Alcolado, P.M., R. Claro, G. Menßndez, P. García-Parrado and
B. Martínez-Daranas.
Institute of Oceanology, Ministry of Science, Technology and Environment
1st Ave. No.18406, Playa, Havana, CUBA
Despite their fairly good general condition, Cuban coral reefs are suffering some degree of deterioration. Great extensions of wide shallow shelves, with surrounding chains of bordering keys, act as a buffer that limits the terrestrial impact on coral reefs (e.g. pollution, sedimentation, direct human influence, etc.). However, the proliferation and dominance of algae at some locations may be because of synergic action of the black urchin die-off and local fairly high concentrations of phosphates. Intense mortality of Acropora palmata was observed in several but not all places of the north and south coasts of Cuba. Over-fishing affects some coral reef populations (Nassau grouper and sharks). Management of coral reefs has not been specifically directed, nor did not it have a systemic and comprehensive approach. Recently, a joint resolution of the Ministry of Fisheries Industry and the Ministry of Science, Technology and Environment established important regulations for the protection and sustainable use of coral reefs. Some additional degree of protection is achieved by fishing regulations; the existing legislation on pollution, collection of marine life, and environmental impact assessment; and the commitments with some international treaties as CITES and the Convention on Biological Diversity. The Cuban Environmental Agency is presently formulating plans and a new legislation for protecting marine ecosystems. Reef research in Cuba is considered of great importance by the Ministry of Science, Technology and Environment but is still fragmentary due to the lack of resources.
Bryant, D., L. Burke, J. McManus, and M. Spalding.
World Resources Institute
1709 New York Avenue, NW, Washington, DC 20006.
"Reefs at Risk, a Map-based Indicator Analysis of Potential Threats to the World's Coral Reefs" will be released by the World Resources Institute on June 23, 1998. This is a first-of-its-kind, standardized, global assessment of anthropogenic threats to coral reefs from coastal development, marine pollution, overexploitation, destructive fishing, and inland (upstream) pollution and sedimentation. The analysis is intended to help fill an information gap, while the majority of the world's reefs remain unassessed. The Reefs at Risk analysis makes use of 14 data sets (including maps of land cover, ports, mines, settlements, and shipping lanes), information on 800 sites known to be degraded by people, and scientific expertise to model areas where reef degradation is predicted to occur, given existing human pressures on these areas. The World Conservation Monitoring Centre's "Shallow Coral Reefs of the World" was the base data set for this analysis. Over 55,000 reef locations were classified by estimated degree of threat. Results are an indicator of potential threats, not a measure of actual condition. Mapped results of the Reefs at Risk analysis will be presented for the globe and the Caribbean.
The Reefs at Risk analysis also made use of data on reef fish species diversity to examine areas of high diversity in light of the estimates of threat to coral reefs. Coupling this data with information on protection status allows for a preliminary analysis of threats to reefs and management response in some of the most biologically diverse marine areas.
Claro. R. F. M.
Laboratorio de Vigilancia Radiologica Ambiental.
CITMA. Juragua. Cienfuegos. Cuba.
On 18 October 1996 a strong storm passed over Cuba, the first contact with land was Cienfuegos Province. Winds reached 180/200 km/hr and waves over 7m were recorded. Due to this exceptional natural phenomenon the coral reef ecosystem was severely damaged along the Cienfuegos coastal region. In order to assess this damage: density, diversity index and percent cover was compared before and after the storm in Guajimico Villa. Both short-term effects and long-term effects after Hurricane Lili were found. The most useful variable was the stony coral cover percentage changed from 17.68/38.35% before the storm to 3.3/26.35% after the storm, the result of diversity index H' and J' calculation were similar from H'=2.08/2.39 and J'=0.79/0.89 to H'=2.03/2.47 and J'=0.82/0.88 because the coral colony density was similar due to coral recruitment. The hard corals most injured were Acropora cervicornis and Porites porites. The wave energy and the dislodged material that they carried devastated Dendrogyra cylindrus and Millepora alcicornis colonies near the coastline.
Claro, R.
Instituto de Oceanología.
Ministerio de Ciencia, Tecnología y Medio Ambiente de Cuba.
1ra. No. 18406. Rpto. Flores, Playa. Ciudad Habana. Cuba.
Reef fish community structure in different zones of the Cuban Archipelago was studied by visual census. Data were comparable between zones and between different reef habitats. Similar surveys where done on slope reefs from Martinique, Guadeloupe, and Key West, Florida. Strip transects, 100m X 6m, were made by two divers. On Cuban reefs, larger differences in community structure (species composition, species richness, density and biomass) were found within reef habitats than among geographical zones in the same reef habitat. Fish species composition on slope reefs was quite similar between the four countries, but there were important differences in the proportion of each species. Fish density was higher in Martinique, due to a great abundance of Chromis multilineatus, but fish biomass and diversity was two orders higher in Cuba and Florida. The presence of herbivores and predators in Guadeloupe and Martinique was very low and the presence of algae on these reefs is higher in comparison with the others. Snappers, groupers, jacks and other medium and large fishes in the Lesser Antilles are scarce, while in Cuba and Florida they are still relatively common. This is due to the overexploitation of the ecosystem in the former islands. Even when fisheries productivity per unit area is higher in the Lesser Antilles (Martinique, Guadeloupe, St. Lucia, Jamaica and other islands), it is based on smaller sizes and lower quality fishes. Fish catches/trap/day in Cuba are 30-40 times higher than in Martinique and Jamaica, but large proportions of the catch are not considered suitable for consumption in Cuba and these species are released alive.
Cortes, J.
