Coral Reef Biota Research Articles

Sexual Biology and Mating Behaviour in Decapod Crustaceans: A Case Study with Coral Reef Dwelling Caridean Shrimps

Crustaceans have diversified sexual systems, incorporating various reproductive modalities such as gonochorism and a wide variety of hermaphroditism. In particular, the coral reef- dwelling caridean shrimps, living in symbiosis with other marine invertebrates, have developed unusual sexual systems that have given origin to a range of social systems, including the highly advanced eusociality. Protandric hermaphroditism, common among the caridean shrimps, has also reached a unique sexual condition, known as protandric simultaneous hermaphroditism, in the genus, Lysmata. Similarly, mating systems in the caridean shrimps are highly diverse and divergent. In addition, their occurrence in the coral reef shrimps is correlated to their life style adaptations such as their commensal association with other invertebrates. Other ecological factors like the predation risk from outside of the host animals and differences in the host characteristics may also be the driving forces in determining mating associations. Furthermore, the transition from sexual monogamy to social monogamy under conditions of their symbiotic life led to complex community living in several synalpheid shrimps. Understandably, the existence of various sexual and mating systems in these caridean shrimps has a dependence on the eco- social conditions prevalent in the coral reef biota.

Determination of Marine Conservation Areas by means of Satellite Imagery and Participatory Planning in Bawean Island, Gresik Regency, East Java

Bawean Island and its marine surrounding hold a lot of potential biotas in its marine ecosystem. To maintain these potential natural resources, it is necessary to make marine conservation efforts, one of which is by means of Bawean marine conservation area determination. This research began with the preparation of image processing to determine the distribution of seagrass and coral reef biota. Furthermore, a groundcheck was carried out to review the condition of the existing ecosystem, the results of which became input for FGD as a form of participatory planning. Categories, types, zones, and subzones of conservation areas are determined based on marine and fisheries regulations. As a result, seagrasses can be found at several points in Bawean waters with a total area of 125.60 ha. The average seagrass closure condition can be considered as moderate, with the most encountered species being Thalassia Hemprichii. Meanwhile, coral reefs distribution is scattered in almost all Bawean marine with a total cover area of 3,037.51 ha. The average live coral reef cover in the observation area reaches 76%, which can be considered as good condition.

Comparison of coral reef communities in proximity to ocean effluent pipes off the north coast of Puerto Rico.

Coral reefs are declining globally as a result of multiple stressors, including land-based stressors, such as sedimentation and pollution, and those that are related to a changing climate, such as increases in ocean acidification. Degradation of US Caribbean coral reef biota has been associated with exposure to sewage effluent from wastewater treatment plants (WWTPs). The Puerto Rico Aqueduct and Sewer Authority (PRASA) maintains WWTPs on the north coast of Puerto Rico, which release effluent into the marine environment in the vicinity of coral reefs. Using data collected by PRASA surveys conducted from 1999 to 2013, we examined coral reef condition at survey sites to identify potential changes or differences in reefs with respect to their proximity to the WWTP effluent pipes (e.g., upstream, downstream). The proportion of coverage represented by all coral, sensitive taxa, and tolerant taxa were compared across sites located upstream and downstream of WWTP effluent pipes using multivariate approaches and analysis of variance. The proportion of healthy, sensitive coral species and invasive or tolerant coral species were not different at sites downstream of the WWTP effluent pipe compared to upstream. These results are caveated by the limited sampling design, highly variable communities across WWTP locations, and the sparsity or absence of well-developed coral reef communities at most stations. We evaluate the strengths and weaknesses of the survey design and provide recommendations for future coral reef surveys investigating potential impacts of WWTP effluent.

