Benthic Habitat Survey Report

Impacted Coral Could be Successfully Translocated From Pier Site

Grand Cayman, Cayman Islands (22 September, 2015) The Benthic Habit Survey Report commissioned on behalf of the Cayman Islands Government to examine marine habitats within the proposed cruise piers dredging footprint estimates that a significant proportion of the impacted coral could be successfully translocated.

Marine Environmental Consultants CSA Ocean Sciences Inc (CSA) which undertook the seabed survey found that within the 32.5 acre (131,523 m2) area of impact, the coral-supporting habitats amounted to a total of 11.2 acres (45,350 m2) and comprised of approximately 4.3 acres (17,560 m2) of hard bottom with sand veneer habitat and 6.9 acres (27,790 m2) of exposed reef formation habitat.

Based on the Consultants calculations, 391,001 hard corals and 61,291 soft corals were estimated to be at risk from the dredging and land reclamation activities. Of these, the report states that more than 116,800 hard corals and over 17,000 soft corals could be successfully translocated. The remaining corals were deemed to be relatively young specimens and unsuitable for translocation due to their small size.

Tourism Minister Moses Kirkconnell stated that the Ministry commissioned the report to get a clearer understanding of the composition of the seabed within the dredging footprint. “The Ministry takes seriously the environmental concerns associated to the proposed development of the piers and commissioned the Benthic Habitat survey to look more closely at the area to eliminate any data or analysis gaps. This survey is both necessary and timely, particularly in light of the differing views and opinions about precisely what exists within the area of impact and how it could potentially be affected if the project proceeded?”
Minister Kirkconnell further explained that while the EIA conducted by Baird stands as is, this supplemental report is like looking at the area through a magnifying glass. “This is the largest project ever being considered for our Islands and government has a responsibility and duty of care to ensure that our collective decision is based on sound scientific evidence, not speculation or impassioned pleas, however well intended those might be. When Cabinet convenes to make its decision on the cruise piers it must be able to do so with full confidence that all of the relevant facts and information have been sourced and objectively presented for consideration. Additionally, proposed mitigation solutions will also have to satisfactorily demonstrate the likelihood of successful outcome, again based on objective data and evidence.”

In the Benthic Survey Report ‘In-kind’ and ‘out-of-kind’ mitigation options are proposed as possible solutions to address impacted coral. In simple terms, in-kind mitigation is the creation of a habitat type similar to that which is impacted by an activity, whereas out-of-kind mitigation is the creation of a habitat that is different to the original environment. The report states that mitigation options which include coral translocation and the establishment of coral nurseries were considered by CSA to be suitable for the George Town Harbour Berthing Project. “Coral translocation, if done properly, can significantly reduce the loss of coral tissue and the ecological services provided by corals,” the report states.

CSA began doing coral reattachment during the infancy of this technique and have been instrumental in refining reattachment procedures. Their opinion is based on their extensive experience in coral reattachment and field-tested applications for reattaching coral, soft coral, and large structural sponges as a means of accelerating habitat recovery.

The survey notes that the Company has conducted coral reattachment on more than 60 programs worldwide, some of which were monitored by the U.S. National Oceanographic and Atmospheric Administration (NOAA), National Coral Reef Institute (NCRI), and Florida Marine Research Institute, to determine the relative success of the coral reattachment technique.

In one example in the Florida Keys, an independent third party reported 100% survivorship and coral colony stability 2 years following the restoration. Another example cites 1,000 coral colonies which were temporarily cached due to construction and reattached to a submerged structure. According to the National Coral Reef Institute, monitoring of the coral stability and health at the reattachment site over a 3-year period showed a 97% success rate.

Commenting on the time government has invested in data gathering, Councillor for Tourism Joey Hew stated “Those for and against the project are understandably keen to know what Governments ultimate decision will be and therefore the time taken to source expert advice and scientific data is proving to be a cause of frustration to some. However, I believe that the majority of our people prefer that this important and necessary process is carried out thoroughly and are supportive of the steps being taken, particularly as all of this intellectual property belongs to the Country.”

