Nature's Indomitable Spirit: New Zealand wilding pines, a reminder about the will to survive

Was just finishing a short opinion piece by Brian Taylor for New Zealand's Otago Daily Times about how best to deal with the wilding pines that spread throughout both the north and south islands. Wilding pines, also referred to as wilding conifers, are invasive species of pine trees, the result of a combination of early settlers stripping indigenous scrubland for agriculture and cattle grazing which provided a fertile base for various imported pine tree species to explode across the valleys and hillsides.

With New Zealand spending millions of dollars annually to try to stem the tide of the ever-expanding wilding pines, Taylor was questioning the wisdom of current strategies. Yes, the pines are an invasive species that is altering the natural landscape and the result is both an economic and environmental threat, but it's a result due in part to man providing the trees with the initial foothold. Taylor questioned whether current land management use - grazing and burning techniques to maintain economically important grasslands - would forever be at odds with wilding pines and whether there could be other natural buffers developed to help manage the pines' growth and expansion, rather than the felling of mature trees and removal of seedlings which has not yielded hoped for results.

Interesting article but what caught my attention most of all was Taylor's description of nature's tenacity, as it is applicable to all environments - land or sea, plant or animal.

"Mother Nature can be a rather intractable old matriarch, and no matter how strenuously Man tries to thwart her advances, she will invariably be the clear winner in a marathon. After all, she has been around far longer than mankind and has not survived millions of years by simply taking a back seat when threatened. She is a formidable contestant, smart, very smart in fact, versatile, highly adaptable, and loves a challenge. When the chips are down, she will always be one jump ahead, ever ready to override our mistaken endeavours by taking control of regeneration her way.

She abhors nudity and will make sure that all of her domain remains well covered. There will be no bare spots for her, no sir. Pull out a weed and see what she does, she will plant another one straight back and will continue to do so as long as we constantly annoy her by perpetuating our misguided attempts at laying the ground bare."

Taylor is describing nature's will to survive. Despite all that can be heaped upon it, whether through natural occurrences or man-made interference, nature will do what it can, do whatever is necessary to carry on. It will adjust; it will adapt. But what we must keep in mind is that to evolve and continue its existence, nature can make some cold, harsh decisions - such as extinctions if that's what it takes. And that can involve the loss of the smallest insect all the way up to the largest mammals in the sea. And it can include us just as easily. For all our accomplishments and all our self-importance, if we push nature too far, it can shake us off like a bad case of fleas.

After pondering whether New Zealand could adopt land management policies that work with nature rather than continually fighting it, Taylor closes with a thoughtful reminder about ecological perspective - in whose playground we are briefly being allowed to roam.

"We live in a mere moment of time in the history of the planet. It has constantly evolved throughout the ages, and will continue to do so long after we have gone. We are able to exist on earth only because nature provides us with all our needs for survival. Yet in this modern world of rapidly diminishing forest cover, some are still prepared to promote the age-old slash and burn mentality - in this case, 'for the good of the view, rather than for the good of the planet'.

Maybe it is time we reconfigured our response strategies and embraced greater biodiversity, which is, after all, the key to a balanced and healthy ecosystem."

Here, here.

Source: Otago Daily Times

Orcas vs. Sharks: whales hunt deep sea sharks in New Zealand

Thought I would pass along this interesting blog post from marine biologist Candace Calloway Whiting, writing in the Seattle PI. She did some digging in regards to a recent event documented in New Zealand of pod of orcas corralling what appear to be some juvenile cowsharks (six- or seven-gill) in a sort of hunting/feeding technique.

Orcas have been known to prey upon sharks, but what makes this news item so noteworthy is that these New Zealand orcas were after deep water sharks and that they managed to bring them to the surface, disorienting the sharks which played to the orcas' advantage. It also appears that the orcas were able to capitalize on the fact that these sharks will stick together - brothers and sisters - which is not a common shark behavior.

Pod of Orcas Rounds Up a Group of Sharks - Were These Sharks Related to Each Other?

Update: 12/28/11 - In reply to my request to identify the shark species involved, Seattle Aquarium shark biologist Jeff Christiansen sent the following :

"It is difficult to make a definitive ID from a partial view and with only one photo but I would hazard a guess the shark in the photo is a sevengill shark Notorynchus cepedianus or possibly even Heptranchias perlo. While I can’t rule out a sixgill the spotting pattern visible on the dorsal surface of the shark is characteristic of the sevengill. The photo is not sharp enough to tell if there are six or seven gill slits. Its definitely one of the Cowsharks as the six and sevengill sharks are called and finding them in groups is not unusual for that species… pack hunting and association is documented in sevengills. The Sevengill can tolerate much higher light levels than its deep water cousin the sixgill."

I’ll update again when I hear back from a New Zealand orca researcher who may have more information on the orca pod that appeared to be hunting the sharks.

