Coral populations and structural coral reefs have undergone severe reductions and losses respectively over large parts of the Galápagos Islands during and following the 1982-83 El Niño event. Coral tissue loss amounted to 95% across the Archipelago. Also at that time, all coral reefs in the central and southern islands disappeared following severe degradation and eventual collapse due primarily to intense bioerosion and low recruitment. Six sites in the southern islands have demonstrated low to moderate coral community (scattered colonies, but no carbonate framework) recovery. The iconic pocilloporid reef at Devil's Crown (Floreana Island) experienced recovery to 2007, then severe mortality during a La Niña cooling event, and is again (as of 2017) undergoing rapid recovery. Notable recovery has occurred at the central (Marchena) and northern islands (Darwin and Wolf). Of the 17 structural reefs first observed in the mid-1970s, the single surviving reef (Wellington Reef) at Darwin Island remains in a positive growth mode. The remainder either degraded to a coral community or was lost. Retrospective analyses of the age structure of corals killed in 1983, and isotopic signatures of the skeletal growth record of massive corals suggest the occurrence of robust coral populations during at least a 500-year period before 1983. The greatest potential threats to the recovery and persistence of coral reefs include: ocean warming and acidification, bioerosion, coral diseases, human population growth (increasing numbers of residents and tourists), overfishing, invasive species, pollution, and habitat destruction. Such a diverse spectrum of disturbances, acting alone or in combination, are expected to continue to cause local and archipelago-wide mortality and degradation of the coral reef ecosystem.

The sudden and sporadic occurrence of anomalous conditions associated with El Nino-Southern Oscillation (ENSO) can precipitate diverse, immediate and long-term effects on eastern Pacific reef-building corals and associated organisms. ENSO is manifested in two complementary phases, namely warm (El Nino) and cool (La Nina) events, which have contrasting and potentially negative effects on coral reef ecosystems. Of the two distinct types of El Nino activity-Eastern-Pacific (EP) and Central-Pacific (CP)-the former exhibits maximum SST anomalies and related climate and weather impacts that affect eastern Pacific coral reefs. Relevant ENSO conditions, with direct or indirect effects, include (a) high and low sea temperature extremes, (b) thermocline and nutricline depths, (c) high and low sea level stands, (d) storm activity, (e) rainfall patterns (and terrestrial runoff), and (f) deviances in surface current direction, velocity and spatial extent. The first sign of ENSO stress to zooxanthellate corals is tissue blanching or bleaching, which may occur during periods of elevated (El Nino) or depressed (La Nina) thermal anomalies. Earlier studies of thermally induced coral bleaching in the Galapagos Islands and Panama are updated to 2012 with attention to anomalous warm and cool events that are stressful to reef-building corals. When thermal conditions normalize, surviving reef-building corals typically re-gain their usual complement of zooxanthellae (symbiotic dinoflagellates) and pigmentation. Long-term ecological effects from extreme ENSO activity, particularly during El Nino sea warming events, may occur over months or years following initial impacts. Such effects can markedly reduce coral cover, cause local species disappearances and significantly change the abundances of coral-associated taxa. The bioerosion of dead corals and carbonate frameworks can eliminate essential habitat space for a multitude of species if coral recruitment is suppressed and recovery unduly prolonged. Coral reef recovery and resiliency are examined in the context of recent ENSO disturbances. Since the last very strong 1997-98 El Nino coral reef bleaching event, live coral cover has increased significantly on many but not all equatorial eastern Pacific (EEP) reefs.

Folly Beach is a case study on the effects of multiple coastal barrier island management techniques. After the emplacement of the Charleston Harbor jetties in the late 1890s altered coastal sediment supply, Folly Island's beaches have retreated, and beachfront homeowners of the 1900s have attempted to slow the beach's retreat to protect their property along an eroding coast. The jetties interfere with the longshore transport of sand, depriving the beach of sand resources that has led to an erosion rate estimated between 0.3 m/yr and 1.8 m/yr. The town of Folly Beach has armored the shoreline and hard stabilization structures to protect property and prevent structures from being overwashed by waves. Now, property owners must rely on beach renourishment to retain a recreational beach and to protect their property.Charleston's wetlands, estuaries, and barrier islands are a major economic engine for the region, and Folly Beach is an important tourist destination. Politics, multiple measurement techniques, and poor understanding of the effects of hard stabilization structures on the beach have complicated the ability of policy makers and the public to navigate the variety of issues associated with coastal erosion in this region. Furthermore, its long history of development and attempts to stabilize the beach qualify Folly Island as one of America's most vulnerable beaches and an excellent case study on the effectiveness of different techniques in this dynamic system.

