Submarine frontier
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All at sea
The publication of this special edition of New Zealand Geographic has been timed to coincide with Seaweek, March 5–12, 2006. Seaweek is an initiative of the New Zealand Association for Environmental Education and aims to increase our appreciation of, and concern for, the ocean around us. Not many small nations have as much sea about them as we do. You can’t leave New Zealand without somehow getting across thousands of kilometres of the stuff. To reach Los Angeles, you fly fast across the Pacific for about half a day and it seems immeasurably vast. The notion that we puny humans could have adverse effects on it seems laughable. But we are numerous and ingenious and we like eating fish. Our pursuit of fish is just one way in which we have changed the ocean. Fish are not evenly distributed throughout the ocean. Most of them live in comparatively shallow water close to land, because that is where fish food is found. The fish we eat mainly feed on smaller fish or invertebrates, which in turn feed on zooplankton, which depends on phytoplankton. Phytoplankton needs light for photosynthesis (so it only grows near the surface) but also a few minerals such as iron. These generally originate from land where such things as large rivers and Antarctic glaciers add much ground rock to the ocean. The vast deep expanses of ocean far from land—perhaps 80 per cent of the total are more or less deserts biologically speaking. All this means fish can be mopped up more readily than at first appears. Fisheries scientists David Pauly and Jay Maclean in In a Perfect Ocean note that old fishermen everywhere say that we don’t know how good the fishing was when they were boys. But their fathers said the same thing and their fathers before them. Although big mechanised trawlers, fish finders and GPS devices have combined to make the slaughter of fish hugely more efficient since the 1960s, fishing has been going on for hundreds if not thousands of years. To give a local example, fur seals and sealions were once common even around much of northern New Zealand but were locally wiped out by Maori seeking food before Europeans arrived here. When Europeans first reached the north-eastern shore of North America in the 1500s, they were astonished at the fish. At that date, by today’s standards, fisheries in Europe were still extravagantly good, but they were nothing compared with eastern Canada where only about 4000 Inuit lived. Cod grew to 2 m or more and were so abundant you could catch them simply by lowering baskets. Sturgeon reached 5 m. Great pods of whales blocked ships from entering harbours. Probably New Zealand waters were once comparably rich. So although the New Zealand fishing industry often claims it is one of the best managed and most sustainable in the world through our Quota Management System (QMS), that is not necessarily saying much. Basically, it indicates fish stocks are not declining precipitately any longer, but says nothing about how present stocks compare with those of a few centuries ago. Pauly and colleagues—who are involved in a survey of fisheries worldwide called the “Sea Around Us Project”—state that virtually every fishery in the world will be annihilated within a decade or two unless we take drastic action. They note that we are increasingly fishing down the ocean food chain. As the big fish we prefer to eat (cod, orange roughy, hapuka) get fished out, we turn to squid (once only esteemed as bait), shrimps, clams and, yes, even jellyfish (described as tasteless but crunchy when cooked). Fishing is changing the whole ecology of the oceans and shorelines. Among the remedies Pauly and team suggest is the reduction of fishing catches by something like 60 per cent and establishing no-take marine reserves over 20 per cent of the world’s oceans. They even suggest we could designate all oceans as no take reserves apart from defined areas where fishing is allowed—a reversal of the present situation. In their view, marine reserves are important refuges where fish stocks can recover and replenish surrounding fisheries. Locally, this way of looking at marine reserves has been rejected by the fishing industry, who, with recreational fishers, have generally opposed the establishment of marine reserves. They have argued (with some justification) that the QMS should provide sustainability and marine reserves are not required for this purpose. In this issue we have a visually splendid article on the Poor Knights Marine Reserve, established 25 years ago as the second marine reserve in the country. Would the area be as rich as it is today if it were not protected by a marine reserve? It is surely no coincidence that the fish species that still form large schools there are mainly plankton eaters, and therefore not taken on hooks with bait. Although fishing was banned in the reserve in 1998, stocks of other fish have still not recovered to levels remembered even 40 years ago. This marine issue of NZ Geographic is not as balanced as I would have liked. There is quite a mixture of biology but little here about human effects on the sea. An article on aquaculture I had planned on including dropped out at a late stage and I had no time to acquire anything comparable. Of course, we have run and will continue to produce a constant smattering of marine articles in our regular issues. But I can already see the contents of another special marine issue: aquaculture, squids and octopuses, seamounts, plankton, an overview of fish and fishing in New Zealand, the effects of changing climate on the ocean. An example of this last problem is that rising levels of atmospheric carbon dioxide mean more is dissolving in the ocean, increasing its acidity and eventually threatening to dissolve the calcium carbonate of coral and the shells of marine organisms. Man is affecting the ocean in more ways than just through fishing. With this issue comes the first poster for several years—a new version of the popular rock pool poster that appeared in issue one, and which has not been available for some time. While it is unlikely that we will return to producing a poster with every magazine, we would like to create one or two each year. To assist readers, I have listed some of the major marine articles we have published in the past, and we will place a more complete list on our website. As always, we hope you find ample to interest and inform you in this issue.
