Along the South African coast, a surprising predator dynamic has emerged. Two killer whales, locally known by names that echo through the scientific community, appear to have made sharks a central focus of their hunting. In recent weeks, roughly twenty hollow shark carcasses have been found buried in sand along the shore, signaling a relentless predation pattern that is reshaping coastal ecosystems. Researchers have focused on two individuals whose attacks show a precision that reads almost surgical, hinting at complex learned behavior and shifting predator roles in the region.
Ralph Watson, a marine biologist aged 33 working with a non-governmental organization dedicated to marine life, documented the count at the end of February. Twenty sharks had been torn apart, with nineteen showing the flat-nosed anatomy typical of the prey. Local residents alerted authorities and scientists when they encountered the grisly findings along the coastline.
The two main predators, dubbed Port and Starboard, or in local terms Babor and Estrbor, were spotted a few days ago off the coast near Gansbaai, a small fishing town about 160 kilometers east of Cape Town. This slaughter marks another chapter in a series of attacks attributed to the duo, recognizable by their curved dorsal fins and distinctive behaviors that have drawn the attention of researchers for years.
Alison Towner, a shark expert with the Dyer Island Conservation Trust, participated in autopsies on the sharks. All specimens bore scratch marks on the pectoral fins consistent with killer whale bites, and several showed liver loss, a sign of selective predation. The findings, shared with the press, have intensified questions about the orcas’ feeding strategies and their impact on local ecosystems.
For the first time, researchers note that these two orcas hunt this particular shark species in this area, a shift from their previously observed prey. The predators have already affected the region for years, contributing to changes in how great white sharks use coastal spaces near Cape Town as some areas become less hospitable due to predation pressure.
The term surgical technique has been used to describe the observed method of attack. Port and Starboard reached Cape Town’s vicinity in 2015 and initially preyed on flat-nosed sharks. By 2017 they expanded their repertoire to include great white sharks, signaling a notable adaptation in their feeding behavior.
Researchers describe the method as methodical and highly coordinated. The orcas are seen tearing open the prey’s chest to reach the liver, an organ rich in lipids and a vital nutrient source for predators. Dramatic aerial imagery released by scientists in 2022 captured the pair circling a great white and engaging in blood-, organ-, and nutrient-focused predation, illustrating a level of predation that astonished observers of marine mammal behavior.
Experts emphasize that this behavior is unusual for orcas in these waters, where dolphins are typically the preferred prey. Early observations suggest Port and Starboard may originate from regions such as West or East Africa or the Southern Ocean, underscoring the mobility of these apex predators. The possibility of cultural transmission of hunting techniques among intelligent animals remains a concern for the scientific community, highlighting the need for ongoing monitoring of behavioral shifts in wild populations.
Unlike many of their peers who roam the open ocean, these two orcas show strong coastal tendencies. Sightings extend from Namibia to the Port Elizabeth area, roughly eight hundred kilometers east of Cape Town, underscoring their willingness to exploit nearshore resources and to venture closer to human activity along popular beaches and fishing grounds.
Experts stress that while the predation by Port and Starboard is alarming, it currently appears limited in scope relative to the vast annual global catch of sharks. Still, observers note the frustration of watching an endangered species engage with another threatened species. The dynamics raise questions about potential long-term effects on shark populations and the broader balance of coastal ecosystems in the region.
Researchers caution that two individual orcas are unlikely to wipe out an entire species, but their actions could influence local dynamics, including prey availability and interspecific interactions. The coastal predation adds a new layer to the already complex picture of apex predators in South African waters and invites renewed attention to the ecological implications of shifting hunting strategies among intelligent marine mammals.
Ongoing inquiries and monitoring efforts continue as scientists seek to understand whether these behaviors will persist and what they might portend for other predator-prey relationships along the southern African coastline. The mystery of Port and Starboard remains a focal point for researchers, wildlife managers, and conservationists alike as they work to balance the needs of endangered species with the realities of changing marine ecosystems.
Notes for context: the region’s marine research community continues to document unusual predation patterns as part of broader efforts to map how large predators adapt to evolving ecosystems and human pressures along the coast.