Category: High risk
MOST whaler sharks are referred to as bronze whalers by anglers, when in fact they may well be related species such as dusky sharks (black whalers) or even thickskin (sandbar) sharks, all being quite similar in appearance.
Small whaler sharks are encountered in your local fish and chip shop where they make up the ‘flake’ portion of the menu – and very nice they are too. However, because of the high mercury content frequently found in large sharks, commercial operators are restricted to selling sharks that have a carcass weight not exceeding 18 kilos (approximately 120cm long). This maximum size limit should be a good guide for anglers who wish to keep a bronze whaler for the table.
At times bronze whalers can be absolute pests, knocking off fine table fish as they are brought up from the bottom on a line. For this they are frequently cursed and rapped on the nose, but they should not be killed, for like just about all sharks they are threatened by over-exploitation (see Threats below).
The best response to the arrival of the men in brown overcoats is to move at least several hundred metres, preferably even farther.
When hooked bronzies, as they are most frequently called, provide a good account of themselves. Indeed many years ago I used to target sharks out wide behind Rottnest Island and bronzies put up the best fight of all the sharks, with the notable exception of the shortfin mako.
I still vividly recall a spearfishing trip, out from Cervantes, when I got my first real good look at a big fat female bronzie right at the edge of my peripheral vision. She simply followed an equilateral triangular pattern around me, refusing to come in and pick up the berley we had in the water. I was absolutely mesmerised by the proportion of the shark and the ease and grace with which she moved – a memorable sight indeed.
I should point out that bronzies are known to attack humans: mostly spearfishermen it would appear…
Bronzies can be distinguished from dusky sharks by their narrower upper teeth and the absence of a low but obvious ridge running along the back between the two dorsal fins. A thickskin shark can be identified from its noticeably higher first dorsal fin.
Bronzies range in colour from a dark, almost golden, brown through to a dull grey on the back and sides with a white belly.
The Game Fishing Association of Australia records the largest bronze whaler caught in Australia as a very respectable 378 kilos, and it was taken at Port Stephens in New South Wales. But most whalers encountered by anglers in WA are under 100 kilos in weight.
Bronzies are found in temperate waters and are encountered along the south coast of WA up as far as Jurien Bay.
Juvenile bronzies are more common on the south coast (east of Windy Harbour) and it is mainly adults that are encountered off the west coast. The closely related dusky and sandbar shark populations are known to be highly segregated by size/age, with adults in the North-West, juveniles in the South-West. Bronzies may be similarly segregated over a more southerly range, that is to say juveniles in the South-East and adults in the South-West, as far north as Jurien Bay.
Bear in mind that in their range bronzies are much less abundant than dusky sharks in water out to the Continental Shelf.
Breeding and migration
Bronze whaler sharks are an inshore species that is viviparous, meaning females nourish embryos with placentae and give birth to live young. One litter will contain from 7-20 pups and newborn shark pups are typically 60-70cm long. Bronzies give birth year round, but there is a peak during the summer.
They feed on a range of pelagic and bottom bony fishes, cephalopods, smaller sharks, and rays. Packs of 20-30 adult bronzies have been observed feeding on schools of pilchards and Australian salmon off southern beaches in summer.
Tagged juvenile bronzies and sub-adults in southern WA have been captured from as far afield as St. Vincent Gulf and Kangaroo Island, so they definitely range into South Australia, where they appear to be the more abundant of the ‘bronze’ whaler species. Bronzies appear much less abundant than the dusky shark west of Windy Harbour, or even Bremer Bay.
Increasing captures in non-selective fisheries, such as longlines, are likely the biggest threat to this species. The practise of ‘finning’ has continued to put pressure on larger bronze whalers.
Many recreational anglers release sharks over 1.5 metres in length these days given the high mercury content in larger specimens. Indeed a 120cm maximum size may well end up being introduced to help protect breeding stocks.
This fact alone would contribute very positively to the conservation of these sharks in WA waters.
This species is slow to reproduce and that means they are vulnerable to over-fishing.
Tackle and bait
Some beach anglers enjoy tussling with bronzies, most of the larger specimens being easy to release off the beach. Bronzies are mostly targeted along our southern beaches, from Preston Beach, south of Mandurah, right the way around to the much calmer waters of Eucla near the WA/SA border.
Live baiting salmon is by far the most successful way of catching large bronzies from the beach, and it’s not uncommon for an angler to play one of these brutes for up to eight hours.
Obviously, heavy gear is needed and 37kg line would be a good starting point, with wire a necessity. A strong beach rod and a reel with plenty of line capacity, such as an Alvey or large overhead, are needed to subdue bronzies.
As you head north, sharks tend to be regarded as little more than pests, but casting a whole herring or large fillet of mullet will give you the best chance of hooking a bronzie from shore.
Few boat anglers target bronzies specifically and they are generally an incidental catch. They can at times be taken when drifting for swordfish or berleying for other species of fish. Standard 15kg and 24kg game fishing gear should do the job nicely. Baits can be a decent size fresh fish such as tuna, or a big squid rigged on a wire trace, the latter point being very important if you wish to land your quarry.
It’s a good idea to ensure that the hook point is clear of the bait when rigging big whole fish or fillets so that the hook can find an anchoring point rather than burying in the big bait.
If I set out to find a bronzie I would start a serious berley trail using fish offal, pilchards and tuna oil. I would set up two 24kg game outfits, one with a whole fish bait set at 20 metres on a balloon and a fillet bait set near the surface, again using a balloon. As when targeting other species I would keep a third outfit ready to go in the boat just in case I saw a bronzie in the berley trail that had swum past the baits.
Indeed, keeping a watchful eye on what appears in the berley trail is a good way to catch big sharks.
References: Sea Fishes of Southern Australia by Barry Hutchins and Roger Swainston.
Rory McAuley, Department of Fisheries, Research Branch.