The Student Dust Counter (SDC) experiment of the New Horizons Mission is an impact dust detector to map the spatial and size distribution of dust along the trajectory of the spacecraft across the solar system. The sensors are thin, permanently polarized polyvinylidene fluoride (PVDF) plastic films that generate an electrical signal when dust particles penetrate their surface. SDC is capable of detecting particles with masses m>10−12 g, and it has a total sensitive surface area of about 0.1 m2, pointing most of the time close to the ram direction of the spacecraft. SDC is part of the Education and Public Outreach (EPO) effort of this mission. The instrument was designed, built, tested, integrated, and now is operated by students.

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, Galápagos, to assess interannual to decadal climate variability in the eastern Pacific. Comparisons of instrumental data sets show that sea surface temperatures (SST) in the Galápagos 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 Niño/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 Galápagos instrumental SST record (r = −0.90 for annual averages). Cross‐spectral analysis shows that SST can explain greater than 80% of the variance in δ18O 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 δ18O variations in the region are very small, we interpret the Urvina Bay coral δ18O 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 δ18O excursions that we observe during the 17th and 18th centuries very likely represent ENSO events that are missing from the historical tabulations. Most interannual δ18O variations between 1607 and 1953 A.D. represent annual average temperature excursions of 1° to 2.5°C. During the Little Ice Age, the annual δ18O 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 (<1°C). Oscillatory modes within the ENSO frequency band dominate the 347‐year δ18O time series, accounting for >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 δ18O 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 δ18O 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.

The disastrous effects of the intense 1982-83 El Nino-Southern Oscillation (ENSO) bring new insight into the long-term development of eastern Pacific coral reefs. The 1982-83 ENSO sea surface warming event caused extensive reef coral bleaching (loss of symbiotic zooxanthellae), resulting in up to 70-95% coral mortality on reefs in Costa Rica, Panama, Colombia and Ecuador. In the Galapagos Islands (Ecuador), most coral reefs experienced > 95% coral mortality. Also, several coral species experienced extreme reductions in population size, and local and regional extinctions. The El Nino event spawned secondary disturbances, such as increased predation and bioerosion, that continue to impact reef-building corals. The death of Pocillopora colonies with their crustacean guards eliminated coral barriers now allowing the corallivore Acanthaster planci access to formerly protected coral prey. Sea urchins and other organisms eroded disturbed corals at rates that exceed carbonate production, potentially resulting in the elimination of existing reef buildups. In other reef building regions following extensive, catastrophic coral mortality, rapid recovery often occurs through the growth of surviving corals, recruitment of new corals from nearby source populations, and survival of consolidated reef surfaces. In the eastern Pacific, however, the return of upwelling conditions and the survival of coral predators and bioeroders hamper coral reef recovery by reducing recruitment success and eroding coral reef substrates. Thus, coral reef growth that occurs between disturbance events is not conserved. Repeated El Nino disturbances, which have occurred throughout the recent geologic history of the eastern Pacific, prevent coral communities from increasing in diversity and limit the development and persistence of significant reef features. The poor development of eastern Pacific coral reefs throughout Holocene and perhaps much of Pleistocene time may result from recurrent thermal disturbances of the intensity of the 1982-83 El Nino event.

The 1954 uplift of Urvina Bay on Islá Isabela exposed porphyritic lava that erupted from a moderately shallow magma chamber onto the southwestern flanks of Volcán Darwin at least 1200 years ago. The lava contains: (1) 20–27% plagioclase xenocrysts, glomerocrysts, and phenocrysts; (2) 0.2–2.7% clinopyroxene xenocrysts and phenocrysts; and (3) 0.2–0.8% olivine phenocrysts, glomerocrysts, and xenocrysts. Whole-rock major-element data corrected for phenocrysts, glomerocrysts, and xenocrysts indicates that the lavas are moderately evolved, (Mg# = 50–52 mol%) transitional basalt. Wholerock chondrite-normalized La/Lu (3.9–5.0) values are similar to those for ocean-island tholeiites and alkali basalts on the western side of the Galápagos Islands platform.

