DataSheet_1_Benthic species patterns in and around the Cape Canyon: A large submarine canyon off the western passive margin of South Africa.xlsx

Although submarine canyons are internationally recognized as sensitive ecosystems and reported to be biological hotspots, regional studies are required to validate this consensus. To this end, hydrographic and benthic biodiversity data were collected during three cruises (2016-2017) to provide insights on the benthic patterns within South African canyon and non-canyon offshore areas. A total of 25 stations, sampled at 200-1000 m depth range, form the basis of the multivariate analysis. Diversity gradients were calculated and then differences were compared across substrate types and depth zones represented within 12 canyon and 13 non-canyon stations. Significant differences in both substrate and depth were evident, despite measures being highly variable. This observation of varying diversity in different substrates is in line with previous studies. No clear pattern was observed for species diversity (delta+). However, non-canyon stations overall showed a higher diversity in comparison to canyon stations. A notable peak in diversity is observed in canyon areas in the 401-500 m depth zone. Species richness followed an opposing pattern, as it decreased with depth and was consistently higher in canyon areas. These results align with the well-defined influence of depth-related variables on the distribution of taxonomic groups and the substrate available, at various scales. The eutrophic characteristic of the Benguela region may have attributed to the insignificant diversity differences between canyon and non-canyon stations. To assess the benthic species structure in canyon and non-canyon areas, we converted the 108 benthic species into a gamma+ matrix. We then modelled the biological response to predictor variables (substrate and depth). Although the canyon and non-canyon areas have an overlapping species composition, the main effects (canyon vs. non-canyon, depth, and substrate) showed significant differences. Thirteen species were characteristic of canyon areas, whilst only three distinguished non-canyon areas. The region has a long history of anthropogenic activities, so the observed benthic profiles may already be altered. The current study therefore provides the first detailed taxonomic description and analysis of benthic species profiles in the Cape Canyon, and advances important baseline information necessary for understanding the ecological importance of the Cape Canyon.</p

DataSheet_2_Benthic species patterns in and around the Cape Canyon: A large submarine canyon off the western passive margin of South Africa.xlsx

Although submarine canyons are internationally recognized as sensitive ecosystems and reported to be biological hotspots, regional studies are required to validate this consensus. To this end, hydrographic and benthic biodiversity data were collected during three cruises (2016-2017) to provide insights on the benthic patterns within South African canyon and non-canyon offshore areas. A total of 25 stations, sampled at 200-1000 m depth range, form the basis of the multivariate analysis. Diversity gradients were calculated and then differences were compared across substrate types and depth zones represented within 12 canyon and 13 non-canyon stations. Significant differences in both substrate and depth were evident, despite measures being highly variable. This observation of varying diversity in different substrates is in line with previous studies. No clear pattern was observed for species diversity (delta+). However, non-canyon stations overall showed a higher diversity in comparison to canyon stations. A notable peak in diversity is observed in canyon areas in the 401-500 m depth zone. Species richness followed an opposing pattern, as it decreased with depth and was consistently higher in canyon areas. These results align with the well-defined influence of depth-related variables on the distribution of taxonomic groups and the substrate available, at various scales. The eutrophic characteristic of the Benguela region may have attributed to the insignificant diversity differences between canyon and non-canyon stations. To assess the benthic species structure in canyon and non-canyon areas, we converted the 108 benthic species into a gamma+ matrix. We then modelled the biological response to predictor variables (substrate and depth). Although the canyon and non-canyon areas have an overlapping species composition, the main effects (canyon vs. non-canyon, depth, and substrate) showed significant differences. Thirteen species were characteristic of canyon areas, whilst only three distinguished non-canyon areas. The region has a long history of anthropogenic activities, so the observed benthic profiles may already be altered. The current study therefore provides the first detailed taxonomic description and analysis of benthic species profiles in the Cape Canyon, and advances important baseline information necessary for understanding the ecological importance of the Cape Canyon.</p

Image_2_Benthic species patterns in and around the Cape Canyon: A large submarine canyon off the western passive margin of South Africa.tif

Although submarine canyons are internationally recognized as sensitive ecosystems and reported to be biological hotspots, regional studies are required to validate this consensus. To this end, hydrographic and benthic biodiversity data were collected during three cruises (2016-2017) to provide insights on the benthic patterns within South African canyon and non-canyon offshore areas. A total of 25 stations, sampled at 200-1000 m depth range, form the basis of the multivariate analysis. Diversity gradients were calculated and then differences were compared across substrate types and depth zones represented within 12 canyon and 13 non-canyon stations. Significant differences in both substrate and depth were evident, despite measures being highly variable. This observation of varying diversity in different substrates is in line with previous studies. No clear pattern was observed for species diversity (delta+). However, non-canyon stations overall showed a higher diversity in comparison to canyon stations. A notable peak in diversity is observed in canyon areas in the 401-500 m depth zone. Species richness followed an opposing pattern, as it decreased with depth and was consistently higher in canyon areas. These results align with the well-defined influence of depth-related variables on the distribution of taxonomic groups and the substrate available, at various scales. The eutrophic characteristic of the Benguela region may have attributed to the insignificant diversity differences between canyon and non-canyon stations. To assess the benthic species structure in canyon and non-canyon areas, we converted the 108 benthic species into a gamma+ matrix. We then modelled the biological response to predictor variables (substrate and depth). Although the canyon and non-canyon areas have an overlapping species composition, the main effects (canyon vs. non-canyon, depth, and substrate) showed significant differences. Thirteen species were characteristic of canyon areas, whilst only three distinguished non-canyon areas. The region has a long history of anthropogenic activities, so the observed benthic profiles may already be altered. The current study therefore provides the first detailed taxonomic description and analysis of benthic species profiles in the Cape Canyon, and advances important baseline information necessary for understanding the ecological importance of the Cape Canyon.</p

