Saturday, 20 April 2019

New Zealand Mag Dive Pacific - Taveuni Rainbow reef

Our latest edition of Dive Pacific features Fiji's silky sharks phenomenon, an interview with Jean-Michel Cousteau, a visit to the Rainbow Reef, and where to find the good spots for spearfishing. Plus lots of dive news from all over.

Thursday, 11 April 2019

Reef Conditions, Somosomo Straits, Taveuni from 2002 onwards – Fiji Coral Reef Monitoring Network (FCRMN)


Background


Reef Surveys have been carried out at two sites (the Great White Wall on the outer face, and the back of Blue Ribbon Eel Reef / Jerry’s Jelly on the inside of the Rainbow Reef) in the Somosomo Straits since 2002, with the exception of 2005 (Rainbow Reef only), 2008 (no surveys), and 2015 – 2017 (no surveys due to poor weather and time constraints).


Figure 1: Map of survey sites on the Rainbow Reef
In 2000 and 2002 Fiji reefs suffered extensive hard coral death from coral bleaching due to exceptionally high water temperatures.
However, coral cover recovered to pre-bleaching levels by 2005, much faster than originally predicted. In the Somosomo Straits, cyclones had some impact around 2006 and 2007, but once more the corals recovered very quickly.
High water temperatures threatened coral health in shallow waters in parts of Fiji in 2014 – 2016, but the Rainbow Reef was unaffected.
A Crown of Thorns Starfish (COTS) outbreak in 2014 caused widespread coral death but stopped after Cyclone Winston in February 2016.
The cyclone caused extensive coral breakage on exposed sites, while others were relatively unscathed, and large numbers of new coral colonies were seen on damaged sites in 2018.

Full report:


Wednesday, 3 April 2019

Strengthening Fiji's laws to protect sharks and other important species

Sharks that are alive and healthy in Fiji's oceans are worth a great deal of money to Fiji's economy. In 2012, the Pew Foundation calculated that shark diving alone generated US$42.2 million for Fiji's economy
Unfortunately, the unnecessary killing of sharks, whether intentional or as a result of an accidental bycatch, removes this opportunity and has adverse effects on marine ecosystems and Fiji’s tourism industry. It is vital, therefore, to provide protection for shark nurseries, and ensure Fiji has effective fisheries laws and initiatives for shark protection that are implemented.
Early this year, dead baby sharks hit the headlines when around 10 juvenile hammerhead sharks were found dumped in a culvert near Suva. These endangered animals may have been caught illegally in nets set across a nearby river mouth where scientists at the Marine School, USP have undertaken a detailed and celebrated study and found a significant and important breeding ground.
Fortunately, the newly created Inshore Fisheries Management Division (IFMD) within the Ministry of Fisheries is currently looking to strengthen a variety of fisheries laws and regulations and their implementation including, but not limited to, the laws that protect sharks. In this bulletin, we consider the existing relevant laws on netting around rivers and discuss additional measures to ensure that sharks are better protected. We also briefly consider other initiatives that are currently being led by the IFMD to make Fiji's inshore fisheries more sustainable for the benefit of all Fijians. For more information regarding other shark conservation measures in Fiji, please see our previous bulletin: “A Legal Policy Discussion of Shark Conservation in Fiji”.
Damian the hero
A scientific study conducted by leading marine scientists Amandine Marie, Celso Cawich, Tom Vierus, Susanna Piovano and Ciro Rico of USP and Cara Miller presented empirical evidence for the existence of a Scalloped Hammerhead Shark (SHS, Sphyrna lewini) nursery in the Rewa Delta in Fiji.
This study focused on developing a more detailed understanding of the reproductive biology and critical habitat of the SHS in the Rewa Delta.
Amongst other things, the research suggested that good information regarding shark species’ biology, ecology and habitat use is essential for developing sustainable management plans. Such information includes:
  • coastal sharks species being known to aggregate at discrete sites
  • the tendency of some sharks to return to their birthplace to breed (including the scalloped hammerhead, Sphyrna lewini) making nursing areas critical habitats
  • the expectation that newborn sharks of coastal shark species use more sheltered areas to reduce their vulnerability to predation and compensate for their limited foraging skills.
Taking those factors into consideration, the researchers recommended the following in order of importance:
  • Complete ban of gillnet fishing in the Rewa Delta throughout the year
  • Partial ban of gillnet fishing in the Rewa Delta from sunset to sunrise throughout the year
  • Partial ban of gillnet fishing in the Rewa Delta from sunset to sunrise during the parturition period (October-April)
  • Partial ban of gillnet fishing in the Rewa Delta from sunset to sunrise during the peak of the parturition period (December-March).

