Southeast Florida Reef-Wide Post-Irma Coral Disease Surveys

Florida’s coral reefs are currently experiencing a multi-year outbreak of coral disease that have resulted in the mortality of millions of corals across southeast Florida, Biscayne National Park, and the Upper and Middle Florida Keys. In early September 2017, Hurricane Irma impacted the entire FRT. The purpose of this project was to conduct field surveys to identify the current state of the coral reefs in southeast Florida and coordinate with other concomitant reef tract efforts to improve the regional understanding of the extent of the disease outbreak and identify recent hurricane injury to direct future restoration. Through a broader partner network, 62 sites from Key Biscayne to St. Lucie Reef were targeted for survey. Twenty-nine sites were chosen based on previous data that indicated high coral values of richness, density, and/or cover at those locations. Thirty-three sites were chosen with FDEP reef managers where there were previous data gaps. A new protocol was developed, which was a modification of the Florida Reef Resilience Program (FRRP) Disturbance Response Monitoring (DRM) methodology. This included collecting additional disease and injury metrics in transects and by rover diver to prioritize sites for triage and restoration activities. The analyses showed that hurricane impacts on corals were quite low where 82.3% (51/62) of the sites were listed as Tier 3 (minimal impact/triage not needed). There were nine sites listed with at least some Tier 2 damage (moderate impact/secondary priority if resources allow). Site 33 was listed as 100% Tier 2 and Site 30 was 100% Tier 1 (triage recommended). Site 30 had some impressive impacts including large (2 - 5 m) slabs of fractured hardbottom lifted and thrown several meters eastward atop other hardbottom affecting a ~ 2 m Orbicella faveolata colony that was mostly covered leaving only the very top exposed. One day of triage was conducted at a dense Acropora cervicornis patch to stabilize many coral fragments and collect loose debris (mostly gorgonians). Lack of capacity and weather deterred further triage attempts for several months. It was eventually decided that triage efforts were not a priority for SE Florida because of the ongoing disease. Coral disease prevalence was high. The rover diver surveys found 11.4% total disease prevalence across all sites (243/2130) infecting 43.3% of the species found, and prevalence at the southern sites was higher. Mean density and richness at sites with previous relatively high values were considerably lower than their historic values with a 57.2% and 42.2% decrease respectively, indicating profound changes in the coral populations. Perhaps the most striking result was the low density of Eusmilia fastigiata, Meandrina meandrites, Dichocoenia stokesi, Colpophyllia natans, Pseudodiploria strigosa, Diploria labyrinthiformis, and Orbicella annularis. We found 36 individuals of all these species combined out of 1,165 colonies (3.1%). A comparison of the percentages of each species to the total in the southern sites to those of the 2004 annual monitoring data in Broward County showed drastic differences in the populations that likely go beyond any bias in survey differences. These data support the idea that the Florida Reef Tract is becoming more homogenous and dominated by eurytopic, generalist species that can tolerate a wider range of environmental conditions. However, this disease event contradicts the notion that the present assemblages are stable because they have “withstood a number of recent perturbations, including thermal stress and disease”. After moving through the more vulnerable species, the disease is now affecting hardier species thought to be more resistant to stress like Montastrea cavernosa and Siderastrea siderea. It is important that actions are taken to curtail this disease quickly so that the remaining population can stabilize and recovery and restoration efforts can begin. There should be continued focus on the remaining corals because they are apparently resistant to the disease and perhaps better acclimated to the stressful conditions over the past several years

Whitsundays Plan of Management: UPDATE 2

[Extract] On 1 January 2018, three of these amendments to the Whitsundays Plan of Management 1998 (the Plan) will come into effect. The Great Barrier Reef Marine Park Authority updated the Whitsundays Plan of Management in August 2017, providing for additional protection to the Reef-wide zoning plan

Reef-wide evidence that the presence of sharks modifies behaviors of teleost mesopredators

The idea that the presence of sharks impacts the behavior of mesopredatory reef fishes is controversial and lacks clear evidence at reef-wide scales. We compared the abundance and behavior of these reef fishes in response to the presence of reef sharks using Baited Remote Underwater Video System (BRUVS) deployments in two adjacent reef systems where sharks have either been exclusively targeted by fishing or protected by a no-take marine reserve. For a subset of videos, we also compared the behavior of mesopredatory reef fishes immediately before and after the appearance of sharks in the video. On reefs where sharks were more abundant, mesopredatory fishes spent less time swimming in midwater (i.e., away from shelter) and guarding bait compared to reefs where sharks have been selectively removed. The same responses occurred after the appearance of sharks in the video. Reactions to sharks varied both in strength and type among species of mesopredator and were mediated by the availability of shelter on the reef and, for one species, by the levels of activity of the reef sharks. In contrast, we did not find that the presence of sharks influenced the abundance of mesopredators at either reef system across hour-long videos or immediately before and after a shark appeared in the video. Collectively, our findings show that the presence of sharks reduces the propensity of mesopredatory fish to engage in potentially risk-prone behaviors over large spatial scales and that these interactions are mediated by the behavioral characteristics of both predators and prey, and the environment in which they co-occur. Our results are consistent with the idea that sharks as predators or larger competitors initiate changes in the behavior of mesopredatory reef fishes likely to affect trophic structuring within coral reef ecosystems

