Pathologies Affecting Reef Corals at the Flower Garden Banks, Northwestern Gulf of Mexico

The Flower Garden Banks are high-latitude reefs consisting of coral caps on the top of salt domes in the northwestern Gulf of Mexico. Limited studies to date report low incidence of coral disease on these reefs. Surveys were conducted to document the extent of coral diseases throughout the Flower Garden Banks, including types of disease present, species affected, percentage of recent colony mortality, cases of false disease, and descriptions of new pathologies. Very few of the known (or reported) Western Atlantic diseases were found, and they occurred at extremely low frequencies. Tissue-skeletal anomalies were common. Several conditions resembled known diseases, although their appearance was not wholly consistent with described pathologies and they may represent different conditions. Both ridge-mortality disease and rapid wasting disease were confirmed to be the result of fish biting activities. Several novel pathologic conditions that do not fit the description or known etiology of any currently described coral disease were discovered at relatively high prevalence rates. Because of an absence of standardized coral disease nomenclature and the unknown etiology of these novel syndromes, they are tentatively named pale ring, pale patch, and mottling syndromes on the basis of field characteristics

Eastern tropical Pacific corals monitor low latitude climate of the past 400 years

EXTRACT (SEE PDF FOR FULL ABSTRACT): We have measured coral growth band thickness and skeletal stable isotopic composition through a 371-year transect (AD 1583-1954) from a massive specimen of Pavona clavus from the Galápagos Islands. ... We observe a general cooling trend during 1860-1954, corresponding to the end of the Little Ice Age, an interval characterized by general warming at many mid-latitude sites. Variance at sunspot cycle frequencies in growth rate, stable isotopic, and trace element composition implies a direct or indirect link between the solar cycle and climate modulation in the eastern Pacific

Oxygen isotope analysis of corals from the Gulf of California and the Gulf of Panama: application and implications for coral-based paleoclimate reconstructions [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Coral-based reconstruction of past variability of sea surface conditions is improving our understanding of the tropical ocean-atmosphere system. We present oxygen isotope records from corals collected near the tip of Baja California (Baja) and the Gulf of Panama (Saboga)

GROWTH AND SHELL VARIATION IN THE TROPICAL EASTERN PACIFIC INTERTIDAL GASTROPOD GENUS PURPURA: ECOLOGICAL AND EVOLUTIONARY IMPLICATIONS

Volume: 164Start Page: 518End Page: 53

Skeletal P/Ca tracks upwelling in Gulf of Panama coral: Evidence for a new seawater phosphate proxy

The supply of limiting nutrients to the low latitude ocean is controlled by physical processes linked to climate variations, but methods for reconstructing past nutrient concentrations in the surface ocean are few and indirect. Here, we present laser ablation mass spectrometry results that reveal annual cycles of P/Ca in a 4-year record from the scleractinian coral Pavona gigantea (mean P/Ca = 118 mmol mol?1). The P/Ca cycles track variations in past seawater phosphate concentration synchronously with skeletal Sr/Ca-derived temperature variations associated with seasonal upwelling in the Gulf of Panama´. Skeletal P/Ca varies seasonally by 2–3 fold, reflecting the timing and magnitude of dissolved phosphate variations. Solution cleaning experiments on drilled coral powders show that over 60% of skeletal P occurs in intracrystalline organic phases. Coral skeleton P/Ca holds promise as a proxy record of nutrient availability on time scales of decades to millennia

The Effect of the El Niño–southern Oscillation Event On the Distribution of Reef-associated Labrid Fishes In the Eastern Pacific Ocean

We surveyed the labrid fishes of the eastern Pacific ocean at multiple sites before, during, and after the 1997–98 ENSO event. Our observations showed that reef fish communities in general did not appear to change markedly as a result of the ENSO. Recruitment of labrids at the Galápagos Islands, Clipperton Atoll and Baja California was generally high near the end of the ENSO, indicating no negative effect on populations. Two labrid species did extend their known range during the ENSO: Stethojulis bandanensis settled onto the tip of Baja California and to the Galápagos Islands, while Thalassoma virens recruited heavily to sites along the southern Sea of Cortez in Baja California. We discuss the oceanographic conditions during the ENSO that may have promoted the range extensions. Adults of these species were present in Baja California and Galápagos 2 yrs after the end of the ENSO. Our observations raise the question why these species do not colonize these sites in normal years, given the potential for long larval durations (up to a maximum of 104 d in T. virens) and rapid long-distance transport between islands in the region (recruits of S. bandanensis spent only about 32 d in the plankton)

Eastern Pacific sea surface temperature since 1600 A.D.; the delta (super 18) O record of climate variability in Galapagos corals