James Sloan and Emily Samuela


Wednesday, 20 March 2019

Send us your best pictures for 2020 NatureFiji-MareqetiViti Calendar “Amazing Fiji Wildlife and Wild Places” Submission Deadline 7 April, 2019


The 2019 NatureFiji-MareqetiViti calendar was a great success, thanks to the contribution of stunning photographs from members and the public.

We are now calling for pictures for the production of 2020 calendars.

Send your photographs to Nunia Thomas at support@naturefiji.org

The image must be your own work and preferably low resolution for the selection, but you must be able to provide high resolution (above 1.5MB) if selected.

Please include your name and contact details (including postal address). Each photograph must have a caption story including the location.

All proceeds will directly support our conservation work in Fiji.

Photographers whose photos are selected will be acknowledged in the calendar and receive a free copy of the calendar. Thank you for supporting Fiji's wildlife conservation.

Tuesday, 19 March 2019

Another great guitarfish pic in Fiji - Rhynchobatus australiae

We know R australis is here from genetic testing, and we have several photos of guitarfish from the Coral Coast (see the Great Fiji Shark count poster)...

Rhynchobatus australiae




Sunday, 17 March 2019

Is Your Old Computer Still Safe? how to determine whether it’s time for an update

The algorithm, the mathematical calculation a dive computer uses to make real-time data measurements on time, depth and gas mix, cannot be seen behind the glass counter in the store, but it's the most important thing to understand about your computer. Just as the launch of a spacecraft is a spectacular thing to see, it's the navigation algorithm that sees the crew safely to its destination and back again to Earth. The same can be said of your dive computer's algorithm -- it's designed to keep you from getting hit with decompression sickness (DCS).

As we age, our bodies change, so it could be the dive computer you bought at age 55 may not have the more conservative algorithm suitable for you at age 70. So, how do you know if it's time to retire that old computer? And how do you decide which is the right one to purchase next?




The First Questions to Ask

To evaluate your current dive computer, ask these questions: Can it be set for nitrox? Does it allow you to set degrees of caution? Does it tell you how long your air will last? Can you read and understand the display easily?

If the answer to any of these questions is no, dump that anachronism and get a modern, more suitable computer. Your tired eyes will also enjoy your new computer's clearer display; many computers now have super-sharp dot matrix systems. If you choose one with an organic light-emitting diode (OLED) colored display, its main figures will change from green to amber if caution is required, and then to red if you've really outstayed your welcome. At night, and in poor visibility, such an illuminated display can be a godsend.

Aside from that feature, don't be misled by the shiny perfunctory knobs and buttons offered by manufacturers as sales bait. You need to ask about the algorithm and understand its ability to return you safely to the surface. After all, what good is a clearly visible display if you don't understand what it's telling you? Buying a diving computer without having a perfunctory understanding of what it does is buying blind.
What good is a dive computer's clearly visible display if you don't understand what it's telling you?

So it's worth understanding a little bit about the development of the algorithm and diving decompression tables.

A Short, Important History of How Your Computer Works


Way back in 1908, a Scottish physiologist named John Scott Haldane was commissioned by the British Royal Navy to prepare the first proper decompression table. He based this on extensive experimentation with DCS in goats, saturating them with nitrogen to depths of 165 feet. Since then, other physiologists have modified Haldane's discoveries to try to theoretically improve things, but, by and large, they're still using the same basic information.

