A citizen science approach: A detailed ecological assessment of subtropical reefs at point lookout, Australia

Subtropical reefs provide an important habitat for flora and fauna, and proper monitoring is required for conservation. Monitoring these exposed and submerged reefs is challenging and available resources are limited. Citizen science is increasing in momentum, as an applied research tool and in the variety of monitoring approaches adopted. This paper aims to demonstrate an ecological assessment and mapping approach that incorporates both top-down (volunteer marine scientists) and bottom-up (divers/community) engagement aspects of citizen science, applied at a subtropical reef at Point Lookout, Southeast Queensland, Australia. Marine scientists trained fifty citizen scientists in survey techniques that included mapping of habitat features, recording of substrate, fish and invertebrate composition, and quantifying impacts (e.g., occurrence of substrate damage, presence of litter). In 2014 these volunteers conducted four seasonal surveys along semi-permanent transects, at five sites, across three reefs. The project presented is a model on how citizen science can be conducted in a marine environment through collaboration of volunteer researchers, non-researchers and local marine authorities. Significant differences in coral and algal cover were observed among the three sites, while fluctuations in algal cover were also observed seasonally. Differences in fish assemblages were apparent among sites and seasons, with subtropical fish groups observed more commonly in colder seasons. The least physical damage occurred in the most exposed sites (Flat Rock) within the highly protected marine park zones. The broad range of data collected through this top-down/bottomup approach to citizen science exemplifies the projects' value and application for identifying ecosystem trends or patterns. The results of the project support natural resource and marine park management, providing a valuable contribution to existing scientific knowledge and the conservation of local reefs

Accuracy of Using Visual Identification of White Sharks to Estimate Residency Patterns

Determining the residency of an aquatic species is important but challenging and it remains unclear what is the best sampling methodology. Photo-identification has been used extensively to estimate patterns of animals' residency and is arguably the most common approach, but it may not be the most effective approach in marine environments. To examine this, in 2005, we deployed acoustic transmitters on 22 white sharks (Carcharodon carcharias) in Mossel Bay, South Africa to quantify the probability of detecting these tagged sharks by photo-identification and different deployment strategies of acoustic telemetry equipment. Using the data collected by the different sampling approaches (detections from an acoustic listening station deployed under a chumming vessel versus those from visual sightings and photo-identification), we quantified the methodologies' probability of detection and determined if the sampling approaches, also including an acoustic telemetry array, produce comparable results for patterns of residency. Photo-identification had the lowest probability of detection and underestimated residency. The underestimation is driven by various factors primarily that acoustic telemetry monitors a large area and this reduces the occurrence of false negatives. Therefore, we propose that researchers need to use acoustic telemetry and also continue to develop new sampling approaches as photo-identification techniques are inadequate to determine residency. Using the methods presented in this paper will allow researchers to further refine sampling approaches that enable them to collect more accurate data that will result in better research and more informed management efforts and policy decisions

Residency patterns and migration dynamics of adult bull sharks (Carcharhinus leucas) on the east coast of southern Africa:

Bull sharks (Carcharhinus leucas) are globally distributed top predators that play an important ecological role within coastal marine communities. However, little is known about the spatial and temporal scales of their habitat use and associated ecological role. In this study, we employed passive acoustic telemetry to investigate the residency patterns and migration dynamics of 18 adult bull sharks (195–283 cm total length) tagged in southern Mozambique for a period of between 10 and 22 months. The majority of sharks (n = 16) exhibited temporally and spatially variable residency patterns interspersed with migration events. Ten individuals undertook coastal migrations that ranged between 433 and 709 km (mean  = 533 km) with eight of these sharks returning to the study site

Retained fishing gear and associated injuries in the east Australian grey nurse sharks (Carcharias taurus): Implications for population recovery

Incidental hooking of Carcharias taurus is a threat to their populations' recovery on the east coast of Australia. Photo-identification techniques were used to investigate the frequency of hooking at 25 aggregation sites along the east coast of Australia between 2006 and 2008. Of the 673 sharks identified, 113 sharks were identified with signs of 119 incidences of hooking. For sharks with both their left and right flank photographed during a single survey day, up to 29% of females and 52% of males were identified with retained fishing gear or an attributed jaw injury. The largest number of sharks identified (222) were from a year-round aggregation of immature and mature sharks at Fish Rock, New South Wales, Australia. Forty-eight per cent of all sharks identified with retained fishing gear were first identified at this site. Fish Rock, a designated critical habitat for C. taurus, allows most forms of line fishing except fishing with bait or wire trace while anchored or moored. As interactions with fishing gear can result in debilitating disease, morbidity and death, the high incidence of hooked individual C. taurus is considered a key threatening process that is likely to reduce this shark population's ability to recover

Reproductive periodicity, localised movements and behavioural segregation of pregnant Carcharias taurus at Wolf Rock, Southeast Queensland, Australia

