La Parguera Research Articles

Effects of Hurricane Maria in hamlet communities (Serranidae: Hypoplectrus spp.) in Puerto Rico

Abstract Hamlets (Hypoplectrus spp.) are hermaphroditic, carnivorous, and highly territorial fishes in the family Serranidae that are endemic to the Western Atlantic. We studied 10 reefs located in the La Parguera Natural Reserve in Puerto Rico and report differences in hamlet communities after the passage of Hurricane Maria. Our results were compared to surveys conducted in the years 2000 and 2017, before the reefs were hit by Hurricane Maria in 2017. Non-metric multidimensional analyses revealed a “boomerang pattern” in species composition and abundance, with high diversity in 2000, low diversity in 2017, and a subsequent return to high diversity levels in 2018. By and large, the study reveals a positive effect on the diversity of hamlet communities in the aftermath of Hurricane Maria. The reemergence of diversity patterns, including the recording of previously unobserved species in the study site serves as indicator of the underlying and often underestimated benefits of major disturbance events.

Detection of gaps in the spatial coverage of coral reef monitoring projects in the US Caribbean and Gulf of Mexico.

As part of the US Coral Reef Task Force's National Program to Map, Assess, Inventory, and Monitor US Coral Reef Ecosystems, a comprehensive survey of projects/programs monitoring coral reef ecosystems and related habitats (i.e., seagrass beds and mangroves) in the US Caribbean and Pacific was undertaken. Information was gathered on a total of 296 monitoring and assessment projects conducted since 1990 in the US Caribbean and the Gulf of Mexico. Substantial gaps in monitoring coverage of US coral reef ecosystems were revealed through geographic information system (GIS) analysis of survey metadata. Although southern Florida contains approximately two-thirds of all marine monitoring projects found in the US Caribbean and Gulf of Mexico, we were unable to identify any ongoing projects that monitor coral reefs along Florida's western coast and off of the Florida Middle Grounds. Additionally, Florida is covered by approximately 1 900 km2 of mangroves, yet there were only four ongoing projects that monitor this ecosystem, leaving gaps in coverage in the Lower and Middle Keys and along the eastern and western coasts. The Flower Garden Banks National Marine Sanctuary, located offshore of the Texas/Louisiana border, has an integral long-term monitoring program, but lacks a monitoring project that gathers long-term, quantitative data on reef lish abundance and certain water quality parameters. Numerous coral reef monitoring projects in Puerto Rico are concentrated on the island's southwestern coast surrounding La Parguera, while far fewer monitoring projects are conducted along the northern and southeastern coasts and around Vieques Island. In the US Virgin Islands, the paucity of monitoring projects in large areas of St. Croix and St. Thomas contrasts with monitoring activity in three marine protected areas (MPAs), where 66% of the US Virgin Islands' coral reef monitoring sites were found. Only a series of assessments have been conducted at Navassa, a small, uninhabited island located 55 km west of Haiti and 137 km northeast of Jamaica. In order to better understand changes in coral reef communities and to produce a series of biennial reports on the status of US coral reef ecosystems, the National Oceanic and Atmospheric Administration (NOAA) is developing a national coral reef monitoring network. This network has already begun to fill some of these gaps in monitoring coverage through issuing cooperative grants to states and territories to build long-term monitoring capacity.

Temporal changes in hamlet communities (Hypoplectrus spp., Serranidae) over 17 years.

Transect surveys of hamlet communities (Hypoplectrus spp., Serranidae) covering 14 000 m2 across 16 reefs off La Parguera, Puerto Rico, are presented and compared with a previous survey conducted in the year 2000. The hamlet community has noticeably changed over 17 years, with a > 30% increase in relative abundance of the yellowtail hamlet Hypoplectrus chlorurus on the inner reefs at the expense of the other hamlet species. The data also suggest that the density of H. chlorurus has declined and that its distribution has shifted towards shallower depths. Considering that H. chlorurus has been previously identified as one of the few fish showing a positive association with seawater turbidity on the inner reefs of La Parguera and that sedimentation of terrestrial origin has increased over recent decades on these reefs, it is proposed that turbidity may constitute an important but so far overlooked ecological driver of hamlet communities.

