Large-scale associations between macroalgal cover and grazer biomass on mid-depth reefs in the Caribbean

Coral Reefs ◽  
2001 ◽  
Vol 19 (4) ◽  
pp. 358-366 ◽  
Author(s):  
I. Williams ◽  
N. Polunin
2020 ◽  
Vol 63 (6) ◽  
pp. 537-540
Author(s):  
Fee O.H. Smulders ◽  
Kelcie L. Chiquillo ◽  
Demian A. Willette ◽  
Paul H. Barber ◽  
Marjolijn J.A. Christianen

AbstractThe dioecious seagrass species Halophila stipulacea reproduces mainly through fast clonal growth, underlying its invasive behavior. Here, we provide morphological evidence to show that the first findings of fruits in the Caribbean were misidentified. Consequently, H. stipulacea reproduction is likely still only asexual in the Caribbean. Therefore, we introduce an identification key of H. stipulacea reproductive structures to encourage careful identification and quantification throughout its invasive range. Until large-scale seed production in invaded habitats is reported, the apparent low rate of sexual reproduction needs to be considered in current studies investigating the invasion capacity of this species.


Author(s):  
Ida Altman

The arrival of Christopher Columbus in the northern Caribbean with three Spanish ships in October 1492 marked the beginning of continuing European contact with the Americas. With his second voyage of 1493 permanent European occupation of the Caribbean began, with enormous consequences for the peoples and ecology of the region. Failing to encounter the wealthy trading societies that Columbus had hoped to find by reaching Asia, Europeans in the Caribbean soon realized that they would have to involve themselves directly in organizing profitable enterprises. Gold mining in the northern islands and pearl fishing in the islands off the coast of Tierra Firme (present-day Venezuela) for some years proved enormously profitable but depended on Spaniards’ ability to exploit indigenous labor on a large scale. The imposition of the Spanish encomienda system, which required indigenous communities to provide labor for mining and commercial agriculture, and the large-scale capture and transportation of Native Americans from one locale to another wrought havoc among the indigenous peoples of the Caribbean and circum-Caribbean, resulting in high mortality and flight. Spaniards in the islands soon sought to supplement indigenous labor by importing African slaves who, in the early 16th century, became a significant if not always easily controlled presence in the region. From the earliest years the Spanish Caribbean was a complex, dynamic, and volatile region characterized by extensive interaction and conflict among diverse groups of people and by rapid economic and institutional development. Although the islands became the launching grounds for subsequent Spanish moves to the nearby mainland, throughout the 16th century and beyond they played a crucial role in sustaining Spain’s overseas empire and integrating it into the larger Atlantic system.


Author(s):  
Tempest Anderson ◽  
John Smith Flett

The islands of the Caribbean chain have been occupied by European colonists for several hundred years, yet they cannot even at the present day be said to be thoroughly known or sufficiently explored. Though small, they are for the most part moun­tainous, and present usually a ridge or backbone of high land forming the main axis of each island, with sharp spurs on each side running down to the sea. Cul­tivation is practically confined to the lower grounds, where alone there are goodroads, and the interior is covered with dense tropical forest, the aspect of which varies greatly with the altitude, and through which there are only rough bush paths. The valleys are usually very deep and narrow, and the steep slopes are covered with plantations of arrowroot, limes, cocoa, coffee, banana or plantain, while most of the level alluvial ground in the valley bottoms is given up to the growth of sugar cane. In all the British islands, at any rate, the principal peaks and ridges have been ascended, and the main features of the country are delineated on the Admiralty charts, which are the best, and in fact the only available maps. As regards the coast-lines and the lower grounds generally, they are very accurate; but in theinterior only the more important points, the principal mountain summits and the like, have had their position sufficiently determined. The rest of the country has apparently been sketched in more or less carefully—but many of the details as, for example, the courses of the smaller streams, and the number of their branches, cannot be relied on. The want of a good map on a fairly large scale is a great drawback in geological work, and prevents the structure of the country being laid down with anyapproach to minuteness.


2009 ◽  
Vol 22 (8) ◽  
pp. 2216-2239 ◽  
Author(s):  
Man-Li C. Wu ◽  
Siegfried D. Schubert ◽  
Max J. Suarez ◽  
Norden E. Huang

