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Institute for Coastal and Marine Research

 

EBSA overview  |  Delineation |  Proposed description

 

 

EBSA overview

The recent discovery of important benthic features that were partially represented in the Offshore of Port Elizabeth EBSA prompted that EBSA to be split into two, with Secret Reef, Kingklip Ridge and Kingklip Koppies EBSA better representing the new features. Secret Reef is a newly discovered biogenic coral reef structure that is outside of the trawl footprint on the shelf edge of the South African south coast. Notably, it contains dense communities of fragile and sensitive coral and bryozoan species. Such features are relatively rare in the area. Secret Reef links to the Kingklip Ridge and Kingklip Koppies, offshore of St Francis Bay. These are a newly discovered unique rocky ridge and undersea hills (koppies in Afrikaans) that support fragile corals and are covered by dense clouds of plankton and hake. Three of the five ecosystem types represented in the EBSA are threatened, including the Endangered Kingklip Ridge and Vulnerable Kingklip Koppies and Agulhas Coarse Sediment Shelf Edge ecosystem types. Further research is encouraged for this site.

 

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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.

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Proposed EBSA description

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

Summary

The recent discovery of important benthic features that were partially represented in the Offshore of Port Elizabeth EBSA prompted that EBSA to be split into two, with Secret Reef, Kingklip Ridge and Kingklip Koppies EBSA better representing the new features. Secret Reef is a newly discovered biogenic coral reef structure that is outside of the trawl footprint on the shelf edge of the South African south coast. Notably, it contains dense communities of fragile and sensitive coral and bryozoan species. Such features are relatively rare in the area. Secret Reef links to the Kingklip Ridge and Kingklip Koppies, offshore of St Francis Bay. These are a newly discovered unique rocky ridge and undersea hills (koppies in Afrikaans) that support fragile corals and are covered by dense clouds of plankton and hake. Three of the five ecosystem types represented in the EBSA are threatened, including the Endangered Kingklip Ridge and Vulnerable Kingklip Koppies and Agulhas Coarse Sediment Shelf Edge ecosystem types. Further research is encouraged for this site.

 

Introduction

An interesting feature was recently discovered inside the Offshore of Port Elizabeth EBSA: a unique rocky ridge protruding out of the upper slope that supports corals and is covered by dense clouds of plankton and hake (Sink 2016). Adjacent to the ridge is a series of rocky koppies (Afrikaans for ‘hills’). A little further west, also on the shelf edge and upper slope of the South African south coast, is Secret Reef. This is a newly discovered biogenic coral reef structure that supports fragile and sensitive corals and byrozoans. Given that these special benthic features appear to be connected along the shelf edge and upper slope, it prompted a split in the Offshore of Port Elizabeth EBSA into Algoa to Amathole, which comprises the bulk of the original EBSA, and this EBSA: Secret Reef, Kingklip Ridge and Kingklip Koppies. This allowed for a better delineation of an EBSA that more accurately reflected the underlying features, which in this case are largely benthic features.

 

Given its position on the shelf edge and upper slope, despite being a relatively small EBSA (approximately 23 km x 233 km), it spans a broad depth range of -150 to -1000 m. It comprises five ecosystem types, three of which are threatened, including an Endangered type. This area is also an important place in which to meet biodiversity targets because it had high selection frequency in a national systematic conservation plan (Sink et al., 2011; SANBI unpublished results in analysis for Madjiedt et al., 2013).

 

The reason this area was not fully included in the original Offshore of Port Elizabeth EBSA is because the constituent features were not yet discovered, and thus the information was not available at the Southern Indian Ocean Regional Workshop to Facilitate the Description of Ecologically or Biologically Significant Marine Areas (UNEP/CBD/RW/EBSA/SIO/1/4) in 2013. It is presented as a Type 2 EBSA because it contains “spatially stable features whose individual positions are known, but a number of individual cases are being grouped” (sensu Johnson et al., 2018).

 

Description of the location

EBSA Region

Southern Indian Ocean

 

Location

Secret Reef lies on the Grue Bank, about 100 km offshore of Knysna, approximately half way along the South African south coast in the Agulhas Current. The EBSA spans from here to offshore of the middle of St Francis Bay, along the shelf edge and a little down the slope. The EBSA falls entirely within South Africa’s EEZ.

 

Feature description of the proposed area

Kingklip ridge rises like a wall on the upper slope, offshore of Cape St Francis. It has dimensions of 530 m wide and about 40 km long, running parallel to the shelf edge on the slope that goes from ‑200 m to -600 m and deeper (Sink 2016). At the crest and edges of the northern end of the ridge, at approximately -350 m, are reef-forming scleratinean corals (Sink 2016). Above the ridge are dense clouds of plankton and hake, and demersal trawlers reportedly use this feature against which they herd fish (Sink 2016). The Kingklip koppies, west of the ridge, are rocky hills that also support fragile benthic species. Even further west, Secret Reef is a newly discovered biogenic coral reef structure on the shelf edge and upper bathyal area (Sink 2016). It includes threatened benthic habitats and fragile, sensitive, vulnerable species, such as: scleractinian corals, stylasterine corals, bryozoans, molluscs, and crabs that have been sampled in this area (Sink 2016). Given the connections among these similar benthic features, they were delineated as a single EBSA. Thus, the EBSA is most important for benthic features, although the overlying water column is also relevant.

