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SEI Jetty: Final Report Little Bay Emergency Jetty, Montserrat, West Indies Marine Monitoring and Mitigation Final Report Executive Summary This is the final report on monitoring and mitigation for the Little Bay Jetty in Montserrat. The report describes the nature and extent of the impacts of jetty construction on marine life in the bay. Observed changes in marine life are evaluated in relation to jetty construction and to island-wide ecological processes and patterns. For these latter comparisons, we provided the Institute’s own data from previous and ongoing work in Montserrat. The results or this project are discussed and evaluated in light of the predictions and recommendations of the Environmental Impact Assessment (EIA). This project reflects the efforts of a broad diversity of individuals and groups that began prior to the EIA in 1996. During the EIA process, SEI scientists concluded that the original design and location were unacceptable from an environmental perspective. L. G. Mouchel prepared a new design, and a new location was identified for the jetty to balance environmental concerns and construction requirements. Through the work of SEI scientists, L.G. Mouchel engineers (R. Trevitt), the EMAD/ODA, the Montserrat Environmental Review Panel, the Physical Planning Unit, and the input of private and concerned citizens, a compromise solution was reached. As part of that solution, a monitoring and mitigation program was put forth in the EIA. The ODA, Physical Planning Unit, and L. G. Mouchel agreed in a Memorandum of Agreement to proceed with the jetty, and to include a marine monitoring and mitigation component. The work was carried out independently by SEI scientists, and by local personnel hired and trained by SEI. This report documents the results of the monitoring and mitigation efforts. The project lasted from late December 1996 through March 1997 and provided a scientific assessment of construction impacts. Our only disappointment is that the monitoring effort was not funded through completion of the entire jetty. This represents a lost opportunity. Much time, effort, and funding was invested in getting such a unique project to this stage. The results to date provide valuable information for all sectors of the community and they can be used in decision making for future projects and proposed developments. This was a unique project and we are unaware of any other similar work. The project successfully provided accurate and scientific information from an independent group, and was effective in training local personnel. It’s early completion is a loss. Monitoring and Mitigation centered around minimizing impacts to the marine life in Little Bay. The program was designed by SEI scientists, and approved by ODA and Montserrat and included the following components: Transplanting corals at risk of mortality from habitat destruction and sedimentation from the construction zone to a safe zone, and subsequently monitoring the effectiveness of the relocation. Monitoring sediment input and its effect on the health of the marine life, and making appropriate recommendations when impacts were detected Monitoring the extent and severity of the construction impacts on the marine life (corals and other sessile species, fish, and invertebrates), providing an early warning when impacts were detected, and suggesting possible solutions. Training of local personnel in scientific monitoring of marine resources This report describes and evaluates the results of these components. During the monitoring and mitigation phase, all interested personnel were kept informed by weekly reports, and monthly summaries of results. These written reports were distributed to L. G. Mouchel, ODA, Physical Planning Unit, Department of Fisheries, and the Montserrat National Trust. Updates were posted on the SEI web site (http://www.sei.org). Little Bay is located in the north coast of Montserrat and bounded by Rendezvous Bluff on the north and Potato Hill on the south end (Figure 1.1a). The emergency jetty currently under construction is located in the North-Central section of the bay. The coral reefs are located along the bluff, and monitoring and mitigation work in Little Bay was concentrated on the coral reefs. For analysis of impacts, the reef section was divided into 4 Areas (A, B, C, and D) from east to west (Figure 1.2b). Area A was closest to the jetty location. Monitoring and mitigation began at the end of December 1996 and continued through March 1997. During that time, Phase 1 of the jetty was completed (Figure 1.2a,b). Coral Transplant Mitigation: Recognizing that certain corals close to the construction (Area A) were at risk of mortality from jetty construction, scientists recommended transplanting them to a safe zone at the western edge of Rendezvous Bluff. Transplanting was carried out according to SEI procedures. Criteria for transplanting included: susceptibility to mortality from construction; size/age of species; importance of the species to the biological community; recruitment rates; and probability of success in transplanting. Based on these criteria, 30 corals and sponges were tagged, measured, photographed and transplanted from the construction zone to a new location off the western edge of Rendezvous Bluff. A further 32 corals were designated controls and these were tagged, measured, and were not-transplanted. An additional 10 corals were transplanted to the same area, as transplant controls (The latter tested the effect of the transplant process on corals). At the time of writing, all transplanted species are alive and healthy. Within a day of transplanting all species were feeding and within a month