Centro de Investigacion en Ciencias del Mar y Limnologia (CIMAR), and
Escuela de Biologia Universidad de Costa Rica, San Pedro, Costa Rica
Coral reefs, in different states of development, exist in the Central American region. These reefs are composed of coral species typical of the Caribbean and consist mainly of barrier and fringing reefs, with several atolls and carbonate platforms. Most coral reefs in the region are still in relatively good condition. The main stress is human related: siltation and fishing (use of destructive gear and overfishing). The degree of protection and awareness of the reefs varies widely in the region. At the present time, there seems to be a local and international interest in the study and conservation of the Central American coral reefs.
Firman, J., P. Glynn, L. Ferrer.
Rosenstiel School of Marine and Atmospheric Science, University of Miami
4600 Rickenbacker, Miami, FL 33149.
Line transects and a census of coral condition (% live coral) and size (maximum diameter) were conducted at 28 sites on 10 reefs off the southwest coast of Puerto Rico. Percent cover by Acroporo palmata ranged from 1-50%. Total coral cover ranged from 5-62%. Percent coral cover tended to be higher on the inner reefs (40+/-15%) than on the outer reefs (31+/-12%). Cover also tended to be higher on the western versus the eastern ends of outside reefs. Montastraea faveolata was the predominant coral at deeper sites on Cayo Laurel (30% cover). Size distributions were plotted for 12 scleractinian species. All coral species surveyed were generally in good condition (>65% live tissue). These results were compared to prior studies carried out at these sites over the last 30 years. Despite the occurrence of several destructive events, coral cover is high and corals are in good condition in many areas, although distributions are very patchy. The long- term effects of strong events are still evident on the exposed outer reefs.
Galvis Castro, N.
Instituto Nacional de Pesca y Acuicultura, Gobierno de Colombia
Diagonal 27 No. 15-09, Santafé de Bogotá, Colombia
The international event REEF CHECK 97 integrated socioeconomic and ecological variables to increase the awareness of Colombian citizens and foreign tourists in order to facilitate appropriate coastal management. Coral reefs in Colombia have high economic value for fisheries and tourist activities. It is necessary to assure their sustainable exploitation.
A team of marine biologists surveyed the southern part of the reef flats of Pavitos Islands in the Park Corales del Rosario. Hard coral cover was high, following by a low-medium cover of sponges and fleshy algae. These low-medium cover and 5% coral bleaching are related to the siltation and enrichment phenomenon caused by the artificial mouth of the Magdalena river located at 45 km. Abundant ophiurods were associated with the sponges and 27 Diadema urchins were found on the belt transect located at 3 m of depth and none at 10 m. Lutjanidae was the most abundant commercial fishes with densities of 89 fishes at 10m and 8 fishes at 3m. Few groupers (4) were found in each belt transect none bigger than 40 cm long. To evaluate the environmental quality of these reefs' is necessary to monitor their changes in structure. Comparisons in time and space will advise appropriate management plans.
Garzón-Ferreira, J., S. Zea and J.M. Díaz.
INVEMAR, AA 1016, Santa Marta, Colombia
Four southwestern Caribbean atolls (Albuquerque, Courtown, Roncador and Serrana) were visited in 1994-95 to evaluate the status of coral reefs. Within this, a study of the health condition of hard corals (Cnidaria: Scleractinia and Milleporina) was performed at 62 SCUBA stations, covering different reef environments from shore to 25 m depth. The surface of nearly 2100 colonies of 30 species, found below haphazardly located linear intercept transects, was carefully examined. Recently dead areas were found in a great number of colonies (mean 78.9%, SE 2.5%), but only 23.7% (SE 2.0%) of the colonies showed evidence of current mortality. Another frequent condition was live tissue invaded by algae (mean 54.1%, SE 2.8%). Remaining recorded conditions (including diseases, predation, invasion by other organisms and physical damages) had frequencies lower than 12%. Mean affected area by condition was lower than 4% of the colony surface, except for recent mortality (mean 33.2%, SE 1.5%). Important differences were found when comparing data between species and reef environments, but not between atolls.
Ginsburg1, R. N., Gischler2, Eberhard, and W. Kiene3.
1Rosenstiel School of Marine and Atmospheric Science,
University of Miami, 4600 Rickenbacker, Miami, FL 33149.
2Institut für Geologie und Paläontologie,
Universität Tübingen, Sigwartstraße 10, D-72076,
Tübingen, Germany.
3Smithsonian Institution, Paleobiology, Washington, D.C.
20560.
The condition of massive corals on 22 patch reefs in the Florida Reef Tract was assessed from visual estimates of the amount of dead tissue/colony. Patch reef locations were chosen to span the 200 km of their occurrence. Most reefs are small (< 150 m), low relief (2-6 m), near surface (1-3 m) and have variable densities of massive corals and gorgonians with usually only minor branched corals. At each reef, observers swam four radial transects from the approximate center measuring the diameter and estimating partial mortality of the 1-3 species assigned to them. Projection diameter of each colony was measured to 10 cm, partial mortality was estimated as < 1/3 of the colony, 1/3 to 2/3, > 2/3. For giant colonies of M. annularis and M. faeolata, ca. 3-5+ m in dimension, partial mortality was measured by counting live vs. dead areas at points 25cm apart on nylon lines stretched over the colonies. The number of points observed on a series of radial transects varied from 100-400/colony.
Size distributions of most common species are skewed negatively with maxima 0.2-0.5 m. Larger colonies are relatively rare, probably a result of the vicissitudes of aging. Indeed, 60% of 65 giant colonies have 40-70% dead surfaces. For smaller colonies (< 1 m), 75% of the 3,232 specimens of 12 common reef-building species assessed have < 1/3 dead tissue. The only significant increases in partial mortality along the Reef Tract (200 km) coincide with the occurrence of naturally unfavorable water quality from a restricted lagoon.
