Rhyne A.L.,New England Aquarium |
Rhyne A.L.,Roger Williams University |
Tlusty M.F.,New England Aquarium |
Schofield P.J.,U.S. Geological Survey |
And 5 more authors.
PLoS ONE | Year: 2012
The aquarium trade and other wildlife consumers are at a crossroads forced by threats from global climate change and other anthropogenic stressors that have weakened coastal ecosystems. While the wildlife trade may put additional stress on coral reefs, it brings income into impoverished parts of the world and may stimulate interest in marine conservation. To better understand the influence of the trade, we must first be able to quantify coral reef fauna moving through it. Herein, we discuss the lack of a data system for monitoring the wildlife aquarium trade and analyze problems that arise when trying to monitor the trade using a system not specifically designed for this purpose. To do this, we examined an entire year of import records of marine tropical fish entering the United States in detail, and discuss the relationship between trade volume, biodiversity and introduction of non-native marine fishes. Our analyses showed that biodiversity levels are higher than previous estimates. Additionally, more than half of government importation forms have numerical or other reporting discrepancies resulting in the overestimation of trade volumes by 27%. While some commonly imported species have been introduced into the coastal waters of the USA (as expected), we also found that some uncommon species in the trade have also been introduced. This is the first study of aquarium trade imports to compare commercial invoices to government forms and provides a means to, routinely and in real time, examine the biodiversity of the trade in coral reef wildlife species.
News Article | November 9, 2015
Capt. Philip Renaud, the executive director of the Khaled bin Sultan Living Oceans Foundation, was exploring the atolls of French Polynesia when he heard a tidbit of local folklore. For thousands of years, the fishermen of the area told tales of a colossal spawning event. Camouflage groupers traveled in schools to the Fakarava Atoll, where they released eggs and sperm into a narrow channel in the water. Renaud was prepared to mobilize a film crew to record the yearly spawning event. However, that wasn’t the only facet of the event. Grey reef sharks "have adapted to learn about this (spawning event) too, so they come in for a free lunch,” Renaud says in an interview with R&D Magazine. “It’s an absolute manic feeding frenzy underwater during daylight hours in a very restricted small pass.” This gave Renaud a unique opportunity, a chance to witness and document a shark feeding event unaided by chum or other artificial means. Capturing a rarity Renaud assembled a team of ace underwater videographers, a diving guide and shark biologist William Robbins. Despite ample preparation, the team was left to the whims of Mother Nature. The spawning event is spurred by a variety of environmental indicators, including temperature and lunar cues, according to Renaud. “You have one opportunity to get this on film and it lasts for about an hour,” he says. On a summer morning in 2012, Renaud entered the waters. Already, a film crew was positioned and ready to capture the event. He dropped underwater and became a witness to the frenzy. Groupers swam in clumps of between 50 and 100. Sharks streamed into the area from the surrounding ocean. Renaud had entered a “wild place,” as he calls it, somewhere untouched by humans. In these waters, humans are the alien. The sharks’ blank, expressionless eyes barely register the human, according to Renaud. “It’s almost like they’re looking right through (you), like you’re so foreign in their world. This scuba diver with neoprene and this big tank, you’re such a foreign object that they really don’t even acknowledge that you exist,” he says. Shark feeding Around 100 ft below the water’s surface, Renaud saw the groupers start to spawn. The event gave the sharks a window of opportunity to catch prey. They darted a mere 3 ft above Renaud’s head. One shark would hit a grouper and a swarm of sharks would follow, coalescing in what Renaud refers to as a “shark tornado.” It was the first instance Renaud saw grey reef sharks cooperatively hunting, a behavior commonly seen in orcas and dolphins. “We saw these things herding a school of fish” and deflecting fish off one another, he says. “To watch this natural feeding is one of the coolest sights you can see underwater,” he adds. “To see them kind of working towards a fish and then strike it underwater is really remarkable.” The team estimated around 20,000 groupers populated the small pass during the spawning event. Four hundred grey reef sharks followed suit. Surprisingly, the sharks weren’t adept at hunting during the event. The team estimated the sharks were successful only between 5% and 8% of the time. Additionally, the sharks fed almost exclusively on the most abundant fish, and showcased undocumented feeding behaviors, such as pulling prey off the coral reef. Research on the event was published in Coral Reefs, and a documentary using the video footage, “Mysteries of the Coral Canyon,” is slated to air on PBS this month. The highly-anticipated educational tracks for the 2015 R&D 100 Awards & Technology Conference feature 28 sessions, plus keynote speakers Dean Kamen and Oak Ridge National Laboratory Director Thom Mason. Learn more.