In the 1960s, Albert Bühlmann, a professor at the University of Zurich, came up with a decompression algorithm for use in an early Uwatec computer, and since it's now freely available in the public domain, most computer manufacturers use a modified version of that. (Look for the nomenclature "Bühlmann ZH-16" with varying suffixes in computer specs.)

Here in the U.S., Drs. Ray Rogers and Michael Powell designed the PADI recreational dive planner, and their work was then turned into the DSAT algorithm for no-deco-stop dives to a depth of less than 100 feet. This proved unsuitable for European divers, who habitually go deeper, so later Americanmade computers came with dual-algorithms -- DSAT and Pelagic+, a derivation of the ZH-16. It is important to know which of these algorithms your computer is set to.

There was a time when divers made a single dive or maybe two in a day, but the modern traveling diver now may make up to six dives in a day. With short surface intervals, an allowance should be made for residual nitrogen levels from previous dives.

The American physiologist Bruce Wienke came up with an algorithm taking into account asymptomatic microbubbles that may be present in a diver but will most likely be added to, making them larger and symptomatic, on a second dive. Many modern computer manufacturers have bought into Wienke's work, most notably, Suunto, Cressi, Atomic and Mares. Some divers complain about the punitive deco stops mandated on subsequent dives, but that is the algorithm writer attempting to keep you safe from harm. Older divers, with less efficient hearts, lungs and circulatory systems, are more vulnerable to an otherwise unwarranted attack of DCS on repeat dives. 

Driven by the competition, other manufacturers, particularly Scubapro, have added adaptations to the ZH algorithm to account for these microbubbles.

The problem with all of this is that no algorithm writer can write one specifically tailored for you. It's all based on hypothesis and Haldane's original research from more than 100 years ago. Not enough divers get bent to provide sufficient data, so computer manufacturers tend to err on the side of safety, while insisting at the same time that none of their products can protect you from getting injured by DCS.

Then Dick Rutowski, formerly the deputy diving coordinator for the National Oceanic and Atmospheric Administration, proposed that leisure divers could be safer if they reduced the amount of nitrogen they breathed by increasing the percentage of oxygen -- i.e., breathing nitrox. 

At first, Rutkowski was pilloried for his suggestion, but now nitrox use is commonplace among recreational divers. It still amazes me that so many older divers cling to the use of air, but remember that it's actually nitrox 21 because it contains 21 percent oxygen.


Setting Your Computer Straight


Modern computers can all be set for nitrox, and if you are getting longer in the tooth, you should certainly breathe that. However, setting the computer to match the nitrox mix does not add safety, it merely increases your no-deco-stop diving time. If you want to add safety, either set a less oxygen-rich mix or add a level of caution, which most modern computers allow you to do.

You might set your computer to air (nitrox 21) when using nitrox 32 -- always bearing in mind the maximum operating depth of the mix you are actually breathing. In this way, it calculates for a higher level of nitrogen absorption. Many divers just use the computer straight out of the box at its factory settings. Wrong!

It's always worth reading the manual. For example, if you buy a Scubapro computer for its microbubble settings but leave it set at MB0, you are not allowing for any micro bubbles whatsoever. Set it at a micro-bubble setting (MB1 To MB3). Other dive computers allow you to set Safety Factors (SF) or Gradient Factors that, provided you follow your computer's advice on the way up, decrease the calculated rate at which you off-gas the nitrogen that you've absorbed during the dive, making your ascent slower.

Many computers can be operated in conjunction with a transmitter that plugs into your regulator first-stage. If you think this sounds too complicated, let me offer you an appropriate analogy: There was a time when we only had a gas gauge to go by in our cars. Nowadays when you drive, which do you refer to first on the dashboard, the gas gauge or the "remaining miles left" indicator? It's the same with gas-integrated computers. They tell you not only the pressure of gas in your tank, but how long it will last you at the depth you're at considering the rate at which you've been breathing. Like the miles-left indicator, you'll soon get used to watching the remaining air time. Keep that longer than the remaining no-stop time and you shouldn't get into trouble.

