Change the world

Institute for Coastal and Marine Research

 

EBSA overview  |  Delineation |  Summary of description updates  | Revised description

Submit feedback on the delineation and description  |  OBIS biodiversity data
 

 

EBSA overview

Childs Bank is a unique submarine bank feature, rising from 400 m to 200 m depth on the western continental margin of South Africa. This EBSA includes portions of five benthic habitat types, including hard and unconsolidated sediments, one of which is Critically Endangered, and another two which are Vulnerable. Although comprising threatened habitats, the benthic area of the bank itself is in good condition. Childs Bank and associated habitats are known to support structurally complex cold-water corals, hydrocorals, gorgonians and glass sponges; all of which species constitute vulnerable marine ecosystems. Further, adjacent to Childs Bank, the shelf edge area is a biodiversity hotspot for demersal fish and cephalopods, and the benthic communities contain a high abundance and biomass of infauna and epifauna.

[Top]

Delineation

Open or collapse the legend as a sidebar by clicking the icon in the top left corner of the map. In the legend you can turn on/off the old/new extents of the EBSA. You can zoom in/out using the mouse or the +/- buttons on the map, and click on the features for more information.

 

[Top]

Summary of updates and revisions to the EBSA description

Relatively minor editing of the previous description. No further research has been conducted in the area.

[Top]

Revised EBSA description

NOTE: Read this here, or download the Word document on the right sidebar.

 

General Information

Summary

Childs Bank is a unique submarine bank feature occurring within South Africa’s EEZ, rising from 400 m to 200 m on the western continental margin on South Africa. This area includes five benthic habitat types, including the bank itself, the outer shelf and the shelf edge, supporting hard and unconsolidated habitat types. One habitat type within this area is assessed to be “Critically Endangered” and another two as “Vulnerable”. However, the benthic area of the bank itself is considered to be in “Good” natural state indicating that the ecological patterns and processes are intact. Childs Bank and associated habitats are known to support structurally complex cold-water corals, hydrocorals, gorgonians and glass sponges, species comprise vulnerable marine ecosystems. The Childs Bank area is highly relevant in terms of the following EBSA criteria: “Uniqueness or rarity”, “Vulnerability, fragility, sensitivity or slow recovery” and “Naturalness”.

 

Introduction of the area

Childs Bank is the only known submarine bank occurring within South Africa’s EEZ and occurs on the shelf, close to the shelf edge, on the western continental margin of South Africa. The base of the bank lies in 350 to 400 m water, rising to less than 200 m, with a large, flattened surface area at the shallowest point. The bank area has been estimated to cover 1450 km2 (Sink et al., 2012a); however, the adjacent habitat towards the shelf edge is considered likely to host vulnerable hard ground species. Childs Bank has been geologically described as a rugged limestone feature, bounded at the outer edges by precipitous cliffs at least 150 m high (Birch and Rogers 1973). The area includes Childs Bank, the shelf and the shelf edge adjacent to the bank. The sediment adjacent to the bank is predominantly fine sand with approximately 25% mud, and in some locations small amounts of gravel have been detected (Atkinson 2010). This area was identified as a priority area for protection through two planning studies identifying areas for offshore protection (Sink et al., 2011, Majiedt et al., 2013). Benthic protection in the region of Childs Bank would ensure protection of the only submarine bank within South Africa’s EEZ, some protection of the adjacent shelf edge and protection of areas where coral records have been detected.

 

Description of the location

EBSA Region

South-Eastern Atlantic

 

Description of location

The Childs Bank area is located approximately 190 nautical miles off Hondeklipbaai on the west coast of South Africa and lies entirely within national jurisdiction.

 

Geo-Location

SEA_37_EBSA.geojson

 

Area Details

Feature description of the area

Childs Bank is a unique offshore submarine bank habitat type within South Africa’s EEZ, defined as the Southern Benguela Submarine Bank (Sink et al., 2012a). No other known submarine banks occur within South Africa’s EEZ. The Childs Bank area also includes four other benthic habitats: the Southern Benguela Hard Outer Shelf, Hard Shelf Edge, Sandy Outer Shelf and Shelf Edge (Sink et al., 2012a, figure 5). Two areas of Southern Benguela Hard Shelf Edge habitat at the shelf edge adjacent to Childs Bank are defined as Critically Endangered (Sink et al., 2012a). A further two habitat types within the area, the Southern Benguela Hard Shelf Edge and Sandy Shelf Edge, are defined as Vulnerable (Sink et al., 2012a). 37% of the Childs Bank slopes (Southern Benguela Submarine Bank habitat) are trawled, yet there’s high potential for areas of Childs Bank to be considered vulnerable marine ecosystems (VMEs; Sink et al., 2012b). In addition to hydrocorals (e.g. Stylaster sp.) in the area, three species indicative of VMEs (cold-water coral fragments, gorgonians (Acbaria rubra) and glass sponges (Rosella Antarctica)), were sampled at a virtually untrawled site adjacent to Childs Bank (Atkinson 2010; see also Gilchrist 1922, 1925, Van Bonde 1928, Atkinson et al., 2011). Further, skippers and deck hands from the trawl industry report fragments of corals sometimes caught in isolated locations in this area and that there are several patches of hard ground, requiring additional footrope protection (e.g., bobbins and rockhopper gear, Sink et al., 2012b).