On Boxing Day (the day after Christmas) in New Zealand a pod of orcas managed to corral at least a half dozen sharks and apparently gave them a good thrashing in the shallows off the beach. Orcas are known to kill and eat sharks in many parts of their range – often eating the nutrient dense livers and discarding the rest – so although witnessing the interaction must have been amazing, the news that the whales went after the sharks was in and of itself not surprising.

But the fact that the orcas managed to get several sharks together in a group for the presumed mayhem is fairly astounding, and I was as curious about the sharks as I was the orcas as I read the article.

Copyright protection prohibits me from being able to use the photo of one of the sharks thought to have been involved in the altercation with the orcas, but it is similar to this one, and is one of the few species that is easily identified with just a head shot. If you look carefully you will see that the shark has six gills [note update above, this may have been a related species of cowshark, not a sixgill] instead of the usual five, and logically is called a six-gill shark (the sixth gill is thought to help extract oxygen from the deep water where the adult sharks are found).

The following video shows both the massive size this species can attain, and the depth to which it can be found. “This six-gill shark (Hexanchus) was filmed during a submersible dive off the northeast coast of Molokai at a depth of 1000m (3280ft). The 2 red laser dots are 6 inches apart, resulting in a length of about 18 ft for the shark.”

But if they were chasing this deep sea species of shark, how did the orcas manage to get several, albeit smaller, of these sharks rounded up in the shallows off the beach?

I found the answer through the Seattle Aquarium’s shark research program, and though I have not gotten a confirmation that this is the shark species involved in the New Zealand fracas, what I learned about six-gill sharks is fascinating and over-turns much of what we believe to be true about sharks in general.

The biologists have discovered that in this local population, sibling six-gill sharks stay together for many years, at least until they become large enough to move out of the protected environment of the Salish Sea.

The mother shark can give birth to over 100 baby sharks (called pups), and each litter of brothers and sisters remains together for years in “loosely associated groups”, possibly finding food together and avoiding predators.

The eyes of six-gill sharks are adapted to low light conditions and they shun the bright light of the surface during daylight hours, so the orcas might have managed to find a group of the sharks in deeper water, driven them to the surface where the sharks would have been blinded and disoriented causing them to swim up onto the beach (the news article reported that observers thought the sharks swam up to get out of the water, certainly possible but not likely.)

Although six-gill sharks are opportunistic feeders often scavenging about anything they can find, humans are not on the menu, and fortunately for them these sharks aren’t usually on our menu either – what a shame it would be to kill off the sharks of the world without ever knowing their secrets.

Brother and sister sharks growing up together, who knew?

For more on orcas and sharks, please see “Orcas and sharks, just who is hunting whom?” Also this report on New Zealand orca expert Ingrid Visser’s discovery of orcas hunting thresher sharks.

Source: SeattlePI.com
Source: Stuff.co.nz

Shark Sightings: a humorous perspective from New Zealand

Here is an amusing article from Stuff, a new Zealand web paper, first brought to my attention by my friends at the SharkDiver blog. The writer is having fun with all the news media hysteria that seems to always erupt with every shark sighting.

With every discussion or screening/lecture I conduct, at some point I have to respond to an audience member's question about whether the oceans are safe. Out comes all the statistics to try to put it in perspective. It still seems to be a "built-in" nervous response with the general public caused by, on average, a half dozen shark-related fatalities worldwide each year. Then they all drive home on the freeways where 50,000 people are killed annually in the U.S. alone.

Here's a part of Linley Boniface's take on it:

Shark yarns make me yawn
Linley Boniface
The Dominion Post | Monday, 26 January 2009

I never thought I'd say this, but I am bored with sharks. This summer, it has been impossible to open a newspaper or turn on the TV without being subjected to yet another daring shark escape story.

On closer inspection, these yarns have invariably turned out to involve nothing more thrilling than an exceptionally timorous surfer paddling for safety after spotting a fishy shadow pottering quietly along the shoreline, minding its own business.

While sharks in Australia do, as the Australians rather wonderfully say, "take" the occasional swimmer, Kiwi sharks are about as predatory as a newborn ladybug.
Occasionally, a shark will accidentally graze a surfer's calf with a tooth, while yawning: cue national panic and the mass closure of beaches.

Silliest of the many absurd shark reports the media has pestered us with this summer was one from Radio New Zealand. The national broadcaster quoted Constable John Paul Tremain as urging people to stay away from beaches near Dunedin because a large shark had allegedly chased a couple of surfers from the water.

RNZ said Constable Tremain did not know the "exact size or breed of shark" - terrifying news in itself; someone is breeding the things! - but was convinced it was "lurking with intent". Lurking with intent? Intent to do what? The sea is where sharks live: sharks no more lurk in the sea than I lurk in my house.

I would have thought the fact that the shark didn't bother eating the two surfers was sufficient proof of its benevolent intentions, but it would have had to have been waving a white flag and making a peace sign with its dorsal fin to alleviate Constable Tremain's suspicions.

(Read complete article.)