30 research outputs found
Field manual for investigating coral disease outbreaks
Coral reefs throughout their circumtropical range are declining at an accelerating rate. Recent predictions indicate that 20% of the world’s reefs have been degraded, another 24% are under imminent risk of collapse, and if current estimates hold, by 2030, 26% of the world’s reefs will be lost (Wilkinson 2004). Recent changes to these ecosystems have included losses of apex predators, reductions of important herbivorous fishes and invertebrates, and precipitous declines in living coral cover, with many reefs now dominated by macroalgae. Causes have been described in broad sweeping terms: global climate change, over-fishing and destructive fishing, land-based sources of pollution, sedimentation, hurricanes, mass bleaching events and disease. Recognition that corals can succumb to disease was first reported in the early 1970’s. Then it was a unique observation, with relatively few isolated reports until the mid 1990’s. Today disease has spread to over 150 species of coral, reported from 65 countries throughout all of the world’s tropical oceans (WCMC Global Coral Disease Database). While disease continues to increase in frequency and distribution throughout the world, definitive causes of coral diseases have remained elusive for the most part, with reef managers not sufficiently armed to combat it
Development of peach flower buds under low winter chilling conditions
Here, we reviewed both endogenous and exogenous factors involved in the processes of flower bud formation and flower development in peach, analyzing how they can be affected by climatic change in temperate zones, explored the expansion of peach to tropical or subtropical zones. The process of flower bud formation in peach differs between low winter chilling and temperate conditions. Although the main steps of flower development are maintained, the timing in which each one occurs is different, and some processes can be altered under low winter chilling conditions, with a great impact on fruit production and crop management. Further studies on flower bud induction and differentiation under warmer conditions are fundamental for addressing the alterations in flower bud development that negatively impact on next season’s harvest. In the future, horticulturalists and scientists will face several challenges, mainly how high temperatures affect the expression of the main genes regulating flower formation and how to improve crop management in these conditions
The importance of the marine ornamental reef fish trade in the wider Caribbean
The marine ornamental fish trade began in the 1930s in Sri Lanka,spread to Hawaii and the Philippines in the 1950s,and expanded to a multi-million dollar industry in the 1970s with fisheries established throughout the tropical Pacific,Indian and Atlantic Oceans.Currently,45 countries supply global markets an estimated 14-30 million fish annually,with an import value of US28- 44 millones.Los mayores exportadores son Indonesia y Filipinas,seguidos por Brasil,Maldivas,Vietnam,Sri Lanka y Hawai.En el Atlántico Occidental tropical,16 países tienen pesquerías de exportación,incluyendo a los Estados Unidos (Florida y Puerto Rico).Estados Unidos es el mayor comprador,seguido de la Unión Europea y Japón. El comercio mundial consiste de más de 1400 especies de peces de arrecife,de las cuales solamente alrededor de 25 son criadas comercialmente.Los peces damiselas, los peces de anémonas y los ángeles,constituyen más del 50%del volumen mundial;mariposas,lábridos,blénidos, góbidos,chanchos,limas,meritos,meros y cabrillas suman el 31%del mercado y el restante 16%está representado por 33 familias.Los peces más importantes del Caribe son los ángeles (seis especies),caballitos de mar (dos especies), bocones,pez chancho reina,blénido de labios rojos, cabeza azul y cromis azul.En la actualidad,el Caribe suple sólo un pequeño porcentaje del mercado mundial de especies ornamentales marinas,sin embargo,las pesquerías ornamentales en esta región representan importantes industrias emergentes.Es crítico que se desarrollen y refuercen planes y regulaciones de manejo efectivos de pesquerías ornamentales y que se recolecte información pesquero-dependiente y pesquero-independiente,que sirva para ser utilizada en los procesos de toma de decisiones,asegurando la sostenibilidad en las pesquerías ornamentales de la región
Dynamics of seasonal outbreaks of black band disease in an assemblage of Montipora species at Pelorus Island (Great Barrier Reef, Australia)
Recurring summer outbreaks of black band disease (BBD) on an inshore reef in the central Great Barrier Reef (GBR) constitute the first recorded BBD epizootic in the region. In a 2.7 year study of 485 colonies of Montipora species, BBD affected up to 10 per cent of colonies in the assemblage. Mean maximum abundance of BBD reached 16±6 colonies per 100 m2 (n=3 quadrats, each 100 m2) in summer, and decreased to 0–1 colony per 100 m2 in winter. On average, BBD lesions caused 40 per cent tissue loss and 5 per cent of infections led to whole colony mortality. BBD reappearance on previously infected colonies and continuous tissue loss after the BBD signs had disappeared suggest that the disease impacts are of longer duration than indicated by the presence of characteristic signs. Rates of new infections and linear progression of lesions were both positively correlated with seasonal fluctuations in sea water temperatures and light, suggesting that seasonal increases in these environmental parameters promote virulence of the disease. Overall, the impacts of BBD are greater than previously reported on the GBR and likely to escalate with ocean warming