Differential habitat use of reef fishes on a shelf-edge reef off La Parguera, Puerto Rico

The biotic community at a shelf-edge reef, which abruptly delineates a continuous fringing reef from the adjacent mesophotic reef off southwestern Puerto Rico, USA, was used to identify patterns of differential habitat use in reef fishes. Our study used multivariate analyses to identify groupings within the fish community associated with this area. These groups were suggestive of differential habitat use by the fish community, in particular with respect to the reef-terrace vs slope locations. The benthic composition among these two location stratifications differed while remaining surprisingly consistent within each location strata (i.e., reef-terrace vs slope). The variability in both the fish and benthic communities was best explained in our model by the location stratifications within each site as opposed to the physical position of the site itself along the shelf edge. Food resources, structure (i.e., habitat complexity), or both may contribute to differential habitat use within the reef-fish communities observed. A lesser division was apparent within the reef-terrace locations that grouped the western samples separately from the eastern. The results presented in the present study suggest that the fish communities along the shelf-edge reef adjacent to La Parguera, Puerto Rico, are divided by habitat type and location as determined by food and shelter availability. Here, we present an analysis whereby community structure can be identified at varying spatial scales within a single depth zone to inform managers prior to strategy implementation.

Are large colonies a "key factor" in the dynamics of gorgonian populations?

Life cycle stages responsible for fluctuations in population sizes have often been described as fac­tors. In this study, a key factor approach was used to examine the dynamics of a shallow-water gorgonian popula­tion from 1983-1996 near La Parguera Gil the southwest coast of Puerto Rico. Gorgonian abundances increased from 8.1 to 99.6 colonies/m2 between 1983 to 1985 and gradually declined to 57.3 colonies/m2 in 1996. These variations in population size are largely attributable to recruitment, which increased from 2.1 to 44.9 colonies/m2 between 1983 to 1985, and declined thereafter. Survival. of recruit colonies which was generally higher after periods of high recruit­ment also played a contributing role in these population fluctuations. In contrast, survival of large colonies (2:10 cm in height) was essentially constant (about 94.1%/yr), and consequently had negligible effects on variations in abun­dances. These results demonstrate that large colonies are no! a key factor underlying fluctuations in gorgonian popu­lations. However, this assessment of large colonies differs if the results are examined in a different conceptual con­text. The combination of high and constant large colony survival, and variable reproductive success (recruitment and recruit survival) conforms to the interpretation of life history pattern. According to bet-hedging theory, large colonies are essential to the persistence of populations.

Comparison of trace metals in different fish tissues of Scomberomorus spp. (“sierra”) and Lutjanus synagris (“arrayado”) from Jobos Bay and La Parguera coastal areas in Southern Puerto Rico

Metal pollution in aquatic systems are a health concern worldwide. This study compared the distribution As, Cd, Cu, Pb, Se, and Zn, in liver, gonad, gill and muscle of S. cavallaand L. synagris from Jobos Bay to levels in S. regalisand L. synagrisfrom La Parguera (reference site). Levels of Hg were only determined in fish muscle. Arsenic, Se, and Hg (only for S. cavalla) were significantly higher in tissues of fish species from Jobos Bay when compared to fish from La Parguera. Liver displayed higher metal concentrations, while muscle tended to accumulate less metals. In all tissues, Zn exhibited the highest concentrations, while Cd and Pb were limited to liver and gill of L. synagris from both sampling areas. Most metal content in different tissues of S. cavalla and L. synagris from the Jobos Bay area fell in the range of metal concentrations that were associated to low aquatic metal pollution, although As and Hg concentrations in fish muscle represent a human health concern based on health criteria values.

Sponge epizoism in the Caribbean and the discovery of new Plakortis and Haliclona species, and polymorphism of Xestospongia deweerdtae (Porifera).

