Responses of Dendronephthya australis to predation by Dermatobranchus sp. nudibranchs

2018 ◽  
Vol 69 (1) ◽  
pp. 186 ◽  
Author(s):  
Tom R. Davis ◽  
David Harasti ◽  
Stephen D. A. Smith
Keyword(s):  
Soft Coral ◽  
Anthropogenic Impacts ◽  
Time Lapse ◽  
Spatial Extent ◽  
Anthropogenic Stressors ◽  
Eastern Australia ◽  
Port Stephens

The soft coral Dendronephthya australis occurs only in large abundance within the tidal-dominated Port Stephens estuary in eastern Australia. In recent years, substantial declines in the spatial extent of D. australis within Port Stephens has led to calls for the species to be listed as ‘threatened’. The causes for these declines are likely to include a range of anthropogenic impacts, as well as natural effects such as predation by the nudibranch Dermatobranchus sp., which can be abundant in winter and spring. The responses of D. australis to the presence of Dermatobranchus sp. were studied at two sites in Port Stephens, using time-lapse and still photography combined with visual surveys. Dermatobranchus sp. was observed consuming D. australis polyps, and colony inflation and polyp expansion were both reduced when Dermatobranchus sp. was present. Although predation by Dermatobranchus sp. is a natural impact, our observations suggest that interactions with additional anthropogenic stressors may exacerbate its overall impact on the spatial extent and survival of the geographically restricted soft coral D. australis.

Is Port Stephens, eastern Australia, a global hotspot for biodiversity of Aplysiidae (Gastropoda: Heterobranchia)?

2016 ◽  
Vol 37 (1) ◽  
pp. 45-65 ◽  
Author(s):  
Matt J. Nimbs ◽  
Richard C. Willan ◽  
Stephen D.A. Smith
Keyword(s):  
Eastern Australia ◽  
Port Stephens

Monitoring climate-driven and anthropogenic impacts on hydrology and agriculture in South-Eastern Australia in the 21st century

2020 ◽  
Author(s):  
Maike Schumacher ◽  
Ehsan Forootan ◽  
Russell Crosbie ◽  
Theresa Mallschützke ◽  
Jonas Rothermel
Keyword(s):  
Remote Sensing ◽  
21St Century ◽  
Agricultural Production ◽  
Anthropogenic Impacts ◽  
Balance Model ◽  
Satellite Mission ◽  
Extreme Precipitation Events ◽  
Millennium Drought ◽  
Eastern Australia ◽  
Precipitation Record

<p>With the climate change, drought events likely become more frequent and severe in Australia, where the worst droughts were recorded during the 21st century. Particularly, in the South-East of the country, the so called "Millennium Drought" showed below average annual precipitation for an entire decade. The precipitation record was then increased by extreme precipitation events generated from the La Niña events in 2010 and 2011. Afterwards, dry conditions began again to develop. The climate-driven events and anthropogenic adaptions to the circumstances resulted in strong impacts on the hydrological resources and agricultural production. In fact, simulating hydrological processes within the (semi-)arid region of South-East Australia is very challenging especially during extreme events. In previous studies, we found a strong underestimation of the decline of total terrestrial water storage (TWS) and of groundwater in comparison to remote sensing data and in-situ station networks. Thus, we successfully calibrated the W3RA water balance model and simultaneously assimilated TWS anomalies obtained from the Gravity Recovery And Climate Experiment (GRACE) satellite mission to improve the model's skill during extreme meteorological conditions. In this presentation, we focus on the comparison of remote sensing observations and W3RA simulations after implementing the calibration and data assimilation with existing data records on anthropogenic intervention into the water cycle, as well as on agricultural production. Our results indicate high correlations between meteorological, hydrological and agricultural variables, and we observe strong similarities in the long-term trends and break points.</p>

Riparian vegetation removal alters consumer - resource stoichiometry in an Australian lowland stream

2012 ◽  
Vol 63 (1) ◽  
pp. 1 ◽  
Author(s):  
Darren P. Giling ◽  
Paul Reich ◽  
Ross M. Thompson
Keyword(s):  
Riparian Vegetation ◽  
Anthropogenic Impacts ◽  
Negative Relationship ◽  
Canopy Cover ◽  
Ecological Impacts ◽  
Molar Ratio ◽  
Freshwater Crayfish ◽  
Resource Quality ◽  
Lowland Stream ◽  
Eastern Australia

Anthropogenic impacts on stream ecosystems generate changes in nutrient and carbon availability which act as stoichiometric challenges to consumers. We tested the hypothesis that removal of Eucalyptus riparian vegetation alters in-stream resource stoichiometry with flow-on effects for a benthic consumer (the freshwater crayfish, Cherax destructor). Sites with high and low riparian canopy cover were selected on a lowland stream in south-eastern Australia. A reduction in riparian vegetation canopy cover was associated with decreased terrestrial detritus (low nutritional quality; high carbon to nitrogen (C : N) ratio) and increased cover of macrophytes and filamentous algae (high quality; low C : N ratio). This resource-quality shift was associated with a small but significant decrease in C. destructor C : N ratio (molar ratio of muscle tissue). This suggests that the animals are deviating from homeostasis and may be in better condition in the stream pools dominated by in-stream productivity. A significant negative relationship between C. destructor length and C : N ratio was observed, suggesting that resource-quality impacts may differ with age. The present study has shown that riparian loss alters stoichiometric interactions in stream benthic ecosystems, with potential consequences for stream processes such as nutrient cycling. Ecological stoichiometric theory should therefore be further utilised to make predictions of ecological impacts in freshwater systems.