News Article | November 16, 2015
As if the world’s coral reefs didn’t have enough problems — killer rising ocean temperatures, crazy bleaching events and oil slicks comprised of sunscreen from sunbathers that denude them, they are now under attack by hordes of thorny sea creatures. That’s what some scientists are calling an explosion of voracious crown-of-thorns sea stars in Maldives that are eating coral reefs with mouths in their stomachs. For some reason — no one quite knows what — their numbers have grown out of control. Where once divers would see one or two eating coral across about a mile, they’re now seeing 100. And a single sea star can produce 50 million eggs per year, scientists said. “Their population is exploding in numbers that haven’t really been seen in the Maldives before,” said Alexandra Dempsey, a coral ecologist for the Khaled bin Sultan Living Oceans Foundation. “They can be clumped in an area with 60 to 80 animals within 20 meters, or four or five animals on one patch of coral. We’ve swam distances of 1,500 meters to collect 100 animals.” The result is a list of major headaches for humans and nature. For Maldives, which took in nearly a billion tourism dollars in 2010, it threatens the economy because coral lures about 800,000 vacationers per year. For coral, it’s the ultimate sacrifice, say scientists who’ve reported a killing field of bleached reefs that stretches for miles. For fish and other animals — sponges, eels, reef sharks, angelfish, it means the loss of their homes, breeding areas and nurseries. “Once the fish lose their home and they have nowhere to live,” Dempsey said, “they’re going to start to die off, affecting the food chain and larger fish.” An organized harvest launched by the foundation Oct. 14 to Nov. 3 netted more than 7,000 animals. “We are … saving hundreds of corals for each starfish that we take off the reef,” said Andrew Bruckner, the chief scientist for the foundation. Sea stars that climb on coral and leave them dead aren’t the only worry. The gigantic El Niño stretching across the Pacific Ocean is warming waters to temperatures coral can’t stand. When it reaches a certain threshold, basically getting too hot, they lose their ability to photosynthesize, break down, die and turn bleach white. The hard part of a coral reef is actually a skeleton upon which a fine, sometimes almost microscopic creature lives. The prickly crown-of-thorns prefers to eat fast-growing coral that make reefs more resilient so that they recover from events such as El Niños. When they’ve chewed up fast-growing coral, they gobble boulder coral, the huge formations that give reefs their photogenic pop and take hundreds of years to grow. So the foundation launched an effort to remove as many crown-of-thorns as they possibly could starting in October and ending this month. It placed an all-points-bulletin for certified scuba divers to help, but when they arrived in Maldives, only divers associated with resorts joined them. Dempsey and Bruckner dove and were astonished to see thousands of sea stars in places they had never seen them. There was a similar outbreak in the mid-1980s, but nothing like this. There have also been outbreaks in Japan and on the Great Barrier Reef, where Australians spend more than $1.5 million each year to remove them, Bruckner said. Bruckner and Dempsey carried plastic pipe to push them off coral and bags to carry them away. The plan was easier said than done. Sea stars really suck. They actually clamp on coral reefs using limbs with thousands of tiny suckers. Those limbs are an evolutionary miracle, or nightmare in this case. Cut one off and it will not only grow back, but it will become another crown-of-thorns sea star. That’s comic book villain kind of scary. “It’s much more exhausting than one would think,” Dempsey said. “We’re on scuba, of course, and the stars can be found from from five meters to 30 meters down.” Most were eight to 10 meters deep, she said. “They’re incredibly