scholarly journals Photosynthesis/irradiance relationships in the Ross Sea, Antarctica, and their control by phytoplankton assemblage composition and environmental factors

2002 ◽  
Vol 226 ◽  
pp. 1-12 ◽  
Author(s):  
CM van Hilst ◽  
WO Smith
Keyword(s):  
Environmental Factors ◽  
Ross Sea ◽  
Phytoplankton Assemblage ◽  
Assemblage Composition

Bioeroding sponge assemblages: the importance of substrate availability and sediment

2018 ◽  
Vol 99 (2) ◽  
pp. 343-358 ◽  
Author(s):  
Joseph Marlow ◽  
Christine H.L. Schönberg ◽  
Simon K. Davy ◽  
Abdul Haris ◽  
Jamaluddin Jompa ◽  
...  
Keyword(s):  
Coral Reef ◽  
Environmental Factors ◽  
Spatial Variation ◽  
Environmental Conditions ◽  
Sponge Species ◽  
Coral Mortality ◽  
Substrate Availability ◽  
Abiotic Conditions ◽  
Assemblage Composition ◽  
Reef Health

Despite global deterioration of coral reef health, not all reef-associated organisms are in decline. Bioeroding sponges are thought to be largely resistant to the factors that stress and kill corals, and are increasing in abundance on many reefs. However, there is a paucity of information on how environmental factors influence spatial variation in the distribution of these sponges, and how they might be affected by different stressors. We aimed to identify the factors that explained differences in bioeroding sponge abundance and assemblage composition, and to determine whether bioeroding sponges benefit from the same environmental conditions that can contribute towards coral mortality. Abundance surveys were conducted in the Wakatobi region of Indonesia on reefs characterized by different biotic and abiotic conditions. Bioeroding sponges occupied an average of 8.9% of available dead substrate and variation in abundance and assemblage composition was primarily attributed to differences in the availability of dead substrate. Our results imply that if dead substrate availability increases as a consequence of coral mortality, bioeroding sponge abundance is also likely to increase. However, bioeroding sponge abundance was lowest on a sedimented reef, despite abundant dead substrate. This suggests that not all forms of coral mortality will benefit all bioeroding sponge species, and sediment-degraded reefs are likely to be dominated by a few resilient bioeroding sponge species. Overall, we demonstrate the importance of understanding the drivers of bioeroding sponge abundance and assemblage composition in order to predict possible impacts of different stressors on reefs communities.

Environmental and spatial factors affect the composition and morphology of tadpole assemblages

2018 ◽  
Vol 96 (10) ◽  
pp. 1130-1136
Author(s):  
N.C.S. Marques ◽  
F. Nomura
Keyword(s):  
Environmental Factors ◽  
Morphological Variation ◽  
Environmental Conditions ◽  
Environmental Variables ◽  
Morphological Diversity ◽  
Oviposition Site ◽  
Spatial Factors ◽  
Assemblage Composition ◽  
Different Types ◽  
Spatial Coordinates

Understanding how community compositions are affected by environmental and spatial factors are essential to provide knowledge about the distributions of species. Furthermore, these factors can play a role in species morphological variation. Tadpoles can be found in different types of aquatic microhabitats, showing a considerable amount of morphological diversity. We hypothesized that tadpole morphological diversity is controlled by ecological and spatial factors other than assemblage attributes, and that tadpole assemblage composition is affected by spatial factors. To test these hypotheses, we recorded the abundance of tadpoles from different ponds, identified eight environmental variables that represented local and landscape descriptors of the ponds, recorded the spatial coordinates of the ponds, and measured the morphological variation of assemblages. Spatial factors significantly affected the composition of tadpole assemblages, while both spatial and environmental factors affected morphological variation. The ability of tadpoles to alter their morphology in response to environmental factors might be a result of poor oviposition site choice, and this probably interacts with spatial factors to control the assemblage composition of tadpoles. Morphological variation is advantageous for tadpoles because it allows them to adjust their morphology to environmental conditions. This study has demonstrated how factors that control the assemblage composition of tadpoles also drive their morphological diversity.