Abstract This study examines the nature of episodes of enhanced warm-season moisture flux into the Gulf of California. Both spatial structure and primary time scales of the fluxes are examined using the 40-yr ECMWF Re-Analysis data for the period 1980–2001. The analysis approach consists of a compositing technique that is keyed on the low-level moisture fluxes into the Gulf of California. The results show that the fluxes have a rich spectrum of temporal variability, with periods of enhanced transport over the gulf linked to African easterly waves on subweekly (3–8 day) time scales, the Madden–Julian oscillation (MJO) at intraseasonal time scales (20–90 day), and intermediate (10–15 day) time-scale disturbances that appear to originate primarily in the Caribbean Sea–western Atlantic Ocean. In the case of the MJO, enhanced low-level westerlies and large-scale rising motion provide an environment that favors large-scale cyclonic development near the west coast of Central America that, over the course of about 2 weeks, expands northward along the coast eventually reaching the mouth of the Gulf of California where it acts to enhance the southerly moisture flux in that region. On a larger scale, the development includes a northward shift in the eastern Pacific ITCZ, enhanced precipitation over much of Mexico and the southwestern United States, and enhanced southerly/southeasterly fluxes from the Gulf of Mexico into Mexico and the southwestern and central United States. In the case of the easterly waves, the systems that reach Mexico appear to redevelop/reorganize on the Pacific coast and then move rapidly to the northwest to contribute to the moisture flux into the Gulf of California. The most intense fluxes into the gulf on these time scales appear to be synchronized with a midlatitude short-wave trough over the U.S. West Coast and enhanced low-level southerly fluxes over the U.S. Great Plains. The intermediate (10–15 day) time-scale systems have zonal wavelengths roughly twice that of the easterly waves, and their initiation appears to be linked to an extratropical U.S. East Coast ridge and associated northeasterly winds that extend well into the Caribbean Sea during their development phase. The short (3–8 day) and, to a lesser extent, the intermediate (10–15 day) time-scale fluxes tend to be enhanced when the convectively active phase of the MJO is situated over the Americas.


1997 ◽  
Vol 48 (8) ◽  
pp. 807 ◽  
Author(s):  
R. N. Lipcius ◽  
W. T. Stockhausen ◽  
D. B. Eggleston ◽  
L. S. Marshall Jr ◽  
B. Hickey

Marine species possess dispersive stages that interconnect subpopulations, which may inhabit ‘source’ and ‘sink’ habitats, where reproduction and emigration either exceed or fall short of mortality and immigration, respectively. Postlarval supply, juvenile density and adult abundance of the Caribbean spiny lobster, Panulirus argus, were measured at four widely separated sites spanning >100 km in Exuma Sound, Bahamas. Adult abundance was lowest at a site with the highest postlarval supply and little nursery habitat; hence, it was tentatively classified as a sink. Circulation in Exuma Sound is dominated by large-scale gyres which apparently concentrate and advect postlarvae toward the nominal sink. The remaining three sites, including one marine reserve, had higher adult abundances despite lower postlarval supply, and are therefore tentatively classified as sources. Postlarval supply is probably decoupled from adult abundance by physical transport. Adult abundance is likely decoupled from postlarval supply by the effects of varying habitat quality upon postlarval and juvenile survival, as indicated by non-significant differences among sites in juvenile density. It appears that some sites with suitable settlement and nursery habitat are sources of spawning stock for Panulirus argus, whereas others with poor habitat are sinks despite sufficient postlarval influx.


2016 ◽  
Author(s):  
Ana María Durán-Quesada ◽  
Luis Gimeno ◽  
Jorge Amador

Abstract. A climatology of moisture sources linked with Central American precipitation was computed based upon Lagrangian trajectories for the analysis period 1980–2013. The response of the annual cycle of precipitation in terms of moisture supply from the sources was analysed. Regional precipitation patterns are mostly driven by moisture transport from the Caribbean Sea (CS). Moisture supply from the Eastern Tropical Pacific (ETPac) and Northern South America (NSA) exhibits a strong seasonal pattern but weaker compared to CS. The regional distribution of rainfall is largely influenced by a local signal associated with surface fluxes during the first part of the rainy season, whereas large scale dynamics forces rainfall during the second part of the rainy season. The Caribbean Low Level Jet (CLLJ) and the Chocó Jet (CJ) are the main conveyors of regional moisture, being key to define the seasonality of large scale forced rainfall. Therefore, interannual variability of rainfall is highly dependent of the regional LLJs to the atmospheric variability modes. The El Niño-Southern Oscillation (ENSO) was found to be the dominant mode affecting moisture supply for Central American precipitation via the modulation of regional phenomena. Evaporative sources show opposite anomaly patterns during warm and cold ENSO phases, as a result of the strengthening and weakening, respectively, of the CLLJ during the summer months. Trends in both moisture supply and precipitation over the last three decades were computed, results suggest that precipitation trends are not homogeneous for Central America. Trends in moisture supply from the sources identified show a marked north-south seesaw, with an increasing supply from the Caribbean Sea to northern Central America. Long term trends in moisture supply are larger for the transition months (March and October). This might have important implications given that any changes in the conditions seen during the transition to the rainy season may induce stronger precipitation trends.


2005 ◽  
Vol 79 (1-2) ◽  
pp. 79-90
Author(s):  
John P. Homiak

Drawing increasingly upon digital technologies and the internet to assert a sense of community even as they cultivate an austere biblical persona, adherents of Rastafari can be thought of as simultaneously modern and antique. Their claim to antiquity is grounded in a collectively professed African-Ethiopian identity that has not only resisted the ravages of enslavement, colonialism, and European cultural domination but is seen to transcend local differences of culture and language. Theirs is a way of life organized around theocratic principles that begin with a recognition of the divine in all peoples and as the basis of all human agency. Rastafari assert the universal relevance of these principles to the conditions of modernity even as they persistently claim social justice on behalf of all peoples of African descent exploited by colonialism and the prevailing global capitalist-imperialist system. Based on these general themes, the Rastafari movement has come to represent a large-scale cultural phenomenon that has long since burst the chains of its colonial containment in Jamaica. From the late 1960s onward it has spread throughout the Caribbean and the Central and South American rimland to the major metropoles of North America and Europe as well as to many sites on the African continent.