Chlorinated and brominated persistent compounds in hard coral, soft coral, and parrotfish from remote Mascarene islands

Persistent halogenated compounds (PHC) are of concern for human and environmental health. Persistent Organic Pollutants (POPs) are regulated by international treaties, but alternative compounds such as novel brominated flame retardants (NBFRs) and Dechlorane Plus (DP) are not—yet they are increasingly used. There are no data on PHCs in coral reef biota from tropical islands in the western Indian Ocean (WIO). For this assessment, three hard coral genera, two soft coral genera, and ember parrotfish (Scarus rubroviolaceus) were collected from the remote Rodrigues, Agalega, and St. Brandon’s Atoll (Republic of Mauritius) in the Mascarene Basin of the WIO. Five compounds — Pentabromotoluene (PBT), γ-HCH, p,p’-DDE, HCB, and BDE-47— were quantifiable in all samples. Hard coral consistently contained the lowest concentrations of PHCs, except for NBFRs. The presence of BDE-47 suggests long-range aerial transport. We quantified DP, currently a candidate POP, in coral reef biota. PBT was measured in all samples also suggests long-range transport. Because the hard coral, soft coral, and fish had differing concentrations and patterns of PHCs, future surveys should stratify sampling accordingly. Agalega and St. Brandon’s Atoll can be considered as locations to monitor changes in background concentrations of pollutants due to their remoteness.

The scleractinian Agaricia undata as a new host for the coral-gall crab Opecarcinus hypostegus at Bonaire, southern Caribbean

The Caribbean scleractinian reef coral Agaricia undata (Agariciidae) is recorded for the first time as a host of the coral-gall crab Opecarcinus hypostegus (Cryptochiridae). The identity of the crab was confirmed with the help of DNA barcoding. The association has been documented with photographs taken in situ at 25 m depth and in the laboratory. The predominantly mesophotic depth range of the host species suggests this association to be present also at greater depths. With this record, all seven Agaricia species are now listed as gall-crab hosts, together with the agariciid Helioseris cucullata. Within the phylogeny of Agariciidae, Helioseris is not closely related to Agaricia. Therefore, the association between Caribbean agariciids and their gall-crab symbionts may either have originated early in their shared evolutionary history or later as a result of host range expansion. New information on coral-associated fauna, such as what is presented here, leads to a better insight on the diversity, evolution, and ecology of coral reef biota, particularly in the Caribbean, where cryptochirids have rarely been studied.

On the occurrence of a widespread contamination by herbicides of coral reef biota in French Polynesia.

Research has been conducted within the framework of the French Initiative for Coral Reefs (IFRECOR) to assess pesticide pollution levels in the coral reef trophic webs in French Polynesia. Unexpected widespread contamination by herbicides was found in algae, fishes and macro-invertebrates located at various levels of the reef trophic web. Concentrations in organisms investigated were for the majority below the lowest observable effect level and do not pose a dietary risk to native population who subsist on these fish. However, the widespread contamination may affect the reef ecosystem in the future as coral symbiotic algae, Symbidinium sp. (Dinophyta) are particularly sensitive to photosystem II herbicides, particularly the substituted urea and triazine derivatives.

A DIVERSE PATCH REEF FROM TURBID HABITATS IN THE MIDDLE MIOCENE (EAST KALIMANTAN, INDONESIA)

The Kutai Basin (East Kalimantan, Indonesia) contains a rich and well-preserved Miocene fossil record of small patch reefs that developed under the influence of high siliciclastic input associated with the progradation of the Mahakam Delta. In this study, we reconstruct the biodiversity and paleoenvironments on one of these delta-front, mixed carbonate-siliciclastic systems that developed at the Serravallian–Tortonian boundary near the city of Samarinda. In two newly exposed sections, we analyzed the sedimentology and distribution of the main fossil biota including corals, foraminifers, coralline algae, and bryozoans. Seven facies are herein defined, including two dominated by platy corals and two by larger benthic foraminifera. Facies distributions were driven by changes in depth and variations in terrigenous input within a range of delta-front habitats. Despite the turbid conditions, fossil assemblages are highly diverse, including 69 coral species and 28 bryozoan species that occur in coral-dominated facies. Crustose coralline algae were mainly associated with the coral-dominated facies. Larger benthic foraminifera showed broader ecological tolerance within the range represented in the studied sections and thus are common in most facies. These diverse patch reef ecosystems were able to cope with high siliciclastic input during the early development of the Miocene coral reef biota.