The new discovery by Vicente et al. (2014) of specialized epizoic symbioses between sponges of the genera Plakortis and Xestospongia revealed the obligate interaction of two new Plakortis spp. associating with Xestospongia deweerdtae and a new Xestospongia sp. In this study we formally describe the two new Plakortis spp. as Plakortis deweerdtaephila sp. nov. (previously reported as Plakortis sp. 1), Plakortis symbiotica sp. nov. (previously reported as Plakortis sp. 2) and describe the new Xestospongia sp. epibiont as Haliclona (Halichoclona) plakophila sp. nov. Plakortis deweerdtaephila associates only with X. deweerdtae, and has very small to large straight diods (24.2-233.7 μm long) and triods (26.4-102.6 μm long) that form large ectosomal circular meshes (114-329 μm diameter). P. symbiotica associates with both X. deweerdtae and H. plakophila, has larger curved diods (71.9-141.8 μm long) and triods (20.4-70.6 μm long) that form smaller ectosomal circular meshes (43-121 μm diameter) than P. deweerdtaephila. Phylogenetic analysis of cox1 and cob gene fragments revealed a strongly supported clade that grouped both Plakortis spp. nov. distantly from any other known Plakortis spp. H. plakophila is described as a thin encrusting veneer of tissue with occasional papillae, so far only found associated with P. symbiotica in La Parguera, Puerto Rico. Phylogenetic analysis of 18S rRNA and cox1 gene fragments place it distantly from any known clade of Haplosclerida. We found a new associated morphotype of X. deweerdtae from Bocas del Toro Panama, which completely overgrew P. deweerdtaephila. In addition, free-living morphotypes from Panama produce larger S-shaped and round bracket shaped strongyles never before observed for this species, leading us to redescribe X. deweerdtae. All X. deweerdtae morphotypes shared >99% sequence homology of cox1, 18S rRNA and 28S rRNA genes with the holotype of X. deweerdtae. This study highlights the highly variable morphological characters of X. deweerdtae influenced by lifestyle and environmental factors. This is also the first time that an obligate symbiosis with a heterospecific sponge is used as a key taxonomic character.

Symbiodinium (internal transcribed spacer 2) diversity in the coral host Agaricia lamarcki (Cnidaria: Scleractinia) between shallow and mesophotic reefs in the Northern Caribbean (20–70 m)

AbstractThis study investigated differences in Symbiodinium diversity in the scleractinian coral species Agaricia lamarcki between shallow (20–25 m) and mesophotic (50–70 m) depths in the Northern Caribbean. Corals were sampled in each of four shallow sites (20–25 m; n = 18) and three mesophotic sites (50–70 m; n = 18) from Mona Island (Puerto Rico) and the US Virgin Islands during a mesophotic exploratory cruise and from the La Parguera shelf edge, off Southwestern Puerto Rico. Symbiodinium diversity was assessed using internal transcribed spacer 2 sequences clustered into operational taxonomic units (OTUs). Clustering resulted in eight clade C OTUs and one clade D OTU. Of these, there were three common Symbiodinium OTUs consisting of C3 and D1a.N14 in shallow reefs and C11.N4 in mesophotic reefs. Statistical tests (permutational multivariate analysis of variance and analysis of similarity) showed significant differences between clade C Symbiodinium OTUs in A. lamarcki colonies located at shallow and mesophotic depths, indicating symbiont zonation. Symbiodinium diversity in A. lamarcki from the Northern Caribbean is comparable to previous reports in the Southern Caribbean for this species. This is the first report of the thermal tolerant species Symbiodinium trenchii (D1a) in A. lamarcki.

Mesophotic coral ecosystems under anthropogenic stress: a case study at Ponce, Puerto Rico

Mesophotic coral ecosystems (MCEs) were compared between La Parguera and Ponce, off the south coast of Puerto Rico. In contrast to La Parguera, Ponce has a narrow insular shelf and hosts several river outlets, a commercial port, a regional sewage treatment plant with associated deep water outfall, and three deep dredge disposal sites. Off Ponce, MCEs receive higher (16×) rates of sedimentation than off La Parguera, a less impacted site. The most impacted sites were located offshore of Cayo Ratones and are in or down-current and in close proximity to one of the dredge disposal sites. There, MCEs are characterized by a steep, irregular, rocky slope with a cover of fine-grained, dark brown sediment, which increases with depth. At shallower depths, scattered rocky outcroppings are colonized by sponges, black corals and algae. The sediment cover contains two to three times the terrigenous content and a significantly higher percentage of the fine-grained fraction than off La Parguera. Thirteen remotely operated vehicle (ROV) dives east and west of Ponce showed that the deepest depth at which corals were observed increased with distance from Cayo Ratones and did not approach depths observed off La Parguera except at the eastern-most (up-current) site, Caja de Muertos, which was also significantly further offshore. Benthic communities off Caja de Muertos were comparable to those at La Parguera, while off Cayo Ratones, there were no mesophotic corals and sparse development of other benthic macrobiota except sponges. Management authorities should include MCEs when assessing potential impacts from anthropogenic activities and take the necessary steps to reduce local threats.

Natural Prey Preferences and Spatial Variability of Predation Pressure by Cyphoma gibbosum (Mollusca: Gastropoda) on Octocoral Communities off La Parguera, Puerto Rico.

