Effects of light of altered spectral composition on coral zooxanthellae associations and on zooxanthellae in vitro

Pocillopora damicornis (Linnaeus) and Montipora verrucosa (Lamarck) were collected from Hawaiian reefs. In two experiments (September 1979-January 1980: ca. 4 mo; August-October 1980; ca. 2 mo), these reef corals were grown under sunlight passed through filters producing light fields of similar quantum flux but different spectral composition. In vitro cultures of symbiotic zooxanthellae (Symbiodinium microadriaticum Freudenthal) from M. verrucosa were cultured under similar conditions for 15 d. Blue or white light promoted more coral skeletal growth than green or red light. In both coral species, blue light increased the total amount of chlorophyll a of the coral-zooxanthellae association. In the perforate species, M. verrucosa, the pigment concentration was elevated by an increase in the density of zooxanthellae, but the pigment concentrations per algal cell remained unchanged; in the non-perforate species, P. damicornis, it appears that pigment concentration was elevated by an increase in pigment per algal cell, and not by an increase in density of zooxanthellae. The sunloving reef-flat coral P. damicornis did not grow as rapidly as the shade-species M. verrucosa at the low quantum flux (about 10% sunlight) provided by the experimental treatments. The in vitro cultures of zooxanthellae from M. verrucosa exhibited growth rates in light of altered spectral quality that correlated with the responses of the host coral species: blue and white light supported significantly greater growth than green light, and red light resulted in the lowest growth rate.Contribution No. 678 of the Hawaii Institute of Marine Biology     

Seasonal decline in intracolony genetic relatedness in eastern tent caterpillars: implications for social evolution

Summary Genetic relatedness in social insect colonies may vary spatially or temporally as a result of changes in colony membership due to immigration or to variation in patterns of maternity and paternity. We estimated relatedness for eastern tent caterpillars (Malacosoma americanum) in laboratory colonies derived from egg masses using multilocus genotypic data derived from electrophoresis. This estimate is compared with estimates obtained from colony samples taken in the field at four intervals spanning the larval developmental season. We found that average intracolony relatedness is close to 0.5 initially but declines through the developmental season due to colony merging, showing that caterpillars do not discriminate between siblings and nonsiblings in order to preserve colony family structure. Using the intracolony values together with relatedness values for higher levels of population structure, we estimated the effective mean number of simple families represented in single colonies through the season. The overall effective number of families per tent increased from one at the time of eclosion to 1.3 by the end of the season. Average intracolony relatedness remained relatively high despite the occurrence of colony merging, apparently as a result of the low density of tents on most trees, combined with high relatedness within the original colonies. Thus, high intracolony relatedness is maintained in M. americanum populations through the effects of adult dispersal, mating, and oviposition patterns, rather than through behavioral discrimination mechanisms of the larvae. These findings underscore the importance of considering the causes of temporal variation in genetic relatedness as well as the consequences for the indirect component of inclusive fitness. Correspondence to: J.T. Costa     

Predatory feeding of two marine mysids

Predatory feeding of the marine mysids Mysidopsis bigelowi and Neomysis americana on several species of co-occurring copepods was examined in laboratory experiments. M. bigelowi exhibited a curvilinear functional response; there was a negative logarithmic relationship between prey density and clearance rates. N. americana also exhibited higher clearance rates at lower prey densities. Increased clearance rates at lower prey densities were probably due to increased swimming speed or reaction distance as hunger increased. This response occurred only when mysids could visually locate prey; in complete darkness clearance rates were significantly lower and independent of prey density. Feeding rates on different prey species were only partially dependent on prey size; prey movement patterns and escape behavior also strongly affected feeding rates. M. bigelowi showed active prey selection when offered a choice of different prey species. Estimates of predation rates of estuarine mysid populations indicate that they could have a significant effect on co-occurring copepod populations.     

