Marine Macroalgae collection dataset from Herbarium João de Carvalho e Vasconcellos (LISI)

Study Extent

Before the start of the current digitization project, the most recent vouchers dated back to 1983. Consequently, a new field sampling campaign was mandatory to update the collection and minimize the temporal gap. Samples were collected during the summer of 2020 and 2021. A total of 16 locations representative of Portugal’s coastline previously sampled between 1880s and 1983 by several collectors were chosen to be revisited and sampled.

Sampling

For the recent survey, in each location, the coastal section from the splash fringe level in the high intertidal to the low fringe level at the low intertidal was extensively surveyed for algae by a three-people team, working during a two-hour period (from one hour before the low tide peak to one hour after low tide).

Method steps

1. Collectors’ biographic research and historical background - following compiling all the material related to mainland Portugal marine macroalgae, collectors’ names and biography were traced to identify the Collection’s history, as well as to understand Collection increment throughout the school’s different periods. Finding all existing documentation associated to this Collection would also increase its understanding, namely on sampling methodology and policy. The performed biographic research was mainly obtained through oral and written testimonies by researchers who contributed during their careers back in 1960’s, as well with paper publications findings related to the different sub-collections on LISI archives. To all contributors we extend our deepest gratitude.
2. Historical specimens’ taxonomic revision - considering the previously existing material, a relatively high percentage of the material was unidentified, had outdated taxonomic ranks (that is, with no meaning or synonym to today’s taxonomic scheme), or had incomplete information regarding the taxonomic status and/or recollection site. In a first stage, taxonomic revision and identification began by using reliable identification guides and keys for morphological and histological identification for Portugal, Iberian, or northern Atlantic regions, such as Pereira (2020); Hiscock (1979; 1986); and Dickinson (1963). During the last years, numerous changes in species taxonomic status have been made given the incorporation of molecular methodologies, and made available through the public repository AlgaeBase (www.algaebase.org), thus the work of Guiry & Guiry (2021) was instrumental in finding the latest accepted taxon names, regarding the different specimens (including those collected in 2020 and 2021). For several genera, due to different reasons such as lack of information on the voucher and/or bad conservation status of the material, specific literature had to be analysed to insure a correct identification.
3. In-situ sampling methodology - in each location, the coastal section from the splash fringe level in the high intertidal to the low fringe level at the low intertidal was extensively surveyed for algae by a three-people team, working during a two-hour period (from one hour before the low tide peak to one hour after low tide). The collected specimens were cleaned from debris and other organisms on seawater and stored in clean plastic boxes with no water. Upon the team’s return, the samples were placed in a dark, cold place to await the corresponding identification and pressing procedures. Concomitantly a minute part of each specimen was separated to dry in a silica-gel bag for DNA extraction (High-purity grade (Davisil Grade 12), pore size 22 Å, 28-200 mesh). It is expected that the work of DNA barcode for some of these specimens, in progress, may confirm or reveal some of the determinations.

Macroalgae, identified to genus or species rank.

1. Plantae
   rank: kingdom
2. Chromista
   rank: kingdom
3. Rhodophyta
   rank: phylum
4. Ochrophyta
   rank: phylum
5. Chlorophyta
   rank: phylum

Before the start of the current digitization project, the most recent vouchers dated back to 1983. Consequently, a new field sampling campaign was mandatory to update the collection and minimize the temporal gap. Samples were collected during the summer of 2020 and 2021. A total of 16 locations representative of Portugal’s coastline previously sampled between 1880s and 1983 by several collectors were chosen to be revisited and sampled.