This study evaluated the natural prey preferences and spatial variability of predation pressure (PP = proportion of colonies with snails and/or clear predation signs) by the gastropod Cyphoma gibbosum on octocoral communities off the La Parguera Natural Reserve, Puerto Rico. All octocoral colonies were checked for presence of C. gibbosum and/or clear predation signs in four permanent band-transects (2 × 10 m), along three depth intervals (0–5, 7–12, >15 m deep) in each of six reefs along an inshore offshore gradient. Results indicate that C. gibbosum preys on at least 16 species, six of which (Briareum asbestinum, Gorgonia ventalina, Pseudoterogorgia americana, P. acerosa, Plexaura flexuosa, and Pseudoplexaura porosa) consistently showed significantly higher (K-W, P < 0.05) (17–37%) PP compared to all other species. Plexaura flexuosa, P. americana, and P. porosa had significantly higher PP (11–38%) among inner and mid-shelf reefs, and G. ventalina had higher PP in shelf-edge reefs (16–20%). A combination of differential spatial distributions and octocoral species abundances seems to explain the observed patterns of predation by C. gibbosum. Prey preference and higher abundances of 3-dimensional octocorals providing increased refuge or microhabitats utilized for mating or egg-deposition could be driving the spatial distribution of C. gibbosum and the observed differential predation pressure.

New records of Bodotriidae (Crustacea: Cumacea) from Puerto Rico with descriptions of three new species.

In a continuing effort to describe the cumacean fauna of Puerto Rico we describe three new species of Bodotriidae, a family that has never been reported from Puerto Rico before. While finding and describing new microcrustacean species may not be an impossible task, if there is available taxonomic expertise, the currently described species were found in large numbers within a short distance from the Marine Laboratories of the University of Puerto Rico where the local reefs have been studied for over half a century, highlighting the large gaps that exist in our estimates of Caribbean marine diversity. The three new species, Cyclaspis gurui sp. nov., Cyclaspis mariae sp. nov. and Vaunthompsonia budaii sp. nov. are reported from a fringing reef off La Parguera, southwest coast of Puerto Rico and Vaunthompsonia cristata Bate, 1858 represents a new record for Puerto Rico from the mesophotic reefs.

Interplay between proteases and protease inhibitors in the sea fan—Aspergillus pathosystem

Environmental conditions greatly impact the dynamics of host–pathogen relationships, affecting outbreaks and emergence of new diseases. In corals, epizootics have been a main contributor to the decline of reef ecosystems and rising sea surface temperatures associated with climate change are thought to exacerbate virulence of pathogens and/or compromise the immune responses of coral hosts. Among pathogens strategies, protease secretion is a common virulence factor that promotes colonization of the host. As such, protease inhibitors play an invaluable role to the host for protection against pathogen invasion. This study describes changes in activity of proteases secreted by the fungal pathogen, Aspergillus sydowii, and protease inhibitors of Gorgonia ventalina under ambient and elevated temperatures and health conditions (disease and healthy). G. ventalina colonies were collected from Florida Keys, Florida (24° 34.138N, 81° 22.905W) or La Parguera, Puerto Rico (17° 56.091N, 67° 02.577W) in 2007 and 2012, respectively. At elevated temperatures, protease activity was significantly higher than at ambient temperatures in A. sydowii. Temperature stress did not induce a change in protease inhibitor activity, but in healthy G. ventalina colonies, inhibitor activity against proteases was higher than in diseased individuals. Healthy colonies appear capable of resisting proteolytic activity, but diseased individuals are still likely affected by pathogen infections. These data suggest that rising sea surface temperatures due to climate change may increase levels of virulence (protease activity) of A. sydowii, while immunity (protease inhibitor) of G. ventalina may not be affected.

Spatial and Temporal Variability of Caribbean Yellow Band Disease Prevalence inOrbicellaspp. off La Parguera, Puerto Rico

