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Hollow rhodoliths increase Svalbard's shelf biodiversity.

Teichert S - Sci Rep (2014)

Bottom Line: In the examined shelf areas, biodiversity in rhodolith-bearing habitats is significantly greater than in habitats without rhodoliths and hollow rhodoliths yield a greater biodiversity than solid ones.This biodiversity, however, is threatened because hollow rhodoliths take a long time to form and are susceptible to global change and anthropogenic impacts such as trawl net fisheries that can destroy hollow rhodoliths.Rhodoliths and other forms of coralline red algae play a key role in a plurality of environments and need improved management and protection plans.

View Article: PubMed Central - PubMed

Affiliation: GeoZentrum Nordbayern, Section Palaeontology, Erlangen, Germany.

ABSTRACT
Rhodoliths are coralline red algal assemblages that commonly occur in marine habitats from the tropics to polar latitudes. They form rigid structures of high-magnesium calcite and have a good fossil record. Here I show that rhodoliths are ecosystem engineers in a high Arctic environment that increase local biodiversity by providing habitat. Gouged by boring mussels, originally solid rhodoliths become hollow ecospheres intensely colonised by benthic organisms. In the examined shelf areas, biodiversity in rhodolith-bearing habitats is significantly greater than in habitats without rhodoliths and hollow rhodoliths yield a greater biodiversity than solid ones. This biodiversity, however, is threatened because hollow rhodoliths take a long time to form and are susceptible to global change and anthropogenic impacts such as trawl net fisheries that can destroy hollow rhodoliths. Rhodoliths and other forms of coralline red algae play a key role in a plurality of environments and need improved management and protection plans.

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Most taxonomic groups favour sites with hollow rhodoliths.For most taxonomic groups, bars (±SE) indicate the lowest mean numbers of taxa at sites without rhodoliths (NR), followed by sites with solid rhodoliths (SR) and led by sites with hollow rhodoliths.
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f3: Most taxonomic groups favour sites with hollow rhodoliths.For most taxonomic groups, bars (±SE) indicate the lowest mean numbers of taxa at sites without rhodoliths (NR), followed by sites with solid rhodoliths (SR) and led by sites with hollow rhodoliths.

Mentions: Hollow rhodoliths occur intermixed with solid forms (Fig. 1a). Although precise quantification of relative abundances proves to be difficult, I have estimated a mean percentage of 50% for each based on the JAGO video footage. The surface of both hollow and solid rhodoliths is occupied by grazing organisms (mainly polyplacophores and echinoids), but CT-scans show that the interior of the hollow forms is also intensely colonised by a variety of organisms (Fig. 1b–d). Accordingly, local biodiversity at sites where solid rhodoliths (SR) are present is significantly greater than at sites were rhodoliths are absent (NR) and the greatest biodiversity was found at sites with hollow rhodoliths (HR). Data from Margalef's richness index (see equation 6) and the Shannon index (see equation 7) are summarised in Table 1 and comparatively illustrated in Figure 2. The mean frequencies of distinct taxonomic groups in NR, SR, and HR environments are shown in Figure 3. Sites with hollow rhodoliths exhibit the highest mean numbers of taxa for bryozoans, polychaets, molluscs, echinoderms, and the group of organisms summarised as “others”. This pattern is less pronounced for cnidarians and fish but still visible when considering the standard errors of the organism counts. The highest mean number of crustacean taxa occurs at sites with solid rhodoliths, followed by sites with hollow rhodoliths. The overall frequency of the taxonomic groups resembles the biodiversity pattern calculated for the three (NR, SR, HR) environmental settings.


Hollow rhodoliths increase Svalbard's shelf biodiversity.

Teichert S - Sci Rep (2014)

Most taxonomic groups favour sites with hollow rhodoliths.For most taxonomic groups, bars (±SE) indicate the lowest mean numbers of taxa at sites without rhodoliths (NR), followed by sites with solid rhodoliths (SR) and led by sites with hollow rhodoliths.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4225531&req=5

f3: Most taxonomic groups favour sites with hollow rhodoliths.For most taxonomic groups, bars (±SE) indicate the lowest mean numbers of taxa at sites without rhodoliths (NR), followed by sites with solid rhodoliths (SR) and led by sites with hollow rhodoliths.
Mentions: Hollow rhodoliths occur intermixed with solid forms (Fig. 1a). Although precise quantification of relative abundances proves to be difficult, I have estimated a mean percentage of 50% for each based on the JAGO video footage. The surface of both hollow and solid rhodoliths is occupied by grazing organisms (mainly polyplacophores and echinoids), but CT-scans show that the interior of the hollow forms is also intensely colonised by a variety of organisms (Fig. 1b–d). Accordingly, local biodiversity at sites where solid rhodoliths (SR) are present is significantly greater than at sites were rhodoliths are absent (NR) and the greatest biodiversity was found at sites with hollow rhodoliths (HR). Data from Margalef's richness index (see equation 6) and the Shannon index (see equation 7) are summarised in Table 1 and comparatively illustrated in Figure 2. The mean frequencies of distinct taxonomic groups in NR, SR, and HR environments are shown in Figure 3. Sites with hollow rhodoliths exhibit the highest mean numbers of taxa for bryozoans, polychaets, molluscs, echinoderms, and the group of organisms summarised as “others”. This pattern is less pronounced for cnidarians and fish but still visible when considering the standard errors of the organism counts. The highest mean number of crustacean taxa occurs at sites with solid rhodoliths, followed by sites with hollow rhodoliths. The overall frequency of the taxonomic groups resembles the biodiversity pattern calculated for the three (NR, SR, HR) environmental settings.

Bottom Line: In the examined shelf areas, biodiversity in rhodolith-bearing habitats is significantly greater than in habitats without rhodoliths and hollow rhodoliths yield a greater biodiversity than solid ones.This biodiversity, however, is threatened because hollow rhodoliths take a long time to form and are susceptible to global change and anthropogenic impacts such as trawl net fisheries that can destroy hollow rhodoliths.Rhodoliths and other forms of coralline red algae play a key role in a plurality of environments and need improved management and protection plans.

View Article: PubMed Central - PubMed

Affiliation: GeoZentrum Nordbayern, Section Palaeontology, Erlangen, Germany.

ABSTRACT
Rhodoliths are coralline red algal assemblages that commonly occur in marine habitats from the tropics to polar latitudes. They form rigid structures of high-magnesium calcite and have a good fossil record. Here I show that rhodoliths are ecosystem engineers in a high Arctic environment that increase local biodiversity by providing habitat. Gouged by boring mussels, originally solid rhodoliths become hollow ecospheres intensely colonised by benthic organisms. In the examined shelf areas, biodiversity in rhodolith-bearing habitats is significantly greater than in habitats without rhodoliths and hollow rhodoliths yield a greater biodiversity than solid ones. This biodiversity, however, is threatened because hollow rhodoliths take a long time to form and are susceptible to global change and anthropogenic impacts such as trawl net fisheries that can destroy hollow rhodoliths. Rhodoliths and other forms of coralline red algae play a key role in a plurality of environments and need improved management and protection plans.

Show MeSH
Related in: MedlinePlus