scholarly journals Dugong dugonfeeding in tropical Australian seagrass meadows: implications for conservation planning

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2194 ◽  
Author(s):  
Samantha J. Tol ◽  
Rob G. Coles ◽  
Bradley C. Congdon
Keyword(s):  
Species Composition ◽  
Nitrogen Content ◽  
Conservation Strategies ◽  
Total Biomass ◽  
Seagrass Species ◽  
Seagrass Meadows ◽  
Eastern Australia ◽  
North Eastern ◽  
Seagrass Biomass ◽  
Intertidal Seagrass

Dugongs (Dugong dugon) are listed as vulnerable to extinction due to rapid population reductions caused in part by loss of seagrass feeding meadows. Understanding dugong feeding behaviour in tropical Australia, where the majority of dugongs live, will assist conservation strategies. We examined whether feeding patterns in intertidal seagrass meadows in tropical north-eastern Australia were related to seagrass biomass, species composition and/or nitrogen content. The total biomass of each seagrass species removed by feeding dugongs was measured and compared to its relative availability. Nitrogen concentrations were also determined for each seagrass species present at the sites. Dugongs consumed seagrass species in proportion to their availability, with biomass being the primary determining factor. Species composition and/or nitrogen content influenced consumption to a lesser degree. Conservation plans focused on protecting high biomass intertidal seagrass meadows are likely to be most effective at ensuring the survival of dugong in tropical north-eastern Australia.

scholarly journals Dugong foraging behavior on tropical intertidal seagrass meadows: the influence of climatic drivers and anthropogenic disturbance

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Anugrah A. Budiarsa ◽  
H. H. De Iongh ◽  
Wawan Kustiawan ◽  
Peter M. van Bodegom
Keyword(s):  
Wind Speed ◽  
Linear Models ◽  
Belowground Biomass ◽  
Foraging Strategies ◽  
Fishing Activity ◽  
Factors Affecting ◽  
Seagrass Meadows ◽  
Seagrass Biomass ◽  
Tropical Areas ◽  
Intertidal Seagrass

AbstractForaging strategies of dugongs in tropical areas are not yet well understood, and that is particularly true for grazing of fast-growing pioneer seagrass meadows in the intertidal zones. In this study, we investigated the driving factors affecting the number of grazing tracks in intertidal seagrass meadows caused by small herds of dugongs in Balikpapan Bay, Indonesia. We investigated seven intertidal seagrass meadows for which the dynamics of seagrass biomass, the ratio aboveground to belowground biomass, and the number of grazing tracks were recorded and measured based on monthly intervals over a year. Seagrass features showed a significant relationship with wind speed, precipitation, desiccation time, the distance of the grazing sward to a residential area, and fishing activity based on multiple (generalized) linear models. While the intertidal seagrass meadows consisted of 5 species in total, only Halodule pinifolia patches were grazed. Dugong feeding tracks were found in four of the seven sites. The strong variation in the number of tracks throughout the year was significantly affected by seagrass biomass of seagrass, location and wind speed. Our results show how the interplay of site conditions related to both shelter (wind speed) and food availability (seagrass biomass) determines its suitability for dugongs.

Exploring the use of a fragmented landscape by a large arboreal marsupial using incidental sighting records from community members

2016 ◽  
Vol 22 (4) ◽  
pp. 386 ◽  
Author(s):  
Sigrid R. Heise-Pavlov ◽  
Alan Gillanders
Keyword(s):  
Average Distance ◽  
Mammalian Species ◽  
Conservation Strategies ◽  
Suitable Habitat ◽  
Fragmented Landscape ◽  
Community Members ◽  
Eastern Australia ◽  
North Eastern ◽  
The Matrix ◽  
Analytical Tools

Effective conservation of large mammalian species within a human-modified landscape depends on the knowledge of their ability to utilise available suitable habitat within a matrix of unsuitable habitat. We use incidental sightings of Lumholtz’s tree-kangaroo (Dendrolagus lumholtzi) in north-eastern Australia that were recorded by community members in a non-standardised way to assess the functional connectivity of the highly fragmented landscape of the Atherton Tablelands for this species. By applying spatial analytical tools to available mapped information on landscape attributes and the reported sightings it was found that the species shows a low matrix resistance. Since most sightings within the matrix were found within 150 m of a patch with suitable habitat and the average distance between these patches was 77 m it can be concluded that Lumholtz’s tree-kangaroos are able to reach most fragmented suitable habitat given certain limitations of the accuracy of the used maps and sighting locations. Based on distances between suitable habitat patches and their predominant size of up to 2 ha we expect that the species can include several fragments into its home range. More sightings of Lumholtz’s tree-kangaroos than expected by chance within the matrix during dry seasons combined with shorter than expected distances into the matrix suggests the existence of seasonal resource-driven movements of this species. Due to the non-standardised nature of the data the derived conclusions need to be tested in rigorous scientific projects before they can be integrated into the development of conservation strategies for Lumholtz’s tree-kangaroos on the Atherton Tablelands.

scholarly journals Density and Biomass of Seagrass Beds and Its Threats on Lamongan Regency