The Benthic Habit Survey Report is currently being assessed by Government officials in the Ministry of Tourism and the Department of Environment and is being posted to the Ministry’s website for public review.
The following and all attached images has been taken from the Benthic Habitat Characterization Survey report

Introduction

CSA Ocean Sciences Inc. (CSA) was contracted by West Indian Marine Group (WIM) and their respective client, the Cayman Islands Government, to conduct a Benthic Habitat Characterization Survey, which consists of ecological and geophysical surveys in support of a proposed dredging and land reclamation program for cruise berthing facilities in George Town Harbor—the George Town Harbor berthing program. The berthing program is considered to have both direct and indirect impacts on the marine habitats within George Town Harbor. The direct impact area of the George Town Harbor berthing program is projected to be approximately 32.5 acres (ac) (131,523 m2) shown in Figure 1 (W.F. Baird & Associates Coastal Engineers Ltd. [Baird], 2015).

CSA’s Benthic Habitat Characterization Survey, which focused on the direct impact area within the proposed footprint of George Town Harbor berthing program, was conducted to meet the following objectives:

• Delineate seafloor habitats;
• Characterize seafloor habitats;
• Quantify hard and soft corals within the projected direct impact area; and
• Assess potential options to mitigate impacts.

In meeting these stated objectives, the survey primarily focused on characterizing the coral-supporting habitats within the study area. This report provides the methods and results for the Benthic Habitat Characterization Survey conducted from 27 to 30 June 2015 as well as descriptions of various
field-tested options that could be considered for mitigation of impacts from the program.

2 Methods

The Benthic Habitat Characterization Survey included ecological and geophysical survey activities that were concurrently conducted within George Town Harbor specific to the berthing program’s projected direct impact area. In the ecological survey, scientific divers collected visual, photographic, and in situ data for delineating and characterizing seafloor habitats. The geophysical survey was conducted to collect side-scan sonar data to delineate and characterize seafloor substrates based on interpretation of acoustic signatures associated with relative sediment consolidation and topographic relief.

2.1 NAVIGATION AND SURVEY VESSELS

The ecological survey used a Garmin global positioning system (GPS) receiver for positioning and WIM’s Booby Cay, a 30-ft utility vessel, with suitable deck space for conducting safe diving operations.

The geophysical survey used a GPS receiver interfaced with Hypack navigation and data acquisition software for positioning and WIM’s Barker Cay, another 30-ft utility vessel, for remote sensing tow system operations.

2.2 ECOLOGICAL SURVEY

2.2.1 Ground Truthing

AAUS-certified scientific divers1 conducted bounce dives at various locations within the berthing program’s direct impact area to ground truth habitat mapping in the Draft Environmental Statement for the Proposed Cruise Berthing Facility, Grand Cayman (Draft ES) (Baird, 2015). Bounce dives
were conducted throughout the area projected to be directly impacted by berthing program operations. Visual observations and video photography were collected to document the habitat type at each
ground-truth location.

2.2.2 Habitat Characterization Transects

Benthic habitat characterization transects were conducted by scientific divers within the projected direct impact area that were interpreted as spur and groove and mixed patch reef habitats (Baird,
2015). At each sampling location, four parallel 10 m × 1 m transects were established to document habitat type, estimate percent coverage of substrates and biota, identify coral taxa, and quantify corals (hard and soft). The four parallel 10-m transects were positioned approximately 3 m apart and defined using survey lead lines. Data collected in situ along each transect included point-intercept counts, quantification quadrats, and qualitative/quantitative video. Point-intercept identifies and counts substrate and biota that are traversed by the transect lead line. The 10-m lead line is demarcated at
10 cm intervals. The substrate type (sand, rubble, and rock) or biological taxa (lowest practical taxonomic level) was identified at each 10-cm demarcation; 100 points were assessed along each transect.

Quantification quadrats were used to determine hard coral taxa, size classifications, and density; soft coral type (sea plume, sea rod, sea whip, and sea fan), size classifications, and density were also determined within each quadrat. These data were collected within 0.5 m × 0.5 m quadrats along the full length of the 10-m transects abutting both the right and left side of the lead line. A total of
40 quantification quadrats were established for each 10-m transect; 20 quadrats along the right and left sides of the lead line. Corals present within the quadrat were counted, identified, and roughly measured to determine size classification (40 cm). To avoid count redundancy, corals traversed by the lead line (portion of the colony to the right and left) were counted only within quadrats along the right side of the lead line. Corals that extended outside and forward of the quadrat (into the boundary of the subsequent quadrat) were counted only once.