Stygofauna biodiversity and endemism in four alluvial aquifers in eastern Australia

2008 ◽  
Vol 22 (2) ◽  
pp. 117 ◽  
Author(s):  
P. J. Hancock ◽  
A. J. Boulton
Keyword(s):  
Water Table ◽  
Anthropogenic Impacts ◽  
Regulated River ◽  
Future Research ◽  
Ecological Knowledge ◽  
Taxon Richness ◽  
Tree Roots ◽  
Alluvial Aquifers ◽  
Ecological Requirements ◽  
Eastern Australia

Short-range endemism is common in groundwater fauna (stygofauna), placing many species at risk from anthropogenic impacts such as water abstraction and pollution. Few of the alluvial aquifers in eastern Australia have been sampled for stygofauna. Fauna from two aquifers in Queensland and two in New South Wales was sampled to improve ecological knowledge of stygofauna and the potential threats posed to it by development. Our surveys found stygofauna in all four aquifers, with most taxa collected from bores with low electrical conductivity (<1500 µS cm–1). Taxon richness decreased with distance below the water table. The most taxon-rich bores in each region occurred where the water table depth was <10 m, were associated with the alluvium of tributaries of large regulated river systems, and were near phreatophytic trees. It is possible that tree roots constitute a habitat and source of organic matter in alluvial aquifers as they do in cave streams. It is important to document the biodiversity of particular regions and aquifers so that species can be conserved in the face of increasing groundwater use. For effective resource management, future research should strive to understand the tolerances and ecological requirements of groundwater communities and the ecosystem services they provide.

scholarly journals Kondisi Barang di Pulau Baranglompo dan Bone Batang Berdasarkan Tabel Kesehatan Karang

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Muh. Nurdin ◽  
Magdalena Litaay ◽  
Dody Priosambodo ◽  
Willem Moka
Keyword(s):  
Coral Reefs ◽  
Soft Coral ◽  
Anthropogenic Impacts ◽  
Health Condition ◽  
Average Value ◽  
Coral Colony ◽  
South West ◽  
Line Intercept ◽  
Healthy Coral ◽  
Wing Scales

The structure of wing scales in four species of papilionid butterflies were The research about the condition of coral reefs in Baranglompo and Bone Batang island was conducted in January to April 2016 based on “Coralwatch” table. The aim of this study was to determine health condition of coral reefs in Baranglompo and Bone Batang island. The data was obtained in the south, west, and north at a depth of 3 meters and 10 meter using Line Intercept Transect (LIT) method along 100 meters of both islands. The health condition of coral reefs was obtained from four coral colony types specifically Branching, Massive, Tabulate, and Soft coral using Coralwatch method. The results of this study showed that the health condition of coral reefs in Baranglompo and Bone Batang islands was still relatively equal. At a depth of 3 meters, the most healthy coral colony was dominated by branching corals while at a depth of 10 meters dominated by massive corals. However, the average value of coral colors indicating coral condition showed that the health condition of coral reefs in Baranglompo was higher than that in Bone Batang island. High anthropogenic impacts were observed by the trash commonly found in Baranglompo island, many fish bombings also found in Bone Batang island. This study recommend that the health condition of coral reefs in Baranglompo island was greater than that in Bone Batang island.

scholarly journals Multiple anthropogenic stressors have inconsistent cumulative effects across a large spatial gradient

2021 ◽  
Author(s):  
Ben Kefford ◽  
Susan J. Nichols ◽  
Richard Duncan
Keyword(s):  
Multiple Stressors ◽  
Cumulative Effect ◽  
Suspended Sediments ◽  
Cumulative Effects ◽  
Spatial Gradient ◽  
Antagonistic Effects ◽  
Stream Insects ◽  
Anthropogenic Stressors ◽  
Spatial Consistency ◽  
Eastern Australia

Biodiversity is declining, typically because of multiple anthropogenic stressors. Cumulative effects of multiple stressors are classified as additive, when cumulative effects are as expected from the stressor’s singular effects, synergistic when greater than additive or antagonistic when less than additive. Less attention has been given to the consistency of cumulative effects. We analysed stream insects, Ephemeroptera, Plecoptera and Trichoptera (EPT) data from two habitats spanning a 3,600 km latitudinal (S11◦-S43◦) gradient in eastern Australia. We found that the cumulative effect of salinity and suspended sediments on EPT family richness was inconsistent with additive, synergistic or antagonistic effects, and the reduction EPT family richness from increasing both stressors varied (48-70%) depending on habitat (riffle vs. edge), water temperature and terrain slope. Studies of cumulative effects of multiple stressors at one location risk not describing cumulative effects elsewhere and ecologists should consider the spatial consistency of multiple stressors.