fish had taken up residence in some of the corals. Control corals in Areas B and C ( west of the jetty construction site) were also healthy. By contrast corals in Area A (close to the jetty) and sponges had disintegrated and were bleached, indicating that construction had a negative effect on coral life. Transplanting successfully increased the probability of survival and reproduction for those individuals relocated to a new habitat. The importance of ensuring the survival of transplanted species must be appreciated, particularly in the context of the marine ecosystem. Corals recruit sporadically to Montserrat (Brosnan et al 1996) and many grow slowly (often only 2-5cm per year). They provide a habitat for a diversity of species and form the base of the food chain on a coral reef. Coral loss can lead to reductions in grazers and carnivorous fish directly, and indirectly through effects on the food chain. Transplanting, by increasing the survival of relocated corals and sponges minimized the negative effects of the jetty on the marine ecosystem, and on the human communities that depend on coral reefs for food. Sedimentation and Other Physical Factors: Sediments kill corals, and increased sedimentation is cited as a key factor in the global decline of coral reefs. Sediments kill marine organisms by smothering them, and by reducing light levels so that photosynthesis is inhibited or reduced. In this program, we monitored changes in sediment load at Little Bay using sediment traps, by measuring sediment directly on the substrate, and by secchi disk measurements. (Secchi disks are used to record water clarity.) Sediments naturally enter the ocean from land (mainly through ghauts) and by movement and re-deposition of marine sediments. In Montserrat, the volcano contributes another source of sedimentation. At Little bay, construction impacts provided an additional source of sediments. At issue is whether this additional source exceeded the normal levels and induced stress in the marine community. It can be difficult to distinguish among different sources, especially during heavy swells. In this study, data from all "designated Areas" of the bay (A-D), and comparisons with data from other sites provided ways to distinguish among sources and effects. Sediment load increased and water clarity significantly decreased at Little Bay in response to jetty construction. Sediment levels were consistently higher at Little Bay in comparison to Garibaldi Bluff (known to be impacted by volcanic runoff) and at Rendezvous Bay. Most changes were confined to Area A (close to the jetty) but on occasions sediment plumes extended the length of the Rendezvous bluff. In mid-January average sediment depth in Area A at Little Bay was 4.74cm. In addition parts of the area were accumulating sediment at the rate of 15.13 grams per day. At the same time sediment depth at Garibaldi Bluff was on average 0.5cm. Increased sedimentation was associated with the use of a fine cement in January. In response to the environmental concerns raised by SEI, the engineering consulting firm L. G. Mouchel and Partners and Edgehill Contractors switched to a coarser cement that tended to settle in the construction blocks. This alleviated much of the problem. Water clarity at all sites increased significantly with distance from shore, indicating that sediment settles out relatively quickly. The sediment data form the basis for interpreting much of the biological changes as most of the impacts on the reef ecosystems appear to be due to increased sedimentation and habitat destruction. Although not within the monitoring and mitigation work, it is important to address the changes to the ghaut at Little Bay insofar as it affects marine processes. Ghauts are a main source of sediment into the marine environment. They also carry nutrients which can lead to the replacement of corals by algae, with an accompanying loss of reef area and function. Changes made to the ghaut at Little Bay (through vegetation removal and modifications) have resulted in increased water flow through the ghaut. This is likely to increase the rate of erosion, and to increase sediment load into the sea. Note that prior to construction, most water percolated through the soil and only rarely flowed through the ghaut. On those occasions when water flowed through the ghaut its velocity was less that currently observed (T. Grubba personal observation). We raise this as an issue of future concern as impacts are likely to be gradual and cumulative. Jetty Impacts on Corals and Other Sessile Organisms (photoquadrat analysis): A series of photoquadrats were established to monitor the impacts of construction on sessile (attached) species including corals, sponges and algae, and to monitor changes in sediment cover. Quadrats were photographed and images scanned into a computer and analyzed for percent cover. Data were subsequently analyzed by Analysis of Variance technique (ANOVA). Comparisons were made between results from the EIA (Little Bay 1996) and Little Bay 1997. Data from our ongoing work (1995-1997) at other sites in Montserrat served as control sites for interpreting changes within Little Bay in comparison to island-wide patterns. The main results of the photoquadrat analysis showed degradation of corals and sponges in the area close to jetty construction (Area A). These impacts included disintegration of sponges and coral bleaching. These phenomena were not observed elsewhere within the bay or at other sites, indicating that construction negatively impacted marine life, and that impacts were localized. Corals showed a downward trend in abundance in Area A, but not elsewhere, suggesting that construction was the causal factor (Figures 4.2-4.4). Algal