Responses of Three Coral Communities to the 1997–98 El Niño–Southern Oscillation: Galápagos Islands, Ecuador

One deep (13–15 m depth) and two shallow water (1.5 and 7 m) coral communities in the Galápagos Islands, Ecuador were monitored for tissue response (bleaching, paling, morbidity) and secondary responses during and after elevated temperature stress associated with the 1997–98 El Niño–Southern Oscillation (ENSO) event. Between March and May 1998, the fungiid coral Diaseris distorta paled and bleached (up to 88.0% of all individuals bleached) at 13–15 m depth. The small branching colonial coral, Psammocora stellata, paled (79.2% of all colonies) with very little bleaching (11.1%), also at 13–15 m depth. However, by May 1998 colonies of this species in shallower water (7 m depth) suffered high mean mortality (72.4% of colony area, 85.1% decrease in numbers of live colonies). In March 1998, colonies of Pavona clavus, a massive coral species, were 100% bleached at 1.5 m depth and experienced subsequent partial mortality averaging 34.0% per colony. Both Diaseris and Psammocorain deeper water (13–15 m depth) recovered pigment by June 1999. Numbers of Diaseris individuals within permanent transect plots decreased 56.1% from March 1998 through August 2000, but this loss was most likely due to coral displacement by currents and surge rather than temperature-induced mortality. Numbers of Psammocora colonies in deep water did not change appreciably during the survey period (−16.1%). In contrast, surviving shallower water (7 m depth) Psammocora recovered pigment by June 1999, but numbers of live colonies remained low through August 2000 (−83.3% compared to March 1998). Initial recovery of pigmented tissue was evident in Pavona by June 1999, but a decline in live tissue again occurred by August 2000. Sea water temperature at the deeper site reached 28–30°C, but periods of semi-diurnal cooling may have mitigated the bleaching response. Highest temperatures occurred in shallower water (7 m), where Psammocora experienced high mortality and periodic subsurface cooling was suppressed. These data cannot be compared with those from the 1982–83 ENSO because of the lack of quantitative data from the earlier event. However, these observations provide a framework of comparison with other ENSO-affected eastern Pacific coral communities and reefs during the 1997–98 event

The Effect of Temperature on the Benthic Stages of Cyanea (Cnidaria: Scyphozoa), and Their Seasonal Distribution in the Niantic River Estuary, Connecticut

There are three benthic stages in the life history of Cyanea: the polyp stage and two kinds of cysts; one kind is produced by the polyp (podocysts), and the other by the planula larvae (planulocysts); both types of cysts develop into additional polyps. Physical and biological factors affecting these benthic stages and their processes influence the success of the ecologically important medusa stage which is produced by asexual budding (strobilation) by the polyp. Experimentally, a transfer from low to high temperature was most favorable for podocyst formation by polyps, and the transfer from high to low temperature led to both the excystment of podocysts and the strobilation of polyps. In the benthos of the Niantic River, planulocysts and podocysts appear during the warmest time of the year having formed during a period of increasing temperature throughout spring. Both types of cyst excyst when temperature decreases beginning in late summer and continuing into early winter. During this period of declining temperature, polyps strobilate forming ephyrae, the young medusae. The relationship between seasonal temperature change and processes of the benthic stages in the field agrees with laboratory results; thus, change in temperature is at least minimally sufficient to account for the regular annual appearance of the medusa. Such a life history requires a longevous ephyral stage resistant to low temperatures and this seems to be the case. Indirect evidence is presented showing that the encysted stages may serve as a defense against predators and competitors for space which are active during the summer

Light and Shadow

My first artistic photographs were in black and white. This form of photography promotes the use of strong graphical elements, a concept that is expressed in these images. I hope that the interplay of light and shadow provokes special insights into the natural world

Butterfly Biology

A photographic exploration of butterflies from larvae to adults in Davie, Florida

Bird Profiles

As part of our undergraduate program in the life sciences, students participate in a wide array of field trips to local and remote locations. These images were obtained during field trips to Everglades National Park, Florida; San Diego, California; and the Galápagos Islands, Ecuador. I have been intrigued by bird behavior. These profiles allude to their personality differences and the diversity and beauty of nature. It is my hope that these images also provoke emotional reactions in us

How Discriminatory Censorship Laws Imperil Public Education

&ldquo;Discriminatory censorship laws&rdquo; regulate classroom conversations about racism, gender identity, and other topics targeted in the backlash against efforts toward inclusive classrooms and curricula. This policy brief examines the proliferation of these laws and their impact on K-12 schools, including the creation of hostile learning environments that expose students and educators to a heightened threat of race- and sex-based harassment and to formal sanctions and social ostracization. The laws also foster a climate of fear and anxiety among educators, effectively coercing them to shun critical inquiry and thought on targeted topics and more generally. The result is a curriculum that subtracts comprehensive, culturally attentive content and adds whitewashed and heteronormative narratives of American history and culture. The brief highlights the need for laws, policies, and practices that promote inclusive learning environments that encourage critical thinking, and offers recommendations to constructively counter discriminatory censorship.</p

Memory and attention while SCUBA diving at shallow and deep depths: An open water study

SCUBA diving requires a high level of cognitive functioning, however, many divers anecdotally report poor memory and attentional skills while underwater. Few studies have documented cognitive deficits resulting from an open-water dive. Here, 23 divers completed both shallow (8 m) and deep (28 m) dives over two days in the open-water. The order of the dives was counterbalanced across participants. While at depth, they completed the State-Trait Anxiety Inventory to assess anxiety levels, learned and were tested on a list of 36 words, and completed the trail making task (TMT) to assess executive functioning. They also gave saliva samples to measure cortisol levels before and after each dive and completed the Profile of Mood States survey after each dive on the boat. Divers remembered fewer words, took longer to complete the TMT, and exhibited higher cortisol levels following a deep dive; they reported no changes in anxiety or mood states. The results contribute to our understanding of how cognition is affected by pressurized environments and has implications for divers, as well as others who engage in high-altitude sports