Approximately 550 measurements of Mn/Ca ratios in three corals from the western Galapagos Islands have been performed to reconstruct a 380-year history of surface ocean variability with respect to this trace element. The time period studied encompasses 1600 A.D. to 1978. Manganese is inferred to be lattice-bound in coralline aragonite at 10–50% of its seawater proportion to calcium; uncertainty about the distribution coefficient stems from inherent variability of oceanic Mn in nearshore settings. Interannual variations at Urvina Bay, Isabela Island are generally small, with the exception of a few decades during the nineteenth century. A large positive Mn/Ca anomaly found between 1821–1830 is hypothesized to have resulted from a major volcanic eruption on nearby Fernandina Island in 1825. On intrannual timescales a pronounced cycle occurs in response to seasonal upwelling. Quarterly changes in Mn/Ca are six months out-of-phase with Cd/Ca variations-a reflection of the opposite distributions of these metals in the upper waters of the eastern Pacific. High frequency reconstructions over brief time intervals from the 17th, 18th, and 20th century reveal that the seasonal onset of warm and cool phases near Galapagos has persisted for at least 340 years. A quantitative assessment of historical changes in upwelling intensity is complicated by offsets in background Mn levels recorded by different corals. One apparent longterm feature is an overall decline in skeletal Mn concentrations from 1600–1978 which results in a net decrease of 20–30%. Several possible explanations exist for this trend, ranging from accumulation of a persistent diagenetic Mn phase in fossil aragonite to a temporal shift in oceanic/atmospheric Mn fluxes reaching the surface waters of the Galapagos Islands.

The intense 1982-83 El Niño-Southern Oscillation (ENSO) event significantly raised sea surface temperature devastating eastern Pacific coral reefs. In the aftermath of this disturbance, slow recovery has led to extensive reef erosion. The death of corals and the subsequent reef erosion have stimulated a reevaluation of the history and the causes for the small, low diversity reefs of the eastern Pacific. Today's eastern Pacific reefs differ markedly in size and species composition and richness from this region's past reefs and other present-day Pacific reefs. The closure of the Panamanian isthmus in the Plio-Pleistocene marked a deterioration in the reef building environment in the eastern Pacific. With this seaway closed, the modern Pacific surface circulation developed, and the components necessary for the ENSO events came together. The termination of the Pacific-Atlantic exchange coincided with the beginning of glacial-interglacial cycles. Since the closure of the Panamanian seaway and the onset of the glacial cycles, the eastern Pacific has faced two different climatic states that restricted reef growth and development: one during glacial periods with cool waters and lowered sea-levels and the other during interglacial periods with higher sea-levels, warmer waters, and ENSO events. During this latest high sea-level stand, between 18 to 65 ENSO events of the 1982-1983 magnitude may have disturbed the eastern Pacific. An uplifted reef at Urvina Bay, Galapagos Islands provides an opportunity to determine how eastern Pacific reefs develop during sea-level high stands. Here, recurrent intense ENSO events start the coral communities on a cycle of death, erosion, and recolonization stunting long-term reef growth. ENSO events, acting in concert with other physical and biological forces, have prevented the buildup of a substantial reef-framework. During the transition to inter-glacial times, melting ice raised sea-level and improved the environmental conditions for coral-reef growth enabling coral recruits to colonize the shelf. In the western and central Pacific, where reefs survived subaerial exposure, corals colonized and built new reefs on these antecedent structures enabling carbonate accumulation to continue. Whereas in the eastern Pacific, where small reefs eroded during low sea-level stands, recruits had to settle on basaltic or other consolidated outcrops rather than on previous carbonate build-ups. New recruits face not only harsh reef building conditions (e.g., upwelling and intense grazing) but recurrent intense and lethal ENSO events. After coral mortality, bioerosion removed much of the coral build-up. This repeated process prevents the coral community from increasing in diversity or developing to a resistant structure that can withstand erosion after death. Thus, one generation's growth is not transferred to the next, and large, persistent reef frameworks are not constructed.