Intellectual Merit: This RAPID project will assess the subtidal ecological impacts of the tsunami that struck Robinson Crusoe Island on 27 February 2010 with support from the Biological Oceanography Program and the Office of International Science and Engineering/Americas. It will take advantage of baseline data collected as part of an ongoing Chilean research project. Robinson Crusoe Island belongs to the Juan Fernandez archipelago, some 600 km west of the coast of Chile in the southeast Pacific. The island group is unique for its high level of marine and terrestrial endemism, including a fishery for the prized Robinson Crusoe Island lobster, Jasus frontalis. Since 2008, a Chilean team of investigators has provided some of the first quantitative data linking nearshore oceanographic conditions to the benthic community of this temperate oceanic island. The Chilean project established study sites around the island at which temperature loggers, current meters, and lobster post-larval collectors have been placed, and which serve as focal points for benthic and planktonic sampling. However, the tsunami devastated the island's waterfront village and swept away the Chilean research team's field lab, equipment and housing. With as much as 1.5 years of ecological and oceanographic data collected prior to the tsunami, a rapid response collaboration between US and Chilean investigators will hasten the recovery of the Chilean project and provide an unusual opportunity for a rigorous before-after assessment of the tsunami's effects on important components of the benthic community, including the island's key fishery species. It is critical to initiate short-term assessments as soon as possible, and at the same time, reestablish the infrastructure and capacity to continue long-term sampling, which was part of the original Chilean project. This RAPID project will focus on objectives for which pre-tsunami data exist: (1) Census lobster dens where social groups of lobsters were previously tagged; (2) retrieve and redeploy artificial post-larval settlement collectors; (3) conduct benthic suction samples of the cobble-dwelling invertebrate assemblage; (4) conduct video-monitored predation experiments to assess changes in the predation pressure by fish and octopus; (5) resume tissue sampling of planktonic larvae and benthic adults for molecular genetic analysis.
This project is relevant to an understanding of the resilience of marine ecosystems, biodiversity and fisheries to agents of natural disturbance of different scales and magnitudes. Current understanding of rare, short-lived, but potentially extreme natural disturbances are inherently poor. To date, documentation of the ecological impact of tsunamis on marine benthic environments is mostly restricted to the relatively recent "Christmas tsunami" of 2004 that largely affected tropical benthic communities with considerable reductions in coral reefs and associated biota in the coastal Indo-west Pacific. There are no published studies of the impact of a tsunami on the benthic assemblages of temperate oceanic islands. The small size and isolation of the Juan Fernandez archipelago dramatically increases the extinction risk for shallow marine populations and communities. Large numbers of demersal fishes and invertebrates were stranded during the tsunami. Some components of the benthic community are likely to be more vulnerable than others to this kind of disturbance.
Broader Impacts: This research will leverage public interest in the dramatic terrestrial impacts of tsunamis, drawing them into the marine realm through geo-tagged, metadata-rich photos and video. Geo-tagging is the process of adding geographical identification to media, metadata that will be particularly helpful to learners who are not accustomed to thinking about submarine locations. This component of the project will add scientific information to the media, allowing users to get instantaneous information about the scenes they are observing by placing their cursors on the images or video. To ensure that the data and information are audience-appropriate, the investigators will work with the Centers for Ocean Sciences Education Excellence (COSEE) - Ocean Systems (OS) program at University of Maine. COSEE-OS has vast experience in working with scientists to frame their research through interactive media that is highly effective with educators. The media will be directly tied to the National Geographic Society's "Ocean Literacy" campaign, specifically addressing the concept "Coastal regions are susceptible to natural hazards". This will provide broad audiences an opportunity to understand the role of ecological disturbance as a force structuring populations and communities, both above and below sea level.
On 27 February 2010 a 15-m tsunami struck Robinson Crusoe Island and leveled the island’s only village, took the lives of 20 residents, and destroyed most of its fishing fleet. Robinson Crusoe belongs to the remote Juan Fernandez archipelago in the southeast Pacific, some 600 km west of Chile, and notable for its high level of marine and terrestrial endemism. At the time, a Chilean marine research team led by Drs. Alvaro Palma and Carlos Gaymer was two years into the first comprehensive study of the ecology of the island’s endemic and commercially valuable Juan Fernandez lobster, Jasus frontalis. One research team member lost her life in the tsunami, and the scientists sustained devastating losses of equipment. This one-year NSF–RAPID project aimed to collaborate with the Chilean research team to capitalize on the opportunity to evaluate the ecological impacts of the tsunami. With as much as a year and a half of ecological and oceanographic data in hand prior to the tsunami, this collaboration represented an unusual opportunity for a before-after assessment of the tsunami’s effects on the lobster and other components of the benthic community. Among our priorities were to continue lobster tagging studies and suction sampling of submerged cobble habitat at locations with pre-tsunami data time series. We also initiated new video transect surveys at multiple sites to document conspicuous changes in the sea bed, such as algal cover and the presence of human debris, in the aftermath of the tsunami. Our findings indicate that despite the devastating impact of the tsunami on the human sector, aggregations of lobsters in subtidal dens remained largely intact; and this is consistent with reports by fishermen that the lobster catch, for those who could fish, remained largely unaffected. There was also little evidence of tsunami-related change in the assemblage of marine invertebrates hidden among cobbles and effectively sampled samped by the suction device. The time series of video transects tells a different story, however. The videos not only document the post-tsunami clean up of human debris by salvage teams, but also reveals what may be an unanticipated lagged ecological effect of the tsunami. In the months after the disturbance, an extensive bloom of the benthic green algae, "sea lettuce" (Ulva), covered large areas of the seabed downstream of the highly disturbed waterfront of the village. Analysis of photographs taken at these sites in the months and years prior to the tsunami support claims by fishermen that such a widespread algal bloom has not been seen in recent memory. We are exploring the hypothesis that this phenomenon was caused by erosion induced fertilization of the seawater from land exposed by the tsunami. Surveys and nutrient sampling by the Chilean research team through March 2012, since the end of our NSF support, are continuing this line of investigation. Studying the ecological impacts of tsunamis has relevance to an understanding of the resilience of marine ecosystems, biodiversity and fisheries to agents of disturbance at different scales and magnitudes. Our understanding of rare, short-lived, but potentially extreme ecological disturbances is inherently poor. To date, documentation of the ecological impact of tsunamis on marine benthic environments has been restricted, and this study will be a valuable contributing to our understanding of tsunami impacts on oceanic islands. The importance of this work was underscored on 11 March 2011 by a coincidence as we were completing the final trip of our RAPID project: Japan’s massive 9.0 magnitude earthquake triggered a notoriously destructive tsunami that mercifully dissipated as it approached the Americas. The broader impacts of the project are multifaceted and international. The field activities provided opportunities for US and Chilean graduate, undergraduate, and a high school student participation in independent projects and theses. To date the project has contributed to one peer reviewed scientific publication in a Chilean marine science journal. The project also contributed to informal and formal presentations given to island fisherman cooperatives, the Chilean Navy and environmental management agencies, as well as international scientific conferences. The large amount of digital video and still image documentation, as well as data bases from benthic collections, form the basis of our outreach materials. In the aftermath of our RAPID project, we are working with education and outreach partners at the Centers for Ocean Sciences Education Excellence (COSEE) - Ocean Systems at the University of Maine to implement an inquiry-based online tool for direct student investigation areas that were affected by the tsunami, both above and below sea level.
