Benthic Intertidal Vegetation from the Tagus Estuary and Aveiro Lagoon

Study Extent

Sampling was carried out across intertidal areas during low tide.

Sampling

Quadrats (0.25 m2) placed on benthic intertidal vegetation were photographed and images were loaded into ImageJ software. Polygons were drawn around visible extent of vegetation types, which allowed the percentage cover of each species or genus per quadrat to be calculated.

Quality Control

Images were analysed consistently, with 10% of images being checked by expert commentators. The dataset was adjusted to the Darwin Core specifications (Wieczorek et al. 2012) in order to be published in the GBIF network.

Method steps

1. Quadrat Photographed alongside taking dGPS location (Trimble Geo 7).

The seagrass tracheophyta (Zostera noltei), the macroalgae ochrophyta Fucus vesiculosus and the rhodophyta Agarophyton vermiculophyllum were ranked to species level, while the chlorophytes Ulva sp. and Chaetomorpha sp. were ranked at the genus level. Nomenclature follows WoRMs (https://www.marinespecies.org).

1. Magnoliopsida
   common name: Angiosperms/Seagrasses rank: class
2. Phaeophyceae
   common name: Brown Algae rank: class
3. Ulvophyceae
   common name: Green Algae rank: class
4. Florideophyceae
   common name: Red Algae rank: class

Atlantic Coast of Portugal. The Tagus Estuary, found on the Western Portuguese Coast, is the mouth of the longest river in the Iberian peninsula. The Estuary is protected by the Tagus Es-tuary Nature Reserve as an IUCN category IV habitat and species management area. Ria de Aveiro is a shallow coastal lagoon located on the North West coast of Portugal. The only connection to the Atlantic Ocean is through a narrow channel 1.3 km in length, 350 m wide and 20 m deep. Ria de Aveiro is a Long-Term Socio-Ecological Research (LTsER) platform (https://www.lterportugal.pt/riadeaveiro) with several important habitats, it is included in the Nature 2000 network and is classified as a Special Protection Area containing Sites of Com-munity Importance.