Latitudinal variation of demersal fish assemblages in the western Ross Sea

2010 ◽  
Vol 22 (6) ◽  
pp. 782-792 ◽  
Author(s):  
Malcolm R. Clark ◽  
Matthew R. Dunn ◽  
Peter J. McMillan ◽  
Matthew H. Pinkerton ◽  
Andrew Stewart ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Fish Assemblages ◽  
Multivariate Analyses ◽  
Ross Sea ◽  
Fish Communities ◽  
Demersal Fish ◽  
The North ◽  
Sample Frequency ◽  
Main Components ◽  
Temperature Depth

AbstractDemersal fishes were sampled using a large fish trawl during two surveys carried out in February and March 2004 and 2008 in the Ross Sea, and around seamounts and islands just to the north at 66°S. The distribution and abundance of 65 species collected in these surveys were examined to determine if demersal fish communities varied throughout the area, and what environmental factors might influence this. Species accumulation with sample frequency did not reach an asymptote, but the rate of new species was low suggesting data were adequate for describing the main components of the communities. Three broad assemblages were identified, in the southern Ross Sea (south of 74°S), central–northern Ross Sea (between latitudes 71°–74°S), and the seamounts further north (65°–68°S) where some species more typical of sub-Antarctic latitudes were observed. Multivariate analyses indicated that environmental factors of seafloor rugosity (roughness), temperature, depth, and current speed were the main variables determining patterns in demersal fish communities.

Environmental factors driving phytoplankton assemblage pattern and diversity: insights from Sundarban eco-region, India

2020 ◽  
Author(s):  
Pranab Gogoi ◽  
Sanjoy Kumar Das ◽  
Soma Das Sarkar ◽  
Thangjam Nirupada Chanu ◽  
Ranjan Kumar Manna ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Phytoplankton Assemblage

scholarly journals Consistency Is Critical for the Effective Use of Baited Remote Video

Oceans ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 215-232
Author(s):  
Robyn E. Jones ◽  
Ross A. Griffin ◽  
Roger J. H. Herbert ◽  
Richard K. F. Unsworth
Keyword(s):  
Species Richness ◽  
Image Quality ◽  
Environmental Factors ◽  
Relative Abundance ◽  
Influential Factors ◽  
Influential Factor ◽  
Faunal Assemblage ◽  
Assemblage Composition ◽  
The North ◽  
Taxonomic Groups

Baited remote underwater videos (BRUV) are popular marine monitoring techniques used for the assessment of motile fauna. Currently, most published studies evaluating BRUV methods stem from environments in the Southern Hemisphere. This has led to stricter and more defined guidelines for the use of these techniques in these areas in comparison to the North Atlantic, where little or no specific guidance exists. This study explores metadata taken from BRUV deployments collected around the UK to understand the influence of methodological and environmental factors on the information gathered during BRUV deployments including species richness, relative abundance and faunal composition. In total, 39 BRUV surveys accumulating in 457 BRUV deployments across South/South-West England and Wales were used in this analysis. This study identified 88 different taxa from 43 families across the 457 deployments. Whilst taxonomic groups such as Labridae, Gadidae and Gobiidae were represented by a high number of species, species diversity for the Clupeidae, Scombridae, Sparidae, Gasterosteidae and Rajidae groups were low and many families were absent altogether. Bait type was consistently identified as one of the most influential factors over species richness, relative abundance and faunal assemblage composition. Image quality and deployment duration were also identified as significant influential factors over relative abundance. As expected, habitat observed was identified as an influential factor over faunal assemblage composition in addition to its significant interaction with image quality, time of deployment, bait type and tide type (spring/neap). Our findings suggest that methodological and environmental factors should be taken into account when designing and implementing monitoring surveys using BRUV techniques. Standardising factors where possible remains key. Fluctuations and variations in data may be attributed to methodological inconsistencies and/or environment factors as well as over time and therefore must be considered when interpreting the data.

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