Effects of depth and ultraviolet radiation on coral reef turf algae

Despite the increasing dominance of turf algae in coral reefs, few studies have investigated their physiological and ecological responses to changes in abiotic factors. We tested the effects of depth and ultraviolet radiation on turf algae at different levels of successional stages using two experiments. Depth-related differences were found for all turf algal communities, characterized by a higher amount of the cyanobacteria taxon Dichothrix and the red filamentous genera Poly-/Herposiphonia in the shallow and the appearance of oscillating cyanobacteria in deeper waters. In the first experiment, cross-depth transplantation of 153days old communities influenced percentage cover, biomass and taxa composition. Downward transplantation lowered overall biomass and abundance of the foraminifera Sorites, whereas the crustose green alga Pringsheimiella and filamentous cyanobacteria colonized the communities. A nearly reverse pattern was observed in upward transplanted communities. Overall we distinguished between sensitive taxa, like Oscillatoria, and taxa able to acclimate to alterations in their environment, like Pringsheimiella, Poly/Herposiphonia and Dichothrix. In the second experiment, algae grown for 285days at 5m were exposed together with a set of sterile settlement tiles to three UVR regimes at 2m for 22days. UVR had no effect on turf algal communities regardless of successional stage. This study highlights the presence of high light and UV tolerant species. The high UV tolerance of turf communities may confer a competitive advantage over other more sensitive coral reef biota, such as corals. This study demonstrates that turf algae are dynamic communities exhibiting species-specific resistance to environmental changes.

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.

Influence of environmental gradients on C and N stable isotope ratios in coral reef biota of the Red Sea, Saudi Arabia

The Red Sea features a natural environmental gradient characterized by increasing water temperature, nutrient and chlorophyll a concentrations from North to South. The aim of this study was to assess the relationships between ecohydrography, particulate organic matter (POM) and coral reef biota that are poorly understood by means of carbon (δ13C) and nitrogen (δ15N) stable isotopes. Herbivorous, planktivorous and carnivorous fishes, zooplankton, soft corals (Alcyonidae), and bivalves (Tridacna squamosa) were a priori defined as biota guilds. Environmental samples (nutrients, chlorophyll a), oceanographic data (salinity, temperature), POM and biota were collected at eight coral reefs between 28°31′ N and 16°31′ N. Isotopic niches of guilds separated in δ13C and δ15N isotopic niche spaces and were significantly correlated with environmental factors at latitudinal scale. Dietary end member contributions were estimated using the Bayesian isotope mixing model SIAR. POM and zooplankton 15N enrichment suggested influences by urban run-off in the industrialized central region of the Red Sea. Both δ15N and their relative trophic positions (RTPs) tend to increase southwards, but urban runoff offsets the natural environmental gradient in the central region of the Red Sea toward higher δ15N and RTPs. The present study reveals that consumer δ13C and δ15N in Red Sea coral reefs are influenced primarily by the latitudinal environmental gradient and localized urban runoff. This study illustrates the importance of ecohydrography when interpreting trophic relationships from stable isotopes in Red Sea coral reefs.

Unforeseen importance of historical collections as baselines to determine biotic change of coral reefs: the Saba Bank case

Botanical and zoological collections may serve as archives for historical ecological research on the effects of global change and human impact on coral reef biota. Museum collections may harbour old specimens of reef-dwelling species that have become locally extinct. Such collections also help to determine whether early records of invasive species can be obtained from times when they were not yet recognized as such. A case study (2006) involving Saba Bank, Caribbean Netherlands (former Netherlands Antilles), suggests that the coral reef fauna here may have become impoverished when compared with data obtained during an earlier expedition in 1972. However, the 1972 sampling may have been incomplete, as it was performed by professional divers who were not trained taxonomists, whereas the collecting in 2006 was done by experienced marine biologists who knew the taxa they were sampling. As Saba Bank has been under stress due to the anchoring of large vessels, and invasive species have been a potential threat as well, future studies are needed to obtain more insights into the changing reef biota of Saba Bank. Using this Saba Bank example, we want to address the importance of natural history collections as reservoirs of valuable data relevant to coral reef biodiversity studies in a time of global change. As such, these collections are still underexplored and underexploited.