Artificial surf reefs—coming to a beach near you
“When I was 14, my father and mother took me to Ocean Grove in Victoria, Australia, and friends had a foamy surfboard, some 8 foot long. I remember the sparkling white water bouncing me back to the beach, droplets going everywhere with a sense of speed and motion, and sliding over a fluid as smooth as oil and bumpy as judder bars. At the third attempt, I got to my feet on the board and life was finally underway. Stamps, table tennis, secretly kissing 11-year-old girls in the back yard were nothing compared to this feeling. The exhilaration and sense of fulfilment was the giant hook which took me around the neck and hauled me into the sea for a lifetime.” So says Kerry Black. He went on, in his twenties, to make a tour of world surfing spots, and although that was a few years ago now, his passion for surf has never deserted him. After 10 years at a research institute in Victoria, Black was appointed a professor in the University of Waikato’s Department of Earth Sciences. For the first time, with a work force of top MSc and PhD students at his disposal, he was in a position to dictate the direction of a major research effort. Thus was born the Artificial Reefs Program, which ultimately led to the invention of the man-made multi-purpose reef. The programme aimed to improve the environment at the same time as creating recreational opportunities. On many exposed beaches, defensive walls of rock or concrete have been erected to prevent storm damage. These can be both an eyesore and of limited effectiveness. A reef a short distance offshore tends to prevent coastal erosion, as waves break on it rather than the beach, spending their energy there and obviating the need for onshore defences. Couldn’t a sophisticated computer-designed reef work as well as, or better than, a natural one, at the same time producing surf, safer conditions for swimming, and a more diverse marine environment? With one of his former students, Shaw Mead, Black set up Artificial Surfing Reefs Ltd (ASR) to “put the theory into practice”. The company, which carries out environmental research in both marine and freshwater locations as well as designing artificial reefs, now has some 30 artificial-reef projects under way around the world. Black designed the world’s first multi-purpose reef, at Narrowneck, on Queensland’s Gold Coast. Over the last four years, independent monitoring has shown this reef to be highly successful in terms of beach protection, ecological enhancement and surf creation. It has won the state’s prestigious environmental award and is functioning as predicted by modelling carried out prior to construction. Now, after nearly a decade of hard work by ASR, Mount Maunganui on the east coast and Opunake on the west are to host the first artificial reefs in New Zealand. Construction started at the Mount in October 2005 and is slated to begin at Opunake, which is to have two reefs, in March this year. None of these reefs has been designed to protect beaches from erosion; rather, all three are intended to improve conditions for surfers. By examining the sea-floor at sites around the world known for their good surf breaks, ASR has determined what underwater shapes and contours produce ideal surfing waves and/or provide coastal protection. It has built a wave pool in Raglan for testing models of its designs so it can be sure they will function as intended. The reef at Mount Maunganui is shaped like a cross between a heavy-limbed V and a delta wing. The apex of the V points seaward and the structure thickens towards the base. It is formed from 24 huge cylindrical bags attached to a securing mesh made from belts of fabric. This structure was taken out to sea in a barge and anchored to the sandy sea-floor 250 m off the beach in 4.5 m of water. Sand is being pumped into the bags as weather permits. The largest bags are 3.5 m high and 50 m long, and hold 660 m3 of sand. In total, the