We measured stable oxygen isotope ratios and skeletal growth rates in the massive corals Pavona clavus and P. gigantea from the west coast of Isabela Island, Galapagos, to assess interannual to decadal climate variability in the eastern Pacific. Comparisons of instrumental data sets show that sea surface temperatures (SST) in the Galapagos region are representative of a broad portion of the eastern equatorial Pacific. The site is especially well-suited for long-term studies of the El Nino/Southern Oscillation (ENSO) phenomenon, as it lies within the eastern Pacific "center of action" for thermal anomalies associated with ENSO. The P. gigantea isotope record is nearly monthly in resolution, spans the period 1961-1982, and shows strong correlation with a Galapagos instrumental SST record (r = -0.90 for annual averages). Cross-spectral analysis shows that SST can explain greater than 80% of the variance in delta (super 18) O at both the annual cycle and within the high-frequency portion of the ENSO band (3-5 years). The P. clavus record is annual in resolution, extends from 1587 to 1953 A.D., and was obtained from a 10-m diameter colony preserved within the Urvina Bay uplift. Because seawater delta (super 18) O variations in the region are very small, we interpret the Urvina Bay coral delta (super 18) O record in terms of annual average SST. The isotopic record appears to be a very good, but not perfect, indicator of ENSO events and shows good correspondence with the historical ENSO reconstruction of Quinn et al. (1987). A number of low delta (super 18) O excursions that we observe during the 17th and 18th centuries very likely represent ENSO events that are missing from the historical tabulations. Most interannual delta (super 18) O variations between 1607 and 1953 A.D. represent annual average temperature excursions of 1 degrees to 2.5 degrees C. During the Little Ice Age, the annual delta (super 18) O series correlates well with many North American tree ring records and shows low temperatures during the early 1600s and early 1800s, and relatively warmer conditions during the 1700s. Unlike most northern hemisphere tree ring and instrumental records, we see no evidence at this site for warming between 1880 and 1940 but rather observe a slight cooling (28% of the total variance. The main ENSO mode is centered at 4.6 years and accounts for 12% of the total variance. Additional significant oscillations occur at periods of 3.3, 6, 8, 11, 17, 22, and 34 years. Both annual growth rate and delta (super 18) O show variance at periods equivalent to the solar and solar magnetic periods (e.g., 11 and 22 years, respectively). In addition, the amplitude of the 11-year delta (super 18) O cycle generally varies with the amplitude of the solar cycle, supporting previous suggestions that the solar cycle may modulate interannual to decadal climate variability in the tropics. The dominant oscillatory modes, both within the ENSO and interdecadal frequency bands, shift to shorter periods from the early to middle 1700s and again from the middle to late 1800s. This may reflect major reorganizations within the tropical ocean-atmosphere system and suggests that tropical Pacific climate variability is linked across timescales ranging from years to decades. Copyright 1994 by the American Geophysical Union

Deconvolving the delta O-18 seawater component from subseasonal coral delta O-18 and Sr/Ca at Rarotonga in the southwestern subtropical Pacific for the period 1726 to 1997

To reconstruct oceanographic variations in the subtropical South Pacific, 271-year long subseasonal time series of Sr/Ca and delta(18)O were generated from a coral growing at Rarotonga (21.5degreesS, 159.5degreesW). In this case, coral Sr/Ca appears to be an excellent proxy for sea surface temperature (SST) and coral delta(18)O is a function of both SST and seawater delta(18)O composition (delta(18)O(sw)). Here, we focus on extracting the delta(18)O(sw) signal from these proxy records. A method is presented assuming that coral Sr/Ca is solely a function of SST and that coral delta(18)O is a function of both SST and delta(18)O(sw). This method separates the effects of delta(18)O(sw) from SST by breaking the instantaneous changes of coral delta(18)O into separate contributions by instantaneous SST and delta(18)O(sw) changes, respectively. The results show that on average delta(18)O(sw) at Rarotonga explains similar to39% of the variance in delta(18)O and that variations in SST explains the remaining similar to61% of delta(18)O variance. Reconstructed delta(18)O(sw) shows systematic increases in summer months (December-February) consistent with the regional pattern of variations in precipitation and evaporation. The delta(18)O(sw) also shows a positive linear correlation with satellite-derived estimated salinity for the period 1980 to 1997 (r = 0.72). This linear correlation between reconstructed delta(18)O(sw) and salinity makes it possible to use the reconstructed delta(18)O(sw) to estimate the past interannual and decadal salinity changes in this region. Comparisons of coral delta(18)O and delta(18)O(sw) at Rarotonga with the Pacific decadal oscillation index suggest that the decadal and interdecadal salinity and SST variability at Rarotonga appears to be related to basin-scale decadal variability in the Pacific. Copyright (C) 2002 Elsevier Science Ltd