2021 ◽  
Author(s):  
Olivier Bock ◽  
Pierre Bosser ◽  
Cyrille Flamant ◽  
Erik Doerflinger ◽  
Friedhelm Jansen ◽  
...  

Abstract. Ground-based Global Navigation Satellite System (GNSS) measurements from nearly fifty stations distributed over the Caribbean Arc have been analysed for the period 1 January–29 February 2020 in the framework of the EUREC4A (Elucidate the Couplings Between Clouds, Convection and Circulation) field campaign. The aim of this effort is to deliver high-quality Integrated Water Vapour (IWV) estimates to investigate the moisture environment of mesoscale cloud patterns in the Tradewinds and their feedback on the large-scale circulation and energy budget. This paper describes the GNSS data processing procedures and assesses the quality of the GNSS IWV retrievals from four operational streams and one reprocessed research stream which is the main data set used for offline scientific applications. The uncertainties associated with each of the data sets, including the zenith tropospheric delay (ZTD) to IWV conversion methods and auxiliary data, are quantified and discussed. The IWV estimates from the reprocessed data set are compared to the Vaisala RS41 radiosonde measurements operated from the Barbados Cloud Observatory (BCO) and to the measurements from the operational radiosonde station at Grantley Adams international airport (GAIA). A significant dry bias is found in the GAIA humidity observations with respect to the BCO sondes (−2.9 kg m−2) and the GNSS results (−1.2 kg m−2). A systematic bias between the BCO sondes and GNSS is also observed (1.7 kg m−2) where the Vaisala RS41 measurements are moister than the GNSS retrievals. The IWV estimates from a colocated microwave radiometer agree with the BCO soundings after an instrumental update on 27 January, while they exhibit a dry bias compared to the soundings and to GNSS before that date. IWV estimates from the ECMWF fifth generation reanalysis (ERA5) are overall close to the GAIA observations, probably due to the assimilation of these observations in the reanalysis. However, during several events where strong peaks in IWV occurred, ERA5 is shown to significantly underestimate the GNSS derived IWV peaks. Two successive peaks are observed on 22 January and 23/24 January which were associated with heavy rain and deep moist layers extending from the surface up to altitudes of 3.5 and 5 km, respectively. ERA5 significantly underestimates the moisture content in the upper part of these layers. The origins of the various moisture biases are currently being investigated. We classified the cloud organisation for five representative GNSS stations across the Caribbean Arc and found that the environment of Fish cloud patterns to be moister than that of Flowers cloud patterns which, in turn, is moister than the environment of Gravel cloud patterns. The differences in the IWV means between Fish and Gravel were assessed to be significant. Finally, the Gravel moisture environment was found to be similar to that of clear, cloud-free conditions. The moisture environment associated with the Sugar cloud pattern has not been assessed because it was hardly observed during the first two months of 2020. The reprocessed ZTD and IWV data set from 49 GNSS stations used in this study are available from the AERIS data center (https://doi.org/10.25326/79; Bock (2020b)).


2017 ◽  
Vol 8 (1) ◽  
pp. 147-161 ◽  
Author(s):  
Ana María Durán-Quesada ◽  
Luis Gimeno ◽  
Jorge Amador

Abstract. A climatology of moisture sources linked with Central American precipitation was computed based upon Lagrangian trajectories for the analysis period 1980–2013. The response of the annual cycle of precipitation in terms of moisture supply from the sources was analysed. Regional precipitation patterns are mostly driven by moisture transport from the Caribbean Sea (CS). Moisture supply from the eastern tropical Pacific (ETPac) and northern South America (NSA) exhibits a strong seasonal pattern but weaker compared to CS. The regional distribution of rainfall is largely influenced by a local signal associated with surface fluxes during the first part of the rainy season, whereas large-scale dynamics forces rainfall during the second part of the rainy season. The Caribbean Low Level Jet (CLLJ) and the Chocó Jet (CJ) are the main conveyors of regional moisture, being key to define the seasonality of large-scale forced rainfall. Therefore, interannual variability of rainfall is highly dependent of the regional LLJs to the atmospheric variability modes. The El Niño–Southern Oscillation (ENSO) was found to be the dominant mode affecting moisture supply for Central American precipitation via the modulation of regional phenomena. Evaporative sources show opposite anomaly patterns during warm and cold ENSO phases, as a result of the strengthening and weakening, respectively, of the CLLJ during the summer months. Trends in both moisture supply and precipitation over the last three decades were computed, results suggest that precipitation trends are not homogeneous for Central America. Trends in moisture supply from the sources identified show a marked north–south seesaw, with an increasing supply from the CS Sea to northern Central America. Long-term trends in moisture supply are larger for the transition months (March and October). This might have important implications given that any changes in the conditions seen during the transition to the rainy season may induce stronger precipitation trends.


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