reef will use 6000 m3 of sand and will measure 75 m from apex to base and almost 100 m across the base. As might be expected, the bags that hold the sand are in a class by themselves when it comes to solidity. They are made of polyester or polyester–polypropylene fashioned into a geotechnical fabric that is either 5.7 mm or 9.5 mm thick. The thicker fabric has a “hairy” surface that traps sand and provides good attachment for marine organisms. It has a service life of at least 20 years and can be readily repaired in situ. The artificial reef at Narrowneck, of the same construction, has survived 10 m waves produced by tropical cyclones without suffering damage, and Mount Maunganui never receives that severe a buffeting. Black says the Mount Maunganui reef will produce hollow waves (especially towards low tide, when water depth over the reef will be less than a metre) with “a fast wave on one side and a slower wave on the other, depending on swell direction”. Fifty surfers at a time should be able to use the reef, taking off in two directions and enjoying rides of 50 m. At Opunake, the first reef to be constructed—to the north—will cost about $1.3 million and produce waves 1.8–2.5 m in height that will give a ride of 100 m. The more expensive south reef won’t be built until the north reef has been completed, but should give a 200 m ride on waves up to 3.6 m high. At present, there are surfable waves in the Opunake district on about one day in eight. The artificial reefs should produce good surf one day in three, and it is hoped that they will cement south Taranaki’s claim to be a major surfing area. The principal reason for building the reefs is to draw more visitors to the town and so create jobs in a district where the population has been in slow decline for some time. The Mount Maunganui and Opunake reefs are not the only ones on the drawing board. ASR has produced reports on possible structures at Wellington’s Lyall Bay, New Brighton and Orewa (the last primarily for erosion control). Black and ASR are also involved in a development that promises surf for the beachless in Orlando, Florida. A pool equipped with wave-generating gear will have a padded, computer-adjustable floor, the contours of which will change at the touch of a button. Called Versareef, this ingenious invention can be programmed to create a near-infinite variety of wave shapes to keep the surfing experience fresh.
Tide of history
In 1258 Hulegu Khan, great-grandson of Genghis, sacked Baghdad, bringing to a close the Golden Age of Islam. On another battle-front, in the climax of its 70-year border conflict, the Mongol Empire vanquished the remnants of the Sung dynasty, claiming dominion over formerly prosperous China. These events occurred a century before the Incas rose to prominence in South America, or civilisation in Western Europe began its journey into the advancing light of the Renaissance. At a time roughly equivalent to these major historical landmarks, sea-faring people—the best and most intrepid navigators the world had known—sailed south-west from East Polynesia in their massive dugout canoes, making eventual landfall on an undiscovered earth. Temperate and fertile, these virgin southern soils had been beyond knowledge, 2000 km east of the nearest human habitation. They harboured forests that teemed with plump, docile birds and were lapped by coastal seas rich in marine life. It was a wondrous discovery. In the broader context, this landfall marked the final chapter in the story of the human diaspora. Palaeolithic nomads, the earliest recognisable humans that swept out of Africa, relied on land-bridges laid bare by low sea levels during the last ice age to venture into new lands. But across the deep trench of the Tasman Sea, there was no such connection. New Zealand had to wait until a sea-going culture, advanced enough in the requisite maritime arts, could bridge its barrier of isolation. The first arrival of