Mallory Escarpment and Trough

 

Data used in the analyses below (ecological condition, threat status, protection, distribution of activities, cumulative pressure from activities) are from the National Biodiversity Assessment 2018: Marine Realm Assessment. See the NBA 2018 website for access to the report.

 

EBSA Status Assessment and Management Recommendations

Ecological Condition, Threat Status, Current Protection and Key Features in the EBSA

Relevant Pressures and Activities (impact, extent) | Management Interventions Needed for the EBSA

Activity Evaluation Per Zone: Zoning Feasibility | Management recommendations for MPAs

Management recommendations for MSP | Research Needs & Future Process

EBSA report download | Back to the SA EBSA status and management home page

 

 

EBSA overview

Mallory Escarpment and Trough is a steeply sloping (20°) part of the Agulhas-Falkland Fracture Zone; a slope that steep is unique in the region, and rare globally. It’s also at the meeting point of two biogeographical provinces, which with the large depth range, means high habitat heterogeneity. Sporadic shelf-edge upwelling enhances productivity. It is also a spawning and retention area for numerous commercially important fish.

Click here for the full EBSA description

[Top]

Ecological Condition, Threat Status, Current Protection and Key Features in the EBSA

Mallory Escarpment and Trough is not well explored, but is a unique and special geomorphic feature in the region that, at the meeting point of the Southeast Atlantic Deep Ocean and the Southwest Indian Deep Ocean biogeographical provinces, supports a highly diverse collection of ecosystem types for an area this far offshore. The criteria for which this EBSA ranks highly are: uniqueness and rarity, importance for life history stages, vulnerability and sensitivity, biological productivity, biological diversity and naturalness. There are six ecosystem types represented that likely contain diverse assemblages also including fragile species that are especially sensitive to damage. It’s an important spawning area for small pelagic fish (sardine, anchovy, horse mackerel) and hake, with high productivity from upwelling attracting foraging turtles and seabirds.

 

Mallory Escarpment and Trough proportion of area in each ecological condition category.

 

Mallory Escarpment and Trough is deeper than 1500 m and is thus largely in good ecological condition (55%), with the rest in fair ecological condition (45%); none of the EBSA extent is in poor ecological condition. Consequently, the full extent comprises ecosystem types that are Least Concern (100%), providing excellent opportunity to protect the biodiversity in this area in a pristine or near-pristine state. 

 

 Mallory Escarpment and Trough proportion of area in each ecosystem threat status category.

 

Mallory Escarpment and Trough proportion of area in a Marine Protected Area (MPA).

 

Protection of features in MPAs in the EBSAs adjacent to Mallory Escarpment and Trough have been considerably expanded and strengthened following the proclamation of the Operation Phakisa MPA network. However, this particular EBSA is one of only two in the country with no protection afforded to its special features, and all the constituent ecosystem types are either Poorly Protected or Not Protected. It is thus highly recommended as a site for future protected area expansion, particularly over the unique slope.

 

Threat status, protection level and ecological condition of ecosystem types in the EBSA. Other key features are also listed.

Feature	Threat Status	Protection Level	Condition (%)
			Good	Fair	Poor
Ecosystem Types
Agulhas Basin Abyss	LC	PP	64.4	35.6	0.0
Cape Basin Abyss	LC	PP	100.0	0.0	0.0
Southeast Atlantic Lower Slope	LC	NP	100.0	0.0	0.0
Southeast Atlantic Mid Slope	LC	PP	100.0	0.0	0.0
Southwest Indian Lower Slope	LC	NP	34.7	65.3	0.0
Southwest Indian Mid Slope	LC	PP	10.0	89.9	0.1
Other Features
Spawning area for small pelagic fish (sardine, anchovy, horse mackerel) and hake and areas of retention of the spawning products Fragile species, e.g., gorgonians Turtles, especially Critically Endangered leatherbacks Foraging seabirds

[Top]

 

Relevant Pressures and Activities (impact, extent)