 

The ecosystem types represented in the EBSA include the Endangered Kingklip Ridge, Vulnerable Agulhas Coarse Sediment Shelf Edge and Kingklip Koppies, and Least Concern Agulhas Rocky Shelf Edge, and Southwest Indian Upper Slope (Sink et al., 2019). Because these features are so recently discovered, there is very little information available about them, other than the data that were collected on the cruise when they were found (Sink 2016). These data include single-beam echo sounder depth transects, in situ samples, and ROV footage (Sink 2016).

 

Feature condition and future outlook of the proposed area

Ecological condition is estimated in South Africa by assessing cumulative pressures to the marine environment (Sink et al., 2012, 2019). Ecological condition is poor in the northern and eastern portions of the EBSA (over Kingklip Ridge and the easternmost Kingklip Koppies), and moderate to mostly good in the south west corner (over Secret Reef; Sink et al., 2019). The primary pressures in the area are from fishing for large pelagic fish, and demersal and pelagic sharks, with some influence from shipping and other fishing industries to a lesser degree. Secret Reef itself is outside of the trawl footprint so the site is high in live coral cover (Sink 2016). However, all of the reef-building coral observed on the Kingklip Ridge was broken, with evidence of both recent and older damage. This is presumed to be the result of trawling damage to the reef (Sink 2016). Research was recently conducted in the area as part of a larger programme to survey South Africa’s marine environment (Sink 2016). No future research is currently planned, although it has been strongly recommended (Sink 2016).

 

References

Johnson, D.E., Barrio Froján, C., Turner, P.J., Weaver, P., Gunn, V., Dunn, D.C., Halpin, P., Bax, N.J., Dunstan, P.K., 2018. Reviewing the EBSA process: Improving on success. Marine Policy 88, 75-85.

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.

Sink, K. 2016. Deep Secrets: the outer shelf and slope ecosystems of South Africa. Cruise Report: ALG 230 – ACEP_DSC.

Sink, K.J., Attwood, C.G., Lombard, A.T., Grantham, H., Leslie, R., Samaai, T., Kerwath, S., Majiedt, P., Fairweather, T., Hutchings, L., van der Lingen, C., Atkinson, L.J., 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. 2012. National Biodiversity Assessment 2011: Technical Report. Volume 4: Marine and Coastal Component. South African National Biodiversity Institute, Pretoria.

Sink, K.J., van der Bank, M.G., Majiedt, P.A., Harris, L.R., Atkinson, L., Karenyi, N., Kirkman, S. (eds) 2019 - in prep. National Biodiversity Assessment 2018 Technical Report Volume 4: Marine Realm.  South African National Biodiversity Institute, Pretoria.

 

Status of submission

The Offshore of Port Elizabeth EBSA was recognized as meeting EBSA criteria by the Conference of the Parties. The revised Secret Reef, Kingklip Ridge and Kingklip Koppies EBSA name, description, and boundaries still need to be submitted to COP for approval.

 

COP Decision

dec-COP-12-DEC-22

 

Assessment of the area against CBD EBSA Criteria

C1: Uniqueness or rarity High

Justification

The coral mound comprising Secret Reef is a relatively rare feature in the broader area. It also contains the only known portions of the Kingklip Ridge and Kingklip Koppies ecosystem types, both of which are unique in South Africa.

 

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

Justification

Further research is required to determine if this site supports important life-history stages of species. However, given the uniqueness of the ecosystem types and the dense clouds of plankton and hake above the Kingklip Ridge and Kingklip Koppies, it is presumed that this area is important for species’ life-histories.

 

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

Justification

The site includes three threatened ecosystem types, two of which are found exclusively in the EBSA: Endangered Kingklip Ridge and Vulnerable Kingklip Koppies. It is not yet known whether this site is important for threatened or declining species, and this would require more research in the area. However, it is presumed that the two unique ecosystem types (Kingklip Ridge and Kingklip Koppies) both support threatened species given that the ecosystem types are threatened.

 

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

Justification

Secret Reef is a biogenic coral mound that has fragile scleractinian corals, stylasterine corals, and bryozoans (Sink 2016). Similarly, Kingklip Ridge was observed to contain reef-building scleratinian corals, and Kingklip Koppies contained Thouarella (a primnoid coral), bamboo coral, many mobile invertebrates (Sink 2016). All of these are fragile, sensitive species that are vulnerable to damage, and that take long to recover from impacts.

 

C5: Biological productivity Medium

Justification

There are dense clouds of plankton and hake over Kingklip Ridge (Sink 2016), suggesting high localised productivity at the site. However, time-averaged MODIS Aqua data on chlorophyll concentration (NASA Giovanni Portal: https://giovanni.gsfc.nasa.gov) shows that productivity inside Secret Reef is not higher compared to that of the surrounding area.

 

C6: Biological diversity Medium

Justification

Because Secret Reef is outside of the trawl footprint, reef diversity inside the EBSA is relatively higher than that in the surrounding area (Sink 2016). Further, the relatively small EBSA comprises five ecosystem types that span a depth range of 850 m.

 

C7: Naturalness Medium

Justification

Secret Reef itself is outside of the trawl footprint, so this feature itself is close to pristine and high in live coral cover (Sink 2016). Based on a national assessment of cumulative pressures on the marine environment, the broader EBSA has portions in good and poor ecological condition, with a much smaller area that is moderately modified, (Sink et al., 2019). Thus, overall, the condition is fair.

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