Spawning surveyors set to research fish maturity in Fiji

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Dr Jeremy Prince from Biospherics teaches shows participants how to assess size of maturity of reef fish

Over the course of three days, 35 Fijian fisheries scientists and managers successfully completed an intensive training program to assess the size of maturity in key coral reef fish and invertebrates.

Led by fisheries biologist Dr Jeremy Prince from Biospherics in Australia, the training was designed so that those participating in the workshop are equipped with the theoretical knowledge and the practical skills to lead these surveys. Part of the training focused on how to work with local fishers to do the surveys, focusing on fish that are important to local people. The idea being is that if communities better understand when fish mature and are able to reproduce, they will value the role size limits play in sustaining their fisheries.

Fijian Department of Fisheries Extension Officer Mr. Anare Luvunakoro said, “This training will help us better understand the sizes that important food fishes are now maturing at and when they are able to reproduce replenishing our reefs. I am from Kadavu and based at the Fisheries Office on the island; this information will enable our fisherman to make informed choices on the sizes of fish like Ta which they harvest”.

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Looking at the maturity of gonads (reproductive organs) of reef fish in Fiji

Organized by the Wildlife Conservation Society, at least fifty percent of the participants were women who were largely from the Ministry of Fisheries and Forests and the University of the South Pacific.
Wildlife Conservation Society Country Director, Dr. Sangeeta Mangubhai says that “on a national scale Fiji currently have over 135 management efforts in 410 iqoliqoli areas representing 79 per cent of Fiji’s inshore fishing area. Using this data, and rapid assessment techniques designed for countries with limited resources, we can quickly assess the health of our reef fish stocks and whether we can continue to fish at current levels or whether we need to reduce our fishing effort.”

A number of fish species were highlighted for survey including kawakawa and donu, which are groupers that have been highlighted through the 4FJ Movement, as well as species that are important to communities, like nuqa (rabbitfish), ta (unicornfish) and damu (mangrove snapper).

“Basically, minimum legal fish sizes are not just random or arbitrary numbers. The size limits in Fiji are there to ensure we are not taking fish before they have had a chance to reproduce and contribute to the next generation of fish”, Dr. Mangubhai concluded.

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Participants of the training of trainers course on the assessment of size of maturity of reef fish in Fiji

Words by Dwain Qalovaki and images by Harriet Davies and Sangeeta Mangubhai

Dropping in for a fish census

Special to WCS by science writer, Amy West

Ready to deploy the BRUV off the support boat

Ready to deploy the BRUV off the support boat

A curious visit by a human or motored robotic vehicle likely sends deep-water fish fleeing. It’s difficult to accurately tally fish if we appear as an ungainly and potential predator. In addition, the robot’s electrical field and narrow camera view may not reflect the actual fish composition. So dropping video festooned with bait that sits patiently on the bottom can harmlessly capture which fish are out and about.

 

An Australian duo from Western Australia University aboard the Waitt Institute research vessel has dropped nearly 60 of these camera systems, fondly called  “BRUVs” (baited remote underwater video). Todd Bond and Jordan Goetze have perfected the art of heaving these awkward rebar frames into and out of the water with sheer brute strength, and, well, the help of a cleverly rigged PVC and wooden winch thanks to the Waitt Institute crew. Angling the pair of cameras also allows length measurements of the fish. Needless to say, these boy’s fish ID skills are top notch.

Winching made easier thanks to the Waitt Institute crew

Winching made easier thanks to the Waitt Institute crew

“Hey what is that fish?” I ask trying to describe the coloration.

Coris aygula,” says Jordan without missing one beat.

“And that one on the…,” I ask.

Heniochus  acuminatus,” he says before I can finish my sentence.  Later a fish shoots across the pixelated television screen, totally unrecognizable to all of us. “That’s an jobfish!” hollers out Todd.

 

 

Dropping these frames along Fiji’s reefs or seamounts gives us a peek into the fish assemblages at deeper depths; which are essentially unexplored. Luckily for us the reef system provides natural ledges. Reefs worldwide will typically level out at roughly 30 meters and 60 meters, and some at 90 meters etc… These natural platforms form from erosion thousands of years ago when sea level stabilized, allowing centuries of wave action to eat away at the coral. When sea level rises or falls, a reef is normally dynamic: either building up or dying off.

 

Finding a ledge after 60 meters was challenging-- it just drops off.

Finding a ledge after 60 meters was challenging– it just drops off.

When the team could locate these ledges on the sonar, they were ideal for their camera frames since most of the reef is so sheer. But the systems can go missing or slip off the line. Their recent loss of two cameras to the deep blue was hard to swallow, but par for the course when tossing expensive equipment overboard beyond our reach. Knots may come undone, and gear can be ripped away by currents or snagged on the way up.

