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Getting to grips with gonads: The trials and tribulations of collecting data to propose new size limits for the Maldivian grouper fishery
Ouch! Yes, that’s the sound of me pinching myself as I continually remind myself how very lucky I am to be living and working in the Maldives with its stunning white sandy beaches and azure blue waters brimming so richly with sea life.
Based on Laamu Atoll at the idyllic Six Senses resort, Shaha (my co-worker) and I work for BLUE conducting research on groupers. Last month we travelled to an island 190 km away, called Thinadhoo in Vaavu Atoll, to carry out our third grouper sampling trip for the project.
Method behind the madness
One of the four main project activities that we are working on is collecting data on how long different species of grouper are when they reach maturity. The Maldivian grouper fishery is currently at risk of collapse because 70% to 90% of groupers are caught before they reach sexual maturity and have a chance to reproduce. This over-exploitation of premature groupers reduces the number of juveniles produced which can repopulate the reefs.
Determining the length at which groupers become sexually mature, will allow BLUE to propose a change in the legal size limit regulations to the Maldivian government to prevent the catching of undersized groupers. Size limits in many other parts of the world are often criticised as a fisheries management tool, simply because fishermen cannot visibly see the size of the fish they catch underwater. But the Maldives is a unique case. Many fishermen here, particularly in Laamu free-dive down with a bag or net and catch the groupers by hand and so can easily see the size of the groupers they are catching. For this reason, size limits (if they stick to them) could very much improve the state of the grouper fishery.
Thinadhoo, Vaavu Atoll
Usually Shaha and I would carry out this work in Laamu, but it was proving difficult to get our hands on large numbers of groupers and every new moon period when the groupers spawn is a precious time for our research. We needed a bigger team and to move to newer and more plentiful grounds. So, joined by three staff from BLUE’s project partner, the Maldivian Government’s Marine Research Centre, Fahmeeda Islam and Maeesha Mohammed and Shareefa Ali (BLUE’s intern), we headed for the island of Thinadhoo in search of groupers.
On our arrival at Thinadhoo, we quickly sought an area where we could dissect the fish. It turned out to be a small open sided hut beside the sea with a pleasing cool breeze. Inside were two large waist-high, flat, concrete blocks which we were told local fishermen use for processing fish. It was perfect. With some spare time on our hands, the five of us went exploring. We strolled down the streets lined with traditional houses where bougainvilleas and frangipani tree branches cascaded over walls and provided us with most welcome temporary havens from the blazing hot sun. The girls educated me thoroughly on local Maldivian botany including one plant called nithabadi pronounced ‘nee-ta-badee’ whose seedling makes a loud ‘SNAP!’ when you pop it on your forehead. This caused us much amusement as we watched each other bang our heads with this seedling. It was a necessarily light moment given the long, sweaty and smelly week we had ahead of us. As we walked lazily along the soft sandy beach, the raging red sun began to settle gently on the horizon, the waves lulled and in the crystal clear blue shallow waters we bore witness to some extremely special visitors, namely, baby black tip sharks.
The grouper cage system in Thinadhoo
Early the following morning, we headed straight out to the cage to select our first batch of groupers. The cage, like others we have seen, was about 500 metres offshore and in plain view of the island, so we boarded a speed boat and were there in less than five minutes.
Grouper cages in the Maldives are typically comprised of nets which hang down from wooden planks arranged in a square shape which sit in the sea water atop floating barrels and reach to a depth of about ten metres. Cages can vary in size with some holding only one very small net whereas others can have as many as twenty.
The cage in Thinadhoo was only just bigger than those we had seen in Laamu but also more advanced with rooms and a generator attached so staff can live simply and comfortably aboard the cage – a clear sign that the cage is very active and business is thriving. As we approached the cage by boat, we could already see the large number of the various species of grouper filling the nets of each cage with their vibrant hues of purple, red and yellow standing out beneath the water’s surface. Each net can hold as much as 500 kg of grouper at any one time. Any one cage, depending on the season, can ship as much as two tonnes of grouper which reaps owners some 1 million Maldivian Rufiyaa (MVR) per shipment; the equivalent of $65,000 USD. These shipments can happen up to three times a week and bring in a weekly revenue of 1-3 million MVR which is highly lucrative.
As we boarded the cage, the male workers looked us up and down rather apprehensively. Presumably they were slightly surprised to see four Maldivian women and a white woman interested in purchasing groupers. We put in our order for the sizes of groupers we wanted and four men gathered at each corner of one of the cages and hauled the net up closer to the surface. One worker jumped in with a small net which he expertly used to catch the groupers. The fish thrashed around violently and I was suddenly aware of just how many were in the cage and of their condition. Many bore marks on their lower jaws from fishing injuries or scabs across their bodies which presumably resulted from competitive aggression among the groupers in such an enclosed environment. The size range of groupers in the cage was equally disturbing with some barely larger than my palm, some 18-20 cm in length and others as large as 1 metre.
