Hydrodynamic characteristics of a fringing coral reef on the east coast of Ishigaki Island,southwest Japan

To investigate the characteristics of currents on a fringing coral reef, a field survey was conducted, mostly under weak wind conditions in summer, on the east coast of Ishigaki Island, southwest Japan, which is encompassed by well-developed fringing reefs. For the same study period, numerical simulations of the current were also performed using a shallow water turbulent flow model with high accuracy reef bathymetry data, which were estimated from high-resolution imagery obtained from satellite remote sensing. The numerical simulation results showed good agreement with the observed data and revealed that the currents have an appreciable magnitude of tide-averaged velocities, even during neap tides, which are governed mostly by wave set-up effects. The results also indicated that temporal variations in velocity and water surface elevation during a tide cycle in the reef exhibit highly asymmetrical patterns; in spring tides especially, the velocities around channels indicate rapid transitions over a short period from peak ebb flow to peak flood flow. The simulations also indicated that a big channel penetrating deeply into the reef attracts the tide-averaged mean flow, even from distant areas of the reef.     

Geographic Tools for Eradication Programs of Insular Non-native Mammals

Non-native mammals are major drivers of ecosystem change and biodiversity loss; this is especially apparent on islands. However, techniques exist to remove non-native mammals, providing a powerful conservation tool. Conservation practitioners are now targeting larger islands for restoration. Leveraging existing and developing new techniques and technologies will prove critical to successful eradications on large islands. Using the removal of introduced goats (Capra hircus) from Santiago Island, Galápagos as a case study, we present a suite of Geographic Information System (GIS) tools that aid island conservation actions. GIS tools were incorporated into the three phases of the eradication campaign: planning, hunting, and monitoring. Further, these tools were adopted for three eradication techniques: ground-based hunting, aerial hunting by helicopter, and Judas goats. These geographic approaches provide a foundation for statistical, spatial, and economic analyses that should increase the capability and efficiency of removal campaigns. Given limited conservation funds and the dire status of many insular species, efficiently removing non-native mammals from islands is of paramount global conservation importance.     

Age‐related Crown Thinning in Tropical Forest Trees

Gap dynamics theory proposes that treefall gaps provide high light levels needed for regeneration in the understory, and by increasing heterogeneity in the light environment allow light‐demanding tree species to persist in the community. Recent studies have demonstrated age‐related declines in leaf area index of individual temperate trees, highlighting a mechanism for gradual changes in the forest canopy that may also be an important, but less obvious, driver of forest dynamics. We assessed the prevalence of age‐related crown thinning among 12 tropical canopy tree species sampled in lowland forests in Panama and Puerto Rico (total N = 881). Canopy gap fraction of individual canopy tree crowns was positively related to stem diameter at 1.3 m (diameter at breast height) in a pooled analysis, with 10 of 12 species showing a positive trend. Considered individually, a positive correlation between stem diameter and canopy gap fraction was statistically significant in 4 of 12 species, all of which were large‐statured canopy to emergent species: Beilschmiedia pendula, Ceiba pentandra, Jacaranda copaia, and Prioria copaifera. Pooled analyses also showed a negative relationship between liana abundance and canopy gap fraction, suggesting that lianas could be partially obscuring age‐related crown thinning. We conclude that age‐related crown thinning occurs in tropical forests, and could thus influence patterns of tree regeneration and tropical forest community dynamics.     

Using miniaturized radiotelemetry to discover the breeding grounds of the endangered New Zealand Storm Petrel Fregetta maoriana

Identification of breeding sites remains a critical step in species conservation, particularly in procellariiform seabirds whose threat status is of global concern. We designed and conducted an integrative radiotelemetry approach to uncover the breeding grounds of the critically endangered New Zealand Storm Petrel Fregetta maoriana (NZSP), a species considered extinct before its rediscovery in 2003. Solar‐powered automated radio receivers and hand‐held telemetry were used to detect the presence of birds on three island groups in the Hauraki Gulf near Auckland, New Zealand. At least 11 NZSP captured and radiotagged at sea were detected at night near Te Hauturu‐o‐Toi/Little Barrier Island with the detection of an incubating bird leading to the discovery of the first known breeding site for this species. In total, four NZSP breeding burrows were detected under mature forest canopy and three adult NZSP and two NZSP chicks were ringed. Telemetry data indicated NZSP showed strong moonlight avoidance behaviour over the breeding site, had incubation shifts of approximately 5 days and had a breeding season extending from February to June/July, a different season from other Procellariiformes in the region. Radiotelemetry, in combination with rigorously collected field data on species distribution, offers a valuable technique for locating breeding grounds of procellariiform seabirds and gaining insights into breeding biology while minimizing disturbance to sensitive species or damage to fragile habitat. Our study suggests an avenue for other breeding ground searches in one of the most threatened avian Orders, and highlights the general need for information on the location of breeding sites and understanding the breeding biology in data‐deficient birds.     