Polynesians in New Zealand was also the dispersal of humanity into the last corner of the planet. To say that New Zealand’s history is a maritime history, is to dally with profound understatement. Discovery, colonisation, start-up economic ventures and trading were exercises in the maritime arts. To this day our culture is framed by our shoreline. A major collection of stories, artefacts and displays at the New Zealand National Maritime Museum speaks of this intrinsic bond with the sea. The museum is aptly situated in downtown Auckland at the Hobson Wharf end of the Viaduct Basin. It is considerably larger than it looks from the outside, housing 14 discrete exhibition galleries in a rabbit’s-warren interior, as well as providing berths for heritage vessels including an 80-ton steam floating crane, the ex-Lyttleton Rapaki. The museum also boasts New Zealand’s oldest steamer, the small but nicely formed SS Puke. A Pacific Discovery Theatre, near the entrance, shows Te Waka: Our Great Journey, a 10-minute animated film which re-creates the first migratory voyages to our shores. With new-media technology, the film also hints at the style of what lies ahead in the museum. In the shadow of Te Papa, no self-respecting modern museum would be without multimedia gilding. The first gallery space you encounter is the Entrance Gallery, which houses temporary exhibitions. “Snapshots” is the current feature and involves a series of photographs and exhibits that explore 20th-century maritime themes. Linking to a larger space and returning to the Polynesian sea-faring theme is “Hawaiki”, a collection of canoes and waka from around the Pacific. This exhibition centres around an impressive set of craft from Polynesia, Melanesia and Micronesia. Among them and easily the largest is Taratai, a 23 m outrigger voyaging canoe built using traditional techniques and materials in Kiribati, which was sailed from Tarawa to Fiji in a successful test of long-distance ocean-voyage capabilities between Pacific islands prior to European contact. Another exhibition space deals with the historic exploitation of marine-mammal resources, including a life-sized model of an ad hoc whaling camp and Tainui, a six-man whaler built in 1860. Other galleries mark European expeditions to New Zealand and the subsequent waves of immigration, early ocean-going craft that plied its waters, a display on the subject of coastal trade and another featuring the tools and techniques of navigation. Peripheral spaces deal with the products of maritime industry (lighthouses, outboard motors and fishing, both commercial and recreational) and how we enjoy the coastal environment (holiday-bach construction, lifeboats and yachting). The Hall of Yachting is particularly extensive, with examples of various classes of popular craft accompanied by explanations of their design features and capabilities. Its mezzanine floor has a tribute to Sir Peter Blake, celebrating New Zealand’s involvement in the America’s Cup, and even exhibiting a full-sized replica of the trophy. This theme is continued outside the museum with what has become an iconic Auckland landmark—KZ1. Visitors to the Viaduct Basin cannot miss our infamous 36 m cup challenger mounted in its high cradle. Financed by Sir Michael Fay, KZ1 was like a Kiwi version of Australia’s underarm bowling incident—an exploitation of the rule book to gain an unsportsmanlike advantage in the sporting arena. This challenge was met on the water by Dennis Connor in a catamaran, but fought, and ultimately lost, its real battle in the courts. It was surrounded by verbal jousting and other shenanigans, but the one thing that could be said in the big boat’s defence was that it might have prompted a return to the grandeur of the J-class yachting era. Packed with details but imbued with a sense of a larger historical sweep, this museum is a one-stop shop for anyone of remotely nautical bent, and worth a look even to land-lubbers.
