Basking sharks- heading towards extinction in New Zealand’s waters
09 May 2011
The basking shark is the second largest fish in the world, reaching a size of up to 12 metres. These spectacular sharks have declined rapidly in New Zealand’s waters in the last 20 years. There are now serious concerns about the conservation of basking sharks in New Zealand.
While schools of basking sharks were sighted frequently in Canterbury’s inshore waters up until the mid- 1990’s, few sharks have been seen in recent years. The Department of Conservation is keen to place satellite transmitters on basking sharks, yet despite trying hard to locate sharks, they have failed to do so for several years now. DOC is urgently asking fisherman and members of public to report basking shark sightings, real time, so that satellite transmitters can be placed on them so we can learn more about this enigmatic species.
Basking sharks often come close inshore over the spring and summer months. They are at risk from entanglement in set nets and cray-pot ropes. Each year basking sharks are also taken as by catch by trawlers. Often destroying the net due to their large size. Yet the sharks are valuable and the livers and fins from an individual shark may reach $10, 000. The species is monitored by the international conservation groups. Basking sharks may also be at risk from increasing amounts of plastic pollution as they are a plankton feeding species. Basking sharks are also preyed upon by Orca. In 2009 DOC processed requests for the export of basking shark fins from about seven fish
In anyone sees a basking shark they are encouraged to report it to their nearest Department of Conservation Office as soon as possible. The satellite tracking project is being funded by National Geographic. Hopefully some sharks will be found to tag. Basking sharks are recognised by their large black triangular fin and habit of swimming slowly on the surface- hence their name. The shark’s body appears quite black from a distance, but at closer range is a blackish- brown mottle. It is ultimately the basking sharks large size that distinguishes them from most other shark species. It would be a pity to lose this giant of our ocean realm.
Sunday, May 8, 2011
Tuesday, April 19, 2011
Monday, April 18, 2011
Rock wren have small and fragmented residual populations in Canterbury. Available data suggests that their have been recent declines in the numbers of this bird. There are no dedicated predator trapping programs in Canterbury, to my knowledge to protect this iconic bird of our alpine environments. Sadly the rock wren's close relative , the bush wren became extinct in the mid 1960's- are rock wrens heading down the some track in Canterbury ?
Sunday, April 10, 2011
Discarded lines and lures kill birds
11 April 2011
Recently I was sent some photographs of a oystercatcher which had eaten a string of soft baits which imitates the birds prey of shrimps. Sadly the bird died. It is important that all anglers take care not to leave behind or discard any fishing gear such as traces with soft baits or fishing lines.
According to Rosemary Tully of Whakatane Bird Rescue “many seabirds and others get caught not only in bait and hooks but the lines wrapping around the legs and wings etc. Shags, Gulls, Penguins, Gannets, and Oyster-catchers have all come into care (some dead) with these problems. “
As more and more people use our coastlines for fishing and recreation there is an increasing amount of pressure on our marine and coastal birds. As anglers much of the experience of heading out fishing is about the wildlife, scenery and catching fish. So take care out there with your fishing gear so that we can conserve the wildlife along our coastlines. Always collect all fishing gear at the end of the day. If anyone finds any birds or wildlife entangled with fishing gear phone the DOC hotline- 0800 362 468 and hopefully an attempt will be made to get the bird to a nearby rescue centre.
It is testament of just how natural and effective that soft baits imitate the real prey that birds will consume them. Birds have much sharper eyesight and are more discerning overall than fish.
Anglers can do their part by picking up discarded fishing line they find on a beach, such as bungles of nylon, which are often deadly to birds. Sadly in addition to recreational anglers, the entanglement of rare seabirds by commercial fishing gear remains a major problem.
Photograph- shows a rare variable oystercatcher at Maketu Spit, with a national population of only several thousand birds, lethally caught in a string of soft baits. (Photo by Julian Fitter).
Thursday, April 7, 2011
Blue times for blue ducks in Canterbury
6 April 2011
A survey in February this year found an alarmingly low number of blue ducks ( Whio) in Arthur’s Pass National Park. The survey was very comprehensive throughout Arthurs Pass involving helicopters for access and also the use of tracking dogs to find birds that may have been concealed along the river margins during the survey. Over several days three survey teams only found six birds.
With the Arthur’s Pass population of blue ducks being so small the regional population is now under threat. Within Canterbury only the odd individual blue duck is found outside Arthurs Pass and outside of the park there are no other known viable breeding populations in Canterbury. The hope is now, and it is at the eleventh hour, that the population will slowly recover in response to predator trapping that has been taking place along the rivers in Arthurs Pass for blue ducks in since 2004.