• There are three pressures present in this EBSA, of which shipping is the only one that covers the entire EBSA extent. Pelagic longlining is also extensive in the EBSA, and has the highest cumulative pressure profile.
• The key pressure in this EBSA that most directly impacts the features for which the EBSA is described is pelagic longlining. This activity will need to be managed particularly well in order to protect many of the species that might be caught as bycatch, e.g., seabirds and turtles, which are important biodiversity features for which this EBSA is recognised. Although offshore trawling does overlap with the EBSA, it comprises 0.01% and thus effectively does not impact the EBSA.
• Activities in South Africa that are not present in this EBSA include: abalone harvesting, alien invasive species, beach seining, benthic (hake) longlining, coastal development, coastal disturbance, dredge spoil dumping, gillnetting, kelp harvesting, linefishing (commercial and recreational), mariculture, mean annual runoff reduction, midwater trawling, mining (prospecting and mining), naval dumping (ammunition), oil and gas (exploration and production), oyster harvesting, tuna pole fishing, ports and harbours, prawn trawling, recreational shore angling, shark netting, small pelagics fishing, south coast rock lobster harvesting, squid fishing, subsistence harvesting, inshore trawling, wastewater discharge, and west coast rock lobster harvesting; noting that some of these are coastal pressures that do not apply to offshore EBSAs.

​

Map of cumulative pressure from all activities in the EBSA and surrounds. Darker reds indicate higher pressure intensity.

 

Pressure (in arbitrary cumulative pressure units, CPUs) summed for each pressure in the EBSA, per proposed EBSA biodiversity zone, ranked left (highest) to right (lowest) by the overall relative importance of pressures in this EBSA. Note that offshore trawling comprises 0.01% of the EBSA pressure profile.

[Top]

 

Management Interventions Needed for the EBSA

Improved place-based protection of EBSA features should be pursued. In support of this, the EBSA is divided into a Biodiversity Conservation Zone and an Environmental Impact Management Zone, both comprising several areas within the EBSA. The aim of the Biodiversity Conservation Zone is to secure core areas of key biodiversity features in natural / near-natural ecological condition. Strict place-based biodiversity conservation is thus directed at securing key biodiversity features in a natural or semi-natural state, or as near to this state as possible. Activities or uses that have significant biodiversity impacts are incompatible with the management objective of this zone. If the activity is permitted, it would require alternative Biodiversity Conservation Zones or offsets to be identified. If this is not possible, it is recommended that the activity is Prohibited. Where possible and appropriate, the Biodiversity Conservation Zones should be considered for formal protection e.g., Marine Protected Areas or Other Effective Area-Based Conservation Measures (OECM). The aim of the Environmental Impact Management Zone is to manage negative impacts on key biodiversity features where strict place-based measures are not practical or not essential. In this zone, the focus is management of impacts on key biodiversity features in a mixed-use area, with the objective to keep biodiversity features in at least a functional state. Activities or uses that have significant biodiversity impacts should be strictly controlled and/or regulated. Within this zone, ideally there should be no increase in the intensity of use or the extent of the footprint of activities that have significant biodiversity impacts. Where possible, biodiversity impacts should be reduced. As far as possible, the Biodiversity Conservation Zone was designed deliberately to avoid conflicts with existing activities. Note that this is one of only two EBSAs in South Africa that does not contain any marine protected areas.

 

Proposed zonation of the EBSA into Conservation (medium green) and Impact Management (light green) Zones. MPAs are overlaid in orange outlines, with the extent within the EBSA given in dark green. Click on each of the zones to view the proposed management recommendations.

 

Protection of features in the rest of the Conservation Zone may require additional Marine Protected Area declaration/expansion. Other effective conservation measures should also be applied via Marine Spatial Planning (MSP) to ensure that the existing activities/uses are appropriately controlled to ensure compatibility of activities with the environmental requirements for achieving the management objectives of the EBSA Biodiversity Conservation and Environmental Impact Management Zones.

Based on the compatibility of sea-use activities with the management objective of each EBSA zone (see table below, from the sea-use guidelines of the National Coastal and Marine Spatial Biodiversity Plan), it is recommended for MSP that compatible activities are managed as General activities, which are those that are permitted and regulated by current general rules and legislation. Activities that are conditional are recommended to be managed as Consent activities, which are those that can continue in the zone subject to specific regulations and controls, e.g., to avoid unacceptable impacts on biodiversity features, or to avoid intensification or expansion of impact footprints of uses that are already occurring and where there are no realistic prospects of excluding these activities. Activities that are not compatible are recommended to be Prohibited, where such activities are not allowed or should not be allowed (which may be through industry-specific regulations) because they are incompatible with maintaining the biodiversity objectives of the zone. These recommendations are subject to stakeholder negotiation through the MSP process, recognizing that there will likely need to be significant compromises among sectors. It is emphasized, as noted above, that if activities that are not compatible with the respective EBSA zones are permitted, it would require alternative Biodiversity Conservation Zones or offsets to be identified. If this is not possible, it is recommended that the activity is Prohibited.