Coastal winds
The desire to save lives by preventing shipwrecks was the spur that drove Robert FitzRoy to start issuing weather forecasts in England in 1860, when the science of meteorology was still rudimentary and weather observations were sparse. Following FitzRoy’s methods, Commander Edwin began forecasting for New Zealand’s coastal waters in May 1874. A retired naval officer and veteran of the Crimean War who had been wounded at Sebastopol, Edwin was employed by the Marine Department to instigate and disseminate warnings of hazardous weather. At this time, around 25 vessels were lost each year along the coast of New Zealand. An initial system, begun in 1869, had seen weather observations, taken at 26 telegraph offices around the country, publicly displayed at ports. This had been a disappointment, in part because of the poor standard of the observations, which had been made by untrained telegraph staff with little time to spare from their other duties. Edwin oversaw the distribution of barometers to 17 coastal stations and ran up a telegraph bill of 800 pounds a year in transmitting the observations and consequent forecasts. The expense gave the colonial administrators pause for thought, but the forecasts met with enough success that Edwin continued forecasting for 32 years, ceasing only when he retired in 1908, age 69. As meteorological knowledge has increased, it has become apparent that coastal weather can be more extreme than weather over the open ocean. The hills and mountains of New Zealand are a complex obstacle in the path of weather coming off the ocean. The land breaks the wind patterns into an intricate mosaic of microclimates that vary with wind direction and atmospheric stability. When the wind is blocked by a mountain range, much of the air flows round the ends of the range, creating an area of gale-force winds that can extend hundreds of kilometres downstream. Cook Strait and the sea west of Puysegur Point, in southern Fiordland, are good examples of places where this happens. Another is the area around East Cape. When a south-easterly airstream blows towards the Gisborne area, gales are typically generated near the Cape and continue downstream as far as Great Barrier Island. If an anticyclone is crossing the North Island and the air is very stable, a modest flow of 20 knots over the open ocean can easily double to 40 knots near the Cape as most of the air streams round the ends of the Raukumara Range. Although the wind speed of 40 knots may hold all the way to the Barrier, over much of the Bay of Plenty, closer in towards Whakatane and Tauranga, it can be as light as 10 knots. Anticyclones are associated with a stable atmosphere, because the air inside them has typically descended from a considerable height. During its descent, the air is warmed by compression, creating a strong temperature inversion between the falling air and the cooler air next to the sea or land surface. Buoyancy forces trap the cooler, denser air near the surface, so that it flows round obstacles rather than over them. When such an inversion near East Cape is lower than about 900 m, most of the air in the south-easterly flow is diverted round the northern end of the Raukumaras. If the inversion is a little higher, say 1200 m, the taller peaks of the Raukumara Range still block the south-easterly but air now spills round both ends of the mountain range. A good example of this was recorded by satellite scatterometer on the morning of 24 August 2003. The resulting computer-generated weather map (below)shows a zone of relatively light 10–15 knots winds, extending downstream from the highest part of the ranges, sandwiched between a belt of 25–30 knots winds close inshore and 30–40 knots winds further out to sea. Meanwhile, back round the corner, east of Gisborne and Hawke’s Bay, another interesting wind pattern is develops in a south-easterly flow. As air piles up against the land, the atmospheric pressure there increases by a few hectopascals, producing lighter winds blowing from the south-west—perpendicular to the main south-easterly flow—in a strip about 10 km wide. Typically, the wind 50 km out to sea is 15–20 knots from the south-east, while close to the coast it is only 5–10 knots from the south-west. This “damming” of the air against the land is also a feature of strong-wind situations. When a front sweeps across New Zealand from the Tasman Sea with a band of northerly gales ahead of it, the wind hard up against the coast is often much lighter than gale force until perhaps the last hour before the front passes. Then a wind of about 25 knots from the north-east swings round to 45 knots from the north and the full force of the gale brings savage conditions to the shore in a short but deadly burst. A feature of the weather map when these strong pre-frontal winds are flowing is the way the isobars have an extra kink in them where they cross the Southern Alps. Known as a lee-trough, this marks an area of lower air pressure that forms downwind of the mountains. The isobars are usually very close together around the top of the lee-trough, where the mountains end near Cook Strait. This can be seen on the map for 16 March 1992, when there was a north-west wind of 65 knots in the strait at Brothers Island, while over the Tasman Sea ahead of the front the wind was only around 35 knots. However, not all gales have such a clear signal in the isobar pattern. When a high drifts across the South Island, a small shift in the angle of the isobars crossing the North Island can cause a southerly through Cook Strait to increase from 10 knots to gale force. Coastal forecasts cover waters out to 100 km from the land. The coastal waters are broken into 18 separate areas, each of several thousand square kilometres. Given the variety of local conditions and the need to be brief, forecasts concentrate on the predominant winds and main trends. A detailed forecast for a typical area could easily cover half a page or more, but the demands of broadcasting require each forecast to be kept to a few lines. The forecasts and a map of the areas are available on the MetService website—www.metservice.com. In recent decades, weather forecasts have steadily improved as ever-more powerful computers have grappled with the complexities of the atmosphere, and the number and quality of observations have increased. In particular, satellite-scatterometer measurements of winds have been a great help in clarifying the initial conditions over the oceans of the Southern hemisphere. Thousands of observations are made each day over areas where once you would have been lucky to get one or two ship reports, meaning weather maps are now sufficiently reliable for MetService to issue extended-range coastal forecasts up to five days ahead, something it began doing in May 2005, 121 years after Edwin’s first forecasts. Judging by the reaction so far, these have been well received by most mariners, even if there are more words to listen to.
