
A number of documents relating to the Central Fladen potential area for an MPA have been
produced. These are relevant to discussion of this paper and include:
 Draft consultation document (including map of potential area for MPA)
 Data confidence assessment (which presents data on features)
 Detailed assessment against the MPA Selection Guidelines
There are also a range of tools and guidance documents that have been produced to
support discussions on management. Weblinks and references are provided under Further
information below.
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Overview of relevant activities
There are a range of activities associated with the Central Fladen potential area for an MPA.
A list of these activities and the sources of this information is provided below:
Infrastructure (UK DEAL and UK Cable Protection Committee1
 Oil and gas pipelines
 Telecommunication cables
Fishing (2006-2009 VMS data)
 Otter trawling
 Demersal seine netting
 Set netting# (Danish shrimp fishery)
 Pelagic trawling and purse seining*
#
Gear codes for non-UK vessels based on EU vessel register primary gear coding, thus
there is an increased likelihood of misclassification error.
1
Now UK Sub-sea cables
*Burrowed mud is not exposed to this activity.
Infrastructure
There is one major telecommunication cable running through the central part of the north of
the location, which re-enters the south-east corner, whilst there are two pipelines running
across the southern part of the location.
Fishing
The following is a summary of the fishing activity associated with the Central Fladen
potential area for an MPA. The majority of the information is derived from VMS effort (hrs
fished) data aggregated over four years (2006-2009) and from UK landings statistics over
the same time period. There is unlikely to be any <15m vessel activity in Central Fladen.
Otter trawling
The greater Fladen Ground region is an area of major importance to the Scottish demersal
fleet, with >1000 hours effort (in a 0.05 x 0.05 degree cell) typical for the southern and
western part of the ground over the four years analysed. The majority of vessels fishing in
the Fladen Ground are from the Scottish fleet, with over 95% of Nephrops landed into
Scottish ports, principally Fraserburgh, Peterhead and Shetland. Lesser quantities of
Neprhops are also landed into western Scottish and northern English ports. The Fladen
Ground is characterised by relatively low burrow densities with the species spread over a
wide area (>30,000 km2), with areas of highest fishing intensity associated with patches of
higher burrow density to the south of the Central Fladen site2. The Fladen Nephrops fishery
tends to be concentrated in the spring and summer.
2
http://www.scotland.gov.uk/Publications/2012/05/9899/20
Apart from the Nephrops fishery, there is also a valuable mixed demersal fishery in the
greater Fladen region. They principally target a mixed whitefish fishery including species
such as haddock, cod and whiting as well as other high value species such as monkfish
using both single and twin rig vessels. Typically, Nephrops also constitute a significant
proportion of the bycatch of this fishery.
Although there is fishing activity throughout the Central Fladen potential area for an MPA,
the south western portion of the site, coincident with the sandy sediment, is less intensively
fished than the north. According to landings data for 2006-2009, Nephrops was the
predominant species landed in the ICES statistical rectangles overlapping the central fladen
site (47E9, 46E9, 46E0) followed by haddock, whiting and monkfish. Over the four year
period 2006-2009, demersal trawling effort recorded in any single VMS grid in the Central
Fladen potential MPA area ranged from 829 hours to the north down to fewer than 100 hours
in the southeast.
Set netting (Danish shrimp trawling)
Although, listed as “set netting” in the VMS data, the most likely activity in this region is the
Danish shrimp trawl fishery occurring to the southwest of the Central Fladen potential MPA
area. The location of greatest activity is coincident with the region of lowest intensity
whitefish and Nephrops trawling in the wider Fladen Ground area. The pink shrimp
(Pandalus borealis) trawl fishery in the Fladen Ground traditionally operates between March
and June. It has predominantly been made up of Danish vessels with a smaller number of
northeast Scottish vessels landing catches into non-UK ports. Over the last 20 years there
has been a dramatic reduction in Danish vessel shrimp landings from Fladen, dropping from
nearly 6,000 tonnes to negligible quantities (<25 tonnes) in recent years3. The decline has
3
http://archive.nafo.int/open/sc/2011/scr11-069.pdf
been attributed to a number of factors including low shrimp abundance, low prices and high
fuel prices. This has resulted in a dramatic reduction in effort (<21 hours over 4 years) as
evidenced by the low VMS fishing intensity data for 2006-2009. Of note, there is a notable
overlap between this fishery and point data records for the tall sea pen (Funiculina
quadrangularis). As most landings from this fishery are into non-UK ports, no official landings
statistics were available for analysis.