Video data were collected by scientific divers along each transect with the lead line in the video’s field of view. To collect quantitative data, a video camera and housing were maintained at a constant height of approximately 50 cm above the substrate, held perpendicular to the substrate, and slowly moved along the length of the transect. A Go-Pro high-definition digital video camera was mounted on the quantitative video camera housing and oriented at an oblique angle relative to the substrate to simultaneously collect qualitative data.

2.3 GEOPHYSICAL SURVEY

A Klein 3900 system was used to collect side-scan sonar data within the proposed footprint of George Town Harbor berthing program. The 3900 system is an extremely high-resolution digital sonar that provides excellent range and resolution. The system includes a towfish transceiver processing unit (TPU), custom-configured laptop, and 50 m of lightweight tow cable. The TPU was towed along
pre-plotted survey lines to provide complete coverage within the survey area.

Side-scan sonar uses sound to obtain distance and reflective characteristics of bottom features, providing images that look like photographs. Side-scan sonar data provide the general location and morphology of bottom features, including hard- (Image 1) and soft bottom substrates (Image 2). Imaging the seafloor with side-scan sonar is accomplished by towing over the study area a side-scan instrument (towfish) equipped with a linear array of transducers that emit, and later receive, an acoustic pulse at a specific frequency range. The acoustic pulse is designed to be wide in the across-track direction and narrow in the along-track direction, as depicted by the bright yellow fan-shaped area in Figure 2.

The reflected acoustic energy received by the side-scan sonar tow vehicle provides information on the general distribution and characteristics of the surficial sediment and outcropping strata. In general, if all other parameters are constant, consolidated substrates and rougher surfaces (e.g. hard bottom) will backscatter more energy than unconsolidated substrates and smoother surfaces and, therefore, return higher amplitude signals. The resultant side-scan sonar images can be put together as a mosaic
(i.e., georeferenced composite) that represents the acoustic characteristic of the seafloor, which can be interpreted to determine various substrate types and features.

1 All CSA divers are certified in SCUBA by internationally recognized organizations, trained as specialty divers for using enriched air (Nitrox), and are American Academy of Underwater Sciences (AAUS) certified Scientific Divers. Additionally, all divers are formally trained in cardiopulmonary resuscitation (CPR) and first aid and all CSA dive operations are conducted in a manner consistent with Association of Diving Contractors (ADC) standards, Occupational Safety and Health Administration [OSHA], U.S. Army Corps of Engineers [USACE], and U.S. Coast Guard regulations. CSA is covered by Marine Employer’s Liability Insurance, which includes Diving Workman’s Compensation, General Marine Liability (including Completed Operations), Jones Act, and U.S. Longshoreman & Harbors. CSA is a member of the ADC.

3.3.1 At-Risk Coral Resources

To estimate the amount of coral-supporting habitat directly impacted by the berthing program, the delineated aerial coverage of consolidated substrates based on interpretation of side-scan sonar and visual data (i.e., ground-truth locations) was integrated with the George Town Harbor berthing program direct impact area (Baird, 2015) using ArcMap software (Figure 6). The total direct impact area of the berthing program is 32.5 ac (131,523 m2). The total area for coral-supporting habitats (symbolized with purple cross-hatch in Figure 6) inside the boundary of the direct impact area is 11.2 ac (45,350 m2). The 11.2 ac of coral-supporting habitat is estimated to comprise approximately 4.3 ac (17,560 m2) of hard bottom with sand veneer habitat and 6.9 ac (27,790 m2) of exposed reef formation habitat. The remaining portion of the direct impact area is considered to be unconsolidated sediment (i.e., sand, shell hash, and gravel).