Modern diving computers can be adjusted to accommodate the fact that we are not as fit as we were. They now give better information regarding nitrogen absorption, especially considering that we now typically make repetitive dives, and that info is displayed in a much-improved way.

The mantra still applies: There are old divers and bold divers, but few old, bold divers. 

Be one of the latter by evaluating your current computer, and if it doesn't meet the criteria I listed above, then be smart enough to know what facets are required in the new one you'll buy -- and understand how it works.
-- John Bantin


https://www.undercurrent.org/UCnow/dive_magazine/2019/OldDiveComputer201903.html

Thursday, 14 March 2019

Do One Thing to Protect Coral Reefs!

Coral reefs support 25% of all marine life with more than one million animal and plant species living in these complex ecosystems. But coral reefs are under serious threat and need your help! This is where YOU come in. 

Join Earth Day Network to protect corals and Protect Our Species across the globe. 
Today, we are asking you to do one thing to help protect coral reefs. Buy only oxybenzone and octinoxate-free sunscreens and send your comments to the U.S. Food and Drug Administration (FDA) urging them to remove these chemicals from sunscreens.  
The FDA has issued a proposed rule that would update regulatory requirements for most sunscreen products in the United States and is seeking public comment until May 28, 2019. A draft letter is available here to use or modify to send to the Administration. Read some suggestions here about submitting effective comments. 
Do one thing to help protect coral reefs!
Oxybenzone and octinoxate have both been linked to hormone disruption and allergic skin reactions while posing a significant threat to coral reefs including bleaching and death. In response, Hawaii has become the first state to pass legislation banning sunscreens containing these ingredients and other governments and nations are following suit. These growing efforts are inspiring, and we must encourage more action to protect these habitats which are irreplaceable parts of ecosystems around the planet. Learn more here about the current threats facing corals and why we need to protect them. 
As we approach Earth Day (April 22), we ask you to protect corals and Protect Our Species across the globe. 
Together we can slow the pace of extinction! 
Thank you for being part of our global movement to Protect Our Species. 
Sincerely, 
Earth Day Network

Sunday, 10 March 2019

Amazing shots from one of our guests while scuba diving at Manta Reef in Kadavu FIJI 🐠 .⁣

Amazing shots from one of our guests while scuba diving at Manta Reef 🐠 .⁣ #fiji #fijiislands #ecoresort #paradise #surfing #fijitime #southpacific #travel #explore #adventure #scuba #Scubadiving #Snorkelling #holiday #underwaterphotography #underwatervideo #holidays #vacation #traveling #travelbug #travelholic #travelgram #explore #explorer #goexplore #travelmore #wonderfulplaces ⁣#mantaray #reel ⁣

Wednesday, 6 March 2019

Tuesday, 26 February 2019

7 ways to dive Fiji - soft coral and shark diving capital of the world!

7 ways to dive Fiji - soft coral and shark diving capital of the world!

Fiji has never looked so good. From the soft corals of Taveuni's Rainbow Reef, the Namena Marine Reserve and Bligh Waters to the exciting shark diving of Beqa Lagoon and the Yasawas. From budget backpackers to family-friendly and luxury resorts - there really is something for everyone.

Now's the time to book a Fiji holiday - check out our unbeatable OZTek Fiji Specials below, and match them to one of Fiji Airways March Madness cheap airfares.

Fiji on sale!

Barefoot Kuata Resort. Dive The Awakening Shark Dive - 5 nights in a Beachfront Bure, 10 dives inc. 4 shark dives, all meals, Wi-Fi and non-motorised water sports for as little as AU $1700 pp twin share.
Garden Island Resort, Taveuni. Dive the world-famous Rainbow Reef with our OZTek Special: 7 nights in Oceanview Suite, 10 dives, all meals, FREE shore dives for only AU $2500 pp twin share.
Volivoli Beach Resort. 7 Nights full board / 5 days boat diving and unlimited shore diving at Volivoli Beach Resort in Fiji. Just AU $2500 pp twin share, that’s 2 Nights FREE!