strong. If you don’t get them on the first try, they try to hide and get away.” The whole time, divers are fighting ocean currents and waves. They struggled to grab them from underneath the coral and in nooks between. They swam off with 40 to 50 in one bag, sea stars heavy with body weight mostly comprised of water. Dragged out of the ocean, a bag could weigh 50 pounds. Divers dug a foot-deep hole in the sand and buried them. “It is vital that the starfish are not returned to the water as they can recover very easily and return to feeding on coral,” Bruckner said. “Traditionally we would never have believed that removing starfish would be the appropriate measure,” he added. “We must stress that we do not like killing any animals, and we do regret killing these starfish. But because coral reef ecosystems are out of balance, and humans are causing imbalances in nutrients that increase the survival of crown-of-thorns larvae, then we see this as the only feasible option.” How we are all contributing to the destruction of coral reefs: Sunscreen Sea stars are wasting away on a wide scale in two oceans Crabs are bulking up on carbon pollution to become giants
Purkis S.J.,Nova Southeastern University |
Rowlands G.P.,Nova Southeastern University |
Riegl B.M.,Nova Southeastern University |
Renaud P.G.,Khaled bin Sultan Living Oceans Foundation
Geology | Year: 2010
Despite differences in reef growth between the Arabian Gulf and the Red Sea, a common distinctive pattern of polygonal sills surrounding ponded depressions consistently occurs in shallow water. Viewed from a satellite, these seafloors are reticulated and maze like. Despite little current rainfall, this patterning is best explained by karst dissolution of limestone during periods of lower sea level. This is a paradox since such fine-scale karstification is confined to areas with considerably more precipitation than currently observed in Arabia. We resolve this apparent contradiction by developing a Pleistocene-Holocene chronology of sea level and climate for the Red Sea and Arabian Gulf, and through the use of pattern analysis and computer simulation, reveal the mechanism of formation for these structures. We demonstrate that this patterning can be taken as a Quaternary signature of paleohumidity in the now hyperarid Red Sea and Arabian Gulf. © 2010 Geological Society of America.
Riegl B.M.,Nova Southeastern University |
Bruckner A.W.,Khaled bin Sultan Living Oceans Foundation |
Rowlands G.P.,Nova Southeastern University |
Purkis S.J.,Nova Southeastern University |
Renaud P.,Khaled bin Sultan Living Oceans Foundation
PLoS ONE | Year: 2012
Three independent line intercept transect surveys on northern Red Sea reef slopes conducted in 1988/9 and 1997/8 in Egypt and from 2006-9 in Saudi Arabia were used to compare community patterns and coral size. Coral communities showed scale-dependent variability, highest at fine spatial and taxonomic scale (species-specific within and among reef patterns). At coarser scale (generic pattern across regions), patterns were more uniform (regionally consistent generic dominance on differently exposed reef slopes and at different depths). Neither fine- nor coarse-scale patterns aligned along the sampled 1700 km latitudinal gradient. Thus, a latitudinal gradient that had been described earlier from comparable datasets, separating the Red Sea into three faunistic zones, was no longer apparent. This may indicate subtle changes in species distributions. Coral size, measured as corrected average intercept of corals in transects, had decreased from 1997 to 2009, after having remained constant from 1988 to 1997. Recruitment had remained stable (~12 juvenile corals per m2). Size distributions had not changed significantly but large corals had declined over 20 years. Thus, data from a wide range of sites taken over two decades support claims by others that climate change is indeed beginning to show clear effects on Red Sea reefs. © 2012 Riegl et al.