Hard bottom with sand veneer habitat (shown with blue dots in Figure 6) was generally characterized by relatively level topography and limited epibiotic development (Image 10). Coral densities for the hard bottom with sand veneer habitat ranged from less than 1 to 8 colonies m-2 of hard corals and
from 0 to 4.1 colonies m-2 of soft corals. The hard bottom with sand veneer habitat was dominated by
smaller corals with more than 85% of the hard corals measuring less than 10 cm and more than 80% of the soft corals measuring less than 25 cm. The dominance of small corals coupled with low coral density would make coral translocation very laborious in this habitat type.

Exposed reef formation habitat (shown in yellow dots in Figure 6) had irregular and relatively high topographic relief that supported a productive epibenthic community with 22 observed hard coral taxa (Image 11). Coral densities for the exposed reef formation habitat ranged from 7.6 to 15.2
colonies m-2 of hard corals and from 0.1 to 5.3 colonies m-2 of soft corals. Although the exposed reef formation habitat was dominated by smaller corals, with 34.2% of hard corals greater than 10 cm and considerable populations of larger soft corals (>25 cm in height) suitable for translocation, the coral community characteristics of this habitat would facilitate efficient and productive coral translocation
efforts.

The coral resources at risk from the direct impact from dredging and land reclamation activities for
the cruise berthing facility within George Town Harbor includes an estimated 391,001 hard corals and
61,291 soft corals. These estimates are based on calculations of average densities of hard and soft corals from each coral-supporting habitat. Of the 391,001 hard corals at risk, more than 274,000 are less than 10 cm in diameter and relatively young specimens. Similarly, of the 61,291 at-risk soft corals, more than 44,200 are less than 25 cm in height and relatively young specimens. Subsequently, the estimated number of hard corals (>10 cm in diameter) and soft corals (>25 cm in height) that could be considered for translocation is over 116,800 and over 17,000, respectively.

Some apparent differences can be seen between habitat delineation based on ground truthing and the interpretation of side-scan sonar data used to map the distribution of consolidated and unconsolidated substrates (Figure 6). These differences emerge because the surveys are conducted at different levels of spatial resolution on a rather heterogeneous landscape. For example, small sand patches present in a landscape dominated by coral-supporting hard bottom may be observed during dive operations but may not be discernable from side-scan sonar imagery. Thus, the randomly selected ground-truthed habitat classification points may have occurred in an area mapped as coral-supporting habitat based on the more generalized sonar classification.

4 Mitigation Options

Possible options to address impacts to coral resources include both in-kind and out-of-kind mitigation. In-kind mitigation is the creation, restoration, or enhancement of a habitat type similar to the habitat that is adversely impacted by an activity. Likewise, out-of-kind mitigation is the creation, restoration, or enhancement of a habitat type different than the habitat that is adversely impacted by an activity. The mitigation options, as prepared, are not comprehensive but reflect our experience and best professional judgment regarding field-tested methods for mitigation of natural resource damages.
CSA considers these mitigation options as possibly suitable for application to the George Town Harbor berthing project.

Coral translocation would probably be the primary mitigation option for the reducing impacts associated with the berthing project. Coral translocation, if done properly, can significantly reduce the loss of coral tissue and the ecological services provided by corals. CSA began doing coral reattachment during the infancy of this technique and procedural development. Senior marine specialists at CSA have been instrumental in refining reattachment procedures and have field-tested applications for reattachment of coral, soft coral, and large structural sponges as a means of accelerating habitat recovery.

CSA has conducted coral reattachment on more than 60 programs associated with marine construction, ship groundings, anchor damage, and habitat enhancement worldwide. The scale of these programs is quite variable, ranging from relatively few corals to many thousands. A recent Caribbean program involved reattaching more than 20,000 corals using hundreds of tons of cement (Images 12a and 12b). Some of these programs were monitored by an outside party to determine the
relative success of the coral reattachment technique using cement. Outside parties that have monitored CSA coral reattachment programs include the U.S. National Oceanographic and Atmospheric Administration (NOAA), National Coral Reef Institute (NCRI), and Florida Marine Research Institute. CSA coral reattachment has been proven to be very successful, and monitoring reports assessing the relative success of these programs are summarized here.