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Archive
Under the ice
Dr miles lamare has spent six weeks of each of the last four years in—and under—Antarctica. A lecturer in the Department of Marine Science at the University of Otago, Lamare has been diving under the sea ice to see how marine invertebrates such as the sea urchin Sterechinus neumayeri and the starfish Odontaster validus (the red seastar) are handling the increase in solar ultraviolet radiation to which they have been exposed as a result of the hole in the atmosphere’s ozone layer. Lamare is particularly interested in effects on the small, free-swimming larval stage that most marine invertebrates undergo. Unfortunately, it seems that the sea urchins and starfish aren’t doing too well. And as they are significant elements in Antarctica’s marine biomass, a depletion in numbers, says Lamare, could lead to considerable changes in the ecosystem. Lamare and his colleagues lower themselves into the coldest water in the world at a place called Cape Armitage, a 30-minute drive by Piston Bullys (a rubber-treaded vehicle for travelling over snow) from Antarctica New Zealand’s Scott Base. Set atop the sea ice, and kept warm by a kerosene heater, is a 2 x 4 m hut. Inside, a hole has been drilled through the 2 m thick ice, through which the dry-suited scientists descend. The hole in the ozone layer was discovered about 30 years ago and is expected to persist for at least the next 50 years. During that time, plenty of organisms (as well as humans living at high latitudes) will be subject to damage—including structural damage to DNA—by UV radiation that was once more completely blocked from reaching the ground by ozone high in the atmosphere. (Ozone, considered a pollutant at ground level, is a colourless gas with a chlorine-like odour. It is an allotrope of oxygen, with the formula 03.) Some marine organisms produce “sun-screen” compounds that absorb the most dangerous wavelengths of UV radiation. But other creatures—and it turns out S. neumayeri is one—have not. It used to be thought that the sea ice that surrounds most of the Antarctic coastline during the summer months provided the organisms that live below it with ample protection from UV radiation. And perhaps creatures like the nearly transparent S. neumayeri larva didn’t need sunscreen anyhow. But research completed by Lamare and his colleagues in 2004 showed that UV radiation was in fact getting through the ice; and, importantly, that UV-B rays—the ones that tend to cause structural damage to DNA (and melanoma in humans)—were penetrating the ice with sufficient intensity to cause developing organisms harm. Lamare, together with Prof. Michael Lesser, from the University of New Hampshire, in the USA, found that UV-B radiation was not only causing significant mortality of larvae and embryos, but was also damaging the DNA of the embryos that survived. Rates of mortality and the extent of DNA damage varied from one year to the next, depending on fluctuations in the severity of the hole in the ozone. Why, Lamare and his co-workers wondered, was S. neumayeri so sensitive to UV-B? For most organisms, damage to DNA is not necessarily fatal (or even serious), as enzyme-mediated mechanisms can repair the lesions. Once Lamare had figured out the sea ice wasn’t affording the sea urchins any protection, he began analysing their rate of DNA repair. It proved to be pretty sluggish. Photolyase is the enzyme that repairs the lesions most often caused by UV radiation. But if this isn’t present, or isn’t working properly or fast enough, an organism can’t repair all the damage. This appears to be the case for S. neumayeri. Lamare wondered whether water temperature was also having an effect on the urchin’s enzyme repair mechanism. For comparison, during the summer of 2005–06 he gathered data from sea urchins elsewhere, including members of the genera Evechinus in Fiordland and Diadema on Australia’s northern Queensland coast. It was important, he says, to get a temperate and tropical comparison in order to deduce whether enzyme activity differed according to temperature: were the Antarctic larvae “suffering” more because it was so cold where they lived and the enzyme couldn’t work to full effect? “Enzyme activity is generally susceptible to cold temperatures,” says Lamare. “Enzymes are proteins that must flex and un-fold to carry out their job. In cold water, enzymes