Green, E.
Marine and Coastal Programme, World Monitoring Center
219 Huntingdon Rd., Cambridge, CB39JT, UK
Satellite and airborne digital sensors have coexisted for over fifteen years but their relative abilities to assess coral reef and seAGRRAss habitats have not been assessed. Such comparisons do not even exist between different satellite systems even though they have been applied to reefal environments world-wide. The absence of this information presents a constraint to anyone charged with planning a remote sensing campaign i.e. "What is the most cost-effective and accurate means of achieving a given objective?". In light of this difficulty, a comparative study was conducted for reef and seAGRRAss habitats of the Caicos Bank (Turks and Caicos Islands, BWI). Digital data were acquired from Landsat MSS, Landsat TM, SPOT XS, SPOT Pan and the Compact Airborne Spectrographic Imager (CASI). 200 sites were sampled quantitatively using 1m2 quadrats for benthic cover and 0.25m2 quadrats for seAGRRAss biomass. An hierarchical classification scheme for reefal habitats was objectively determined from field data using agglomerative clustering. 600 independent sites were surveyed for accuracy assessment. Each type of imagery was subjected to unsupervised and supervised spectral classification and a variety of advanced image processing techniques including depth-compensation and textural analysis. Depth-compensated CASI imagery gave the greatest accuracy for most habitats and seAGRRAss biomass. Landsat MSS yielded the lowest accuracies. This presentation describes a full analysis of costs and accuracies based on (i) the type of imagery, (ii) the degree of image processing and (iii) the type of habitat / seAGRRAss biomass.
Guzman, H.
Smithsonian Tropical Research
Unit 0948, APO, AA 34002-0948
The Smithsonian Tropical Research Institute has supported a coral reef biological survey and monitoring program in Caribbean Panama since 1985. Survey of reefs for coral cover, recruitment, abundance, size, growth, and diversity, as well as for cover of algae, sponges, octocorals and zoanthids, has been the core of the program. We have surveyed approximately 75 disturbed and pristine reefs using fixed or random belt transects (quadrats). Only scleractinian corals are surveyed and identified at species level. In general, the conservation status of reefs have been described based on coral cover and recruitment, and cover of macroalgae. These variables seem to be a good indicator of reef condition only for extreme cases, e.g., pristine or severe degraded reefs. Intermediate disturbed reefs have shown mixed results with no clear patterns in coral recruitment. Also, censuses of coral partial mortality were done from 1986 to 1991 to evaluate sublethal effects of oil pollution in reef corals. Frequency and size of recent injuries in four major reef coral species increased within polluted reefs showing that this parameter might be another good indicator. It will be suggested to AGRRA participants that coral growth time-series (sclerochronology) might provide another dimension for assessing changes in reef structure in a real time-scale.
Harborne, A.R., P.S. Raines, J.M. Ridley and S.C. Withey.
Coral Cay Conservation
154 Clapham Park Road, London, SW4 7DE, UK.
Coral Cay Conservation (CCC) is an international organization dedicated to providing resources to aid the protection and sustainable use of coastal areas. Since 1986 CCC has provided the Belize Department of Fisheries with data for the classification of marine habitats along the Belize Barrier Reef and around associated atolls. CCC does not charge the host country for the service it provides and is primarily self-financed through a unique volunteer participatory scheme. Within the scheme, members of the public are given the opportunity to join a phase of each project in return for a financial contribution to the CCC program. At the expedition site, volunteers are provided with suitable training and collect data under the guidance of project scientists. CCC also provides conservation education, technical skills training, and capacity building within Belize.
The CCC survey program is designed to provide data to ground-truth remotely sensed imagery in order to produce GIS marine resource maps. CCC has, therefore, developed a rapid assessment technique that generates information on reef topography, substratum, benthic and fish assemblages and human impacts using teams of four trained volunteers. The technique uses plot-less transects and can be utilized on reef, back reef, and lagoon environments. Furthermore, a critical assessment has shown the data to be precise and consistent. CCC has also tested and developed protocols to allow volunteers to collect quantitative data on benthic assemblages and commercial fish populations. The data collected by CCC has been used to both develop and test a national classification scheme and marine habitat map for Belize.
Hernandez-Delgado1 E.A., L. Alicea-Rodriguea2, J. E. Martinez-Suarez2, and J. O. Melendez2.
1University of Puerto Rico, Dept. Biology, Coral Reef
Research Group, PO BOX 23360, San Juan, P.R. 00931-3360,
2U.P.R., Humacao Campus, Dept. Biology, CUH Station, Humacao, P.R.
00791.
A preliminary validation test of the proposed AGRRA protocol was carried out in Culebra Island, PR. The objective of this preliminary study was to determine the degree of training needed among team members in order to standardize methods and reduce variance among observers. Fish surveys were carried out at a 3-5 m depth interval by establishing 7 random 50 x 2 m-long belt transects parallel to the shoreline. Benthic surveys were carried out in 4 permanent 10 m-long line transects. Parametric and/or nor parametric analyses of variance (i.e., One-way ANOVA; Kruskal-Wallis) showed no significant differences (p=0.05) among observers in parameters such as fish abundance, species diversity, evenness, abundance of herbivores (total), scrappers, generalist carnivores and piscivores. There were significant differences among observers in parameters such as total biomass at the family level, with exception of the % of damselfishes. No significant differences in biomass at the family level were detected. No significant differences were observed in the diameter and height of coral colonies. But major differences were observed in colony depth (p=0.0014), recent mortality (p=0.0468) and % of dead coral tissue (p=0.0002). No significant differences were detected in the % and height of the macroalgae. However, there were differences in the % if crustose algae (p=0.0016) and in the % of filamentous algae (p=0.0111). These results suggest that prior to initiating data collection, it is of paramount importance to carry further training in the identification of coral conditions, estimation of algal cover, % of dead coral tissue and abundance of damselfishes. A combined lecture/in-the-field training protocol has been designed to overcome such problems.