Bruckner A.W.,Khaled bin Sultan Living Oceans Foundation
Current Opinion in Environmental Sustainability | Year: 2014
Precious corals in the family Corallidae have a long history of exploitation characterized by boom and bust cycles. Past approaches to manage these fisheries, including gear restrictions, limits on effort, defined fishing areas, quotas, and size limits, have been ineffective at preventing overharvest. The US and EU responded in 2007 and 2009 by proposing trade restrictions through a CITES Appendix II listing. The industry vehemently opposed this, claiming that available data do not meet the criteria for a CITES listing and advocating for local management. Yet, management measures implemented since 2009 fall short of conservation needs. In the Mediterranean, a recommended 10. mm minimum diameter was not adopted. A no fishing zone extends to 50. m instead of the recommended 80. m, but poaching in shallow water is widespread; new (deeper) areas are being exploited without initial stock assessments. Also in the Pacific, disconcerting trends are observed. -the size structure of populations is being altered and landings consist of declining numbers of live corals. Unless harvest guidelines are revised using models which incorporate new information on biological attributes, genetics, and stock assessments, fished areas are likely to continue to be quickly depleted. © 2013 Elsevier B.V.
Bruckner A.W.,Khaled Bin Sultan Living Oceans Foundation
Marine Ecology Progress Series | Year: 2010
In the comment on Bruckner (2009; Mar Ecol Prog Ser 397:319-332), Santangelo & Bramanti (2010; Mar Ecol Prog Ser 418:295-297) suggest that the available data for Corallium rubrum populations cannot be used to make conclusions about population trends for the species throughout the Mediterranean. Their main concerns relate to (1) different methodologies used to sample populations; (2) insufficient population information from deep water; and (3) limited data on sampling area and density of colonies. While I recognize many of the limitations of the data, the conclusions in Bruckner (2009) were based on multiple datasets, including population demography and reproductive patterns, as well as landings data, trade statistics and biological information. The primary comparison involves differences between depths, levels of fishing pressure, and historic populations using information from representative habitats off Costa Brava, Spain; recent data were collected using similar methods and included size structure, reproductive information, and density and abundance of colonies. At the time of Bruckner (2009), most fisheries were in shallow water (<70 m depth), but they were already progressively expanding into deeper areas. Since publication of the manuscript, the fishery for C. rubrum has entered a new phase, SCUBA fishing using mixed gases and new technology (e.g. ROVs) to reach greater depths (70 to 150 m) and increase landings, mostly because shallow populations have been overharvested. This new trend is problematic, because the science does not exist to determine sustainable harvest levels at these depths. © Inter-Research 2010.
Robbins W.D.,Wildlife Marine |
Renaud P.,Khaled Bin Sultan Living Oceans Foundation
Coral Reefs | Year: 2016
Knowledge of an animal’s predatory interactions provides insight into its ecological role. Until now, investigation of reef shark predation has relied on artificial stimuli to facilitate feeding events, with few sightings of natural predation events. Here we document two different foraging modes of the grey reef shark, Carcharhinus amblyrhynchos (f. Carcharhinidae), recorded without the influence of baits or burley. The first mode saw an aggregation of sharks targeting a morning mass spawning event of marbled grouper (f. Serranidae). We observed 120 separate grouper spawns over a 104-min period. Detailed analysis of 52 spawns showed an average of five groupers and 2.7 sharks involved in each spawn, with sharks usually on site within 1.29 s of spawn initiation. The success rate of investigating sharks was relatively low (8.1 %), and conspecific competition, rather than cooperative behaviour, was repeatedly observed among sharks. The second foraging mode documented was the nocturnal predation of individual fishes in the same reef pass 2 weeks later. Here, 128 separate fish pursuits were observed, with fusiliers (f. Caesionidae) comprising 88 % of targeted individuals. Multiple sharks usually investigated each fish, with over 300 interaction events recorded. Over 100 bite attempts were observed, and again the rate of predation was low, with fish taken in only 5.3 % of investigations (16 % of attempted bites). Our findings show that grey reef sharks naturally prey on species across a range of trophic levels, employing foraging techniques optimised for prey species and circumstance. Although a high-order mesopredator, the low rates of predation success observed suggest that grey reef sharks may have limited direct impact on lower-trophic-order species; however, this remains to be verified. © 2015, Springer-Verlag Berlin Heidelberg.
