Kenneth Banks

Severe 2010 Cold-Water Event Caused Unprecedented Mortality to Corals of the Florida Reef Tract and Reversed Previous Survivorship Patterns

Background Coral reefs are facing increasing pressure from natural and anthropogenic stressors that have already caused significant worldwide declines. In January 2010, coral reefs of Florida, United States, were impacted by an extreme cold-water anomaly that exposed corals to temperatures well below their reported thresholds (16°C), causing rapid coral mortality unprecedented in spatial extent and severity. Methodology/Principal Findings Reef surveys were conducted from Martin County to the Lower Florida Keys within weeks of the anomaly. The impacts recorded were catastrophic and exceeded those of any previous disturbances in the region. Coral mortality patterns were directly correlated to in-situ and satellite-derived cold-temperature metrics. These impacts rival, in spatial extent and intensity, the impacts of the well-publicized warm-water bleaching events around the globe. The mean percent coral mortality recorded for all species and subregions was 11.5% in the 2010 winter, compared to 0.5% recorded in the previous five summers, including years like 2005 where warm-water bleaching was prevalent. Highest mean mortality (15%–39%) was documented for inshore habitats where temperatures were <11°C for prolonged periods. Increases in mortality from previous years were significant for 21 of 25 coral species, and were 1–2 orders of magnitude higher for most species. Conclusions/Significance The cold-water anomaly of January 2010 caused the worst coral mortality on record for the Florida Reef Tract, highlighting the potential catastrophic impacts that unusual but extreme climatic events can have on the persistence of coral reefs. Moreover, habitats and species most severely affected were those found in high-coral cover, inshore, shallow reef habitats previously considered the “oases” of the region, having escaped declining patterns observed for more offshore habitats. Thus, the 2010 cold-water anomaly not only caused widespread coral mortality but also reversed prior resistance and resilience patterns that will take decades to recover.

Orange Cup Coral Tubastraea coccinea invades Florida and the Flower Garden Banks, Northwestern Gulf of Mexico

The azooxanthellate scleractinian coral Tubastraea coccinea has recently been reported to have invaded the Gulf of Mexico (Fenner 2001) and Brazil (Castro and Pires 2001; Ferreira 2003; Figueira de Paula and Creed 2004). It may have been spreading in the Caribbean since it was reported there by Vaughan and Wells (1943), based on material from Curaçao and Puerto Rico, and may even have been introduced into the Caribbean from the Pacific (Cairns 2000; Humann and DeLoach 2002, p. 164). No Caribbean fossils of this species are known (Cairns 1999). Most Caribbean reef building corals (88%) were described before T. coccinea was reported from the Caribbean in 1943, with the median date of description being 116 years earlier. All other genera had been found in the Caribbean before Tubastraea, the last having been found 75 years before Tubastraea was found. The type locality of T. coccinea is Bora Bora, date 1829. Its range includes most or all of the tropical Indo-Pacific (Cairns 2000). Alternatively, it may have come from the Cape Verde Islands or Gulf of Guinea in the eastern Atlantic, where it is also known (Laborel 1974; Cairns 2000). It has not been reported from Florida (Wheaton and Jaap 1988; Jaap and Hallock 1990; Cairns 2000; Fenner 2001; Dawson 2002; see also http://floridakeys.nos.noaa.gov/sanctuary_resources/ specieslist.pdf), and in the Gulf of Mexico it has only been reported from oil platforms (Fenner 2001). It is reported here for the first time in Florida and the Flower Garden Banks of the northwestern Gulf of Mexico.

Elevated Sedimentation on Coral Reefs Adjacent to a Beach Nourishment Project

An increasingly common method to restore eroding beaches is nourishment, a process by which lost sand is replaced with terrestrial or offshore sediments to widen beaches. The southeastern Florida coastline contains shore-parallel coral reef communities adjacent to eroding beaches. Scleractinian corals and other reef-associated organisms are known to demonstrate sensitivity to elevated sedimentation levels. Sediment traps were used to examine spatio-temporal sedimentation patterns and assess the effects of nourishment (dredge and fill) activities. Several environmental variables correlated with among-site spatial variability of sediment parameters. Intra-annual variability correlated with wind velocity and direction. Nourishment activities showed localized effects, with sites in close proximity to dredging areas exhibiting significantly higher collection rates and lower percent fines than control sites. A regional increase in sedimentation occurred while nourishment activities were ongoing. Due to concurrent impacts of hurricanes, only one during-construction sampling interval revealed substantially higher collection rates relative to corresponding pre-construction sampling intervals.

Evaluation of sewage source and fate on southeast Florida coastal reefs

Water, sponge and coral samples were collected from stations impacted by a variety of pollution sources and screened for human enteric viruses as conservative markers for human sewage. While human enteroviruses and adenoviruses were not detected, noroviruses (NoV; human genogroups I and II) were detected in 31% of samples (especially in sponge tissue). Stations near inlets were the only ones to show multiple sample types positive for NoV. Fecal indicator bacteria and enteric viruses were further evaluated at multiple inlet stations on an outgoing tide. Greatest indicator concentrations and highest prevalence of viruses were found at the mouth of the inlet and offshore in the inlet plume. Results suggest that inlets moving large volumes of water into the coastal zone with tides may be an important source of fecal contaminants. Efforts to reduce run-off or unintended release of water into the Intracoastal Waterway may lower contaminants entering sensitive coastal areas.

Environmental Enhancement Gone Awry: Characterization Of An Artificial Reef Constructed From Waste Vehicle Tires

In 1967, Broward County, Florida resource managers initiated a project to construct an artificial reef using an estimated two million unballasted waste vehicle tires. These tires were deployed in bundles approximately 1.8km offshore in 21m of water. Over time, the bundle bindings failed and the tires have moved extensively, some displaced kilometers from their original location. The loose tires have physically damaged benthic reef fauna on the natural reef, including corals that have recruited onto individual tires. Due to the biological damage caused by the mobile tires, a large-scale removal plan has been initiated. To assess damage, and to acquire a baseline to evaluate the effectiveness of the tire removal, an examination of existing biota was accomplished. Live corals were absent on the natural substrate of the Middle reef edge buried by tires. However, on tires the abundance of corals is similar to that found on neighboring hardbottom reef tracts. Likewise, fish abundance and richness on the tire reef is similar to bordering natural reef tracts. Significantly higher fish abundance was found along the edge where tires were present, than on control sites. Future monitoring will determine what changes in reef biota resulted from the removal operation and the effectiveness of the attempted restoration.