Threshold Decline in Mesoamerican Coral Growth and Resiliency

Caribbean coral reefs have been massively altered in recent decades due to human impacts, resulting in a dramatic reduction of live coral cover but quantitative data before the 1970s have not been available to assess how these changes came about1,2,3. We produced master chronologies of growth rates in massive Montastrea faveolata corals from the Mesoamerican reef tract that provide a method for extending records of coral health further back into the past. Our records reveal a unique reduction in growth rate associated with the 1998 coral bleaching event that has no parallel in the past 75 to 150 years. Of 92 cores collected from live coral heads in 2006-2007, 94% have severely reduced growth rates and 14% exhibit partial mortality scars in 1998-1999 whereas only 3 stress bands are found in single cores prior to 1998, and none of these cores exhibited earlier partial mortality. Some corals returned to pre-1998 extension rates by 2001, although corals in areas affected by sediment-laden runoff or high human population density still had not fully recovered by the time of sample collection eight years later. Previous episodic stresses like hurricane strikes and a warming event in 1983 more severe than 1998 had little to no effect on M. faveolata growth rates. The 1998 event apparently surpassed a threshold in coral tolerance precipitating a catastrophic shutdown in growth that had lasting effects throughout the Mesoamerican reef system but was particularly prolonged in areas exposed to other stressors. These findings suggest that projected increases in global temperatures over the next century are likely to result in drastic reductions in growth rather than a gradual decline in coral health, but that corals with fewer local stresses will be better able to survive bleaching events, underscoring the need for local conservation measures

Nocturnal dissolved organic matter release by turf algae and its role in the microbialization of reefs

The increased release of dissolved organic matter (DOM) by algae has been associated with the fast but inefficient growth of opportunistic microbial pathogens and the ongoing degradation of coral reefs. Turf algae (consortia of microalgae and macroalgae commonly including cyanobacteria) dominate benthic communities on many reefs worldwide. Opposite to other reef algae that predominantly release DOM during the day, turf algae containing cyanobacteria may additionally release large amounts of DOM at night. However, this night-DOM release and its potential contribution to the microbialization of reefs remains to be investigated. We first tested the occurrence of hypoxic conditions at the turf algae-water interface, as a lack of oxygen will facilitate the production and release of fermentation intermediates as night-time DOM. Second, the dissolved organic carbon (DOC) release by turf algae was quantified during day time and nighttime, and the quality of day and night exudates as food for bacterioplankton was tested. Finally, DOC release rates of turf algae were combined with estimates of DOC release based on benthic community composition in 1973 and 2013 to explore how changes in benthic community composition affected the contribution of night-DOC to the reef-wide DOC production. A rapid shift from supersaturated to hypoxic conditions at the turf algae-water interface occurred immediately after the onset of darkness, resulting in night-DOC release rates similar to those during daytime. Bioassays revealed major differences in the quality between day and night exudates: Night-DOC was utilized by bacterioplankton two times faster than day-DOC, but yielded a four times lower growth efficiency. Changes in benthic community composition were estimated to have resulted in a doubling of DOC release since 1973, due to an increasing abundance of benthic cyanobacterial mats (BCMs), with night-DOC release by BCMs and turf algae accounting for >50% of the total release over a diurnal cycle. Night-DOC released by BCMs and turf algae is likely an important driver in the microbialization of reefs by stimulating microbial respiration at the expense of energy and nutrient transfer to higher trophic levels via the microbial loop, thereby threatening the productivity and biodiversity of these unique ecosystems. Read the free Plain Language Summary for this article on the Journal blog

A reef-wide framework for managing traditional use of marine resources in the Great Barrier Reef Marine Park

The stated aims of the Authority include protecting the natural qualities of the Great Barrier Reef while providing for reasonable use of the reef region, and minimising regulation of, and interference in, human activities, consistent with meeting the goal and other aims of the Authority. Consistent with these obligations, the Authority is responsible for conserving threatened and protected species in the Marine Park. This is achieved through managing human activities that impact on the species occurring in the Marine Park, including both current activities and predicted future activities. To the extent that it is consistent with protecting the natural values of the Great Barrier Reef, the Authority provides for ecologically sustainable use of the Marine Park, including traditional use by Aboriginal and Torres Strait Islander peoples

A co-operative framework for the sustainable use and management of tourism and recreation opportunities in the Great Barrier Reef Marine Park

co-operative framework for the sustainable use and management of tourism and recreation opportunities in the Great Barrier Reef Marine Park (the Framework). The TRRAC is a broadly based advisory committee to the Great Barrier Reef Marine Park Authority (the GBRMPA). Its membership comprises competency-based representatives of the tourism industry, recreational users, conservation groups, indigenous interests, commercial fishing, Commonwealth and Queensland governments and tourism industry associations

A Co-operative Framework for the Sustainable Use and Management of Tourism and Recreation Opportunities in the Great Barrier Reef Marine Park 2002

The proposal for “A Co-operative Framework for the Sustainable Use and Management of Tourism and Recreation Opportunities in the Great Barrier Reef Marine Park” (the Framework) has been prepared by the Tourism and Recreation Reef Advisory Committee (TRRAC), based on the principles of ecologically sustainable development. The Framework adopts a triple-bottom line approach that provides for environmental sustainability in terms of protecting the reef environment, economic sustainability in terms of operating in a contemporary business-like fashion and social/cultural sustainability in terms of respecting the needs of the wider community including Aboriginal and Torres Strait Islander people. In this way, the TRRAC believes that the Framework will not only be responsive to tourism and recreation needs, but also address the concerns of resource managers, environmental interests and other stakeholders

Genetics and genetic tools in coral reef management 2011

This report forms a synthesis of current knowledge and future applications of genetics in coral reef management. It is divided up into three parts, (1) the coral host, (2) the Symbiodinium, and (3) other coral associated microbes. Within each of these parts current knowledge is summarised and examples are provided to illustrate how this knowledge may be applicable to the management of the Great Barrier Reef. The synthesis ends with a summary of how it is all linked together and possible future developments, uses and risks associated with the use of genetics in coral reef management. Words in dark blue with a dotted underline are part of the glossary, which can be found at the end of the document