Rowlands G.,Nova Southeastern University |
Rowlands G.,Rowlands Ecology Ltd. |
Purkis S.,Nova Southeastern University |
Bruckner A.,Khaled bin Sultan Living Oceans Foundation
Marine Pollution Bulletin | Year: 2016
Lack of knowledge on the conservation value of different reef types can stymie decision making, and result in less optimal management solutions. Addressing the information gap of coral reef resilience, we produce a map-based Remote Sensed Resilience Index (RSRI) from data describing the spatial distribution of stressors, and properties of reef habitats on the Farasan Banks, Saudi Arabia. We contrast the distribution of this index among fourteen reef types, categorized on a scale of maturity that includes juvenile (poorly aggraded), mature (partially aggraded), and senile (fully aggraded) reefs. Sites with high reef resilience can be found in most detached reef types; however they are most common in mature reefs. We aim to stimulate debate on the coupling that exists between geomorphology and conservation biology, and consider how such information can be used to inform management decisions. © 2015 Elsevier Ltd.
Bruckner A.W.,Khaled bin Sultan Living Oceans Foundation
Revista de Biologia Tropical | Year: 2012
The progressive downward shift in dominance of key reef building corals, coupled with dramatic increases in macroalgae and other nuisance species, fields of unstable coral rubble,2, and declines of major functional groups of fishes is a common occurrence throughout the Caribbean today. The incorporation of resilience principles into management is a proposed strategy to reverse this trend and ensure proper functioning of coral reefs under predicted scenarios of climate change, yet ecosystem processes and functions that underlie reef resilience are not fully understood. Rapid assessments using the Atlantic and Gulf Rapid Reef Assessment (AGRRA) and the IUCN Resilience Assessment protocol can provide baseline information on reef resilience. A key aspect of these surveys focuses on coral population dynamics, including measures of coral cover, size, partial and whole-colony mortality, condition, and recruitment. One challenge is that these represent static measures involving a single assessment. Without following individual corals over time, it is difficult to determine rates of survival and growth of recruits and adult colonies, and differentiation of juveniles from small remnants of older colonies may not be possible, especially when macroalgal cover is high. To address this limitation, corals assessed in Bonaire in July 2010 were subdivided into two categories: 1) colonies on the reef substrate; and 2) colonies colonizing dead corals and exposed skeletal surfaces of living corals. Coral populations in Bonaire exhibited many features indicative of high resilience, including high coral cover (often 30-50%), high levels of recruitment, and a large number of corals that settled on dead corals and survived to larger size-classes. Overall, the skeletal surfaces of 12 species of corals were colonized by 16 species of corals, with up to 12 settlers on each colony, most (67%) on M. annularis (complex) skeletons. Nevertheless, completely dead M. annularis colonies were common, survivors were frequently reduced in size and subdivided into smaller tissue remnants, and these species exhibited higher amounts of partial mortality than all other spe- cies. A notable absence of sexual recruits and juveniles of M. annularis illustrates a progressive shift away from a Montastraea dominated system. This shift, characterized by an increasing dominance of smaller, short-lived species such as Agaricia and Porites and a reduction in size of longer-lived massive corals, is occurring through- out the Caribbean. Monitoring of the survival of recruits is necessary to determine whether Caribbean reefs will retain the same function, structure, identity and feedbacks (key signs of resilience) if the losses of M. annularis (complex) continue at present levels. The rapid assessment protocol utilized here allows characterization of colony size structure, partial mortality, recruitment, and whether small corals represent surviving recruits that increased in size or larger (older) colonies that continue to shrink in size. This approach can help determine the history of a site and its resilience.