• A ship grounding program completed by CSA monitored by an independent third party reported
100% survivorship and coral colony stability 2 years following restoration in the Florida Keys National Marine Sanctuary (FKNMS). The program included coral reattachment, reef structural repair, and placement of artificial reef structure (Franklin et. al., 2005).

• CSA reattached more than 400 corals in restoration modules in the southern portion of the FKNMS. Monitoring of the site 3 years after the restoration found all modules were stable with elevated coral coverage due to growth of reattached corals (Schittone et. al., 2006).

• More than 1,000 coral colonies were removed from an offshore construction site in Broward County, Florida, temporarily cached for the construction period, and reattached to a submerged structure following construction activities. Monitoring of the coral stability and health was conducted at the reattachment site over a 3-year period and showed a 97% success rate (National Coral Reef Institute, 2004).

Outside monitoring that verifies successful reattachment and coral survivorship is the only science-based means to establish credibility in providing these types of services. All of CSA’s reattachment programs use experienced AAUS-certified scientific divers with similar field-tested techniques using cement as the primary bonding agent. The monitoring results, as presented for relatively small programs, expresses the expected relative success for CSA coral reattachment/translocation regardless of the scale of the program.

4.1 CORAL TRANSLOCATION

Coral translocation may significantly accelerate both the expansion of coral habitat and recovery of existing, impacted areas. The objective and primary benefit of coral translocation is to reduce or minimize potential impacts to these resources as a result of a particular activity (Images 13a and
13b). The procedures for coral translocation as a feasible mitigation option to be considered for
Cayman resources are addressed in this section.

Site Reconnaissance Surveys should be conducted at both the coral donor site (i.e., berthing project direct impact footprint) and recipient (i.e., translocation) site(s). Based on the results of the CSA Benthic Habitat Characterization Survey there may be adequate baseline information specific to the George Town Harbor berthing project coral assemblage. However, if any aspect of the current data is considered inadequate after further review an assessment would be conducted to augment the existing data concerning 1) delineation of specific coral colony collection areas within the donor site,
2) estimation of coral abundances, and 3) characterization of coral community species composition and size-classes, in particular coral listed under the endangered species act. A very important consideration for successful coral translocation is proper recipient site selection. The parameters used to confirm the suitability of the recipient site for coral reattachment include 1) similarity to the donor site concerning oceanographic conditions (e.g. water quality) and water depth, 2) adequate space for transplants, 3) distance from donor site, and 4) proximity to future development.

Collection and Transport would be conducted following the reconnaissance surveys and identification and/or establishment of suitable recipient site(s). Coral colonies would be collected “in-whole” representing all taxa present within the donor site. In lieu of collecting all corals present, the colonies selected for translocation would be prioritized based on relative health and size to provide representative specimens of all species present at the donor site. The relative abundance (i.e., proportional distribution) of the various coral species selected for translocation would be similar to their occurrence at the donor site (Image 14).

Prior to transport, selected coral colonies would be removed from the point of attachment. If conditions precluded immediate translocation of the dislodged corals, they can be stabilized and properly cached pending transport to the donor site. Corals properly cached can remain viable for transportation for over 2 months, barring any extreme oceanographic events.

The coral transport method will depend primarily on the how long it takes to get from the donor site to the recipient site(s) and the number of corals being relocated from the donor site. The coral transport options are the “containerized-cover” method and the “pool-system” method. The “containerized-cover” method involves placing and securing the coral colonies in a suitable container and covering the corals with seawater-dampened sheets. The “pool system” method involves the containerization of coral colonies and placement in a continuous fresh seawater flow-through pool. This “pool system” method was designed and previously used by CSA and was used for a long- distance transport (duration over 2 hours and a distance of over 45 km) for large numbers of coral colonies.

Reattachment of the corals would be conducted immediately after transport and deployment of the specimens at the recipient site(s). Reattachment locations should be selected ensuring a spatial distribution of the reattached corals that is similar to natural conditions of the selected recipient site(s) coral habitat. Following selection and preparation of attachment sites, a concrete mixture would be prepared and applied to the reattachment surfaces. Reattached corals would be checked intermittently during reattachment operations to ensure their stability and the aesthetic quality of the reattachment matrix.