The shelf edge area adjacent to Childs Bank is also a biodiversity hotspot for demersal fish and cephalopods in the southern Benguela (Kirkman et al., 2013). Benthic communities sampled adjacent to the Childs Bank mound revealed high abundance and biomass of benthic infauna and epifauna (Atkinson 2010, Atkinson et al., 2011), indicating that a rich benthic fauna occurs in this region. Two species of burrowing urchins (Spatangus capensis and Brissopsis lyrifera capensis) and a burrowing anemone species (Actinauge granulosus) were detected in high abundances in the Childs Bank region, contributing to the bioturbation and oxygenation of sediment, important ecological functions.

 

Feature conditions and future outlook of the proposed area

Childs Bank is currently in Good ecosystem condition, based on cumulative impact scores (Sink et al., 2012a). Good-condition sites are those which, based on the low levels of pressure, are expected have both biodiversity pattern and process largely intact and hence can be considered to be in a largely "natural" or "pristine" state. However, the area south and towards the shelf edge of Childs Bank were categorized as Fair and Poor, indicating that there is some impact on biodiversity pattern and/or ecological processes in a small component of the broader area (Sink et al., 2012a, Figure 40).

 

The trawl fishing intensity in the northern region of the fishing grounds, including Childs Bank, has declined since the mid-1990s (Russell Hall, Sea Harvest pers. comm.), and it is unlikely that this region was as intensively fished as the western grounds, closer to the port of Cape Town. No trawling occurs on the top of the bank, with most fishing taking place around the slope where hard ground, supporting vulnerable habitat-forming species, is most likely to occur. There is scope to protect this feature with limited, if any, adverse impact on the fishery (Sink et al., 2012b).

 

References

Atkinson, L.J. 2010. Effects of demersal trawling on marine infaunal, epifaunal and fish assemblages: studies in the southern Benguela and Oslofjord. PhD dissertation, University of Cape Town pp. 141.

Atkinson, L.J., Field, J.G., Hutchings, L. 2011. Effects of demersal trawling along the west coast of southern Africa: multivariate analysis of benthic assemblages. Marine Ecology Progress Series: 430:241- 244. doi:10.3354/meps08956.

Camhi, M.D., Valenti, S.V., Fordham, S.V., Fowler, S.L. and Gibson, C. 2009. The Conservation Status of Pelagic Sharks and Rays: Report of the IUCN Shark Specialist Group Pelagic Shark Red List Workshop. IUCN Species Survival Commission Shark Specialist Group. Newbury, UK. x + 78 p.

Birch GF and Rogers J. 1973. Nature of the sea floor between Luderitz and Port Elizabeth. South African Shipping News and Fishing Industry Review 18(7): 1-7.

FAO. 2006. Management of Demersal Fisheries Resources of the Southern Indian Ocean. FAO Fisheries Circular No. 1020 FAO Rome 2006.

FAO. 2009. Annex F of the Report of the Technical Consultation on International Guidelines for the Management of Deepsea Fisheries in the High Seas. Rome, 4–8 February and 25-29 August 2008.

Gilchrist, J.D.F. 1925. List of fishes, etc., procured. Annexure A in Report of the Fisheries and Marine Biological Survey for the period June, 1923 – June, 1925 4: xxiii-xliii.

Kirkman SP, Yemane D, Kathena J, Mafwila S, Nsiangango S, Samaai T, Axelsen B, Singh L. 2013. Identifying and characterizing of demersal biodiversity hotspots in the BCLME: Relevance in the light of global changes. ICES Journal of Marine Science: 70, 943–954.

Lagabrielle E. 2009. Preliminary report: National Pelagic Bioregionalisation of South Africa. Cape Town: South African National Biodiversity Institute.

Majiedt P, Holness S, Sink K, Oosthuizen A, Chadwick P. 2013. Systematic Marine Biodiversity Plan for the West Coast of South Africa. South African National Biodiversity Institute, Cape Town.

Rogers A.D., Clark M.R, Hall-Spencer K.M and Gjerde K.M. 2008. The Science behind the Guidelines: A Scientific Guide to the FAO Draft International Guidelines (December 2007) For the Management of Deep-Sea Fisheries in the High Seas and Examples of How the Guidelines May Be Practically Implemented. IUCN, Switzerland.

