Survey results of white (Carcharodon carcharias) and sevengill sharks (Notorynchus cepedianus) at Seal Island in False Bay, South Africa between 2000 and 2018

This dataset is associated to the article “Disappearance of white sharks leads to the novel emergence of an allopatric apex predator, the sevengill shark” by Hammerschlag et al. (2018), published in Nature Scientific Reports, https://doi.org/10.1038/s41598-018-37576-6. Specifically, these are the data used to create figures 3,4, and 5 as well as supplementary figures S1, S2, and S3. These data are the results of monitoring between 2000 and 2018 of white shark (Carcharodon carcharias) abundance patterns (N=6,333 shark sightings) and predatory activity (N=8,076 attacks on seals) at Seal Island, a Cape fur seal (Arctocephalus pusillus pusillus) colony in False Bay, South Africa. All data are based on standardized boat-based observations. Over the 18-year study, declines in white shark abundance and attack rates were documented between 2015-2018, with anomalous lows occurring in 2017 and 2018. This included prolonged periods of white shark absence from Seal Island. The disappearance of white sharks from Seal Island coincided with the appearance of sevengill sharks (Notorynchus cepedianus; N=120 sightings), an otherwise allopatric kelp-associated apex predator in False Bay. These data provide empirical evidence for behavioral shifts in sevengill sharks following the decline and disappearance of white sharks from a foraging site.