The spatial and temporal variability in mean prevalence of Caribbean yellow band disease (CYBD) in the scleractinians Orbicella faveolata and O. franksi was assessed during 2008 and 2009 in reefs off La Parguera, Puerto Rico. All diseased and healthy-looking colonies were counted along each of four band transects (20 m2) in each of 3 depth intervals (3–8; 8–15; > 15 m) in two inner (Pelotas and Enrique) and two mid-shelf (Turrumote and Media Luna) fringing reefs, and two deep bank reefs at the shelf-edge (Weinberg and Old Buoy). Overall, densities of O. faveolata were higher at intermediate depth habitats (0.5 col./m2) while those of O. franksi were higher at deep habitats (1.7 col./m2). In inner-and mid -shelf fringing reefs both O. faveolata and O. franksi showed significantly higher mean CYBD prevalence at intermediate depth habitats (25 ± 24 % and 17 ± 36 %) compared to deeper (13.4 ± 27 % and 5.2 ± 11 %) and shallow habitats (7.9 ± 11 % and 0 %, respectively). Mean CYBD prevalence in O. faveolata and O. franksi were significantly higher (p<0.05, H=31.6; df=2; U=1756; p<0.05) in mid-shelf reefs (28 ± 27 % and 16.3 ± 31 % respectively) compared to shelf-edge reefs (5.3 ± 5.6 % and 1 ± 1.4 %) and to inner-shelf reefs (9.9 ± 20.6 %) only for O. faveolata. There was a significant positive correlation between CYBD prevalence and densities of O. faveolata (Spearman's r = 0.7; p<0.05). In contrast, O. franksi showed a significant but negative correlation (Spearman's r = -0.5; p<0.05). No significant change in mean CYBD prevalence was observed between seasons and years (2008 to 2009) for both species (26.9 ± 24.9 % and 24.1 ± 23.4 % in O. faveolata and 5.4 ± 10.7 % and 5.0 ± 12 % 5.4 ± 10.7 % to 5.0 ± 12 % in O. franksi respectively). Overall, O. faveolata had significantly higher CYBD prevalence compared to O. franksi which indicates that this species is more susceptible to CYBD. Deep habitats with low quality/quantity of light might serve as a refuge from CYBD in both species. The slight decrease over time in the proportion of infected colonies in both species, indicates no new infections, possibly because of lack of more susceptible colonies after 12 years, reduced virulence, an immune response, or any combination of these.

Contrasting responses of coral reef fauna and foraminiferal assemblages to human influence in La Parguera, Puerto Rico

Coral reef biota including stony corals, sponges, gorgonians, fish, benthic macroinvertebrates and foraminifera were surveyed in coastal waters near La Parguera, in southwestern Puerto Rico. The goal was to evaluate sensitivity of coral reef biological indicators to human disturbance. Proxies for human disturbance were measured as distance to town (DTT) and rankings of a low-level sediment contamination gradient analyzed from a previous study. Contaminant rank and DTT showed that percent mud, stony coral taxa richness, reef rugosity, and numbers of invertebrates and sponges were higher at sites closer to human disturbance, but a foraminiferal assemblage index was significantly lower at sites with higher proxies for human disturbance. Fish indicators showed no significant relationships with human activity, but associations between fish community measures and certain measures of stony corals, gorgonians and sponges were found. Contrasting responses between foraminifera and reef organisms may be due to greater exposure and sensitivity of foraminifera to sediment contaminants.

The role of scientific studies in building consensus in environmental decision making: a coral reef example

We present a new approach for characterizing the potential of scientific studies to reduce conflict among stakeholders in an analytic-deliberative environmental decision-making process. The approach computes a normalized metric, the Expected Consensus Index of New Research (ECINR), for identifying where additional scientific research will best support improved decisions and resolve possible conflicts over preferred management actions. The ECINR reflects the expected change in agreement among parties over preferred management actions with the implementation and consideration of new scientific studies. We demonstrate the ECINR method based on a preliminary application to coral reef protection and restoration in the Guanica Bay Watershed, Puerto Rico, focusing on assessing and managing anthropogenic stressors, including sedimentation and pollution from land-based sources such as sewage, agriculture, and development. Structured elicitations of values and beliefs conducted at a coral reef decision support workshop held at La Parguera, Puerto Rico, are used to develop information for illustrating the methodology. The ECINR analysis was focused on a final study group of seven stakeholders, consisting of resource managers and scientists, who were not in agreement on the efficacy and respective benefits of reducing loadings from three sources: sewage, agriculture, and development. The scenario assumed that loadings would be reduced incrementally from each source through a series of management steps, which would be ranked in order of maximizing anticipated benefits. An examination of whether beliefs exhibited greater confidence and coherence between stakeholders when informed by plausible study results followed. The results suggest that new scientific research would be generally likely to bring people who initially disagreed to agree. Seventy-five percent of the hypothetical research results were projected to result in more agreement among the stakeholders. However, there can be situations where prior beliefs may be too different from the study results to shift perspectives enough to result in more agreement. Furthermore, in a few cases, hypothetical research results were projected to lead to more conflict among stakeholders. Priority research, according to the seven stakeholders, would be to quantify loadings from agriculture and sewage, and not loadings from development, since it is predicted to make little difference in the outcome. Assuming the stakeholders are conflict-averse, they would likely opt for research on sewage loadings as the highest priority. Though preliminary, these results suggest that ECINR can provide useful insights into the social implications of a research program.