Hernandez-Delgado, E.A. and A. M. Sabat.
University of Puerto Rico, Dept. Biology, Coral Reef Research Group,
PO Box 23360, San Juan, P.R. 00931-3360
In this study we describe the distribution and conditions of major coral reef systems of the northeastern PR coast and offshore islands. The dominant type of coral reefs are fringing reefs, extensive system of shelf edge submerged reefs at the eastern PR shelf drop-off. A total of 48 scleractinian and 4 hydrocoral species, and over 200 coral reef fish species have been identified through the range. There is an statistically significant trend of increasing % of living coral cover, coral and fish species richness, species diversity, abundance and in dominance by Montastraea annularis with increasing distance from coastal development, thus suggesting the presence of a strong environmental gradient. There is also a strong positive correlation between % of living coral cover and fish abundance, thus supporting the hypothesis that there is an association between the ecological status of coral reef fish and epibenthic communities. The most threatening anthropogenic factors identified on coral reefs include:
Highstead, G.
Texas A&M University,
1625 Church St., Galveston, TX 77550
In April 1996, a characterization and monitoring study of the reefs surrounding the island of Guanaja Bay Islands, Honduras was established. This study employed a variety of reef assessment techniques, including a rapid visual assessment protocol similar to the proposed AGRRA protocol. The study was designed for small teams of 2-4 divers and was limited to six dominant reef-building corals (Colpophyllia natans, Diploria labyrinthiformis, D. strigosa, Montastraea annularis complex, M. cavernosa, and Siderastrea siderea) in water depths less than 35 m. Trained observers swam a loose pattern covering as much of the reef site as possible and evaluated 75-100 coral colonies each per dive. Divers estimated the percent area in four categories (Mortality, Discoloration, Bleaching, and Healthy) for each coral colony. This assessment protocol provided information on significant changes in reef health when estimates of percent area in each category were confined to specific ranges (e.g. 0%, < 33%, 33%-66%, >66%, 100%). Diver parity was maintained over a two-year period through consistency training at regular intervals.
Horta-Puga, G., J.L. Tello-Musi and G. Barba-Santos
Invemar Universidad Nacional Autónoma De México
The Veracruz Reef System (VRS), is a reef complex consisting of 22 single reefs situated off the Port of Veracruz in the Western Gulf of Mexico. The Rapid Assessment Protocol (RAP) was chosen for the evaluation of reef condition, because is a powerful, simple and easy to use tool for evaluation purposes. The assessment was divided in two phases: the first is an evaluation during 1998 of the platform-type reefs: Anegada de Adentro, Isla Verde (representatives) and Galleguilla (strategic and highly degraded), and the second will be conducted next year of the reefs in the south end group of the VRS. Each reef will be sampled in the reef flat, and fore reef (windward) slope end at 3, 9 and 15 m depth. Some changes have been performed to the RAP:
Kramer, P. and P. Richards.
Rosenstiel School of Marine and Atmospheric Science, University of Miami
4600 Rickenbacker, Miami, FL 33149.
The Andros Barrier Reef Complex is one of largest (>150 km) and least studied reef systems in the greater Caribbean with relatively low anthropogenic impacts. Using the AGRRA-Rapid Assessment Protocol (RAP), the condition of major reef-building corals and other principal indicators of reef vitality - fish, algae, recruitment, and urchins were measured between August 1-21, 1997. Over 3,000 large (>25 cm) corals were assessed on 26 reefs (13 from 1-3 m depth, 13 from 8-12 m depth) spanning a distance of over 100 km. Shallow barrier reef sites were dominated on the seaward slope by Acropora palmata. Deeper fringing fore-reef sites were dominated by dense mono-stands of Montastraea annularis. Partial mortality ("recent/old") averaged 4/37 % for A. palmata and 9/32 % for M. annularis. Causes of recent mortality were most commonly bleaching (7%) and algal overgrowth in the deeper sites and white lesions (24%) in the shallow sites. Size frequency distributions for all corals were skewed towards smaller colonies and the degree of partial mortality was significantly lower in the smaller size classes. Recruitment was low to moderate at both depths, with brooding species dominating. Algal communities were predominantly coralline at the shallow sites and macro at the deeper sites. Fish assemblages at all sites were dominated by acanthurids and scarids, with abundance and diversity being highest in northern shallow sites. All of the sites surveyed are in relatively good condition, although additional assessments are necessary before final conclusions can be made about the entire reef complex.
