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Echinoderm mass mortality events shape marine ecosystems by altering the dynamics among major benthic groups. The sea urchin Diadema antillarum , virtually extirpated in the Caribbean in the early 1980s by an unknown cause, recently experienced another mass mortality beginning in January 2022. We investigated the cause of this mass mortality event through combined molecular biological and veterinary pathologic approaches comparing grossly normal and abnormal animals collected from 23 sites, representing locations that were either affected or unaffected at the time of sampling. Here, we report that a scuticociliate most similar to Philaster apodigitiformis was consistently associated with abnormal urchins at affected sites but was absent from unaffected sites. Experimentally challenging naïve urchins with a Philaster culture isolated from an abnormal, field-collected specimen resulted in gross signs consistent with those of the mortality event. The same ciliate was recovered from treated specimens postmortem, thus fulfilling Koch’s postulates for this microorganism. We term this condition D. antillarum scuticociliatosis.

Mesophotic coral ecosystems occur on fore-reef slopes (~25 to 55 m) and near-vertical deep fore reefs (~55 to ~122 m) off the north Jamaican coast. In the 1960s, T.F. Goreau and colleagues found corals and calcareous green algae (Halimeda) thriving to depths of ~70 m and coralline sponges even deeper. Boring sponges and calcareous algae produced prodigious quantities of carbonate muds and sands, some becoming lithified into reef rock and the remainder draining into deeper water. Low-light flattening of corals facilitated sediment shedding and stabilized dislodged colonies. Huge pinnacle reefs with frame work-building Orbicella dominated the upper fore-reef slope (~25 to 45 m) at Discovery Bay. Foliaceous agariciids monopolized some lower slopes and the upper deep fore-reef. Submersible-based explorations of the deep fore-reef cliff in 1972 confirmed active framework construction by corals at ~55 to 70 m and by coralline sponges and crustose coralline algae at ~70 to 105 m. Species of deep reef fishes occurred below ~60 to 90 m. The base of the cliff at ~91 to 145 m consisted of lithified sediments and debris. Non-coralline sponges and algae were the dominant benthos from 53 to 120 m in a 1984 submersible study. Fore-reef slope corals have declined greatly since the 1980s, and their skeletons are largely overgrown with algae. Contributing factors include enhanced herbivore losses from overharvesting (fish) or disease (Diadema), repeated bleaching-mortality events, increased trapping of sediments, degraded water quality, hurricanes, and coral diseases. Apart from identified sponges collected with open circuit trimix scuba in the 1990s, the post-1984 condition of the deep fore reef is unknown.

The Atlantic and Gulf Rapid Reef Assessment (AGRRA) Program, consisting of non-fixed, transect- based visual surveys, provides "snapshot" characterizations of a number of structurally or functionally important benthic and fish indicators on tropical northwestern Atlantic (TNWA) coral reefs and Brazil. To ameliorate the confounding factors inherent in multiyear temporal variation, a region-wide collaborative program for conducting rapid reef assessments at regular (five-year) intervals in sites that are representative of each sub-region of the TNWA is proposed. Member institutions of the Association of Marine Laboratories of the Caribbean (AMLC) and individual colleagues are invited to join in developing the vision. Rev. Biol. Trop. 54 (Suppl. 3): 23-29. Epub 2007 Jan. 15.El Programa de Evaluación Rápida del Atlántico y el Golfo (AGRRA, por sus siglas en inglés) consiste en sondeos visuales no-fijos, basados en transectos, que permiten caracterizaciones puntuales de un número de peces y organismos bénticos que sean estructural o funcionalmente importantes como indicadores en arrecifes del Atlántico tropical noroeste (ATNO) y de Brasil. Para disminuir los factores de confusión inherentes a variaciones temporales multianuales, se propone un programa de colaboración a nivel regional, que sirva para conducir evaluaciones rápidas de los arrecifes en intervalos regulares (cinco años), en los sitios que sean representativos de cada sub-región del ATNO. Se invita a las instituciones miembro de la Asociación de Laboratorios Marinos y del Caribe (ALMC), así cómo a colegas individuales para participar en el desarrollo de esta visión.

Editors' Note: At the 14th International Conference on Environmental Bioindicators (14th ICEBI) held in Linthicum Heights, Maryland, USA on 24–26 April 2006, the Conference Chairs and Program Committee initiated the Roundtable Discussion Groups as a regular feature of this and future conferences. The Discussions are designed to generate focused debate around key topic areas, led by academic, government and industry experts, and are structured to produce definitive papers for peer review and publication in EBI's first-quarter issue of each publication year, albeit this year the papers will be published over the first two issues of 2007. The three Roundtables of the 14th ICEBI posed questions revolving around the chosen topic areas of Mercury Bioindicators, Marine Ecosystem-level Indicators, and Regulatory and Policy Uses of Bioindicators, and moved from “what we know” to “where we need to go” and “what are the policy implications from our discussions and conclusions.” The following paper on coral reef indi...