Sink KJ, Attwood CG, Lombard AT, Grantham H, Leslie R, Samaai T, Kerwath S, Majiedt P, Fairweather T, Hutchings L, van der Lingen C, Atkinson LJ, Wilkinson S, Holness S, Wolf T. 2011. Spatial planning to identify focus areas for offshore biodiversity protection in South Africa. Unpublished Report. Cape Town: South African National Biodiversity Institute.

Sink K, Holness S, Harris L, Majiedt P, Atkinson L, Robinson T, Kirkman S, Hutchings L, Leslie R, Lamberth S, Kerwath S, von der Heyden S, Lombard A, Attwood C, Branch G, Fairweather T, Taljaard S, Weerts S, Cowley P, Awad A, Halpern B, Grantham H, Wolf T. 2012a. National Biodiversity Assessment 2011b: Technical Report. Volume 4: Marine and Coastal Component. South African National Biodiversity Institute, Pretoria.

Sink KJ, Wilkinson S, Atkinson LJ, Sims PF, Leslie RW, Attwood CG. 2012b. The potential impacts of South Africa’s demersal hake trawl fishery on benthic habitats: historical perspectives, spatial analyses, current review and potential management actions. Unpublished report. Cape Town: South African National Biodiversity Institute.

 

Other relevant website address or attached documents

SEA_37_EBSA-GIS shapefile.zip (/api/v2013/documents/5CA36870-999C-C5C3-760C-3790605A11F5/attachments/SEA_37_EBSA-GIS%20shapefile.zip)

 

Status of submission

Areas described as meeting EBSA criteria that were considered by the Conference of the Parties

 

COP Decision

dec-COP-12-DEC-22

 

Assessment of the area against CBD EBSA criteria

C1: Uniqueness or rarity High

Justification

The Childs Bank submarine mound is the only such feature known to occur within South Africa’s EEZ and therefore represents a highly unique feature in this region (Sink et al., 2011, Sink et al., 2012, Majiedt et al., 2013). The selection of this area in a systematic biodiversity plan for the South African west coast is driven by the uniqueness of the site and reduced cost values (few anthropogenic pressures) in the area (Majiedt et al., 2013).

C2: Special importance for life-history stages of species Low

Justification

There is no evidence to suggest that the Childs Bank area is of special importance for life history stages of particular species or populations; however, the habitat type is a unique feature within South Africa’s EEZ, and it is possible it may support key ecological processes that are, as yet, unstudied (Sink et al., 2011). Tuna fishers report that this area is a feeding area for tuna (Sink et al., 2011).

C3: Importance for threatened, endangered or declining species and/or habitats Medium

Justification

There are some threatened habitat types in Childs Bank and surrounds: Southern Benguela Hard Shelf Edge (Critically Endangered), Southern Benguela hard outer shelf (Vulnerable) and Southern Benguela sandy shelf edge (Vulnerable; Sink et al., 2012a). This area also has some importance for declining species. Some long-lived pelagic species (e.g., blue shark (IUCN Near Threatened) and mako shark (IUCN vulnerable)) are also caught in fair numbers (~15% of total Atlantic catch) around Childs Bank (DAFF Linefish Section). Populations of these species are believed to be in global decline (Camhi et al., 2009).

C4: Vulnerability, fragility, sensitivity, or slow recovery High

Justification

This area has hard ground habitats on the outer shelf and shelf edge that are considered sensitive to demersal trawling and mining (FAO 2006, FAO 2009, Rogers et al., 2008, Sink et al., 2011, 2012a, 2012b). Samples of cold-water corals, sponges and gorgonians have been reported from this area (Gilchrist 1922, Von Bonde 1928 and Atkinson 2010, 2011) and more recently, skippers and deck hands from commercial trawl vessels have indicated occurrences of such species in their nets when fishing in this area (Sink et al., 2012b).

C5: Biological productivity Low

Justification

Fine-scale variability within this area has not been examined but this area falls within the highly productive shelf area of the Benguela upwelling region (Lagabrielle 2009, Sink et al., 2011).

C6: Biological diversity Medium

Justification

This area is considered to host high levels of biodiversity (e.g., infauna and epifauna – Atkinson 2010, Atkinson et al., 2011, demersal fish and cephalopod – Kirkman et al., 2013) and likely vulnerable marine ecosystems that support habitat-forming species, associated with high biodiversity.

C7: Naturalness High

Justification

Childs Bank is in “Good” ecosystem condition, based on cumulative impact scores (Sink et al., 2012a) suggesting that, based on the low levels of pressure, the site is expected have both biodiversity pattern and process largely intact and hence can be considered to be in a largely "natural" or "pristine" state.

[Top]

Files you can download
Sort by: Name Date Size
Childs-Bank (17.2 kB)