Leão 1,Z.M.A.N., V. Testa 1; R. K. P. Kikuchi
1,2
1Laboratório de Estudos Costeiros, Centro de
Pesquisa em Geofísica e Geologia, Universidade Federal de Bahia,
Rua Caetano Moura 123, 40210-340, Salvador, Bahia, BRAZIL
2Departamento de Ciências Exatas, Universidade Estadual de
Feira de Santana, BR116, km 3 s/n, Campus Universitário, 44033-390,
Feira de Santana, Bahia, BRAZIL
Reefs in Brazil are intriguing. Despite the carbonate deposition along 2,000 kilometers of the tropical continental shelf, reefs occur mainly in the inner shelf, as pinnacles, patches, banks, and as spatially limited fringes; drowned reefs occur at some spots of the shelf break. The widening of the upper part of the reef in relation to its base gives to a pinnacle the particular mushroom shaped feature that Hartt (1870) described for the first time as 'chapeirão'. The Brazilian reef fauna is the poorest of all tropical reef provinces but is composed by endemic species adapted to high hydrodynamic, sedimentation and water turbidity. Despite the absence of branching corals, reefs caught up to sea level during the Holocene, erecting reef structures up to 12 m thick. Additionally, coralline algae can also have an important role as a reef framework component. Reefs began to grow after 7,000 years ago when sea level was already at or above its present position. Contrasting with the well known sea level curves in the Caribbean and in the Indo-Pacific, the Western South Atlantic had a sea level 5 m higher than today, 5,100 years BP. Quantitative surveys using line intercept and belt transects account for a very wide range of coral cover. In offshore reefs such as the Abrolhos' 'chapeirões', they may cover up to 30% of the reef surface. At nearshore areas, such as the northern Bahia coast, while less than 5% of reef surface is coral, corallines and macroalgae cover more than 90% of reef surface.
Martinez-Daranas, B.
Instituto de Oceanologia
Ave. 1ra No. 18406, Playa, Ciudad de la Habana 11600, Cuba.
The structure of some macroalgal communities and the methods used in some Cuban coral reefs are analyzed. Macroalgae were sampled with a suction device. Macroalgal density as dry or wet biomass, number of species and species richness were obtained. Seasonal and spatial differences in dry biomass and number of species were found in the Juan Garcia Key. Spatial differences and higher values of dry biomass and species were found at Sabana-Camaguey Archipelago in ten transects. These values of biomass possibly indicate a nutrification process. This analysis was also used to assess the impact produced by sewage pollution at El Chivo Beach reefs near Havana Bay.
McField1, M., D. Gomez2 and J. Azueta3
1Dept. of Marine Science, University of South
Florida, 140 Seventh Ave S, St. Petersburg, FL 33701
2Bacalar Chico Marine Reserve, San Pedro Town, A.C. Belize
Central America
3Fisheries Department, Princess Margaret Dr., Belize City,
Belize, Central America.
Belize's barrier reef complex is the largest in the Western Hemisphere, including approximately 250 km of barrier reef, three oceanic atolls, and numerous inshore reefs including: rhomboid faroes, deep pinnacle reefs, shallow fringing and patch reefs. Belize's first marine protected area (MPA) was established in 1982; today there are now a total of eight MPA's. There is an active coastal zone management program, with a newly established Coastal Zone Management (CZM) Authority and Research Institute. A coordinated national coral reef monitoring project began in 1991-92, when a total of seven sites were established and one year of baseline data was collected. In 1995, a rapid assessment method weighted-bar swimming-transect was developed specifically to monitor the first mass bleaching event in Belize. In 1997 the general monitoring program was renewed and expanded to 17 sites, utilizing a video-based methodology. A Coral Reef Monitoring Working Group has recently been established to coordinate and encourage additional monitoring efforts throughout the country with representatives of government, NGOs, and the university. There are currently two active CARICOMP sites and several MPA's with additional monitoring activities. A preliminary GIS marine habitat classification has now been completed. While there has been extensive scientific research since the early 1970s, particularly in the vicinity of Smithsonian's field station, surprisingly little general information has been collected about the "health" of Belize's reefs. An extensive assessment of the condition Belize's reefs is currently needed, particularly in those areas with little to no information.
Miller M.W.1, A.M. Szmant1, and E. Weil2.
1RSMAS/Univ. of Miami, 4600 Rickenbacker Cswy. Miami, FL 33149, USA. 2 University of Puerto Rico, Dept. of Marine Sciences, PO Box 908, Lajas, PR 00667.
Coral cover is unusually low on the offshore barrier reefs of the northern part of the Florida Reef Tract in Biscayne National Park. To determine if high mortality or low recruitment is responsible, we measured the population size frequency distributions (SFD) on five reefs for both long-lived (Siderastraea siderea, Montastraea cavernosa, M. faveolata) and shorter-lived (Porites astreoides) head corals. Frequencies of older/larger individuals are generally low because of reduced survivorship with time, but for long-lived/colonial corals, larger size can increase survivorship, leading to an accumulation of larger colonies. However, partial mortality and reduced growth rates can inflate the frequencies of smaller size classes. Thus, SFDs can be used to infer processes affecting population dynamics of reef corals.
On offshore reefs, S. siderea and M. cavernosa showed SFDs skewed severely to small size classes despite the fact that these species usually grow to larger sizes; SFDs were more even on patch reefs. The smaller coral P. astreoides also had SFDs skewed to smaller sizes on the offshore reefs, while patch reef sites had more even SFDs with greater abundance of intermediate sizes. These results suggest that smaller colonies of corals on the offshore BNP reefs have higher rates of mortality than those of patch reefs, and that higher mortality, as opposed to lack of recruitment, is a major determinant to low coral cover on the offshore reefs. Determining coral SFDs can be a useful rapid assessment tool that can suggest variations in dominant population processes among and within sites over time.
Mumby, P.J.
Department of Geology, University of Sheffield,
Winter Street, Sheffield, S10 2TN, UK
Recent advances in digital airborne remote sensing enable the identification and mapping of coral reef assemblages on shallow (<18 m) Caribbean reefs with good water quality (horizontal Secchi distance 20-50m). Of the coral assemblages, Acropora palmata stands and three soft coral/ hard coral classes were distinguished in situ using percent cover data in 1m 2 quadrats and mapped using CASI (Compact Airborne Spectrographic Imager) with accuracy exceeding 80%. These results suggest that the cover of habitat classes (e.g. Montastraea reef with a mean of 18% live coral cover) can be monitored synoptically. However, field survey is always required to identify the average coral cover within habitat classes.