Seine Netting
The Fladen Ground seine net fishery is a mixed demersal fishery that predominantly targets
whitefish (haddock, cod and whiting) but with significant landings of monkfish and several flat
fish species. The vast majority of landings are into Peterhead and Fraserburgh with lesser
quantities landed into Shetland and Wick. From the VMS data, the seine net fishery in the
Central Fladen potential MPA area is concentrated to the south of the Fladen Deeps with up
to 125 hours activity estimated between 2006 and 2009 in this area. There is some evidence
of seine net activity to the north of the Fladen deeps, but this is low by comparison (< 20
hours over four years).
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Assessment of sensitivity and risk
The sensitivity matrices developed further by SNH and JNCC show the relationships
between different features, pressures and activities to which they are linked.
4.1 Pressures associated with activities occurring in Central Fladen potential area
The pressures associated with otter trawling, and to a degree seine netting and set netting,
to which burrow mud habitat is sensitive include: removal of non-target species; surface and
subsurface abrasion/penetration; and changes in siltation. They are likely to interact with the
characterising species living within and on the surface of the burrowed mud habitat
distributed across the potential area.
The pressures associated with pipelines and cables to which burrowed mud habitat is
sensitive: physical change (to another seabed type), physical removal (extraction of
substratum), sub-surface abrasion/penetration.
Pelagic trawling and purse seining also occur across the potential area; however burrowed
mud habitat is not exposed to the pressures associated with these activities.
4.2 Sensitivity of burrowed mud to pressures
Physical abrasion and penetration of the seabed surface may remove species living on the
surface. Non-mobile fauna including sea pens may be uprooted and / or suffer mechanical
damage. Because of its inability to retract into the sediment, the tall sea pen (Funiculina
quadrangularis) is considered to be particularly vulnerable. There is evidence of resilience to
frequent disturbance from the burrowing megafauna within burrowed mud which is not
affected to the same degree as species on the seabed.
Species living on the surface of burrowed mud habitats such as sea pens may be affected
by smothering as a result of increases in suspended sediment arising from localised
disturbance of the seabed. This pressure may affect the feeding efficiency of suspension
feeders such as sea pens. The capacity to recover from smothering will be determined by
the scale, longevity and frequency of siltation rate changes.
Given the variation in the response on components of this habitat to the associated
pressures, burrowed mud has been assessed as having medium sensitivity to the pressures
considered.
4.3 Burrowed mud vulnerability in Central Fladen potential area
The burrowed mud habitat and the activities thought to be associated with physical loss or
damage occur across the entire potential area. As such, burrowed mud within Central
Fladen has been assessed as having a moderate vulnerability.
Note that with higher resolution data on fishing activity, such as VMS point data, a more
accurate picture of the extent of the areas exposed to potential pressures would become
apparent.
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Management options
The aim of managing activities within the site should be to ensure that the abundant and
diverse species that constitute the burrowed mud habitats and the important ecological
functions they provide are conserved in good condition while allowing valuable human
activities to continue. If properly managed, the Central Fladen potential area could make an
important contribution towards meeting Scotland’s commitments under the EU Marine
Strategy Framework Directive and the OSPAR Convention as well as providing wider
benefits to our marine environment. Good management would be expected to result in
increased diversity and abundance of marine species in line with the biological communities
that would naturally occur in the area, improved ecosystem functioning and possibly
enhanced production of some commercially exploited species.
The draft fisheries management guidance4 for demersal towed gears notes that fished areas
of the burrowed mud habitat may support a modified biological community with lower
diversity, reduction or loss of long-lived filter-feeding species and increased abundance of
opportunistic scavengers. This effect was greatest in the more heavily fished offshore areas
suggesting that impact is related to the intensity of fishing5. Modelling studies suggest that
the greatest impact is produced by the first pass of a trawl with subsequent exposure having
less effect5. The sea pen Virgularia mirabilis does not appear to be negatively affected by
trawling at low levels, possibly as a result of its ability to withdraw into the sediment, however
the tall sea pen has no such ability and its distribution in Scottish waters may have been
reduced as a result of demersal trawling. Furthermore, damage to sea pen species is likely
to take place as a result of greater sediment disturbance as a result of towed demersal gear.
There is no direct evidence for the impacts of netting or long lining so the assessment is
based on the assumption of similar effects to potting. The draft fisheries management
guidance summarises studies that found that the mortality rates following experimental creel
disturbance are low generally with impacts on the tall sea pen being much lower than with
demersal towed gear.
4
Draft Advice Scottish MPAs and fisheries: burrowed mud, inshore deep mud with burrowing heart
urchins and offshore deep sea muds (2012)
Baxter, et al., 2011. Scotland’s marine atlas: Information for the national marine plan. Marine
Scotland, Edinburgh. pp191.
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5.1 Fisheries management options
There is no direct evidence that mud habitats in central Fladen have been impacted by
trawling but studies on comparable habitats elsewhere and current understanding of the
sensitivities of mud habitats to the types of pressures associated with towed gears suggest
that it is likely that the habitats have been modified to some extent by fishing.