Dissection ‘a go-go’
Shaha and I were by now very au fait about cutting open groupers. A year ago I would never have thought I would so thoroughly enjoy being immersed in fish gore while slicing open groupers and sawing off their heads without even flinching at the spurt of an artery or the sight of an unexpected post-mortem gill reflex. Gone were the days when we were too afraid to even penetrate the fish with the knife blade as it would skid along the scales of the grouper’s belly (ever so feebly) until we realised we had to put some ‘oomph’ into it if we were to find any gonads.
Once we had our groupers we headed back to Thinadhoo to set up our work space ready for sampling. We lifted the groupers out of their ice box, praying that they were actually dead and wouldn’t flinch once we had a hold on them, which was a challenge in itself, given that they were covered in layers of thick mucus. With them peacefully laid out on the measuring board we took the length measurements before prying open their mouths to shove a hook in so that we could hold them up and record their weight. That was the easy part. We were eager to show our new colleagues how it’s done so that they could readily assist us and speed up the process.
Lethal weapon in hand I began cutting along the belly of the grouper. ‘Steady now!’ As I approached the anus region excretory materials, a violent shade of yellow unexpectedly exploded from the grouper’s backside and flew onto my trousers.’ It’s all washable’ and ‘I love groupers’ I told myself. Keep the end goal in sight girl! ‘Important research’, ‘key predators on reefs.’ To open the fish properly, we needed to break the gill and head bones of the fish. Twisting my knife in I waited until I heard a ‘’CRACK’’. Yes, the bone had broken.
The girls, having never done such work before, at first looked apprehensively on from a safe distance. Thankfully when it was their turn to give it a go, they all took it on readily and with huge enthusiasm. Whew! Nonetheless, a few groupers in, they spotted some enthusiastically mobile parasitic worms and let out some dolphin frequency squeals. As we all roared together with laughter I slowly felt like slightly less of a wuss as I painfully recalled my first encounter with the beastly things. Shudder.
In exchange Fahmeeda and Maeesha showed Shaha, Shareefa and me how to locate and remove otoliths. All fish have otoliths which are small ear bones located beneath the brain. In the same way as trees can be aged through their rings which form due to temperature changes over time, otoliths can be used to estimate the age of fish species. Determining the age at which groupers become sexually mature would complement our research into the length-maturity relationships of Maldivian grouper species and provide greater insight into grouper life history traits which need to be well understood if wild stocks are to be managed properly.
Otoliths are unfortunately opaque white which matches the colour of their surrounding flesh and very small indeed. To even get close to finding them necessitates sawing through the head just behind the eyes. This task job seriously challenged my gag reflex as I was forced to take hold of the eyes with my thumb and forefinger to steady the slimy head as I continued to saw back and forth with so much strength and sweat pouring out of me that I felt as if I just done a gym class after 20 years of being sofa bound.
Success! Head decapitated, I began searching for those precious little ear bones. ‘Shoulda gone to Specsavers’ crossed my mind as I tried desperately to locate the inconspicuous damn things by holding the head up high so the sunlight shone into the dark cavities where they were buried, eyes scrunched up and squinting desperately all the while continuously picking away at the soggy brain with tweezers.
Over the next eight days we spent our early mornings visiting the cage and the rest of our days up to our elbows in grouper guts. As the days passed I found my inner Neanderthal self and was totally un-phased by the three Ss: slime, smell and slaughter. Finally inured to it all I began to thoroughly enjoy it, spurred on by the masses of undersized groupers I had seen in the cage.
Our most shocking find during the trip was the presence of a plastic bag in one of the groupers we were sampling. The bag was in the oesophagus of the fish and had clearly been consumed and consequently become lodged there. Plastic pollution in the Maldives is a huge problem. Most islands simply do not have basic waste facilities like dustbins and so all rubbish is thrown onto the ground or in the ocean.
The size range of groupers currently being caught in the Maldives is an example of extreme overfishing. Groupers of any size are currently fished for simply because there is a market for them. While larger individuals can be exported live as part of the live reef fish trade, smaller groupers are also exported chilled and frozen to Asian markets. Seeing hundreds of undersize groupers in the cage only reinforced our conviction of the value, both the ecological and socio-economic of this work.
The grouper fishery is currently at great risk of collapse and if the fishery is to continue with any decent profits to be had, current size limit regulations must not only be revised but enforced and communicated to the Maldivian fishing community. Once the data has been collected, BLUE’s plans are to do just this. In the next phase of the project, a team will be travelling across the whole country to speak to grouper fishermen about the new size limits and why are they integral to a long-term grouper fishery.
As the trip drew to a close we all breathed a small sigh of relief at the prospect of some rest and freedom from smelling, touching and breathing fishiness but equally we felt a deep and definite small pang in our hearts as we left Thinadhoo. The trip overall had been a huge success. We had sampled 186 groupers in total, which was far more than Shaha and I alone could ever have done in Laamu.
What I will always cherish and remember was working interdependently with four special inspirational Maldivian women who worked together in challenging circumstances to everyone’s mutual benefit and for something bigger than ourselves. The synergy and team work was magical because we combined all our strengths to achieve something I could not have done on my own. For BLUE and the groupers, it was a huge a step in beginning to create a long term sustainable outcome for the fishery. In other words, sharpening the saw!