Predicting water toxicity: Pairing passive sampling with bioassays on the Great Barrier Reef

Many coral reefs worldwide occur adjacent to urban or agricultural land which places these ecosystems at threat of exposure to complex mixtures of pollutants. In this study, the pairing of passive sampler extracts with bioassays is proposed as a tool for predicting effects of organic pollutant mixtures on key biota within coral reef ecosystems. Passive samplers, SDB-RPS Empore™ disks, which sequester a mixture of the contaminants present in the environment, were deployed at three sites in the Great Barrier Reef (GBR). Extracts from these samplers were analysed for herbicides and applied to bioassays targeting integral life stages or functions of coral reef biota. Biota included scleractinian coral larvae, sea urchin larvae, a marine diatom and marine bacteria. Photosynthesis in the marine diatom Phaeodactylum tricornutum was inhibited at the sampled environmental concentration while an environmental concentration factor of 15 times inhibited luminescence in the marine bacterium Vibrio fischeri. Concentrations of 50 times sampled environmental levels of organic pollutants inhibited >90% of Acropora millepora settlement and 100-fold environmental enrichment inhibited 100% Heliocidaris tuberculata larval development. These results demonstrate the utility of pairing passive sampling with bioassays and reveal that mixtures of organic pollutants in the GBR have the potential to cause detrimental effects to coral reef biota.

Crises on coral reefs and in coral reef science in the 21st century: the need for a new peer-review system

ESEP Ethics in Science and Environmental Politics Contact the journal RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections ESEP 8:109-119 (2008) - DOI: https://doi.org/10.3354/esep00093 AS I SEE IT Crises on coral reefs and in coral reef science in the 21st century: the need for a new peer-review system Paul W. Sammarco Louisiana Universities Marine Consortium (LUMCON), 8124 Hwy. 56, Chauvin, Louisiana 70344, USA *Email: psammarco@lumcon.edu ABSTRACT: Coral reef biota have suffered mass mortality globally in the last 30 yr. Causes include: (1) coral disease, (2) coral bleaching, (3) coastal nutrient enrichment, (4) over-fishing, and (5) mass mortality of grazing echinoids. In this paper, I examine data from a US funding agency, a global funding agency, and abstracting indices, and demonstrate why the peer review system has become dysfunctional under these circumstances. Research funding and the number of funded projects have not kept pace with increases in environmental problems, the increased researcher population and researcher demand, resulting in a chronic support gap. This has undermined trust, mutual support, and free-flow of information, and resulted in a poorly functioning review system. I examine the advantages and disadvantages of masking and the double-blinded review system, and recommend a more transparent review system—the reverse-blind review system (RBRS), utilizing (1) Lack of identity of authors/proponents to reviewers, to promote objectivity, (2) identification of reviewers to the authors/proponents, to promote accountability, (3) utilization of expert ‘panel’ members in grant proposal review, similar to the editorial system of scientific journals, each making direct recommendations to funding agencies, (4) elimination of grant panel meetings to help eliminate input by non-experts and confounding group interactions and assign greater responsibility to funding bodies, and (5) allowing researchers to appeal decisions based on inaccurate or misleading information. Such a system would be fairer to the researchers, enhance research, and increase information exchange. KEY WORDS: Coral · Peer review · Proposals · Manuscripts · Publishing · Funding · Panel · Appeal Full text in pdf format NextCite this article as: Sammarco PW (2008) Crises on coral reefs and in coral reef science in the 21st century: the need for a new peer-review system. Ethics Sci Environ Polit 8:109-119. https://doi.org/10.3354/esep00093 Export citation Mail this link - Contents Mailing Lists - RSS Facebook - Tweet - linkedIn Cited by Published in ESEP Vol. 8, No. 2. Online publication date: October 08, 2008 Print ISSN: 1863-5415; Online ISSN: 1611-8014 Copyright © 2008 Inter-Research.