Reach and messages of the world's largest ivory burn

Recent increases in ivory poaching have depressed African elephant populations. Successful enforcement has led to ivory stockpiling. Stockpile destruction is becoming increasingly popular, and most destruction has occurred in the last 5 years. Ivory destruction is intended to send a strong message against ivory consumption, both in promoting a taboo on ivory use and catalyzing policy change. However, there has been no effort to establish the distribution and extent of media reporting on ivory destruction events globally. We analyzed media coverage of the largest ivory destruction event in history (Kenya, 30 April 2016) across 11 nation states connected to ivory trade. We used an online‐media crawling tool to search online media outlets and subjected 5 of the largest print newspapers (by circulation) in 5 nations of interest to content analysis. Most online news on the ivory burn came from the United States (81% of 1944 articles), whereas most of the print news articles came from Kenya (61% of 157 articles). Eighty‐six to 97% of all online articles reported the burn as a positive conservation action, whereas 4–50% discussed ivory burning as having a negative impact on elephant conservation. Most articles discussed law enforcement and trade bans as effective for elephant conservation. There was more relative search interest globally in the 2016 Kenyan ivory burn than any other burn in 5 years. Ours is the first attempt to track the reach of media coverage relative to an ivory burn and provides a case study in tracking the effects of a conservation‐marketing event.     

Assessment of the Effects of Sugar Cane Plantation Burning on Daily Counts of Inhalation Therapy

ABSTRACT

This study was designed to evaluate the association between sugar cane plantation burning and hospital visits in Araraquara in the state of São Paulo, Brazil. From June 1 to August 31, 1995, the daily number of visits of patients who needed inhalation therapy in one of the main hospitals of the city was recorded and used as health impairment estimation. Sedimentation of particle mass (the amount of particles deposited on four containers filled with water) was measured daily. The association between the weight of the sediment and the number of visits was evaluated by means of Poisson regression models controlled for seasonality, temperature, day of the week, and rain. We found a significant and dose-dependent relationship between the number of visits and the amount of sediment. The relative risk of visit associated with an increase of 10 mg in the sediment weight was 1.09 (1-1.19), and the relative risk of an inhalation therapy was 1.20 (1.03-1.39) on the most polluted days (fourth quartile of sediment mass). These results indicate that sugar cane burning may cause deleterious health effects in the exposed population.     

Variability in the chemical defense of the sponge Chondrilla nucula against predatory reef fishes

Chondrilla nucula is a common Caribbean demosponge that grows in a range of habitats, from coral reefs to mangrove swamps. On reefs, C. nucula grows as a thinly encrusting sheet, while in mangrove habitats it surrounds submerged mangrove roots as fleshy, lobate clumps. Previous feeding experiments using predatory reef fish revealed a high degree of variability in the chemical defenses of C. nucula. The present study was undertaken to determine whether a relationship exists between habitat, growth form, and chemical defense of C. nucula. Both laboratory and field feeding-assays of crude extracts confirmed that C. nucula possesses a chemical defense with high intercolony variability, but there was no significant variation in feeding deterrency between reef and mangrove habitats at either geographic location (Bahamas and Florida). Extracts of C. nucula collected during September and October 1994 from the Bahamas were significantly more deterrent than those collected during August 1993, May 1994, and May 1995 from Florida, and extracts of these spring and summer Florida collections were more deterrent than extracts of C. nucula collected in December 1994 and February 1995 in the same locations. There was no evidence that deterrent compounds were concentrated in the surface tissues of the sponge, or that chemical defense could be induced by simulated predation. Laboratory and field assays of the fractionated crude extract revealed that feeding deterrency was confined to the most polar metabolites in the extract. Field transplants were used to determine whether predation influenced the growth form of C. nucula. Uncaged sponges transplanted from the mangrove to the reef were readily consumed by spongivorous reef fishes. Lobate mangrove sponges became thinner after being caged on the reef for 3 mo, but encrusting reef sponges did not become thicker after being caged in the mangroves for the same period of time. Reef sponges that were caged for 3 to 15 mo thickened by only a small amount (<1 mm) compared to uncaged and open-caged (i.e. in cages lacking tops) sponges. Simulated bite marks on both reef and mangrove sponges were repaired at a rapid rate (0.8 to 1.6 mm d⁻¹). Fish predation has an important impact on the distribution and abundance of C. nucula, but the thin growth form common to reef environments may be more the result of hydrodynamics than of grazing by spongivorous fishes. Received: 6 October 1997 / Accepted: 19 March 1998     