Blue ducks used to be common in Canterbury, even being on the Avon River- but like many native birds have retreated in their range to higher altitude and remote locations. There were about 50 blue ducks remaining in Canterbury in the early 1980s but since then the population has continued to decline with a corresponding contraction in the bird’s range. Sadly nowadays these populations are being hit by stoats. Without a doubt now it is known that blue duck populations will not survive in the wild unless predator trapping takes place along river margins.
Blue ducks only nationally number about 3000 and the species is considered nationally vulnerable by DOC. The department’s Waimakariri Office is always keen to hear of any sightings of blue ducks from trampers especially in the Canterbury Region and any breeding records any sightings of blue ducks with ducklings would be very significant.
Predator trapping to protect blue ducks specifically is a recent development in Arthurs Pass and has been funded by sponsorship from the Coast to Coast and other sources. Yet the trapping is relatively recent and may need refining as it has been shown in many other areas in New Zealand such as Fiordland and on the West Coast that blue duck’s breeding productivity, and survivorship, increases dramatically after stoat trapping takes place. Stoats are recognised as being the number one predator of eggs, chicks and even on occasions adults. That there are a few isolated blue ducks in other parts of Canterbury may be due to the fact that blue ducks are relatively long-lived ducks with records of birds living over 13 years of age.
For many whom venture into the outdoors the blue duck is a symbol of our remoter wilderness waterways. I hope that we can keep this iconic bird in the wild Canterbury. Our wilderness rivers will see very empty without them !
Sunday, February 27, 2011
Kea - The world’s most intelligent bird and the bird that flies closest to the stars.
C. Peter Langlands
Keas are nothing less than a joy to encounter. For me they are always the highlight when passing through any of our major alpine passes, and are like visiting a long lost friend. Our kea is perhaps the worlds’ most intelligent bird and I have to wonder when I watch them, are they are watching me back just as intensely. Maybe waiting for me to walk just far enough from my car so that they can have a good chew on the rubber around my cars’ window ?
Recently while at the Homer Tunnel I walked up from the car park , to view an array of alpine plants, and looking down on the car park all the keas seemed to have miraculously disappeared. Then I looked at my car, with a sea kayak on it, in the corner of the car park, and then I noticed, with a mild level of shock, all the keas perched on the edge of my cockpit having a good chew. Fortunately I got back down to my car before they hit the bungy chords, which would have been a mess. Oddly they liked chewing on the hard rim, perhaps sharpening their beaks on the entrée before the main course !
Of course we may have simply mistaken the kea’s apparently mischievous nature for just a general sense of curiosity. Living in an alpine environment keas have to be naturally curious to survive, and in many areas have become opportunistic, feeding in a range of seasonally available foods. Indeed it is the keas ability to quickly learn new behaviours that has also got them into to trouble.
While farmers have rumoured, for over a hundred years, that certain rouge kea will hop onto the backs of sheep and peck away at the live animal, aiming for it’s kidney, and often causing blood poisoning, this fact has only been proved in recent decades. Night viewing gear has allowed cameramen to document these attacks, in which only a small number of birds participate. The “bikey” gang of the kea clan. Under special permit these rogue bird have been shot , before the behaviour spreads amongst the other birds.
Fortunately today keas are fully protected. This is only a recent development and up until the mid- 1980’s keas were regularly shot by high country merino sheep farmers. Earlier in the centaury keas had a bounty on them ! Farmers used to use calling birds in cages next to the farm homestead, to bring the birds down from the mountain slopes, where they could be shot with relative ease. In other cases beer bottles were smashed on the mountainside side and the inquisitive keas would come down to investigate the shiny glass, and were shot. Historically the green and orange feathers of the kea were also used for trout flies. A practice that has since ceased.
Today probably only around 5000 keas survive, so we can not be complacent about their survival. They are long-lived birds and breed at a slow rate. It is easy to get an inflated idea of how many keas there are, as they are very gregarious around spots where people stop , hoping to scavenge some food scraps, or when flying through valleys, call loudly over several kilometres, highlighting their presence.
For me seeing, or more often, hearing keas, is a defining part of the alpine experience in the South Island’s high country. In some areas, such as Fiordland, the keas will come down to sea level. Where earlier this year another mob ( from the Homer Tunnel birds) accosted my sea -kayak !. The kea’s close relative, the kaka, is critically endangered. Kakas are also very intelligent, but for survival in alpine environments, where the ability to learn quick to survive, the kea is king.
Monday, February 7, 2011
"just had a call from the kea conservation trust yesterday. There has been an 80% reduction in their numbers in Nelson Lakes and other areas due to predation and lead poisoning. I am sending them cards for sale to support their work. Visit keaconservation.co.nz"
( from Pauline Morse 08/02/11)
( from Pauline Morse 08/02/11)