Group Characteristics, Site Fidelity And Seasonal Abundance Of Bottlenosed Dolphins (Tursiops Aduncus) In Jervis Bay And Port Stephens, South-Eastern Australia

2002 ◽  
Vol 24 (1) ◽  
pp. 11 ◽  
Author(s):  
LM Möller ◽  
SJ Allen ◽  
RG Harcourt
Keyword(s):  
Group Size ◽  
Site Fidelity ◽  
Human Impacts ◽  
Bottlenose Dolphins ◽  
Seasonal Abundance ◽  
Tursiops Aduncus ◽  
Photo Identification ◽  
Eastern Australia ◽  
Group Characteristics ◽  
Port Stephens

Social organisation and abundance of bottlenose dolphins (Tursiops aduncus) in Jervis Bay (JB) and Port Stephens (PS), NSW, were investigated through behavioural/photo-identification surveys between May 1997 and April 2000. Mean group size was significantly larger at JB (12.3 � 0.87, n =167) compared to PS (6.8 � 0.37, n = 218). At both sites, groups were significantly larger when calves were present. Group size varied with activity, being smallest when feeding and largest when socialising. While mean group size of feeding dolphins did not vary between sites, travelling and socialising groups were significantly larger in JB. Site fidelity was assigned based on sighting rates and presence across seasons. Sighting rates varied significantly between areas, but the proportion of dolphins categorised as residents, occasional visitors and transients did not. Minimum abundance by season, based on mark-resighting of recognisable individuals, ranged from 61 � 3.2 to 108 � 7.1 in JB and 143 � 8.1 to 160 � 8.1 in PS. Differences in group size at the two sites may relate to social factors and/or human impacts, while differences in abundance may be associated with habitat size and complexity. The lack of dolphin matches between areas suggests that they represent distinct populations.

Distribution and spatial modelling of a soft coral habitat in the Port Stephens–Great Lakes Marine Park: implications for management

2016 ◽  
Vol 67 (2) ◽  
pp. 256 ◽  
Author(s):  
Davina E. Poulos ◽  
Christopher Gallen ◽  
Tom Davis ◽  
David J. Booth ◽  
David Harasti
Keyword(s):  
Great Lakes ◽  
Soft Coral ◽  
Species Distribution Model ◽  
Management Strategies ◽  
Environmental Parameters ◽  
Spatial Modelling ◽  
Distribution Model ◽  
Marine Park ◽  
Environmental Requirements ◽  
Port Stephens

Habitat mapping is a useful method for understanding the complex spatial relationships that exist in the marine environment, and is used to evaluate the effectiveness of management strategies, particularly in regards to marine protected areas. This study explored the observed and predicted distribution of an uncommon soft coral species, Dendronephthya australis within the Port Stephens–Great Lakes Marine Park. Dendronephthya australis was mapped by video operated by a SCUBA diver towing a time synchronised GPS. A species distribution model was created to explore the possible occurrence of D. australis outside of the mapped area, using four environmental parameters: bathymetry, slope of seabed, velocity of tidal currents, and distance from estuary mouth. Dendronephthya australis colonies occurred along the southern shoreline in the Port Stephens estuary between Fly Point and Corlette Point, but no colonies were found within sanctuary (no-take) zones within the marine park. The model illustrated limited habitat suitability for D. australis within a larger section of the estuary, suggesting this species has specific environmental requirements survival. Owing to its current threats (anchor damage and fishing line entanglement), implications from these findings will assist future management and protection decisions, particularly in regard to its protection within a marine park.

scholarly journals Extinction risk in extant marine species integrating palaeontological and biodistributional data

2018 ◽  
Vol 285 (1887) ◽  
pp. 20181698 ◽  
Author(s):  
K. S. Collins ◽  
S. M. Edie ◽  
G. Hunt ◽  
K. Roy ◽  
D. Jablonski
Keyword(s):  
Anthropogenic Impacts ◽  
Marine Invertebrate ◽  
Extinction Risk ◽  
Marine Species ◽  
Marine Biodiversity ◽  
Effective Management ◽  
Anthropogenic Stressors ◽  
Extinction Rates ◽  
Information Gap ◽  
The Face

Extinction risk assessments of marine invertebrate species remain scarce, which hinders effective management of marine biodiversity in the face of anthropogenic impacts. To help close this information gap, in this paper we provide a metric of relative extinction risk that combines palaeontological data, in the form of extinction rates calculated from the fossil record, with two known correlates of risk in the modern day: geographical range size and realized thermal niche. We test the performance of this metric—Palaeontological Extinction Risk In Lineages (PERIL)—using survivorship analyses of Pliocene bivalve faunas from California and New Zealand, and then use it to identify present-day hotspots of extinction vulnerability for extant shallow-marine Bivalvia. Areas of the ocean where concentrations of bivalve species with higher PERIL scores overlap with high levels of climatic or anthropogenic stressors should be considered of most immediate concern for both conservation and management.

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