MEL: Marine cladocera collected from St. Margarets Bay between May to November, 1967-1969

Study Extent

Two sampling stations were used, Station A and Hubbards Cove. The latter has a depth of 15m is a more sheltered station than that of Station A where the depth was 50m. Hydrographic conditions at the two stations were essentially the same. During the 1967 sampling period samples were collected from both stations. In 1968 and 1969 only Station A was sampled. In 1967 and 1968 all tows were made in duplicate, one in a northerly direction, the other in a southerly direction. In 1969 only single tows were made.

Sampling

During the season of their occurrence, (May to October), the animals were sampled once a week. A Clarke-Bumpus net, 12.5 cm in diameter, with mesh-size 153u, was used. Horizontal tows of 10 minute duration (speed ~2 knots) were made at fixed depths. The volume of water filtered was from 1 to 20 m3 , depending on conditions. Depth of towing was verified by a Benthos depth recorder attached to the wire below the net. Sampling depths were as follows: Station A: 1967 (1,5,10,20,45m); 1968 (1,5,10,15,20m); 1969 (1,5,10,20m) and Hubbards Cove 1967 (1,5,10m). During most of the sampling the mouth of the net was fitted with a screen to exclude ctenophores, which are abundant in St. Margaret's Bay from the samples. Samples were preserved in 5% formalin. Samples were counted using a compound microscope at 100x total magnification and a Sedgwick-Rafter cell (minus coverglass).

Quality Control

Scientific names associated with resource occurrence records have been mapped to recognized standards - marine taxa have been mapped to the World Register of Marine Species (WoRMS). The WoRMS codes, the AphiaIDs have been included as LSIDs in the occurrence record DwC field scientificNameID. Sample locations were plotted to confirm points located within the defined study area. Location place names are standardized to entries in the Canadian Geonames database and the CGNDB identifiers have been included as LocationIDs in the DwC record.

Method steps

1. This resource was created by OBIS Canada and is a republishing of species occurrence records contained in source data report (Platt 1977)
2. The October 2018 version of this resource contained refreshed metadata information and many additional DwC terms were added to the occurrence file. The resource data records and metadata were revised again in October 2020.

Cladocera

1. Evadne nordmanni
   rank: species
2. Evadne spinifera
   rank: species
3. Podon intermedius
   rank: species
4. Podon leuckartii
   rank: species
5. Podon polyphemoides
   rank: species

Hubbards Cove and St. Margaret's Bay, Nova Scotia, Canada