Calcareous Algae. Report on the Danish Oceanographical Expeditions 1908-10 to the Mediterranean and adjacent seas

Study Extent

Rhodophyta samples were collected during the 1908-9 and 1910 expeditions of Thor vessel from a wide geographical (from the Aegean Sea to the eastern Atlantic Ocean) and bathymetric range (3-98 m).

Sampling

Sampling gear used for the collection or rhodophytes is not clarified in the respective paper by Lemoine (1915). A thorough examination of the different types of sampling gear used in the 16 stations, where calcareous algae were sampled from, suggests that they were collected using dredges (e.g. D1: dredge with rectangular opening of 27 x 117 cm; D2: dredge with triangular opening of 45 x 45cm; and hand-dredge of 18 x 14 cm) and also possibly trawls (e.g. Y200: young-fish trawl, 200 cm in diameter at opening and/or Monaco trawl, 56 x 170 cm at opening). In the introductory paper by Schmidt (1912) it is mentioned in page 12 that “When at anchor the motorboat of the “Thor” was often used for fishing in shallow water, for example, with the same dredges as used from the ship and with small hand-dredges intended for the collection of marine algae” supporting that the hand-dredges were also used in certain cases. However, given that different types of sampling gear were deployed in all stations, it is quite probable that samples were mostly collected on an opportunistic basis with complementary sampling methods.

Quality Control

The dataset was digitized manually from scanned documents. Original names regarding taxonomy and sampling location were kept as a reference. At the same time taxon names were cross-checked against the World Register of Marine Species (WoRMS); while the original sampling coordinates were plotted using Google Earth in order to double check that they are located in the sea. All data were checked for inconsistencies, both for the range of values, but also compared to other datasets from the same series, collected at the same station. Any problematic records were recorded in a remarks field in the data.

Method steps

1. Data were digitized by hand, then quality controlled, and published through the MedOBIS IPT installation.

The dataset includes 59 records of Rhodophyta (Corallinales and Peyssonneliales).

1. Rhodophyta
   rank: phylum
2. Corallinales
   rank: order
3. Peyssonneliales
   rank: order

Mediterranean Sea and eastern Atlantic Ocean