Schistosoma mansoni-Related Hepatosplenic Morbidity in Adult Population on Kome Island,Sengerema District,Tanzania

Schistosomiasis is one of the important neglected tropical diseases (NTDs) in Tanzania, particularly in Lake Victoria zone. This baseline survey was a part of the main study of integrated control of schistosomiasis and soil-transmitted helminths (STHs) aimed at describing morbidity patterns due to intestinal schistosomiasis among adults living on Kome Island, Sengerema District, Tanzania. Total 388 adults from Kome Islands (about 50 people from each village) aged between 12 and 85 years, were examined by abdominal ultrasound according to the Niamey protocol. Liver image patterns (LIPs) A and B were considered normal, and C-F as distinct periportal fibrosis (PPF). The overall prevalence of PPF was 42.2%; much higher in males than in females (47.0% in male vs 34.4% in females, P=0.007). Abnormal increase of segmental branch wall thickness (SBWT) and dilated portal vein diameter (PVD) were also more common in males than in females. Hepatosplenomegaly was frequently encountered; 68.1% had left liver lobe hepatomegaly and 55.2% had splenomegaly. Schistosoma mansoni-related morbidity is quite high among adults in this community justifying the implementation of integrated control strategies through mass drug administration, improved water supply (pumped wells), and health education that had already started in the study area.     

Tsunami impact on the population development of a critically endangered hummingbird species of a Pacific island

It is a long-standing question how tsunamis can influence wild populations of animals and plants. Here, we assessed short-term changes in the population of the critically endangered Juan Fernández Firecrown (Sephanoides fernandensis) by using abundance data recorded 1 year before and 1 year after the 2010 Chilean tsunami. We tested that the abundance of Firecrowns declined in the areas where the tsunami caused the massive loss of Cabbage Trees, an important seasonal nectar source for Firecrowns. The abundance of Juan Fernández Firecrowns decreased after the tsunami, but also was affected by the habitat type, altitude, and the abundance of Cabbage Trees. Firecrowns tended to be more abundant in settlement areas than in native forest whereas the reduction in Firecrown abundance after the tsunami was more intense in settlement areas than in native forest. As expected, this habitat effect was dependent on the massive loss of Cabbage Trees in settlement areas following the tsunami. In spite of the short-term nature of our data, our results are conclusive in showing that the loss of an important food source causes short-term changes in the distribution and abundance of Firecrowns, which, in turn, could contribute to population decline.     

Occurrence and removal of parasites, enteric bacteria and faecal contamination indicators in wastewater natural reclamation systems in Tenerife-Canary Islands, Spain

Two wastewater natural reclamation systems (WWNRS) have been compared regarding their efficiencies on faecal bacteria removal and the persistence of enteric pathogens. These WWNRS are constituted of a combination of anaerobic treatment, small sub-surface flow constructed wetland refilled of volcanic ashes and a final pond as water reservoir. Faecal coliforms, enterococci, Escherichia coli, Clostridium perfringens, somatic coliphages, Salmonella sp., Campylobacter sp., Cryptosporidium sp., Giardia sp. and helminth eggs were analyzed in constructed wetlands inlet and outlet and storage pond effluent. Low numbers of protozoan positive samples (4.54% in Albergue de Bolico for both protozoa, and 19.05% in Carrizal Alto for Giardia sp.) and absence of helminth eggs were found. Both systems demonstrated efficient reduction of faecal contamination indicators in the wastewaters (removal rates values of 2 log₁₀). The natural systems for wastewater treatment used to be efficient in Salmonella abatement, this fact was confirmed in the reported systems, since enterobacteriaceae were found in only one of the effluents. Campylobacter species associated with the access of animals to storage ponds were detected in the reclaimed water.     

Tri-trophic interactions affect density dependence of seed fate in a tropical forest palm

Natural enemies, especially host-specific enemies, are hypothesised to facilitate the coexistence of plant species by disproportionately inflicting more damage at increasing host abundance. However, few studies have assessed such Janzen-Connell mechanisms on a scale relevant for coexistence and no study has evaluated potential top-down influences on the specialized pests. We quantified seed predation by specialist invertebrates and generalist vertebrates, as well as larval predation on these invertebrates, for the Neotropical palm Attalea butyracea across ten 4-ha plots spanning 20-fold variation in palm density. As palm density increased, seed attack by bruchid beetles increased, whereas seed predation by rodents held constant. But because rodent predation on bruchid larvae increased disproportionately with increasing palm density, bruchid emergence rates and total seed predation by rodents and bruchids combined were both density-independent. Our results demonstrate that top-down effects can limit the potential of host-specific insects to induce negative-density dependence in plant populations.     

海南岛尖峰岭热带林土壤渗透水的初步研究

 本文应用开口托盘式集水器收集不同土层的渗透水,研究尖峰岭热带山地雨林,半落叶季雨林及其游耕地的土壤渗透水状况,分析了不同植被—土壤类型与利用状况的渗透特点、降水与渗透水的关系、渗透水量与水质的动态变化,初步揭示了尖峰岭热带林对水分的输导—涵贮性能,及热带林生态系统中物质迁移的特点,并据此分析了游耕农业的生态恶果。