Reduction in effort may be required to allow recovery to good condition; however, the degree
of modification that would be acceptable within good condition, and therefore the degree of
reduction required, has not yet been determined. It is hoped that discussions with fishermen
and scientists at a workshop to be held in August6 may improve our understanding of the
nature and degree of management that will be required.
The following options for management are proposed as a starting point for discussion. This
is intended to give a broad overview of the range of management options available and their
probable consequences in terms of effects on the habitats and risk of failure to conserve the
features of the site in good condition. It is not intended to indicate that any of these options is
currently preferred by the nature conservation agencies and, as such, all options remain on
the table for further discussion with stakeholders, scientists and fisheries managers. There
is insufficient evidence to differentiate between the effects of trawlers targeting Nephrops
and whitefish species and, until such evidence becomes available, the same management
options should be applied to both.
5.1.1 Option 1. No additional management
The likely consequence of this option is that the habitats would be maintained in a modified
state with altered sedimentary characteristics and reduced abundance of sea pens and
some burrowing species. There is risk that cumulative effects from ongoing fishing may
result in increasing levels of modification and if fishing activity increases, the degree of
modification would be expected to increase. In particular, there is a risk that the remaining
population of tall sea pen may be reduced or removed.
This option therefore poses a significant risk that the burrowed mud within the potential area
for an MPA would not be conserved in good condition.
5.1.2 Option 2. Managed access
In order to achieve the aims described at the start of section 5, possible objectives of
management could be;
 To reduce the overall level of disturbance experienced within the MPA (i.e. frequency
of disturbance events, extent and severity).
 To allow recovery of features between fishing/disturbance events.
 To reduce mortality and increase abundance of species living on the seabed.
 To improve habitat structure / heterogeneity and increase the diversity & population
structure of species living in the seabed.
Appropriate management would be determined through a process which would include
dialogue between stakeholders, scientists and fisheries managers. Suitable management
measures may include (but are not restricted to) temporary or seasonal closure of selected
areas, closure of the area within which tall sea pens have been recorded, modification of
gears or fishing practices or effort limitation.
6
MAIA (Marine Protected Areas in the Atlantic Arc) workshop, lead by JNCC, on setting conservation
objectives and possible management options for MPAs identified for the protection of burrowed mud,
2 August, Glasgow 2012.
If appropriate management measures are introduced resulting in an overall reduction in
fishing pressure and increased protection of tall sea pens, the biological community within
the closed area would be expected to recover to a more natural condition and the population
of tall sea pens would be maintained and may increase if conditions are appropriate.
This option would be expected to result in improvement in the condition of the burrowed mud
within the potential area for an MPA, however, it is not currently known whether this would
be sufficient to conserve the features in good condition.
This option would provide an opportunity for a well designed scientific study to investigate
the effects of fisheries management measures and the features’ potential for recovery which
could inform future management decisions.
5.1.3 Option 3. No access
The habitat will not be subject to further modification. If there are no other unregulated
pressures, recovery would be expected to take place at a natural pace.
This option would present to lowest risk of the site failing to achieve good condition but
would impose the highest cost on the fishing industry.
5.2 Infrastructure management options
Options for managing the effects of pipeline and cable installation and maintenance would
be considered as part of the Environmental Impact Assessment for any development.
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Recommendations
Based on the existing evidence, JNCC’s advice is that managed access is likely to be
required within the Central Fladen potential area for an MPA. Before any final
recommendations are made about management of the Central Fladen potential area for an
MPA, Marine Scotland will lead consultation with the following groups of stakeholders to
ensure that there is a good understanding of the features and the likely interactions with
activities:



Demersal fishing - Scottish Fishermen’s Federation (SFF) and constituent bodies
(e.g. SWFPA, SFA), Scottish Fishermen's Organisation limited (SFO), Fishermen’s
Association Limited (FAL), Danish Fishermen’s Association (DFA), National
Federation of Fishermen’s Organisations (NFFO), North Sea RAC, individual
fishermen with practical experience of working in the area, Marine Scotland
Compliance
Cables - UK Sub-sea cables
Pipelines – Oil and Gas UK, Department for Energy and Climate Change
These discussions may result in JNCC being more specific in their advice to Marine
Scotland on management requirements for the potential area should it be designated as a
Nature Conservation MPA. Marine Scotland will then make management recommendations
to Scottish Ministers. Any fisheries management measures required in this potential area
would need to be implemented through the Common Fisheries Policy.
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Further information
See the following webpage for further information:
http://www.scotland.gov.uk/Topics/marine/marineenvironment/mpanetwork/engagement/270612