Background:The rising temperature of the world’s oceans has become a major threat to coral reefs globally as the severityand frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropicalAtlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin.Methodology/Principal Findings:Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers’ field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles.Conclusions/Significance:Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA CoralReef Watch’s Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality willundoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate NOAA Coral Reef Conservation Program Article Nr: e13969

Western Atlantic coral reefs were differentially affected by a mass bleaching (discoloration) event in 1987. We periodically assessed the »appearance« of zooxanthellate organisms between December 19 87 and June 198 8 at nine conspicuously affected sites in the Bahamas, Florida, St. Croix, and Venezuela, using a standardized point-count technique. Three to four months after the local initiation of the event, the »bleached« state was still present in one to three of the most abundant reef coral taxa and in a few of the less common species (n = 5 sites). »Recovery« occurred somewhat faster at shallower depths, at least in the Bahamas and Florida. Scleractinian corals which were »prolonged bleachers« had foliaceous or massive, rather than branching, morphologies. »Bleached« points disappeared from the point counts after +6 to +8 months

The extent of colonial integration in structurally simple animals like scleractinian corals is poorly understood. We have used sexual reproductive characters (location of fertile polyps and colony size at maturation) to assess colony-level individuality, i.e., the development, in coral colonies, of characters above the polyp level. Ten morphologically-diverse species of reef corals were used: Acropora cervicornis, A. palmata, Diploria clivosa, D. strigosa, Favia fragum, Montastrea cavernosa, Porites astreoides, P. furcata, Siderastrea radians, and S. siderea. In no species were equally fertile polyps homogeneously distributed throughout a colony. Most inhomogeneities of fertile polyps could be attributed to intra-colony position or ontogenetic effects. The results of simple manipulations simulating natural wounds in three massive species strengthen the evidence that the position of polyps within a colony determines fertility. Small colonies are not reproductive. Puberty size (colony size at maturation) could be explained by the infertility pattern along the colony margin, which does not require colony-level integration. Shape-related growth constraints could also produce the puberty size patterns found in massive corals. Infertility in the short radial polyps of A. palmata and in the axial polyps of A. cervicornis provided the only clear evidence of reproductive integration in this study: both are related to a morphological characteristic (polyp dimorphism) commonly associated with integration in colonial invertebrates.

Large variations in skeletal microarchitecture, and in the carbon and oxygen isotopic composition of the skeleton, exist within single calices and over the surfaces of single colonies of various species of West Indian (Jamaican) scleractinian reef corals. Rapidly extending parts of individual colonies are depleted in both C13 and O18 regardless of the abundance of zooxanthellae in the overlying tissues. We suggest that this relationship is due to active translocation of organic compounds to sites of rapid calcification. Considerable variation in isotopic composition is found in skeletons of different specimens of the same species even when the skeletons are sampled in a consistent manner, come from the same locality and depth, and have a comparable growth history. The isotopic composition of the scleractinian skeleton is vastly more complex than has heretofore been realized.

The δC13 and δO18 values of skeletons of shallow water, ahermatypic scleractinian corals from Jamaica show an excellent correlation over a wide range of isotopic composition. Within individual specimens there are large differences in the isotopic composition of separate skeletal elements. Some of these ahermatypes are enriched in O18 relative to equilibrium precipitates of calcium carbonate from Jamaican sea water. Therefore our data do not support a two-reservoir mixing model for calcification if one of these reservoirs consists of dissolved marine (inorganic) bicarbonate. As some of these ahermatypic species are enriched in both C13 and O18 relative to hermatypic corals from the same reefs, calcification models based on withdrawal of metabolic CO2 by photosynthesizing zooxanthellae must also be modified.

Time series of annual linear growth increments from 12 Montastrea annularis (E. and S.) collected at the East Flower Gardens Bank reef in the northwestern Gulf of Mexico have a common pattern. This is best expressed in an index master chronology (average by year of the annual percentage deviations from the mean of each coral). Comparisons with time series of environmental data indicate that coral extension rates vary positively with seasonal (February through May4 months) surface water temperature and negatively with annual discharge of the Atchafalaya River. We propose that secular variations of water temperature and other parameters are the major long term controls of coral growth in the area. Our data do not support the view that sinking of the Flower Gardens reef, caused by catastrophic collapse of the underlying substrate, has been a prime influence on the corals.

Severe tropical storms can cause widespread mortality in reef corals1,2. The Caribbean staghorn coral, Acropora cervicornis, although dependent on fragmentation for asexual propagation3–5, is particularly vulnerable to hurricane damage6,7. The most important agents of post-hurricane mortality are assumed to be high wave energy6 and change in salinity8, factors which typically soon diminish in intensity. We report here that there was substantial delayed tissue and colony death in A. cervicornis on a Jamaican reef damaged by Hurricane Alien. This previously undocumented degree of secondary mortality, sustained for 5 months and unrelated to emersion9, was over one order of magnitude more severe than that caused by the immediate effects of the storm. The elimination of >98% of the original survivors suggests potentially complex responses to catastrophes, involving disease10,11 and predation, which may explain the widely variable rates of reef recovery previously reported12–15.