cover (Dictyota species) almost doubled in Area A, but there was an island-wide increase in algae and so results cannot be attributed only to jetty construction (Figures 4.2-4.4). Sediment increased in Little Bay both in cover and depth. We cannot fully evaluate the long-term impacts of the jetty construction as the process is ongoing, and changes in slow growing species cannot be observed in a short (3 month) period. Long-term changes, if any, can only be detected by further monitoring. Construction Impacts on Fish Life: The effect of jetty construction on fish life was monitored using a series of 20m transects in Little Bay and at control sites (Rendezvous Bay and Garibaldi Bay). Jetty construction led to a decrease in fish life throughout the bay between January and February 19, 1997. This corresponded to a period of high turbidity resulting from the use of fine sediments in the construction. When conditions cleared in late February 1997, the abundance and diversity of fish rebounded. Some fish, e.g. grunt species, which were present in Area A prior to construction, disappeared from this area and were not observed during the monitoring work. Chromis and juvenile wrasse increased at Little Bay and at other sites in February and March. Towards the end of the monitoring study we began to observe further recruitment of a diverse range of fish species in Areas B-D of Little Bay. This indicates that the site remains an important recruitment site for fish. It further illustrates the importance of relocating the jetty to a more southerly site in the bay and preserving the reefs for key juvenile species in Areas B-D. Construction impacts on invertebrates: The abundance and diversity of invertebrates was recorded by visual transects. Transects were carried out at Little Bay (Areas A-D), Garibaldi Bluff and Rendezvous Bay. T-test analyses were used to test for differences among sites and between years. For between year comparisons, we used data from the Institute’s other and ongoing work at Garibaldi Bluff and Rendezvous Bay. Brittle stars (Ophiuroidea) increased between 1996 and 1997 at Little Bay (figure 6.1) and at Garibaldi Bluff, but not at Rendezvous Bay. This pattern is consistent with an increase in sediment at these sites, as brittle stars live under rocks and coral rubble in soft substrates. At Little Bay, jetty construction increased sediment load while at Garibaldi Bluff, volcanic activity has increased the amount of soft sediments. There has been no change in sediment input at Rendezvous Bay. Feather duster worms (Sabellidae) increased at all sites suggesting that jetty construction is not a causal factor in their increase. Feather duster worms are filter feeders, and their increase coupled with an increase in planktivorous fish suggests that nutrient and productivity levels around the island have increased. Whether this is due to volcanic activity or other factors (e.g. the Orinoco Plume brining nutrient rich water to the Antilles in December 1996) is unknown at this stage. Octopus were observed to leave dens in Area A during the construction phase and they did not return. Other Observations: The marine environment was kept generally free of garbage and waste materials during the construction phase from December 1996 to March 1997. L. G. Mouchel instituted a policy of not-dumping materials in the sea and this was successful. Training of Local Personnel: Many small islands lack local personnel with the technical skills necessary for monitoring and management of their natural resources (UNEP 1994; GCRMN 1996). A key component of this work was the training of local personnel in coral reef monitoring and mitigation. SEI scientists trained (and hired during the training process) Dwayne Cassell and Patrick Laplace in monitoring techniques. The Institute sponsored Gerard Gray (chief environment officer for Montserrat) to qualify as a SCUBA diver, and subsequently trained him in reef monitoring, The Institute adapted its manual "Ecology in Action: Coral Reef Monitoring , Answers to Frequently Asked Questions" by Timothy Grubba specifically for this program, and copies were presented to trainees and the National Trust. This training provided Montserrat with local personnel (including a high-level civil servant with responsibility for the environment) who are skilled in scientific monitoring and with a general knowledge of coral reef ecology and species identification. Prior to this training, marine ecological and monitoring skills did not exist locally on the island. Other: As a service to Montserrat, SEI independently developed an educational snorkel trail in Little Bay. The trail was developed by SEI biologist Alan Cooper. A map and description of the trail was provided to local organizations, and government agencies. Overall Conclusions The EIA recommended the relocation of the jetty to a more southerly site in Little Bay, and a new location was subsequently chosen. This was a wise choice. The marine life close to the construction is now degraded from construction activity and habitat destruction. The reefs and marine life from Area B-D (westward along the bluff) remain healthy. Further, juvenile species have recruited successfully to these areas (B-D), and juvenile lobster are still common. The relocation of the jetty ensured the continued survival of the coral reef ecosystem and ecological processes in Little Bay. Based on the results from this monitoring and mitigation study, had the proposed original location been adopted, the coral reefs over much of Rendezvous Bluff would have perished, with important consequences for marine life and fisheries at an island-wide level. The EIA additionally recommended a new design that allowed for increased