We examined grey nurse shark Carcharias taurus utilisation of Wolf Rock (which is located within a marine sanctuary zone and is the most northern known aggregation site on the eastern Australian seaboard) between December 2002 and February 2008 using underwater censuses, photo-identification and acoustic tracking of individual sharks. Photo-identification surveys identified 181. individual C. taurus (161 mature females, 1 immature female and 19 mature males). Eighty-one of these were re-identified at least once at Wolf Rock (77 females and 4 males) between December 2002 and February 2008. A biennial reproductive cycle was indicated for 18 out of 28 females for which re-identifications spanned at least 2 mating and/or pregnancy events. Re-identifications of 9 out of 28 female sharks suggest that., on occasion, there may be 3 yr between pregnancy events. Male C. taurus were observed between July and January, but were absent between February and April. Fresh mating scars on female sharks were observed in late November and December and pregnancies were visible from late-February. Many pregnant sharks remained at Wolf Rock until August or September (9 to 10 mo post-mating) and demonstrated strong site attachment with 78 to 90'% of their time spent within 500 m of the Wolf Rock aggregation site. C. taurus is listed as critically endangered along the east coast: of Australia and there is concern about their population's resilience globally. The improved knowledge of the reproductive periodicity of C. taurus and their behaviour during pregnancy will provide valuable information to assist with management throughout their distribution

Sex- and maturity-based differences in movement and migration patterns of grey nurse shark, Carcharias taurus, along the eastern coast of Australia

Photo-identification techniques were used to investigate temporal and spatial distributions of Carcharias taurus (Rafinesque, 1810) in relation to maturity, sex and pregnancy status at 19 sites along Australia's eastern coastline. Of 931 individual sharks identified between 2004 and 2008, 479 were female (271 mature, 208 immature) and 452 male (288 mature, 164 immature). Mature, non-gravid females and mature males were mostly observed in the southern to central parts of this species range, along the eastern coast of Australia, in early summer to early winter. These sharks subsequently moved northward, and mating occurred in late spring to early summer in waters off the coast of northern New South Wales and southern Queensland. Pregnant C. taurus aggregated at Wolf Rock in southern Queensland, at the most northerly part of their known range, from late summer to early winter. These sharks subsequently migrated south to pup in central and southern waters of their range in late winter to late spring. Immature sharks of both sexes moved less than mature sharks, showed no synchronised migration patterns, and were mostly restricted to central and southern waters. The improved understanding of sex-and maturity-based migration of C. taurus provided here should facilitate a conservation strategy appropriate for this species in Australian waters

A survey of the cadmium concentration in kidney, liver and muscle of Aough Australian cattle

A survey to assess the extent of cadmium accumulation in South Australian cattle was undertaken in 1989–91. Of the 8635 cattle sampled, about 12% of the kidney samples and 1% of the liver samples contained cadmium concentrations above the maximum permitted concentration for human consumption of 2.5 mg/kg wet weight for kidney and 1.25 mg/kg wet weight for liver. None of the 262 muscle samples assayed contained cadmium concentrations above the maximum permitted concentration of 0.2 mg/kg wet weight. There was a significant effect of location, gender and season on the extent of non-compliance. Of the regions examined, non-compliance rates for Kangaroo Island, Lower Eyre, South East and Lower Central were significantly higher than for the other regions. In general, non-compliance rates were higher in female cattle than in male cattle, increased with age and were lowest in spring. After adjustment for these factors, non-compliance rates were similar across farm types, namely dairy, beef and feedlot. Although there was a significant correlation between cadmium concentrations in liver and in whole kidney, the confidence limit was considered excessive, rendering liver cadmium values an unreliable predictor of cadmium values in kidney

Evidence for ice particles in the tropical stratosphere from in-situ measurements

In-situ ice crystal size distribution measurements are presented within the tropical troposphere and lower stratosphere. The measurements were performed using a combination of a Forward Scattering Spectrometer Probe (FSSP-100) and a Cloud Imaging Probe (CIP), which were installed on the Russian high altitude research aircraft M55 "Geophysica" during the SCOUT-O-3 campaign in Darwin, Australia. One of the objectives of the campaign was to characterise the Hector convective system, which appears on an almost daily basis during the pre-monsoon season over the Tiwi Islands, north of Darwin. In total 90 encounters with ice clouds, between 10 and 19 km altitude were selected from the dataset and were analysed. Six of these encounters were observed in the lower stratosphere, up to 1.4 km above the local tropopause. Concurrent lidar measurements on board "Geophysica" indicate that these ice clouds were a result of overshooting convection. Large ice crystals, with a maximum dimension up to 400 mu m, were observed in the stratosphere. The stratospheric ice clouds included an ice water content ranging from 7.7x10(-5) to 8.5x10(-4) gm(-3) and were observed at ambient relative humidities ( with respect to ice) between 75 and 157%. Three modal lognormal size distributions were fitted to the average size distributions for different potential temperature intervals, showing that the shape of the size distribution of the stratospheric ice clouds are similar to those observed in the upper troposphere.In the tropical troposphere the effective radius of the ice cloud particles decreases from 100 mu m at about 10 km altitude, to 3 mu m at the tropopause, while the ice water content decreases from 0.04 to 10(-5) gm(-3). No clear trend in the number concentration was observed with altitude, due to the thin and inhomogeneous characteristics of the observed cirrus clouds.The ice water content calculated from the observed ice crystal size distribution is compared to the ice water content derived from two hygrometer instruments. This independent measurement of the ice water content agrees within the combined uncertainty of the instruments for ice water contents exceeding 3x10(-4) gm(-3).Stratospheric residence times, calculated based on gravitational settling, and evaporation rates show that the ice crystals observed in the stratosphere over the Hector storm system had a high potential of humidifying the stratosphere locally.Utilizing total aerosol number concentration measurements from a four channel condensation particle counter during two separate campaigns, it can be shown that the fraction of ice particles to the number of aerosol particles remaining ranges from 1: 300 to 1: 30 000 for tropical upper tropospheric ice clouds with ambient temperatures below -75 degrees C