Phase Shift from a Coral to a Corallimorph-Dominated Reef Associated with a Shipwreck on Palmyra Atoll

Coral reefs can undergo relatively rapid changes in the dominant biota, a phenomenon referred to as phase shift. Various reasons have been proposed to explain this phenomenon including increased human disturbance, pollution, or changes in coral reef biota that serve a major ecological function such as depletion of grazers. However, pinpointing the actual factors potentially responsible can be problematic. Here we show a phase shift from coral to the corallimorpharian Rhodactis howesii associated with a long line vessel that wrecked in 1991 on an isolated atoll (Palmyra) in the central Pacific Ocean. We documented high densities of R. howesii near the ship that progressively decreased with distance from the ship whereas R. howesii were rare to absent in other parts of the atoll. We also confirmed high densities of R. howesii around several buoys recently installed on the atoll in 2001. This is the first time that a phase shift on a coral reef has been unambiguously associated with man-made structures. This association was made, in part, because of the remoteness of Palmyra and its recent history of minimal human habitation or impact. Phase shifts can have long-term negative ramification for coral reefs, and eradication of organisms responsible for phase shifts in marine ecosystems can be difficult, particularly if such organisms cover a large area. The extensive R. howesii invasion and subsequent loss of coral reef habitat at Palmyra also highlights the importance of rapid removal of shipwrecks on corals reefs to mitigate the potential of reef overgrowth by invasives.

Historical biogeography of Indo‐western Pacific coral reef biota: is the Indonesian region a centre of origin?

AimTo apply the modern theory of vicariant biogeography to the study of evolution of the coral reef fauna in the Indo‐western Pacific region.LocationIndian and western Pacific Oceans.MethodsUse of taxa ladograms and Brooks Parsimony Analysis to reconstruct relationships between geographical areas.ResultsThe analysis seems to indicate that the Indonesian region, long stated to be a `centre of origin' for most of the Indo‐West Pacific marine fauna, is a very derived area in the general area cladogram; and that most of the lineages may have originated in the western Indian Ocean, Australia, or the South‐western Pacific (probably from lineages that had remained isolated after the breakup of the Gondwanan supercontinent, or because of the movement of island arcs). A series of events that fragmented an originally widespread biota seems to be highly congruent with geological events that caused the break up of Gondwanaland.Main conclusionsContrary to several previous claims, based mostly on descriptive, rather than analytical, studies, most lineages of coral reef fauna inhabiting the Indo‐western Pacific region probably originated through vicariant events associated with, and following the break up of Gondwana. A general pattern of biotic distribution that is highly congruent with geological data shows that even if long range dispersal and sympatric speciation may in some cases have taken place, they have not probably been the predominant mechanism of speciation in the clades examined.

ENCORE: The Effect of Nutrient Enrichment on Coral Reefs. Synthesis of Results and Conclusions

