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Using Fish Population Metrics to Compare the Effects of Artificial Reef Density.

Froehlich CY, Kline RJ - PLoS ONE (2015)

Bottom Line: In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts.Fish communities did not significantly differ among density categories; however, highest species richness and total abundances were observed at intermediate culvert densities and at natural reefs.Whereas the abundance of L. campechanus did not differ among density categories, mean total lengths of L. campechanus were greatest at the lower density.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of Texas at Brownsville, Brownsville, Texas, United States of America.

ABSTRACT
Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1-190 culverts. Abundances of adults and species evenness of juvenile populations differed between the years. Fish communities did not significantly differ among density categories; however, highest species richness and total abundances were observed at intermediate culvert densities and at natural reefs. Whereas the abundance of L. campechanus did not differ among density categories, mean total lengths of L. campechanus were greatest at the lower density. Our findings suggest that reefs should be deployed with intermediate patch density of 71-120 culverts in a 30-m radius to yield the highest fish abundances.

No MeSH data available.


Principal component analysis (PCA) of percent substrate cover, substrate rugosity, average height, and maximum heightVectors point in the direction of increasing values. Distance relative to the outer circle provides indication of how much variation is explained by each vector. If a vector connects to the outer circle, then 100% of the variation in the variable is explained by the two PC axes shown.
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pone.0139444.g004: Principal component analysis (PCA) of percent substrate cover, substrate rugosity, average height, and maximum heightVectors point in the direction of increasing values. Distance relative to the outer circle provides indication of how much variation is explained by each vector. If a vector connects to the outer circle, then 100% of the variation in the variable is explained by the two PC axes shown.

Mentions: PCA analysis produced four PC axes to explain variations in substrate rugosity (1.001–1.288), average vertical relief (0–1.49 m), maximum vertical relief (0–2.95 m), and percent substrate cover (0.76–100%). Two PCs explained 91.6% of variation among the variables tested (Fig 4), and both were interpreted for further analysis. Substrate rugosity, average vertical relief and maximum vertical relief were positively correlated with PC1, while percent cover was positively correlated with PC2 (Fig 4). Natural sites were strongly correlated with PC2, whereas culvert reefs were strongly correlated with PC1. Natural sites had the highest range of percent cover compared to culvert sites. A total of 14 species were repeatedly found at both culvert and natural sites, however no significant correlations were observed between any species and the two PC axes.


Using Fish Population Metrics to Compare the Effects of Artificial Reef Density.

Froehlich CY, Kline RJ - PLoS ONE (2015)

Principal component analysis (PCA) of percent substrate cover, substrate rugosity, average height, and maximum heightVectors point in the direction of increasing values. Distance relative to the outer circle provides indication of how much variation is explained by each vector. If a vector connects to the outer circle, then 100% of the variation in the variable is explained by the two PC axes shown.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4589336&req=5

pone.0139444.g004: Principal component analysis (PCA) of percent substrate cover, substrate rugosity, average height, and maximum heightVectors point in the direction of increasing values. Distance relative to the outer circle provides indication of how much variation is explained by each vector. If a vector connects to the outer circle, then 100% of the variation in the variable is explained by the two PC axes shown.
Mentions: PCA analysis produced four PC axes to explain variations in substrate rugosity (1.001–1.288), average vertical relief (0–1.49 m), maximum vertical relief (0–2.95 m), and percent substrate cover (0.76–100%). Two PCs explained 91.6% of variation among the variables tested (Fig 4), and both were interpreted for further analysis. Substrate rugosity, average vertical relief and maximum vertical relief were positively correlated with PC1, while percent cover was positively correlated with PC2 (Fig 4). Natural sites were strongly correlated with PC2, whereas culvert reefs were strongly correlated with PC1. Natural sites had the highest range of percent cover compared to culvert sites. A total of 14 species were repeatedly found at both culvert and natural sites, however no significant correlations were observed between any species and the two PC axes.

Bottom Line: In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts.Fish communities did not significantly differ among density categories; however, highest species richness and total abundances were observed at intermediate culvert densities and at natural reefs.Whereas the abundance of L. campechanus did not differ among density categories, mean total lengths of L. campechanus were greatest at the lower density.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of Texas at Brownsville, Brownsville, Texas, United States of America.

ABSTRACT
Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1-190 culverts. Abundances of adults and species evenness of juvenile populations differed between the years. Fish communities did not significantly differ among density categories; however, highest species richness and total abundances were observed at intermediate culvert densities and at natural reefs. Whereas the abundance of L. campechanus did not differ among density categories, mean total lengths of L. campechanus were greatest at the lower density. Our findings suggest that reefs should be deployed with intermediate patch density of 71-120 culverts in a 30-m radius to yield the highest fish abundances.

No MeSH data available.