Effects of Grazing on the Demography and Growth of the Texas Tortoise

Abstract: Considerable effort has been exerted in attempts to understand the complex ecological effects of grazing. North American tortoises, by virtue of their distribution, provide a good model taxon through which to study how grazing effects vary with grazing regime, habitat, and climate. We studied the Texas tortoise (  Gopherus berlandieri ) , which is restricted primarily to privately owned rangelands of southern Texas and northeastern Mexico. Management of this species is hampered by a lack of information on the effects of common land-use practices. We evaluated the effects of moderate grazing by cattle (short-duration, winter-spring rotational grazing regime; 6–28 animal-unit days/ha/year) on this tortoise by comparing two grazed and two ungrazed sites in the Western Rio Grande Plains, Texas ( U.S.A.), from April 1994 to October 1997. We made 132 captures of 106 individuals in the ungrazed pastures and 324 captures of 237 individuals in the grazed pastures. We also radiotracked 22 tortoises in the ungrazed pastures and 25 tortoises in the grazed pastures. Comparisons of relative abundance, body-size distribution, age distribution, body mass, sex ratio, adult survival, proportion of juveniles, and growth rates revealed no differences (  p > 0.05 for all parameters) between tortoises on grazed and ungrazed areas. Based on these results, we suggest that moderate grazing by cattle is not incompatible with maintenance of Texas tortoise populations. Our data were consistent with a general model of tortoise biogeography and tolerance of disturbance which suggests that Texas tortoises are tolerant to intermediate levels of disturbance. Generalities about the effect of cattle grazing on the four North American tortoises should be avoided unless they can be placed in the context of grazing regime, precipitation, habitat quality, and tortoise requirements.     

Obligate Cave Fauna of the 48 Contiguous United States

Abstract: We assembled a list of obligate cave-dwelling species and subspecies, their county distribution, and their provisional global conservation rank. A total of 927 species and 46 additional subspecies in 96 families exclusively from cave and associated subterranean habitats have been described in the 48 contiguous states of the United States. The terrestrial (troglobitic) species are concentrated in northeast Alabama (especially Jackson County), with other concentrations in Kentucky, Texas, Virginia, and West Virginia. Only 23 counties, comprising less than 1% of the land area of the 48 contiguous states, account for over 50% of the terrestrial species and subspecies. The aquatic (stygobitic) species are concentrated in Hays County, Texas, with other concentrations in Florida, Oklahoma, Texas, Virginia, and West Virginia. Only 18 counties, comprising less than 1% of the land area, account for over 50% of the aquatic species and subspecies. Endemism is high, with 54% of the species known from a single county. Approximately 95% of the species are listed by The Nature Conservancy as vulnerable or imperiled in the United States. These cave species comprise 50% of all vulnerable or imperiled species listed in databases of the Natural Heritage Program. Less than 4% of these subterranean species have federal status. Conservation can best be accomplished through habitat protection, which must include protection of the associated surface habitat.     

Climate Variability and Deforestation—Reforestation Dynamics in the Philippines

Changes in the conditions in the 'warm pool' in the Pacific region are reflected in the changes in the local climate system of the Philippines. Both El Niñno and La Niñna episodes in the Pacific Oceans introduce high variability into the local climate pattern, especially rainfall, in the Philippines. Whereas El Niñno appears when annual rainfall is ≥10% lower than normal annual rainfall, La Niñna occurs when annual rainfall is at least equal to the normal. About 15.7 million ha of forest cover had been lost between 1903 and 1998, but only 1.64 million had been reforested in the same period, indicating the presence of unbelievably low ecological stability. Apart from this, the denuded forests freed about 8.24 × 10⁹ Mg C into the atmospheric greenhouse pools. Neither deforestation nor reforestation was undertaken with deliberate regard to the occurrences of El Niñno or La Niñna. Very high rates of deforestation were observed to coincide with or precede strong El Niñno or Niñna episodes, thus confounding further the ecological instability of denuded forest systems, especially those with slope ≥18%. Similarly, the reforestation cycle indicates that saplings are at most 5 years old every time an El Niñno or a La Niñna occurs; in most reforestation schemes, saplings are only 1–2 years old when these events occur. These reforested areas are vulnerable to drought in El Niñno years and to high runoff erosion during La Niñna years. Because they are young, saplings in reforested areas dry easily and pose hazards to forest fires, which were observed to destroy larger tracts of forest cover during El Niñno more so when annual rain ≥10% below the normal. In retrospect, the study indicated that had forests been exploited with conscious regard to the recurrence of El Niñno or La Niñna episodes, ecological impacts could at least be toned down. In the same vein, reforestation should have been more successful it were implemented with due considerations to extreme climate variability. Once trees were planted, the weather elements become more crucial than politicians' meddling and other socio-economic factors to the growth and development of reforested sites.