Coral reef degradation resulting from nutrient enrichment of coastal waters is of increasing global concern. Although effects of nutrients on coral reef organisms have been demonstrated in the laboratory, there is little direct evidence of nutrient effects on coral reef biota in situ. The ENCORE experiment investigated responses of coral reef organisms and processes to controlled additions of dissolved inorganic nitrogen (N) and/or phosphorus (P) on an offshore reef (One Tree Island) at the southern end of the Great Barrier Reef, Australia. A multi-disciplinary team assessed a variety of factors focusing on nutrient dynamics and biotic responses. A controlled and replicated experiment was conducted over two years using twelve small patch reefs ponded at low tide by a coral rim. Treatments included three control reefs (no nutrient addition) and three+N reefs (NH 4Cl added), three+P reefs (KH 2PO 4 added), and three+N+P reefs. Nutrients were added as pulses at each low tide ( ca twice per day) by remotely operated units. There were two phases of nutrient additions. During the initial, low-loading phase of the experiment nutrient pulses (mean dose=11.5 μM NH 4 + ; 2.3 μM PO 4 −3) rapidly declined, reaching near-background levels ( mean=0.9 μM NH 4 + ; 0.5 μM PO 4 −3 ) within 2–3 h. A variety of biotic processes, assessed over a year during this initial nutrient loading phase, were not significantly affected, with the exception of coral reproduction, which was affected in all nutrient treatments. In Acropora longicyathus and A. aspera, fewer successfully developed embryos were formed, and in A. longicyathus fertilization rates and lipid levels decreased. In the second, high-loading, phase of ENCORE an increased nutrient dosage (mean dose=36.2 μM NH 4 + ; 5.1 μM PO 4 −3 declining to means of 11.3 μM NH 4 + and 2.4 μM PO 4 −3 at the end of low tide) was used for a further year, and a variety of significant biotic responses occurred. Encrusting algae incorporated virtually none of the added nutrients. Organisms containing endosymbiotic zooxanthellae (corals and giant clams) assimilated dissolved nutrients rapidly and were responsive to added nutrients. Coral mortality, not detected during the initial low-loading phase, became evident with increased nutrient dosage, particularly in Pocillopora damicornis. Nitrogen additions stunted coral growth, and phosphorus additions had a variable effect. Coral calcification rate and linear extension increased in the presence of added phosphorus but skeletal density was reduced, making corals more susceptible to breakage. Settlement of all coral larvae was reduced in nitrogen treatments, yet settlement of larvae from brooded species was enhanced in phosphorus treatments. Recruitment of stomatopods, benthic crustaceans living in coral rubble, was reduced in nitrogen and nitrogen plus phosphorus treatments. Grazing rates and reproductive effort of various fish species were not affected by the nutrient treatments. Microbial nitrogen transformations in sediments were responsive to nutrient loading with nitrogen fixation significantly increased in phosphorus treatments and denitrification increased in all treatments to which nitrogen had been added. Rates of bioerosion and grazing showed no significant effects of added nutrients. ENCORE has shown that reef organisms and processes investigated in situ were impacted by elevated nutrients. Impacts were dependent on dose level, whether nitrogen and/or phosphorus were elevated and were often species-specific. The impacts were generally sub-lethal and subtle and the treated reefs at the end of the experiment were visually similar to control reefs. Rapid nutrient uptake indicates that nutrient concentrations alone are not adequate to assess nutrient condition of reefs. Sensitive and quantifiable biological indicators need to be developed for coral reef ecosystems. The potential bioindicators identified in ENCORE should be tested in future research on coral reef/nutrient interactions. Synergistic and cumulative effects of elevated nutrients and other environmental parameters, comparative studies of intact vs. disturbed reefs, offshore vs. inshore reefs, or the ability of a nutrient-stressed reef to respond to natural disturbances require elucidation. An expanded understanding of coral reef responses to anthropogenic impacts is necessary, particularly regarding the subtle, sub-lethal effects detected in the ENCORE studies.

Development of coral reefs of the Ryukyu Islands (southwest Japan, East China Sea) during Pleistocene sea-level change

The Pleistocene coral reef deposits called the Ryukyu Group are widely distributed through the Ryukyu Islands. Lithofacies are represented by conglomerate, calcareous sandstone and limestones. The limestones can be divided into six lithofacies on the basis of macro-benthos and large foraminifers. They are coral, rhodolith, Cycloclypeus-Operculina, Halimeda, and poorly- to well-sorted detrital limestones. Their depositional environments are reconstructed referring to the depth range of the Recent coral reef biota around the Ryukyu Islands. Depositional history of the Ryukyu Group is recorded in a stratigraphic cross-section on Toku-no-shima. Sequence stratigraphical units are recognized in the vertical section of the limestones. Units 1 and 3 are considered to have been formed when the relative sea-level was high, while Units 2 and 4 were deposited during the low stands of sea-level. It is noteworthy that the coral limestones of the Units 2 and 4 were accumulated during glacial stages. The generalized sequence of the limestones is deduced from a transition probability on Miyako-jima. It begins with the Cycloclypeus-Operculina limestone and is followed by rhodolith limestone and ends with coral limestone. These facies indicate a shallowing upward succession.