become rigid and less flexible, which inhibits their normal activity. Organisms that live in cold water have to modify their enzymes so that they become more flexible and compensate for the cold.” It appears that temperature compensation isn’t one of S. neumayeri’s strong suits. Thus, while photolyase in the Australian urchins repairs the damage to DNA caused by UV radiation (which the animals are exposed to all year-round), the same enzyme in the urchins in Antarctica doesn’t do nearly as good a job, suggesting that it hasn’t been modified for operation in a cold–water environment. This isn’t altogether surprising. Lamare explains that organisms such as S. neumayeri have been isolated in the Antarctic for about 20 million years, during which time they have evolved under relatively low levels of UV-B radiation and so may not have needed to repair the kind of damage it can cause. “The Antarctic larvae have a very sensitive metabolism. With an increase in ultraviolet radiation,” says Lamare, “the Antarctic species is really vulnerable. It can’t repair its DNA, because it has an enzyme that hasn’t adapted to the cold. Now we’re trying to figure out why.” Research is continuing into this question, not only at Scott Base but also at Lamare’s regular place of work at the University of Otago’s marine laboratory at Portobello. Lamare has imported live Antarctic sea urchins and starfish, which now spend their days living at –1.0° C in a large freezer. He is currently focusing his efforts on how the structure of photolyase differs between Antarctic and non-Antarctic species. This includes identifying and examining the gene that codes for it. Antarctica New Zealand’s science-strategy manager, Dean Peterson, is supportive of the work done by Lamare and his team. “New Zealand is intensifying its commitment to research in the Southern Ocean,” he says, adding that Antarctica New Zealand plans to increase the amount of marine research undertaken at Scott Base and in the Southern Ocean. “Global climate change, particularly in the Antarctic and Southern Ocean, is a significant focus of both national and international scientific attention,” says Lamare. The results of his work will not only allow predictions of the effects of UV-B radiation on Antarctic marine invertebrates, but will also show how susceptible to future environmental change these species may be in view of their geographical isolation and long evolution in the Antarctic environment.
Orca - Dressed to Kill
My first close encounter with an orca took place in May 1991. I was a student at the Leigh marine lab when I heard that orca had been sighted in the bay. Grabbing my snorkelling gear, I sprinted down to the beach and dived in. Nearby, the tall fin of an adult male was projecting from the surface, but under the murky water I couldn’t see him. I dived deeper, hoping to glimpse him, but moments later, as I headed up for a breath, there was a large female orca between me and the surface, lying on her side and looking down at me. We surfaced for air together, then I dived back down while she circled me before heading off. A few minutes later she was back, this time with a calf. They swam past me, then the calf started circling me rapidly, while I span round and round trying to hold eye contact. It was a game played under Mum’s watchful eye, and lasted until dizziness forced me to stop. Alas, the magic was broken. The female swam up and both creatures moved sedately out of the bay.
Matanaka Caves
Some of the caves at Matanaka are hundreds of metres long with extensive dry floors beyond the reach of the sea.
Poor Knights, rich seas
French oceanographer Jacques Cousteau rated the Poor Knights Islands off Northland’s east coast as one of the top 10 dive spots in the world. Twenty-five years after they were gazetted a marine reserve, they remain as magnificent as ever, a place of rare undersea richness where exciting biological discoveries continue to be made.
Invertebrate biodiversity
Taxa: a survey of marine invertebrate biodiversity
Joseph Conrad's ship
Joseph Conrad and the Otago.
Triplefins
Triplefins are found on temperate and tropical reefs in most parts of the world, where they are generally inconspicuous small fish. The blue-dot triplefin (Notoclinops caerulepunctus), here photographed on a rock wall at the Poor Knights Islands, is, at 5 cm, one of the smallest of the 26 species of triplefin found in New Zealand waters.