Image_1_Benthic species patterns in and around the Cape Canyon: A large submarine canyon off the western passive margin of South Africa.jpeg

Although submarine canyons are internationally recognized as sensitive ecosystems and reported to be biological hotspots, regional studies are required to validate this consensus. To this end, hydrographic and benthic biodiversity data were collected during three cruises (2016-2017) to provide insights on the benthic patterns within South African canyon and non-canyon offshore areas. A total of 25 stations, sampled at 200-1000 m depth range, form the basis of the multivariate analysis. Diversity gradients were calculated and then differences were compared across substrate types and depth zones represented within 12 canyon and 13 non-canyon stations. Significant differences in both substrate and depth were evident, despite measures being highly variable. This observation of varying diversity in different substrates is in line with previous studies. No clear pattern was observed for species diversity (delta+). However, non-canyon stations overall showed a higher diversity in comparison to canyon stations. A notable peak in diversity is observed in canyon areas in the 401-500 m depth zone. Species richness followed an opposing pattern, as it decreased with depth and was consistently higher in canyon areas. These results align with the well-defined influence of depth-related variables on the distribution of taxonomic groups and the substrate available, at various scales. The eutrophic characteristic of the Benguela region may have attributed to the insignificant diversity differences between canyon and non-canyon stations. To assess the benthic species structure in canyon and non-canyon areas, we converted the 108 benthic species into a gamma+ matrix. We then modelled the biological response to predictor variables (substrate and depth). Although the canyon and non-canyon areas have an overlapping species composition, the main effects (canyon vs. non-canyon, depth, and substrate) showed significant differences. Thirteen species were characteristic of canyon areas, whilst only three distinguished non-canyon areas. The region has a long history of anthropogenic activities, so the observed benthic profiles may already be altered. The current study therefore provides the first detailed taxonomic description and analysis of benthic species profiles in the Cape Canyon, and advances important baseline information necessary for understanding the ecological importance of the Cape Canyon.</p

Results of chi-square tests with Bonferroni corrections to test whether or not the frequency of ARS depends on the size of the area inside vs outside the MPA, in each season.

<p>In the test, the frequencies were weighted by the size differences between the MPA and non-MPA areas (0.34: 0.66).</p

Switching state space model predicted tracks of the adult Subantarctic fur seal females (n = 12) tagged at Prince Edward Island in March 2011 and tracked between then and February 2012, overlaid on bathymetry (m).

<p>The individual seals identified by their PTT numbers are in the legend; the black circle is the study site.</p

Foraging Behavior of Subantarctic Fur Seals Supports Efficiency of a Marine Reserve’s Design - Fig 3

<p><b>Switching state space model predicted tracks of adult Subantarctic fur seal females tagged at Prince Edward Island in March 2011, overlaid on seasonal averages of sea surface height anomaly for (A) Autumn (March-May; n = 12 seals), (B) Winter (June-August; n = 8 seals), (C) Spring (September-November; n = 6 seals), (D) Summer (December-February; n = 4 seals).</b> The segments of predicted tracks that were associated with area restricted search (ARS) behaviour are distinguished from those associated with travelling. The dashed lines show the average surface locations of the Subtropical Convergence (STC), Subantarctic Front (SAF), and Antarctic Polar Front (APF), identified by the 14°C, 8°C, and 4°C sea surface temperature isotherms, respectively.</p

Statistics (mean, standard deviation, minimum and maximum) summarising attributes of completed foraging trips (duration, distance travelled from study site and round trip distance) by individual study animals, per season at Prince Edward Island (2011–2012).

<p>Where trips extended between seasons they were allocated to the season within which the longest period of the trip occurred. An X in the ID field indicates a female which behaved aberrantly, relocating to Marion Island shortly after deployment. This female is omitted from the “All combined” statistics at the end of the table.</p

Distance rose plots summarising the distances, within different direction classes, of all positions of the adult Subantarctic fur seal females tagged at Prince Edward Island (n = 12), from the study colony during the study period (March 2011-Feb 2012).

<p>Distance rose plots summarising the distances, within different direction classes, of all positions of the adult Subantarctic fur seal females tagged at Prince Edward Island (n = 12), from the study colony during the study period (March 2011-Feb 2012).</p

Random forest model response curves for the different predictors of behavioural activity of the twelve adult Subantarctic fur seal females tagged at Prince Edward Island in March 2011 and tracked between then and February 2012.

<p>Distance represents distance from the study colony, Distance8 is the distance from the Subantarctic Front and Distance14 is the distance from the Subtropical Convergence Zone. The final panel shows the relative importance of all the predictors in terms of their influence on the predictive accuracy of the model.</p