Muñoz-Chagin, R. and D. Aquilar.
Depto de Recursos del Mar, Merida, Yucaton, Mexico
Two modified methods for rapid assessment of the condition of reef corals were developed and tested for special situations near Cozumel Island, Mexico. The first, done at Paraiso coral reef where the current is strong, used a drift dive of 30 minutes covering depths of 5 and 10 m for each of the preselected coral species. Colony size, partial mortality and where possible the causes of tissue death were recorded using predetermined categories, including small colonies (< 25 cm). The second method was done at Chankanaab State Park, where a dolphin enclosure is planned. Here, the same information about coral colonies as at Paraiso was collected, but by examining all the corals in 12 quadrats of 25 2 m.
The drift dive method is appropriate for reconnaissance in locations like Paraiso where the currents are strong. In contrast, quadrats are more useful for detailed assessment of small areas such as the proposed dolphin enclosure. Both approaches provide density of coral populations, colony sizes, and partial mortality but using quadrats may provide higher resolution. Predetermined categories may be less accurate than direct observations but using them does speed assessment. Including colonies smaller than 25 cm is a valuable measure of recruitment. These two examples illustrate how the protocol may be adapted to different situations.
Nemeth, R.S.
Eastern Caribbean Center, University of the Virgin Islands, St. Thomas,
V. I.
Clearing of land for development has been identified as one of the major contributors to reef decline. Disturbance of stable topsoils greatly increases erosion during heavy rainfall and subsequent runoff to the sea is often heavily laden with fine sediments that are harmful to corals and other reef organisms. This study is documenting rates of sedimentation and changes in coral abundance and coral health at Caret Bay, St. Thomas USVI during construction of condominiums. Six permanent transects were established perpendicular to shore and represented a range of potential impact. Monthly monitoring was initiated prior to construction in June 1997. The diversity, abundance and percent cover of corals, gorgonians and sponges were measured with 1m 2 quadrats placed randomly along each transect. Coral health was monitored with monthly photographs of individual Montastraea annularis and Porites astreoides coral heads. Incidence of disease and damage on all corals were recorded in a 3m wide strip along each transect. Results to date indicate an increase in abundance of corals, gorgonians and sponges in all transects which seems to indicate a growing reef. Although there was a large number of corals showing signs of disease and damage (fish bites) along all transects, most are probably unrelated to construction activity. However, a dramatic increase in pigment loss of focal Montastraea following heavy rainfall may indicate an increase in coral stress due to construction induced sedimentation. The proposed AGRRA protocol was also tested at Caret Bay and at several distant sites for comparison.
Prect, W.F.1, R.B Aronson.2
1Law engineering and Environmental Serv. Inc., Miami, FL, 2Dauphin Island SeaLab, Dauphin Island, AL.
Over the past two decades, coral reefs in the Caribbean have changed dramatically. Reef-building corals have declined, and the cover of fleshy, noncoralline macroalgae has increased. Many authors have argued that the loss of herbivores has been the culprit in the community shift, while others have cited reef nutrification. It is our contention, however, that coral mortality is the crucial precursor to macroalgal dominance. For example, ten years after Hurricane Hattie devastated reefs from Belize in 1961, the once lush coral community was deduced to a layer of coral rubble covered by fleshy macroalgae. This was identical to the pattern observed on Jamaican reefs ten years after the passage of Hurricane Allen (1980). However, in Belize this community change occurred despite high herbivory and low nutrient levels on relatively 'prestine' reefs. On a regional-scale, the mass mortality of acroporid corals due to White-Band Disease has been largely responsible for the present increase in macroalgae. These widespread biotic disturbances, which still active today, has diminished coral populations, thereby opening space for colonization by algal species. These observations highlight the primacy of coral mortality in general, and disease induced mortally in particular, in changing the face of Caribbean reefs.
Reed, J.K.
Harbor Branch Oceanographic Institution,
5600 U.S. 1 North, Fort Pierce, FL, USA, 34946
An extensive area of unique deep-water Oculina coral reefs stretches over 120 miles along the shelf edge from Fort Pierce to Daytona, Florida, and at depths of 70-100 m. A single species of scleractinian coral, Oculina varicosa, the Ivory Tree Coral, grows on these reefs. The reef system consists of over one hundred individual coral pinnacles, mounds, and ridges that are high relief structures, up to 17-25 m in height and 100-300 m in width. The deep-water Oculina grows as discrete spherical colonies, 1-2 m in diameter, and as massive thickets of contiguous colonies up to 2 m in height that occur predominately on the steep slopes (30-450) of the pinnacles. In shallower water at 6-m, 27-m, and 42-m reef sites, colonies of O. varicosa grow on limestone ledges that parallel the Florida coast. These do not form the massive thickets and bank structures like the deep-water form but grow as sparsely scattered, individual colonies.
By use of lockout diving from the Johnson-Sea-Link Research Submersibles, we recorded in situ growth rates of 16.1 mm/yr for Oculina at the 80-m site where bottom temperatures range from 7.4 to 26.70C ( -=16.20C) and transmittance of surface light is less than 1%. Paradoxically, at the 6-m site, Oculina growth rate is only 11.3 mm/yr even though bottom temperatures average 24.60C and the coral harbors zooxanthellae. For unknown reasons, in the central region between 27045'N and 27052'N, where the pinnacles reach their maximum diversity and number, extensive areas of dead Oculina rubble exist with only a few scattered living colonies. Generally the coral fragments are <10 cm in length and well encrusted with various fouling species. The exact cause of the extensive areas of dead coral rubble is yet unknown. Several unproved hypotheses exist including human damage and natural processes such as bioerosion, physical abrasion, and episodic coral die-off.