water flow and was more stable and permanent. The new design has met many of these requirements. However, we cannot fully evaluate its impacts in this study as the jetty has not been fully completed. Specific conclusions Coral Transplants: The goal of the coral transplant project was to prevent the mortality of corals close to the construction zone. The results presented in this report illustrate that this goal was achieved. At the time of writing, all transplanted corals were alive and feeding, and fish had taken up residence on some coral heads. By contrast, corals and other species close to the construction zone were bleached and buried by sediment. Monitoring Physical Factors: Impacts on Sediment and Water Clarity: The goal of this component was to monitor changes in sedimentation and water clarity, and to provide an early warning system in the case of serious damage to the environment. Our results indicated increased sediment input from the construction. Impacts were largely localized, as predicted. However, when fine fill material was being used, impacts began to spread to a wider area, and scientists observed a decrease in fish life. SEI scientists presented the findings and concerns to Mr R. Trevitt of L. G. Mouchel and to Edgehill Contractors. As a result action was taken to remedy the situation. In this case, a new and coarser fill material was found. Fish life subsequently rebounded. Monitoring Changes in the Marine Life: The goal of this component was to monitor changes in the marine life in Little Bay, and to relate those changes to jetty construction. Based on the results of this project and on other data from our ongoing studies, we were able to detect and evaluate impacts from jetty construction and changes due to natural phenomena. As predicted by the EIA, marine life close to the construction was impacted, but impacts rarely extended beyond the immediate area (Area A). Because of the short-term duration of this project, we cannot fully evaluate the long-term changes due to jetty construction, particularly in the central and eastern sections of Little Bay. Key Outcomes The monitoring and mitigation work provided valuable information for managers and decision-makers, scientists and conservation groups. In this project, we were able to document specific impacts of jetty construction on the physical habitat (through changes in sedimentation and water clarity), and learn how those changes affected marine life. This included identifying which particular species are more susceptible to impacts and how some groups (e.g. fish) respond to disturbance. The monitoring work provided important information on the spatial extent of construction impacts on marine life over the 3 month construction period. As a result of the monitoring and mitigation work we learned that we can provide an early-warning system for unacceptable levels of sedimentation, and its impacts on marine life. In a climate of co-operation, changes can, and in this case were made, to stop activities leading to unacceptable damage. The results of the monitoring and mitigation work enabled an evaluation of the recommendations and predictions of the EIA. This information is useful for decision-makers in future policy and planning. We learned that it was possible to prevent the mortality of key coral species by transplanting them carefully to a new location. The availability of original scientific data collected during other monitoring and research studies proved invaluable in interpreting changes in the marine life. For instance, it was possible to identify changes that could clearly be attributed to construction, and also to identify changes that were occurring on an island-wide basis and therefore unlikely to be due to construction. Continued monitoring of coral reefs is essential. Finally, the project showed that, with careful planning and work, it is possible to meet the safety requirements for Montserrat, without bankrupting the marine natural resource base. This project minimized damage to the marine environment and ensured the conservation of fragile marine resources. This was achieved through the collaborative and committed work of a diverse groups. We hope that Montserrat and all parties involved in this project will continue in similar framework on all future ventures. A note on figures: The figures accompanying this document are the main summary figures illustrating some of the results of this project. More detailed figures can be found in the full report. In the figures on Little Bay, data are presented from the "designated Areas (Areas A-D)" For comparison, data are also presented from the EIA results. These columns are labeled NC, N, and O. NC refers to the North-Central location identified in the EIA, this is the site of the current construction and it is equivalent to Area A; N refers to the North location further west, and O refers to the westernmost edge and of Rendezvous Bluff (approximately Area D). ACKNOWLEDGMENTS Sustainable Ecosystems Institute thanks the individuals and organizations that helped to make this project a success. Thanks to Richard Trevitt (consulting engineer for L. G. Mouchel and Partners), to Edgehill and the workers at the Little Bay construction site for assistance and co-operation during the project, John Adam, Sarita Francis, Alan Gunne-Jones, Mike Emmanuel, Bruce Farara, and Joel Osborne, Thanks also to the ODA, Department of Fisheries, Physical Planning Unit, and the Montserrat National Trust. Coral Reefs Homepage Volcanic Impacts on Coral Reefs in Montserrat Snorkel Trail Little Bay Montserrat Emergency Jetty in Montserrat Underwater Video St Barthelemy Marine Reserve Volcano Homepage

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