 

List of all sea-use activities, grouped by their Marine Spatial Planning (MSP) zones, and scored according to their compatibility with the management objective of the EBSA’s Biodiversity Conservation Zone (i.e., Critical Biodiversity Area, CBA) and Environmental Impact Management Zone (i.e., Ecological Support Area, ESA). Activity compatibility is given as Y = yes, compatible, C = conditional or N = not compatible, with major activities that are present in the EBSA shaded in grey.

[Top]

 

Activity Evaluation Per Zone: Zoning Feasibility

Proposed zonation of the EBSA, with the cumulative intensity footprint of activities within the EBSA (sorted highest to lowest) given relative to the national footprint of those activities to illustrate feasibility of management interventions.

Pelagic longlining is the most notable activity within this EBSA, although it comprises <10% of the national footprint of this activity. It is recommended to continue with appropriate controls and regulations as a Consent activity. Shipping is recommended to continue in both the Conservation and Impact Management Zones under current general rules and legislation. Thus, in all cases, the EBSA zonation has no or minimal impact on the national footprint for the listed marine activities.

 

Management recommendations for MPAs

There are no MPAs in this EBSA. Potential MPA expansion within the EBSA should be explored to ensure that the features for which the EBSA was described receive adequate protection. It is also important to consider ways in which connectivity among MPAs in the Protea Seamount Cluster, Mallory Escaparment and Trough, Browns Bank, and Shackleton Seamount Complex can be enhanced to strengthen persistence of biodiversity and climate-change adaptation. See Future Process below for more details.

 

There are no marine protected areas (MPAs) in the Mallory Escarpment and Trough EBSA.

[Top]

Management recommendations for MSP

 

Developing the biodiversity sector’s input to the national Marine Spatial Planning process

Following the initial management recommendations proposed for Mallory Escarpment and Trough, outlined above, South Africa iteratively developed a National Coastal and Marine Spatial Biodiversity Plan (NCMSBP; Harris et al. 2022a,b) that underpinned the Marine Biodiversity Sector Plan (DFFE 2022). The latter constitutes the biodiversity sector’s input into the national Marine Spatial Planning (MSP) process. The NCMSBP comprises a Map of Critical Biodiversity Areas and Ecological Support Areas (abbreviated to CBA Map), and a set of sea-use guidelines that indicate activity compatibility with the management objectives of each of the CBA Map categories. These two components form the basis for the proposed biodiversity zones and management recommendations for the Marine Area Plans. EBSAs are an integral part of the NCMSBP, and thus the Biodiversity Sector Plan. Therefore, these products informed the proposed zoning and sea-use guidelines for EBSAs in the MSP process.

 

Schematic diagram illustrating that the National Coastal and Marine Spatial Biodiversity Plan will inform the Marine Area Plans through the Marine Biodiversity Sector Plan (DFFE 2022), and will be iteratively updated and refined based on feedback. The process for deriving the sea-use guidelines is also shown, indicating that it is based on an assessment of activity compatibility with the management objective of Critical Biodiversity Area (CBA) Natural, CBA Restore and Ecological Support Areas (ESAs). Marine Protected Area (MPA) expansion, focussing on CBAs, will also take place in a separate but related process. The outcomes of the Marine Spatial Planning and MPA expansion processes will be incorporated into the Marine Area Plans and will be fed back into future updates of the National Coastal and Marine Spatial Biodiversity Plan.

[Top]

Proposed Zones

The proposed biodiversity zones for the EBSA in MSP comprises two types: a Strict Biodiversity Conservation Zone; and a Biodiversity Impact Management Zone. The former has three sub-categories: Marine Protected Area; Biodiversity Conservation Area; and Biodiversity Restoration Area. All of these zones and sub-categories are found in Mallory Escarpment and Trough, except MPAs.

