Entity

Time filter

Source Type

Landover, MD, United States

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. Source


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. Source


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. Source


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. Source


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. Source

Discover hidden collaborations