Since whales were deified (some areas called them Ebisu, viewing them as incarnation of 'Ebisu'), it was also a mound to enshrine them so that they did not become Araburu Kami (Malignant gods) due to their losing their lives accidentally, or from whaling.
鯨を神格化して捉えていたので（「恵比寿」の化身としてエビスとも呼んでいた地域も存在する）偶然または、捕鯨により命が奪われた事で荒ぶる神にならぬ様祀った塚でもある。