 

The Strict Biodiversity Conservation Zone is primarily a Biodiversity Conservation Area, where the management objective of this zone is to maintain the sites in natural or near-natural ecological condition. The rest of the Strict Biodiversity Conservation Zone comprises a Biodiversity Restoration Area, where the management objective of the zone is to improve the ecological condition of the sites and, in the long term, restore them to a natural / near-natural state, or as near to that state as possible. As a minimum, avoid further deterioration in ecological condition and maintain options for future restoration. The rest of the EBSA is a Biodiversity Impact Management Zone. This is a multi-use area that may already be heavily impacted, but needs to be kept ecologically functional because it is still important for marine biodiversity patterns, ecological processes, and ecosystem services. Therefore, the management objective is to avoid further deterioration in ecological condition.

 

Proposed biodiversity zones for the Mallory Escarpment and Trough EBSA for South Africa’s Marine Area Plans.

 

Proposed Sea-Use Guidelines

All sea-use activities were listed and evaluated according to their compatibility with the management objective of each of the proposed biodiversity zones. Where various aspects of an activity have a different impact on the environment, these were reflected separately, e.g., impacts from petroleum exploration are different to those from production. Activity compatibility was based largely on the ecosystem-pressure matrix from the NBA 2018 (Sink et al. 2019), which is a matrix of expert-based scores of the functional impact and recovery time for each activity on marine ecosystems (adapted from Halpern et al. 2007). Activities were then classified into those that are Compatible, Not Compatible or have Restricted Compatibility with the management objectives of each proposed biodiversity zone. This classification followed a set of predefined principles that account for the severity and extent of impact, similar to the IUCN Red List of Ecosystems criterion C3 (Keith et al. 2013). Some exceptions and adjustments were made based on initial discussions as part of the MSP process.

 

Sea-use guidelines for Mallory Escarpment and Trough. List of all sea-use activities, grouped by their broad sea use and Marine Spatial Planning (MSP) Zones, and categorised according to their compatibility with the management objective of Strict Biodiversity Conservation Zone: Biodiversity Conservation Area (SBCZ: BCA); Strict Biodiversity Conservation Zone: Biodiversity Restoration Area (SBCZ: BRA); and the Biodiversity Impact Management Zone (BIMZ). Activity compatibility is given as Y = yes, compatible, R = restricted compatibility, or N = not compatible. Strict Biodiversity Conservation Zone: Marine Protected Areas (SBCZ: MPA) are managed according to their gazetted regulations.

 

Proposed management recommendations for activities with each of the different compatibility ratings:

• Compatible: Activities should be allowed and regulated by current general rules. Notwithstanding, there should still be duty of care, possibly requiring monitoring and evaluation programmes, to avoid unintended cumulative impacts to the biodiversity features for which this area is recognised.
• Restricted compatibility: A robust site-specific, context-specific assessment is required to determine the activity compatibility depending on the biodiversity features for which the site was selected. Particularly careful attention would need to be paid in areas containing irreplaceable to near-irreplaceable features where the activity may be more appropriately evaluated as not permitted. The ecosystem types in which the activities take place may also be a consideration as to whether or not the activity should be permitted, for example. Where it is permitted to take place, strict regulations and controls over and above the current general rules and legislation would be required to be put in place to avoid unacceptable impacts on biodiversity features. Examples of such regulations and controls include: exclusions of activities in portions of the zone; avoiding intensification or expansion of current impact footprints; additional gear restrictions; and temporal closures of activities during sensitive periods for biodiversity features.
• Not compatible: The activity should not be permitted to occur in this area because it is not compatible with the management objective. If it is considered to be permitted as part of compromises in MSP negotiations, it would require alternative Strict Biodiversity Conservation Zones and/or offsets to be identified. However, if this is not possible, it is recommended that the activity remains prohibited within the Strict Biodiversity Conservation Zone.

[Top]

 

Research Needs

There are no specific research needs for this EBSA in addition to those for all EBSAs. However, the importance of acquiring foundational biodiversity information is emphasised here, and surveys for sampling biodiversity and understanding the ecological significance of Mallory Slope, in particular, is strongly recommended.

 

Future Process

There needs to be full operationalisation and practical implementation of the proposed zoning in the national marine spatial plan, with gazetted management regulations following the proposed management recommendations outlined above. MPA declaration within the EBSA should be explored, with relevant areas included into focus areas that can be considered further in a dedicated MPA expansion process with adequate and meaningful stakeholder engagement. Options for MPA declaration also need to take strengthening connectivity among MPAs in Protea Seamount Cluster, Browns Banks, and Shackleton Seamount Complex.

 

References

[Top]