Riegl1, B., K.E. Luke.2
1Institut für Geologie und Paläontologie der Karl-Franzens-Universität Graz, Heinrichstraße 26, 8020 Graz, AUSTRIA 2School of Biology and Biochemistry, University of Bath, BA27 AY Bath, UK
In order to evaluate the status of reefs and the boundaries for new marine reserves in the northern Red Sea, a large-scale survey, which included all reefs between the Straits of Gubal and Ras Banas, was initiated. The methodology was aimed at providing a maximum of information in a minimum of time. As key organisms, corals, fish, and algal turfs received most attention. Corals were visually assigned to one of six community types which had been identified by previous quantitative studies (exposed Acropora reef, sheltered Porites reef, current exposed Millepora or Dendronephthya reef, Porites carpet, faviid carpet, soft coral carpet). Notes were made of dominant species, deviations from predetermined average cover values, framework integrity, disease frequency, damage frequency, unusual species, and frequency of high algal turfs. Additionally, photo transects of 10x2m areas were taken in depths of 20, 15, 10, 5 and 1 meters and four 2x2 m squares were photographed at 4m depth. These photographic records allow a more sophisticated evaluation of coral health parameters (vitality, lesion frequency, etc) and are a good visual database. Fish were counted at the same depths by 5 minute point counts, or, where necessary, by 100m transect swims. During the counts frequency was only recorded to family level. The 21 most common families were counted. Additionally, a list of all encountered species was made. The occurrence of other important organisms (crown-of-thorns starfish, Drupella cornus, unusually high sea urchin density, etc.) was recorded.
The REA data were consistent and provided good results, also for the description of impact severity. Degradation of coral communities and concomitant shifts in fish community structure were clearly proven whenever encountered.
Riegl B., W.E. Piller.
Institut für Geologie und Paläontologie der
Karl-Franzens-Universität Graz,
Heinrichstraße 26, 8020 Graz, AUSTRIA
Sea floor types, biota and sedimentary facies were mapped in northern Safaga Bay, Red Sea Egypt. After quantitative evaluation by line transects and adequate statistical description, coral communities were visually identified according to the statistically obtained groupings and superimposed on the base-line map. A series of maps detailing the distribution of key biota, like sea grass meadows, mangroves and coral reefs, including spatial patterns in the ecological differentiation of coral communities was produced. Damaged areas and the type of damage were mapped as well. The maps, together with ecological baseline information, allowed drawing conclusions about the most sensitive areas in the bay, particularly in the face of massive development. A similar approach was taken at Ras Banas, which made identification of sensitive areas possible. In both cases, the maps can be used for monitoring changes.
In the Arabian Gulf, at Dubai (United Arab Emirates), the spatial patterns of coral communities were mapped in early 1996. Later the same year, a mass mortality affected all Acropora. Using the map, it was possible to evaluate the extent of the areas that had suffered community phase-shifts due to Acropora mortality and the extent of the areas that had remained unaffected. It would now be possible to calculate the areal extent of recovery growth at any given time interval.
In July 1997, with R. Claro and J. P. Garcia, Instituto de Oceanologia, Havana, and N. Tolimieri, University of Windsor, I visited reefs southwest and southeast of Isla de Juvendad, Cuba. Our primary goal was to establish the logistic constraints to working in the region, and to have a preliminary look at the reefs present. Time (one dive per site), and depth averaging 25m limited data collection. In some sites we sampled fish faunas using 30 x 2m and 30 x 1m transects for adults and juveniles, respectively. In others we ran modified random swims to build species lists. In all sites we looked for evidence of coral disease and at general condition of the environment. Reefs in this region are predominantly deep structures at or close to the shelf edge. We snorkeled on two shallower, cresting reefs. At all sites coral cover was good and coral diseases were rare. Fish species were abundant, and included many specimens of large size. The overall fish diversity was high, compared to other Caribbean sites we have seen. These reefs do not appear to have suffered from any Caribbean-wide decline.
Schmitt, E.
The Nature Conservancy, Marine Science Conservancy Center
PO Box 249118, Coral Gables, FL 33124-0421
Reef fish assemblages can be more comprehensively surveyed via the simultaneous use of several techniques, especially when a rapid assessment is required by field workers of varying skill levels. As an example of the benefits of using multiple field methods, we evaluated the reef fish assemblage in the southeastern Dominican Republic using the roving diver and transect visual survey methods. Species composition, sighting frequency and density of all fishes were collected using both methods and compared while length distributions of herbivorous and predatory fishes were collected only via the transect method. Both methods were similar in recording the most abundant species, while the roving diver method identified a greater number of less abundant species, especially fishery-targeted species. The most abundant groupers (Fam. Serranidae) observed were Epinephelus cruentatus and Epinephelus fulvus. These groupers were small and no groupers 35 cm were observed. The most abundant parrotfishes were Scarus taeniopterus, Sparisoma aurofrenatum, and Scarus croicensis. Parrotfishes were also small, with no individual 30 cm in length. The overall fish species list was similar to that of other areas in the tropical western Atlantic. However, intensive fishing has likely changed rank-order abundance, density, and size of reef fish in the area. The most conspicuous difference between fishes in southeastern Hispaniola and elsewhere was the low density and smaller size of commercially harvested species such as groupers (Fam. Serranidae), snappers (Fam. Lutjanidae), and even grunts (Fam. Haemulidae).
