Characterization of Zostera marina meadows in the Artabro Gulf (NW Iberian Peninsula).
-
1
University of A Coruña, BioCost Research Group, Spain
Zostera marina is the most widely distributed seagrass, which dominates the northern temperate region. In the Atlantic Iberian Peninsula, Zostera marina is common in wave-protected areas, including a few locations in Portugal and the Cantabrian coast. By contrast, it is much more abundant in Galicia where the convoluted shoreline, with numerous rias, provide large extensions of habitat suitable for eelgrasses. Nevertheless, the knowledge of the distribution, extension and biology of Galician seagrass beds is variable and dispersed, because it comes from works focused in specific geographical areas and/or particular components of the community. The loss or reduction of many meadows along its range in relation to anthropogenic impacts has been documented in several studies. This means that many meadows of Z. marina may disappear and remain anonymous due to lack of knowledge. Therefore, the need for improve global knowledge of seagrass beds has increased in recent years. The main objective of this work is to characterize the Zostera marina meadows in the Artabro gulf (NW Iberian Peninsula). The specific aims are: 1) constructing a map showing the distribution and extension of Z. marina meadows, 2) estimating the characteristics of seagrasses (abundance, length and width) and 3) studying the algal diversity associated with meadows. The present study is part of an extensive Galician survey of Zostera marina meadows.
The study was conducted between April-July 2014 in the Artabro Gulf, located in the northwestern Iberian Peninsula. This Gulf is formed by 3 rias (A Coruña, Ares and Ferrol) and extends approximately 1500 km2. This area was surveyed with the aim to detect Z. marina meadows. Once detected, the extension of eelgrass meadows was delimited by transects and GPS points. Furthermore, transects about 20-50 m length (depending on the extension of seagrass beds) were established in each meadow. Five sampling quadrats of 0,25 m2 were randomly positioned along the transect to estimate visually Z. marina cover, as well as the cover of the macroalgal species living in the beds. Z. marina density was estimated counting the number of Z. marina shoots in a quadrat of 0,0625 m2, placed inside each quadrat used to estimate cover. Ten plants were collected in each quadrat to estimate the length and width of leaves, as well as, to determine the reproductive status in the laboratory. Samples were preserved in 4% formalin in seawater at 4ºC and stored in the dark for later study. Data were analyzed using univariate and multivariate PERMANOVA.
SIMPER analysis was performed to determine the species responsible of the differences among groups detected by PERMANOVA.
A distribution map of Zostera marina meadows was constructed using 800 GPS sampling points, of which more than 50% had Z. marina. Five and six eelgrass meadows were detected in Ares and Ferrol rias, respectively. Extension of eelgrass beds was variable with larger meadows in Redes (Ares ria) and Caballitos (Ferrol ria), in contrast to small extensions found in Sada (Ares ria) and Cariño (Ferrol ria). Mixed meadows of Z. marina and Z. noltii were found in Sada and Ares, two sites influenced by an input of los salinity water.
Cover (47.70 ± 20.43; mean ± SD, n=50) and density (8.32 ± 3.66; mean ± SD, n=50) of Z. marina were similar between rias. By contrast, cover and density differed among sites.
Regarding biometry of Z. marina, length of leaves did not differ between rias (46.04 cm ± 14.92; mean ± SD, n=500), whereas plants were significantly wider in Ferrol ria (6.78 mm ± 1.06, n=250) regarding Ares ria (5.77 mm ± 0.90, n=250). Furthermore, significant diferentes were detected among sites and quadrats for both variables. Interestingly, plants with spathes were collected between April-June in various sites from both rias.
In total, 132 macroalgal species were recorded in Zostera marina meadows. The commonest species were the green algae Ulva australis and Ulva rigida, and the red algae Ceramium secundatum and Gracilaria gracilis. Multivariate PERMANOVA detected significant differences among both, rias and sites. SIMPER analysis showed that ten taxa accounted for most of differentiation between rias. Among them, eight are ephemeral species. Furthermore, we observed high abundances of several non-native species that we consider invasive in Z. marina meadows of the study area (Bonnemaisonia hamifera, Dasysiphonia japonica, U. australis).
Keywords:
Zostera marina,
Macroalgal assemblages,
Iberian Peninsula,
Biodiversity,
Seagrasses
Conference:
XIX Iberian Symposium on Marine Biology Studies, Porto, Portugal, 5 Sep - 9 Sep, 2016.
Presentation Type:
Poster Presentation
Topic:
1. ECOLOGY, BIODIVERSITY AND VULNERABLE ECOSYSTEMS
Citation:
García-Redondo
V,
Díaz-Tapia
P and
Bárbara
I
(2016). Characterization of Zostera marina meadows in the Artabro Gulf (NW Iberian Peninsula)..
Front. Mar. Sci.
Conference Abstract:
XIX Iberian Symposium on Marine Biology Studies.
doi: 10.3389/conf.FMARS.2016.05.00173
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
27 Apr 2016;
Published Online:
03 Sep 2016.
*
Correspondence:
PhD. Verónica García-Redondo, University of A Coruña, BioCost Research Group, A Coruña, A Coruña, 15071, Spain, v.garciar@udc.es