2020 ◽  
Vol 7 (3) ◽  
pp. 186-191
Author(s):  
Citra Satrya Utama Dewi ◽  
Defri Yona ◽  
Pratama Diffi Samuel ◽  
Rizqi Aimmatul Maulidiyah ◽  
Ahdiya Syahrir ◽  
...  
Keyword(s):  
Total Biomass ◽  
Total Density ◽  
Seagrass Beds ◽  
Seagrass Species ◽  
Sample Processing ◽  
Tourism Sector ◽  
Seagrass Biomass ◽  
Density Values ◽  
Density And Biomass ◽  
Seagrass Density

This study aimed to determine the density of seagrass species, seagrass biomass, and threats faced by seagrass communities in the Coastal District of Lamongan. The study was conducted from August to November 2019 in three coastal villages of Lamongan Regency, namely Tunggul Village (Station 1), Kranji Village (Station 2), and Banjarwati Village (Station 3). Furthermore, the stages of the study consisted of preparation, data collection on density, threat data, seagrass stand samples, sample processing, and data analysis. The results showed that the total density of seagrass species at Stations 1, 2, and 3 was 160 stands/m2, 172 stands/m2, and 185 stands/m2, respectively. Moreover, the total biomass of seagrass at Stations 1, 2, and 3 was 4633 g/m2, 2136 g/m2, and 9234 g/m2, respectively. In addition to seagrass species, seagrass density values also affected seagrass biomass. As development progresses in Lamongan Regency, it is known that the biggest threat of seagrass communities in the study site is human activity (anthropogenic), especially the anchor ships when anchored and the use of coastal areas as tourist areas. This occasion often cleans up seagrass communities because they are deemed unfit to be enjoyed tourism sector.

Seagrass characterization on the southern Pacific coast of Costa Rica: history, vegetation, and environment

2020 ◽  
Vol 63 (5) ◽  
pp. 429-438
Author(s):  
Jimena Samper-Villarreal ◽  
Jorge Cortés
Keyword(s):  
Costa Rica ◽  
Pacific Coast ◽  
Management Strategies ◽  
Shoot Density ◽  
Nutrient Concentrations ◽  
Seagrass Habitat ◽  
Spatial And Temporal Variability ◽  
Seagrass Species ◽  
Seagrass Biomass ◽  
Herbarium Collections

AbstractSeagrass conservation and management requires scientific understanding of spatial and temporal variability, information that is currently limited for the Eastern Tropical Pacific (ETP). Here, we analysed seagrass presence based on previous reports, herbarium collections and stakeholder knowledge, combined with field characterization in Golfo Dulce, southern Pacific coast of Costa Rica. Seagrasses were found at multiple locations along a narrow border close to shore and in up to 6 m depth within Golfo Dulce, dating back to 1969. Two seagrass species were found, Halophila baillonii and Halodule beaudettei. Seagrass biomass values for Golfo Dulce (12.0 ± 8.5 g DW m−2) were lower and water nutrient concentrations were higher than previously reported in the gulf. Shoot density (1513 ± 767 shoots m−2) was similar to previous reports. Stable isotope values in seagrass were −11.3 ± 1.0‰ δ13C and 1.2 ± 0.9‰ δ15N; while those in sediments were −26.1 ± 1.3 and 2.5 ± 0.9‰. In Golfo Dulce, isotopic values of both seagrass species do not overlap with other known primary producers. Management strategies should aim to minimize known seagrass stressors, protect potential seagrass habitat, and take into account the dynamic life strategies of the two seagrass species found.

The sediment carbon stocks of intertidal seagrass meadows in Scotland

2021 ◽  
pp. 107442
Author(s):  
Maria Potouroglou ◽  
Danielle Whitlock ◽  
Luna Milatovic ◽  
Gillian MacKinnon ◽  
Hilary Kennedy ◽  
...  
Keyword(s):  
Carbon Stocks ◽  
Seagrass Meadows ◽  
Intertidal Seagrass ◽  
Sediment Carbon

Freshwater Cyanobacteria of North-Eastern Australia: 2. Chroococcales

Phytotaxa ◽  
2013 ◽  
Vol 133 (1) ◽  
pp. 1 ◽  
Author(s):  
GLENN B. MCGREGOR
Keyword(s):  
Light Microscopy ◽  
Natural Populations ◽  
Northern Territory ◽  
Detailed Account ◽  
Ecological Data ◽  
Eastern Australia ◽  
North Eastern ◽  
Rivers And Streams ◽  
Original Illustrations ◽  
Freshwater Habitats

This volume provides the first detailed account of the Chroococcales of north-eastern Australia. It provides keys, morphological and ecological data for 6 families, 33 genera and 112 species, and photomicrographs and original illustrations to enable the identification of natural populations based on stable and recognizable characters observable with the aid of light microscopy. Distributional data are based on extensive surveys at 270 sites representing the major freshwater habitats including rivers and streams, palustrine and lacustrine wetlands, thermal springs, and man-made reservoirs in Queensland and the Northern Territory as well as a review of the Australian phycological literature. 

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