Improving sampling designs for measuring restoration in aquatic habitats

Restoration of degraded habitat is an increasingly important toll for management. Unfortunately, much of the emphasis has been on restoring large structural elements of habitat (e.g. planting vegetation,removing weeds), with little consideration about how well these activities restore ecologically functioning habitat. There has been considerable research in recent years into improving sampling designs and analytical techniques to measure the effects of environmental impacts taking into account the large spatial and temporal variability that occurs naturally in undisturbed habitats. In a similar manner to detection of impacts, restoration needs to be measured as an interaction between spatial and temporal components of variation against a variable background. Very few studies of restoration have explicitly addressed how best to do this. Neither have they attempted to assess the usefulness of some of these new techniques for measuring restoration. This review discusses some of the problems that need to be considered when measuring restoration and the potential value of some of these new methodologies. This revised version was published online in July 2006 with corrections to the Cover Date.     

Temporal patterns in the acoustic signals of beaked whales at Cross Seamount

Seamounts may influence the distribution of marine mammals through a combination of increased ocean mixing, enhanced local productivity and greater prey availability. To study the effects of seamounts on the presence and acoustic behaviour of cetaceans, we deployed a high-frequency acoustic recording package on the summit of Cross Seamount during April through October 2005. The most frequently detected cetacean vocalizations were echolocation sounds similar to those produced by ziphiid and mesoplodont beaked whales together with buzz-type signals consistent with prey-capture attempts. Beaked whale signals occurred almost entirely at night throughout the six-month deployment. Measurements of prey presence with a Simrad EK-60 fisheries acoustics echo sounder indicate that Cross Seamount may enhance local productivity in near-surface waters. Concentrations of micronekton were aggregated over the seamount in near-surface waters at night, and dense concentrations of nekton were detected across the surface of the summit. Our results suggest that seamounts may provide enhanced foraging opportunities for beaked whales during the night through a combination of increased productivity, vertical migrations by micronekton and local retention of prey. Furthermore, the summit of the seamount may act as a barrier against which whales concentrate prey.     

Yeast diversity in the acidic Rio Agrio-Lake Caviahue volcanic environment (Patagonia, Argentina)

The Rio Agrio and Lake Caviahue system (RAC), in Northwestern Patagonia, is a natural acidic environment. The aims of this study were to characterize the yeast community and to provide the first ecological assessment of yeast diversity of this extreme aquatic environment. Yeast occurrence and diversity were studied at seven sites where the water pH varied between 1.8 and 6.7. Yeast CFU counts in the river ranged from 30 to 1200 CFU L⁻¹, but in the Lake the values were lower (30–60 CFU L⁻¹). A total of 25 different yeast species were found, 11 of which belonged to undescribed taxa. Among these was an unusual strongly acidophilic Cryptococcus species. The RAC yeast community resembles that of acidic aquatic environments resulting from anthropic activities such as the São Domingos mines in Portugal and the Rio Tinto in Spain, respectively. The isolated yeast species were organized into different grades of adaptation to the RAC aquatic system. Based on the proposed grades, Rhodotorula mucilaginosa , Rhodosporidium toruloides and two novel Cryptococcus species were the most adapted species. These Cryptococcus species are apparently specialists of acidic aquatic environments, and might bear physiological features that possibly account for their ability to thrive in such extreme environments.     

Do soundscape indices predict landscape‐scale restoration outcomes? A comparative study of restored seabird island soundscapes

Measuring restoration outcomes is essential, but challenging and expensive, particularly on remote islands. Acoustic recording increases the scale of monitoring inexpensively; however, extracting biological information from large volumes of recordings remains challenging. Soundscape approaches, characterizing communities using acoustic indices, rapidly analyze large acoustic datasets and can be used to compare restoration sites against reference conditions. We tested this approach to measure nocturnal seabird recovery following invasive predator removal in the Aleutian Islands. We used recordings of nocturnal seabird soundscapes from six islands with varied histories of predators, from never invaded (one island) to 9–34 years post‐predator removal (four islands) and currently invaded (one island). We calculated 10 indices of acoustic intensity and complexity, and two pairwise indices of acoustic differences. Three indices reflected patterns of seabird recovery. Acoustic richness (measuring temporal entropy and amplitude) increased with time since predator removal and presence of historical predator refugia (r² = 0.44). These factors and moonlight accounted for 30% of variation in cumulative spectral difference from the reference island. Over 10% of acoustic richness and temporal entropy was explained by Leach's Storm‐petrel (Oceanodroma leucorhoa) calls. However, indices characterized the soundscape of rat‐invaded Kiska Island like a never invaded island, likely due to high abiotic noise and few seabird calls. Soundscape indices have potential to monitor outcomes of seabird restoration quickly and cheaply, if confounding factors are considered and controlled in experimental design. We suggest soundscape indices become part of the expanding acoustic monitoring toolbox to cost‐effectively measure restoration outcomes at scale and in remote areas.     

Description of the larva of Kempnyia colossica (Navás) (Plecoptera: Perlidae) with biological notes

In this paper, the larva of Kempnyia colossica (Navás 1934) is described based on material collected in Parque Estadual Intervales, São Paulo State, and biological notes are presented.     

Identification of Regions with High Ozone Concentrations Aiming the Impact Assessment on Childhood Asthma

High concentrations of near-surface ozone are known to have negative impacts on human health, especially among risk groups such as persons with respiratory problems, children, and the elderly. The aim of this work was to identify regions with high ozone concentrations and very low concentrations of other pollutants, where further studies will be performed regarding the specific impact of ozone on childhood asthma. For that, the concentrations of ozone and of its precursors at remote areas were assessed and compared with those observed at an urban area influenced by traffic. Measurements using passive samplers were compared with those performed with continuous monitors and it was possible to conclude that measurements with passive samplers had satisfactory reproducibility and precision. For O₃, the comparison of both methods showed a maximum absolute difference of +4.10 μ g.m^?3 and relative differences lower than ?8.8%. The maximum absolute difference for NO₂ was +5.2 μ g.m^?3 and the relative differences were greater than 12% only for very low concentrations (2–3 μ g.m^?3). Comparing with one urban site, the results obtained at remote sites showed significantly lower concentrations of nitrogen dioxide (12 to 20 times) and volatile organic compounds (2 to 8 times) and greater ozone concentrations (2 to 3 times). It was inferred that the lower concentrations of nitrogen dioxide were the main reason for the greater ozone concentrations found at the remote sites. The remote areas studied showed very high ozone concentrations and very low concentrations of other pollutants, being an adequate zone to perform further studies regarding the specific impact of ozone on childhood asthma without the confounding effects of other pollutants.     

水生态功能分区研究中的基本问题

重点流域水生态功能一级二级分区研究是当前我国正在开展的一项重要工作,如何进行科学、合理的分区是值得深入探讨且亟待回答的重要问题。从水生态功能分区与水生态区划的关系、水生生物在分区中的应用、以及如何选取合适的定量分析方法等方面入手,阐述了对分区目的、指标体系和技术方法等关键问题的理解。并建议:(1)统一选用流域水生态系统结构、功能空间差异的环境驱动因子作为分区指标体系;(2)用生境尺度的水环境、水生生物指标来验证分区结果;(3)尽可能统一定量分析方法,以便为不同流域间分区结果的比较,以及为将来在全国尺度上开展分区工作奠定基础。