 

 

 

Reviewing the footage back on board reveal fish fighting for bait, groupers stopping in for a mouth cleaning at cleaner stations, and a black blotch emperor at ~50 m losing its colors when near the bait. The sea bream at 70 meters changed its colors and striped pattern, too. If they didn’t capture this metamorphosis on video, it could be challenging to identify these fish from a still image without their markings. On this trip the duo have seen more cod and emperor fish at 70 to 80 meters, which have been largely fished from the shallower depths. They’ve also seen fish that extend well beyond their range as noted in fish ID guides.

 

Checking to make sure the cameras stayed on and what fish they captured

Checking to make sure the cameras stayed on and what fish they captured

Recently Jordan and WCS used this video technique to conclude whether the marine protected area had an effect on sharks. These baited cameras inside and outside of Fiji’s largest protected area, Namena Marine Reserve, showed twice as many sharks in the shallow waters of the reserve. Their numbers are thought to be higher inside the safe zone because of the larger number of prey fish available to them.

 

 

Surprisingly it’s the selective practice of spearfishing that’s taken a toll on Fiji’s reefs. It’s too craggy and steep to cast nets on the offshore barrier reefs, but with the expanding market for fish, more poaching, more spearfishing at night, and more boats carrying spearfishers occurs. There’s hope though: fish may be more intelligent than we think. The idea of “deepwater refuges” is a relatively new concept, but an old simple observation made by many divers: more fish are seen below the limits of where they are fished. The BRUVs finally quantified that observation. By dropping cameras both inside and outside an established and newer marine reserve at five meters and 30 meters, scientists found that fish targeted by fishing were missing in the shallower areas, yet seen deeper. The types of fish found deeper were similar within and outside the two marine reserves, indicating depth can be a natural refuge.

 

Though these one-hour videos give just a glimpse into a tiny cross section of the ocean, over time the data can show trends to help manage marine life that are beyond our view.  It keeps the fish counters safe and dry, which the boys aren’t ecstatic about, but they know sacrificing underwater time means collecting more data. All they need to do is grab a cup of coffee and start shouting out fish names.

 

Amy West has traveled worldwide as a marine scientist, specializing in fisheries and deep-sea ecology. Now as a science communicator she brings stories about ocean realms to the public through radio, video, photography, and writing. She’s usually diving into adventurous stories that take her on or below the water.

Parrotfish help research traditional knowledge

I joined up with the research team on a Friday in Namalata village in the district of Kubulau. I have always had a keen interest in traditional knowledge, which is in danger of draining away, so this trip was my chance to help investigate whether and how it is being passed on to the next generation.

Team “Bubute” (named after the parrotfish that our interviewees were asked to identify) included Rachel (collecting data for her PhD thesis), Lai and Seini (graduate researchers from USP) and me trying to use my local connections and experience to explore traditional knowledge in these parts.

As Lai was wrapping the waka (kava root used to make the drink for traditional ceremonies), I worried that it would be turned against us – used for an early morning drinking session. This proved right next morning when we presented the sevusevu on the island of Navatu. As soon as Buli Navatu (the local chief) accepted our offering, he ordered for it to be pounded and served to us in the village hall – at 9.00 am on Saturday morning!

When we escaped the drinking, my first interviewee was a man who hailed from Ono-i-Lau in the Lau group of islands. He had married a woman from Navatu and lived there for most of his life. We talked about the different plants and their uses for medicine, food, to sell and for special occasions. I noticed he used most plants at home, rather than selling or donating them to village functions. My traditional links meant I was duty bound to joke that as he is not contributing to the village, maybe they should send him back to Lau without his wife!

The elders relate closely with seasonal weather patterns and know which crops to plant where and when. They will plant a certain species of uvi (yam) in certain weather at a certain time of year to ensure it is perfect to harvest for a feast at Christmas, New Year or a big i-sevu (presentation of root crops to the vanua or church). I now know that planting in July and harvesting the following March will give me the biggest yams (I made a note to take back to my village).

The next stage is to analyse the data and assess the links between traditional knowledge and natural resource management. Hopefully the results will help enhance the effective transfer and application traditional knowledge to meet current needs as well as providing for future generations.

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Notes from the field: periodic harvests

I thought I’d be tweeting and blogging away from the field – but alas, since Digicel installed a tower in Kubulau, Vodafone signal is but a figment of my imagination. So I am cut off from all forms of communication with the outside world – six days in, it feels like a weight has been lifted.

After 18 long months of slogging it in the office and pitching proposals non-stop to donors, we are finally back in the field for a new project. During the past few years we have been collecting information about the reefs to provide recommendations about where to set up no-fishing zones (or marine protected areas – MPAs) and monitoring their effectiveness over time. This trip is different – we have asked the village of Kiobo in Kubulau District to open their MPA to see what happens. “What!” the purists would yell, “Open an MPA? Are you crazy?” But the simple fact is that rural communities in Fiji routinely open their MPAs to provide food for social functions. This practice comes from a cultural legacy throughout Melanesia of creating short-term, no-fishing zones specifically so that they would be able to have a great harvest for a social event and redistribute the food as a show of wealth and status. Thus, even though most communities within the Fiji Locally Managed Marine Area network say that they want to have fish for the future, they also very much want to have fish for the present.

