Sharks in the city: Getting to know the neighbours

A White Shark feeds on a whale carcass off a Perth metropolitan beach in 2009. This was happening before Homo Sapiens existed. AAP/Channel10

The vast majority of Australians live in coastal cities. This means most of us have sharks as neighbours.

Living alongside sharks in metropolitan cities in Australia requires urban resilience. Unlike birds, deer, rats or other land-animals sharks often “live” somewhere else, but visit coastal cities in Australia to enjoy the warmer water at the same time of the year that we do. Since there is no feasible way to relocate sharks, unlike bats for instance, adapting to sharks in the city means focusing on public awareness and prevention.

During the summer, shark numbers increase in the inner-most city centers along the Brisbane River, Gold Coast canals, Paramatta River, and Sydney Harbour. The takeaway in living next door to sharks; however, is not that they are there; it is that they ignore us so often.

No news is good news

Being ignored by sharks does not usually make the news. When there are shark bites these are generally front page stories and can be incredibly tragic. But reports are often unable to give the entire context. Part of a larger snapshot would note how many Australians live near the coast and how many sharks go out of their way to avoid us in the water. There are two illustrations of this. First, the numbers: “more than 8 in 10 Australians (85%) lived within 50 kilometres of the coastline,” and 65% live in “major urban centres.” In addition, the number of Australians moving to coastal areas between 1996 and 2004 was 12 times higher than the national average. This all adds up to a lot more people in the water and more development of coastal urban areas.

We only notice shark attacks because they are so rare. AAP

Second, sharks do swim away. On Australia Day 2011, as hundreds of bathers competed in the Harbour Swim, two tagged bull sharks also swam in the Sydney Harbour region. In total, seven mature male bull sharks were in vicinity.

This story repeats itself in Port Stephens, where juvenile great white sharks have been tagged and the tracking shows them staying behind the surf zone, and further afield in Cape Town South Africa, Shark Spotters have had over 1,000 white shark sightings, signaled the public and watched the sharks swim away.

Yet even as unlikely and infrequent as shark bites are, there is a natural tension on the use of ocean beaches, rivers, estuaries and harbours. Being aware of the shared waterways is important and recognizing the impact that human behavior or development can have on sharks is key.

Being good neighbours

Some rules for living next door to sharks include the following: first, do not take away their food. Over-fishing or building on areas that diminish the coastal habitats where sharks find fish can alter patters and bring sharks into areas where people are.

Second, what we dispose of in the water can attract sharks or the fish that sharks hunt. Sewage outfalls and abattoirs can put waste near metropolitan beaches and attract marine life that sharks eat.

Third, being a good neighbor means paying attention to personal behavior. Avoiding times in the water when we know bull sharks tend to be more likely, such as dawn or dusk, is helpful as is awareness of water temperature. Bull sharks like warm, cloudy water so being aware of how warm and murky the water is can be key.

A learning process

As a people we are still learning how to live along the coast, with the animals that already live there. In the past, sharks were seen as an urban blight. In the 1960’s, Japanese shark finners were hired to fish and fin sharks near Sydney’s beaches. Today, healthy harbours and estuaries mean more people want to live near them and more baitfish in the water. It does mean that more awareness is needed but it also means that sharks avoid more people, more often.

Prevention education in urban settings acknowledges that these areas are active ecosystems. Tagging and tracking is now part of beach safety in Queensland, New South Wales, Western Australia, and South Australia and through research at CSIRO. The next step is community engagement to make sure we understand what impact we have on shark numbers and movements.

Sharks in the city is not a simple story, but with a bit of caution and effort we are capable of being more resilient when we understand our neighbours better.