Fishes associated with mesophotic coral ecosystems in La Parguera, Puerto Rico

Fishes associated with mesophotic coral ecosystems (MCEs) of the La Parguera shelf-edge were surveyed between 2007 and 2011 using mixed-gas rebreather diving. Fishes were identified and counted within belt transects and roving surveys at 30, 40, 50, 60 and 70 m depth. Vertical transects from 70 to 30 m depth helped determine depth distribution ranges. One hundred and three species were identified at MCEs (40–70 m), with high abundances and species richness, though both varied greatly among transects. Most species at MCEs were common inhabitants of shallow reefs, but some were restricted to mesophotic depths. An additional 15 species were added to those previously classified as indicator species of mesophotic areas in Puerto Rico. The MCE fish assemblage was distinct from shallow areas (30 m), with taxonomic composition, abundance and the proportion of trophic guilds varying with increasing depth. The dominant trophic guild within MCEs was the zooplanktivores, while herbivores dominated shallow reefs. Both herbivores and zooplanktivores responded strongly, and oppositely, to depth. The few herbivores associated with deep MCEs are small-bodied species. The largest changes within the mesophotic fish community along the depth gradient occurred at 60 m, similar to that reported for algae and corals, and seem to represent both a response to reduced light and variations in herbivory. The presence of commercially important fishes at MCEs, many considered to be threatened by fishing pressure in shallow areas, suggests that MCEs are important for the conservation of these species. This study represents the first quantitative in situ observations and descriptions of fishes inhabiting MCEs at depths of 50–70 m in Puerto Rico and highlights the role of MCEs as valuable habitats for reef fishes. The composition and distribution of the MCEs fish community should be incorporated when planning for the spatial management of coral reef resources.

Erratum to “Incidence and Spatial Distribution of Caribbean Yellow Band Disease in La Parguera, Puerto Rico”

Erratum to “Incidence and Spatial Distribution of Caribbean Yellow Band Disease in La Parguera, Puerto Rico”

Hydrolithon abyssophila sp. nov. (Hydrolithoideae, Corallinales), a bisporic coralline from the insular shelf edge of Puerto Rico and the Virgin Islands (US)

Abstract A new species of Hydrolithon is described from mesophotic habitats, between 30 and at least 76 m depth, off La Parguera, Puerto Rico, and St Thomas, Virgin Islands (Caribbean Sea). Its encrusting thallus covers corals and rocks. Hydrolithon abyssophila sp. nov. is distinctive in developing bisporangia that are about twice as large as its congeners and in lacking both perithallial protuberances and trichocytes in horizontal or vertical groups. It reproduces primarily by uninucleate bispores that presumably recycle the parental phase. Unfertilized carpogonia were observed in one collection suggesting the rare occurrence of gametophytic reproduction in the species.

Parguerene and Precarriebowmide, Two Classes of Lipopeptides from the Marine Cyanobacterium Moorea producens

Two new marine cyanobacterial natural products, parguerene (1) and precarriebowmide (2), were isolated from a collection of Moorea producens obtained from La Parguera, Puerto Rico. The planar structures of both were deduced by 2D NMR spectroscopy and mass spectrometry. Parguerene is a modified acyl amide with some structural similarity to the bacterial metabolite stipiamide (3), whereas precarriebowmide is a lipopeptide and represents a minor modification compared to two other known metabolites, carriebowmide (4) and carriebowmide sulfone (5). The identification of 2 led to an investigation into whether carriebowmide and carriebowmide sulfone were true secondary metabolites or isolation artifacts.

Detection of verotoxin producing Escherichia coli in marine environments of the Caribbean

The goal of this study was to determine the potential for Enterohemorrhagic Escherichia coli O157:H7 (EHEC) contamination in tropical marine waters. Samples were collected from urban, suburban, and rural sites around the islands of Puerto Rico and The Republic of Trinidad and Tobago. Quantification of E. coli and EHEC was evaluated using MI plates and qPCR. EHEC was detected in six sites in Puerto Rico: West of La Parguera Town, Boquilla, Oro Creek, Fishers Association, Joyuda Lagoon, and Boqueron Wetland Creek and in two rural sites in Trinidad: Balandra Bay and Quinam Bay. Plate count enumeration of E. coli was not a reliable indicator for the presence of EHEC. The sites where EHEC was detected on both islands are used for recreational bathing, water sports and recreational/commercial fisheries and therefore pose a public potential health risk.