Bream_bbp 2006-004

Report of Norwegian Crown Ship Grounding Thad Murdoch, Jack Ward, Annie Glasspool, Sarah Manuel and Mark Outerbridge 28th June 2006

This report aims to document the location of the June 8th 2006 grounding of the cruise ship Norwegian Crown, describe the site conditions found after the ship was successfully re-floated, and present remediation options and recommendations.

Location: The vessel ran aground on the eastern side of Dundonald Channel near the northern end of the dredged channel. Figure 1 below depicts this grounding site as yellow lines. In this image the channel shows clearly as the dark blue swath running approximately northsouth. The dark brown patches to either side of the channel are live reef surrounded by a shallow sandy seafloor. The grey-blue patches within the sandy zones are seagrass beds. This photograph is part of an aerial photo-mosaic created from images taken in 1997. Figure 1 – Dundonald Channel with grounding site indicated.

Careful examination of this image reveals a gradation from dark to light blue in the background colouration underlying the yellow lines that depict where the ship came to rest. The darker colour to the north represents deeper water. This reflects the fact that the ship travelling south struck a sloping bottom and ran up this slope until cleaving and coming to rest on a substantive patch reef.

Site conditions: The ship hit a shoaling sand bar leaving a clear impact scar in the form of a trench in this soft material for approximately 120m. It encountered and broke a small patch reef in two, displacing half of this reef 40 – 50m prior to striking and coming to rest in contact with a second, larger reef. This second reef was also split in two with the larger portion of the reef remaining in situ but shattered, whilst the smaller portion was pushed forward on the bow until the vessel came to rest. Figure 2 below provides an overview of the impact site whilst Figure 3 illustrates the location in higher detail.

Figure 2(a) – Site map depicting approximate locations of major features (scale is approximate as is location of bathymetric contours)

Figure 2(b) – Close-up site map detailing major features.

Over the entire area there are many soft corals which have become unattached from the substrate, and in close proximity to the actual grounding site much of the hard corals have also been shattered. These reefs were clearly dominated by soft corals and branching hard corals. This is typical of coral reefs living in high sedimentation areas. These silt-tolerant corals had become established on a foundation of massive dome-forming brain corals which may have been killed many years ago from the increased siltation caused when this actively used shipping channel was created. Many of these highly branched corals have been shattered by the cruise ship’s impact and remain as flattened shards of once complex structures. Anecdotal information indicates that this was recently a thriving reef which made a great inshore dive site in the winter. The reef has been dramatically changed with very little live coral remaining. Much of the reef today reveals the underlying structure of ancient coral skeletons. This is very clean calcite substrate presenting a complex threedimensional nature which will probably form good settlement sites for coral recruits. Much sediment was moved during the effort to re-float the vessel and this has inundated some adjacent coral reefs. Figure 3: Ancient Coral Skeletons and Soft Corals Strewn over the Impact Site (A Survey Tape Marks the Mid-line of the Scar)

Extent of the impact: The site was mapped in order to document the area affected by the ship grounding and subsequent recovery effort. A grid was established over the site with the scar made by the ship’s keel forming the baseline. This baseline was extended for 30m beyond the point where the ship’s bow came to rest. At right angles every 10m along this line, 200m transects were surveyed extending 100m to both the west and east. These transects were shortened whenever the line ran out of the area of impact or into the channel. At every 10m along these transects the degree of impact was assessed on a scale of 1-3 and the nature of the substratum (rubble, sand, seagrass or coral) was recorded. Each point sampled was taken to represent the 10m x 10m cell in which it was recorded. Figure 4 presents the results of this survey. Figure 4: Assessment of the extent and severity of the impact on benthic communities.

The most dramatic feature of this site is the remarkable scar left where the ship actually came in contact with the bottom. This is an area of complete destruction. The ship literally ploughed through, leaving a deep furrow and shattered corals. Our estimate of the “scar” or the area destroyed as a direct result of the ship running aground is 1,100m2. Figure 5: The Ship left a Deep Scar in the Sea Floor

Figure 6: Shattered Corals at the Site of Impact

The survey revealed that an additional 3,900m2 was heavily impacted, having clearly been exposed to extreme currents which scoured sand and rubble from the seafloor, bombarding nearby reefs and subsequently settling to smother adjacent reefs and seagrass beds. Amongst the areas further from the source of this blasting action, an additional 2,300 m2 was classified as moderately and 2,900 m2 as lightly impacted. Whilst our methodology classified areas beyond these zones as “no impact”, at many locations within this area we observed clear but scattered evidence that disturbance had occurred. From this analysis we conclude that an area of at least 10,200m2 was impacted as a result of this ship grounding and the subsequent re-floating effort. Of this, 1,100m2 or approximately 10% was completely destroyed by the actual grounding whilst the remaining 90% of the area was impacted to various degrees by the salvage operation. Remediation Options: In jurisdictions where there is clear legislation which holds the owners of ships that run aground liable to fund restoration projects, businesses have developed to perform this service. Whilst full recovery of impacted systems will take time there are several welltested methods to hasten this process. One key variable determining the success of remediation efforts is timely response. In locations where trained labour and legal incentives exist this is often initiated within days of the grounding.

Despite the time which has passed since the Norwegian Crown grounding, live soft corals remain scattered over the area. Many of these could probably be reattached to the remaining reef structure with a fair degree of success. This would improve the habitat for the abundant fishes at this site. This work is labour intensive and a rough estimate of the cost is $25,000. This would provide for a first level of remediation. A full-blown restoration and compensation package for environmental damage as would be required in many jurisdictions could easily be an order of magnitude more expensive than this. Costing of full-service remediation would require a formal RFQ to contractors with expertise in this area. The most likely source of such expertise in this part of the world would be Florida. Figure 7: Some of the Dislodged Soft Corals adjacent to the Impact Site

The results of the survey to assess the extent of biocide contamination of the site are not yet available. However, there is a patch of antifouling paint coating approximately 20 square metres of the sediment the on the west side of the main furrow. This may present a potential for removal of a significant proportion of the biocide contamination of the site. The most effective method of accomplishing this is not known to us. However it does appear that this may be a feasible endeavour. It is proposed that no action be taken on this aspect of the grounding impact until results documenting the extent of contamination have been scrutinized.

Recommendations: It is our recommendation that clear guidelines for responding to ship grounding events be developed. It is proposed that this guidance follow the form of the very effective oil pollution contingency plans. Such an integrated plan is essential to ensure that due consideration is given to; safety, legal responsibility, continuity of essential services, and environmental impacts. Examples of some of the issues that may require consideration include: • A chain of command would need to be established, areas of responsibility would have to be clarified, and callout lists maintained. • If a prosecution aimed at recovering damages were contemplated the site may be considered a Crime Scene which should be secured and appropriately documents with protocols established for chain of custody of evidence, training of first response team, etc. • If remediation of damage to grounding sites is desired, rapid response with funding facilities to contract for this work should be established, etc. In the case of the current grounding event it is clear that a very large proportion of the damage was caused by the re-floating effort. This is common to most ship groundings. However, in this case it is frustrating as it appears that much of this impact was avoidable. Without intent to detract from the fine efforts of the response team who effectively recovered this ship, it is respectfully suggested that the damage could have been dramatically reduced if longer hausers were used to position the tow boats in deep water further from the shoaling water. This would have dramatically reduced the scouring of the seafloor and destruction of coral and seagrass communities. Figure 8: Tugs Attempting to Recover the Ship using Short Tow Lines