More and more frequently, there are expectations that the MPAs can provide a source of income whenever the community needs money to pay school fees, church fees, provincial levies, etc. This is leading to more intense and more frequent harvests from MPAs, and the fish just don’t stand a chance. Here is where we come in – our current project is evaluating how much you can extract from an MPA and still have sustainable fisheries for the future. We recognise that the MPAs in Fiji work best where cultural practice is strong – and if cultural practice demands occasionally opening an MPA, then we need to be able to offer some better guidelines about how much can be harvested besides just “don’t take all the biggest fish.”

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In the field with us this time is Jordan Goetze, a PhD student from University of Western Australia, whom I’ve recruited to look at the ecological impacts of harvesting MPAs for his doctoral research. On this trip, he is testing out a range of survey methods to see which ones best document the impact of a week-long harvest from the Kiobo MPA. Our WCS staff are collecting our standard underwater visual census data, which he will compare with before and after harvest surveys of the reefs using diver-operated video and baited remote underwater video surveys (BRUVs). The diver-operated video information is certainly more efficient to collect than our laborious fish and benthic counts, while the BRUVs potentially allow us to collect a better record of predatory fish that are often skiddish of SCUBA divers. At the same time, we have sent out WCS staff and a Masters student from the University of the South Pacific to conduct household interviews to find out what the local people are expecting from the harvest in terms of food and monetary benefits, and then we will resurvey them after the event to see how these expectations were met.

Conducting fieldwork in remote Fiji is always challenging. Today we are stuck in the village as the fuel hose for our dive compressor became shredded, thus preventing us from filling our dive tanks. Waisea and Akuila have gone to Savusavu in search of a replacement. The winds have been up, causing rather treacherous conditions mooring at sites. Under pressure to complete 4 dives a day, we often find ourselves returning to the village for a low tide swap of empty for full tanks, which must be lugged across hundreds of meters of intertidal seagrass and algal beds. And there is no rest for the weary in the evening – data must be entered, kava drunk, and special efforts made to conduct awareness presentations in the surrounding villages so they understand what they stand to gain from the information collected from these surveys. Full support of the local communities is crucial for this project to succeed, so it is worth the extra effort to haul our generator, projector and white sheet around to the various villages by boat, often in the dark, for evening presentations to ensure that everyone knows what is happening.

What will we find when the MPA is opened? Unfortunately, it looks as though the local reports of emboldened poachers encroaching on inshore fishing grounds may be true. We certainly did not see overly abundant fish life in the MPA, and invertebrates were few and far between. Yet, hopefully the men and women of Kiobo village will still be able to pull in a sizeable catch, which can provide them a modicum of income while allowing us to gather a piece of the puzzle to evaluate thresholds of impact. Keep your coconut wireless tuned for the results . . . moce mada. Stacy

Sea cucumber harvest provides church roof

Holothuria scabra collected in Natuvu village

On the 24th September 2012 the communities of Natuvu village in Wailevu district started harvesting sea cucumbers (Holothuria scabra, or dairo in Fijian) from the shallow waters outside their marine protected area. Sea cucumbers are being cultured in Natuvu village through a joint project with Fiji Department of Fisheries, the Secretariat of the Pacific Community, and James Cook University. The dried animals fetch a high price for sale in Asian markets – up to $100 per kilo. Around 1,200 of the valuable animals were collected on the first day of the harvest and 1,000 individuals on the second day. We are waiting to hear the final catch figures for the harvest from the communities.

During the harvest I saw first-hand the long drying process to prepare the catch for sale. First the communities cooked the dairo then buried them in sand for 24 hours. After this, they cleaned them and cooked again for 10 minutes and then dried the cooked animals using dryers. Finally, the sea cucumbers are cooked again for 15-20 minutes and then sun dried until they are sold.

It was very encouraging to see the community come together as the women of the village cleaned the dairo while all the men helped out in the cooking, cleaning and drying. Harvesting will continue until enough money is collected from selling sea cucumbers to purchase new roofing material for their village church.

Catch information collected from this harvest will contribute to a study by the University of Georgia in the US. In August, WCS Fiji staff assisted Professor Mark Hay and his team to carry out surveys inside and outside the marine protected area owned by Natuvu village, for example gathering seabed sediment samples and assessing the density of sea cucumbers before the planned harvest. These data are now being analysed by Professor Hay, before he returns to Natuvu for a post-harvest survey. The research hopes to answer questions about the effects of large-scale harvests of sea cucumbers on ecosystem functions such as nutrient cycling.