Steneck1, R.S. and J.C. Lang.2
1School of Marine Sciences, University of Maine, Darling Marine Center, Walpole, ME, 04573 2 2Texas Memorial Museum, University of Texas, 2400 Trinity, Austin, TX 78705
We field tested the proposed AGRRA protocols primarily in fore-reef habitats between 10 and 26 m depths at three, widely-separated geographic locations. Collaborating students and scientists rapidly quantified mortality and abundance (as size, spacing, height) of over 1000 large (25 cm diameter) reef corals, as well as abundance of algal assemblages and Diadema. Percent mortality was low on most reef corals. "Recently dead" portions of coral heads at Flower Gardens Banks in the Gulf of Mexico were <1.5%. In Mexico over 25% of the heads showed no partial mortality. The percent of coral heads that were "long dead" ranged from <21% to <33% at those two regions, respectively. Estimates of algal assemblages, coral recruits, reef fishes, and herbivory (fish bite rates) were also made at most sites. Moderately low macroalgal abundance, few coral recruits, no Diadema, and relatively diverse fish assemblages were found at most sites. In both regions, scarids were the dominant herbivore and turfs the dominant algal assemblage. Reefs with lower rates of mortality at our Mexican sites generally had higher cover of crustose coralline algae, but lower cover of turf algae.
Revilla Urra1, N., R. Suárez Alemañy2 and L. Hevia Delgado.2
1Fisheries Research Center, 2Ministry of Basic Industry
The damages suffered by coral reefs and sea grass beds in the fishing ground of Casilda, Cuba and resulting from heavy rains, hurricanes and an increase in water temperature, is presented. Lobster (Panulirus argus) shelters and feeding areas have also been affected as a result of these phenomena. By means of the optical and analogical interpretation of images from different years, samplings in situ and using the System of Geographic Information - CARIS, maps were made (scale 12:250 000) for the different biotops and their main variations in the area between Casilda and Cayo Breton. It was determined that 25% of the total area of coral reefs was affected, in some cases with bleaching while seAGRRAss beds were even more affected.
Vergara, S.
ICLARM, Bloomingdale Building, 205 Salcedo Street, Legaspi Village,
Makiti, metro Manila, Philippines
There is a growing awareness on the steady decline of the world's coral reef resources. Reef-related fisheries loss due to reef degradation amounts to millions of dollars a year, and affects hundreds of millions of people. Addressing these declines on habitat and income values requires a source of comprehensive biophysical, socioeconomic and institutional information. ReefBase attempts to provide a dynamic repository of reef-related information thus facilitating informed decisions for sustainable coral reef management. ReefBase is a user-friendly database on coral reefs and their resources. Designed as a repository of the available information on coral reefs, ReefBase disseminates this information through a user-friendly software on a CD-ROM. Since early 1997, ReefBase has served as the official database of the Global Coral Reef Monitoring Network. The ultimate goal of ReefBase is improved global coral reef health. ReefBase presents coral reef information in a relational database designed to accommodate a wide spectrum of coral reef references. Its major activities are the extraction of data from existing publications and the production of standardized digital maps of the world's coral reefs. Information gathered from reef assessment activities in the Caribbean regions through AGRRA is welcome contributions to ReefBase.
Villamizar, E.
Instituto de Zoologia Tropical, Facltad de Ciencias, Universidad Central
de Venezuala.
Morrocoy National Park, the most important coastal coral reef system of Venezuala is located in the central western region of the country. In January 1996, the system suffered an accelerated and massive mortality event, decreasing the living coral cover by 95% with a consequent algae invasion. The following study aimed to evaluate the effect of herbivory on these algae communities and its relationship with the possible recovery of the reef communities through the generation of free spaces. The community structure of the coral reefs, algae, herbivorous fishes and invertebrates are being evaluated. Methods of transects and quadrats, visual census and fixed transects (1 m wide) are being used. The herbivory intensity by fishes will be determined as the number of bites per time unit over 1 meter square areas. Additionally, the empty spaces produced by herbivory will be measured and counted on coral surfaces of 0.25 meter square covered by algae. Preliminary results suggest that these coral reefs are severely perturbated high values of dead coral and algae cover (Dyctiota sp.), and abundance and diversity of herbivorous fishes (Scaridae), Acanthuridaw and Pomacentridae.
Weil, E.
Dept. of Marine Sciences, U. of Puerto Rico.
PO BOX 908, Lajas, PR 00667.
Modified AGRRA protocols were used to assess the status of fringing reef (7-18 m depth) at Mona Island, 45 miles west of Puerto Rico. Twelve 10 m long transects parallel to the long axis of the reef and 73 quadrats were surveyed for organism/substrate cover and coral colony injuries. Two fish censuses in each of three widely separated, 50 m long transects were made. Modifications of the protocols included:
I found macro algae 35%, corals 23%, sand 13%, crustose algae 12%, turf algae 8.8%, and sponges 6%. Of the 170 coral colonies examined, 58% had old injuries. At least, 39% of the injuries were fish bites, 35% were dead areas killed by the sponge Cliona aprica, 22% was algae overgrowth, and 4% was yellow band disease. Cliona produced the larger injuries and fish bites the smallest (37% and 7.4% of colony surface, respectively). Montastraea faveolata was the most abundant species, had the largest colonies, and the highest frequency of new (18.8%) and old (28.7%) injuries. Except for low numbers of commercial fish, the reef seems healthy with low frequency of new coral injuries, good coral cover, and almost no coral diseases.
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