bluff oysters

Bluff oyster Tiostrea chilensis, is found throughout New Zealand, most commonly in the south and famously in Foveaux Strait, between Bluff and Stewart Island. The same species is also found in Chile.

These egg-shaped medallions live in gravelly sand as opposed to clinging to rocks, ropes or structures like the Sydney rock oyster or the Pacific oyster. Another point of difference is that Bluff – more recently known as Dredge – oysters live well out of the intertidal zone, at a depth of 25 to 50m and we collect them by clawing them out of the seabed. This wasn’t always the case. When oystering began in the area in the 1860’s, they were collected on sand bars at low tide. After about 15 years the beds had been over-harvested to the point of exhaustion. A couple of years later new beds were found in deeper water and commercial harvesting continued.  Skipping forward to 1987, the catastrophic Bonamia parasite decimated populations and ceased the commercial harvest until 1994. The disease popped up again in the 2002 season, taking out most of the harvest. It continues to take around 9% of the population annually. Their commercial sale is restricted to a season, beginning in March, and running to about July or August, depending on when the quota is met. This year the quota is (its complicated) around 15million oysters.

Dredging technology doesnt seem to have evolved much over the decades. While looking into the subject I found this wee gem of a historic video about Southland in the 1950’s which shows much the same technology in use (~8mins in) as this one does (with great dredge-eye-view) from our National Institute of Water and Atmospheric Research (NIWA) 50 years on..

So.. Bluff oysters are truly wild, and grow up in pristine conditions but are combatting a disease that has dug its heels in and are harvested in a way that stirs up sediment, and dislodges whatever else is down there. Their commercial harvest seems at best quaint, but more realistically archaic and unsustainable. They’re scarce, and they’re expensive, and… they’re delicious! They are really beefy in composition, have a robust creamy flavour, and in comparison to Pacific oysters they really benefit from a squeeze of lemon.


I certainly don’t intend to permanently add Bluffies to my diet, but Im glad I know a bit more about them. And.. since we are eating them, why not push the boat RIGHT OUT, and get our hands dirty with some empirical data vis-à-vis Carpetbagger steaks!


Lock me up! Im a food-criminal!


What can I say? .. I reckon the carpetbagger was not greater than the sum of its parts. I mean.. it was grand.. and the novelty factor was off the charts, but it simply tasted like a steak, with an oyster inside it. I was surprised how the oyster became firm and matched the texture of the steak as it was heated, bulking it out, rather than providing a gooey centre like I had somehow imagined. I also failed to take into account the extra cooking time the extra bulk would require. Alas, we won’t be trying this one again.. I’ll take my next Bluff oyster neat, with just a splash of lemon juice, thanks.

albacore tuna


Albacore tuna can be found in tropical, subtropical and temperate waters the world over and consequently are known under many names, commonly: pigfish, tombo (Japan), pacific albacore, longfin tuna and others. They generally stay away from coastlines, apparently preferring cooler, deeper water as they age, growing to around 1.2metres in length and weighing about 60kg. Looking at a side-on sketch, it is easy to miss the large pectoral fin behind the gill. When seen swimming these appear like large wings sticking out from their sides.


They are a member of the Scombridae family which includes the other tunas, mackerels and bonitos. The scombridaes have in common a need to be continuously swimming as they lack a swimming bladder to help with buoyancy. They are a predator at the top of the food chain and dive over 400 metres down in search of food therefore limiting our knowledge of what they get up to down there. It is thought that they host elaborate cocktail parties and engage in lengthy discourse on contemporary literature. They are known to eat fish, crustaceans, tiny deep-sea squids and gelatinous organisms. What is a gelatinous organism you say? Oh… that’s stuff like gummy bears and sour worms. Apparently the bigger and older the tuna the higher the content of mercury, but also the deeper they live, so the less likely they’ll be caught by trawlers.

In terms of sustainability, it depends a lot on which geographic fishery you’re referring to and how the fish was caught. This is true to some extent of all fisheries but with tuna being so popular the world over it leads to the frustrating situation of being marked as unsustainable in one place and given the green light in another. That’s okay if you’re willing to read 15 articles on the subject and really get under its skin, but for the punter making a decision about what’s for dinner, it’s just confusing. Presumably the albacore tuna steak I purchased the other day was from the New Zealand fishery, which – according to Forest and Bird – is mainly caught by troll (80%) and longline (20%) off the west coast of New Zealand’s North and South Islands, and is marked as a good choice. That’s right… 80% of our albacore is caught by trolls! LOL. Clearly I’m just scraping the surface of this topic here and intend to revisit parts of it later. Greenpeace recommend buying tuna caught via pole-and-line fishing and particularly avoiding long line and purse and seine methods, which have particularly bad outcomes in terms of by-catch of turtles and dolphins etc. Here’s a handy diagram. I’ve also read about ‘ranching’, which appears to be more prevalent in the States for the tinned tuna market, where juvenile tuna are caught then reared in captivity. Whether or not this is problematic belongs under a separate discussion on farmed fish.

While researching all of this I came across the following gem of a webpage, published by “a retired aerospace systems engineer, long time boater and ocean fisherman”. If you ever wanted to know absolutely everything there was to know about the habits of the albacore, this is the place. For example a discussion on the amount of oxygen present in the water required to keep them happy. Apparently during intense feeding frenzies the oxygen levels drop so low only sharks can handle it… so the other predators leave them to it. I have absolutely no idea about the scientific veracity of all this but it’s great reading.


Anyway I fried my tuna steak, treating it like I would a thick rump steak. The meat of the albacore is sought after for its mild flavour and white flesh. In the US it is known as “chicken of the sea”, but to me it lacks the romance that red tuna has when cut through to reveal the contrasting centre. The pan fried albacore had a creamy appearance and came away in distinct meaty ribs on the plate. It was super tasty, but I can’t help think that the subtlety of the light coloured flesh was lost in the pan. Raw fish salad next time, perhaps?