Little Skate and Winter Skate Demographics in Minas Basin, Bay of Fundy, Nova Scotia

Little Skate (Raja erinacea) and Winter Skate (Raja ocellata) are significant contributors to the Bay of Fundy marine ecosystem as top-level scavengers, but are nearly morphologically identical. Little Skate are near threatened and Winter Skate endangered in coastal Nova Scotian waters, yet the assessments excluded skates located in the Minas Basin, Bay of Fundy, and species identification was suspect. Population demographics for both species is warranted to assist in species conservation. Skates were sampled and tagged at a commercial weir in Bramber, Nova Scotia from July – September 2012, and April – August 2013 over 111 tides. Sampling included length and width, weight, clasper length, and number of ocelli (Winter Skate only). Skates were tagged with individually-numbered dart tags for capture-mark-recapture analysis. Over the two years, 948 of 2,051 skates were tagged and 20 recaptures found. A preliminary population estimate was 42,471 (26,758 – 71,165) skates. A comparison of catch abundance to tidal cycle showed that skate catch increased at night and were highest during low-low tides. Sequencing of mtDNA cytochrome oxidase I genes was used for species identification. About 10% of skates captured were Little Skate. Further population demographics will be presented.