Building Various Pueruli Traps for use in Lobster 'grow-out' Aquaculture

[jamesmusslewhite]

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This is a spin-off thread from the 'Building a Small Lobster Hatchery here in the Philippines' https://www.istorya.net/forums/busin...ilippines.html I will be discussing several types of lobster Pueruli traps which are commonly used with success in pueruli collection in neighboring countries, but have yet to be widely used here in the Philippines. I have also designed two different units which I have already constructed the frames which I will be deploying on Dinagat Island. This is for a study I will be conducting and sharing findings with a local university and fisheries department. These two prototypes are a floating 'light' trap and a coconut log trap which will be durable, inexpensive to construct and easy to use and maintenance. These will be used to safely 'live capture' lobster Pueruli (plural)/Puerulus (singular) for 'grow-out' and fed research. I will be maintaining logs to document nightly catch numbers throughout the collection season, details as to preferred locations and water depths. The captured Pueruli will be quickly relocated to 'nursery grow-out' nets where they will be properly sized and monitors. Individuals will be maintained in a low-stress environment, properly sized and sufficiently sheltered. This will allow accurate monitoring as to their individual weekly growth rate and total body weight. As latent stage Pigment-pueruli enter their 'Puerulus' Instar cycle they will be separated and monitored. This will allow the documentation and accurate accounting of individual mortality rates. The 'Puerulus' Instar historically has a mortality rate of 40%-60%. My goal is to lower stress levels, minimize acts of aggression and cannibalism and decrease mortality rates. Those which survive the 'Puerulus' Instar (moult) then are in a feeding state.

These individuals will then strictly monitored as to food types, food preferences, total growth/weight gaind, stocking densities. The goal is to accurately determine optimum levels needed to maximize stock growth, general health; while minimizing food costs, labor costs and environmental stresses. This information will assist 'grow-out' aquaculture operators, fishery services and environmentalist.

I imagine most readers of this thread really do not know what Pueruli/Puerulus (lobster fingerlings) look like. But I am sure most have seen more mature size lobster. This little sea bug is commonly referred to as a seedling, seed or fingerling in most text you will read, and it is the very heart of the lobster aquacultural industry. This is a Puerulus of the species Panulirus ornatus commonly referred to as the '''Ornate Rock Lobster' or 'Tiger Lobster' and is one of eight different species of Panulirus lobsters commonly found in these waters around the islands of the Philippines. It grows the fastest and the largest of any species of lobster in this region, and is most prized by the Asian markets (Singapore, S.Korea, Japan, Hong Kong and China). It yields 38% more usable meat per individual (per weight size) than do North American and European lobsters species, and the meat yielded has been proven to possess a creamer texture and sweeter tasting meat. Sorry Canada, Maine and Europe but the fact is that your clawed lobsters are actually considered as 2nd rate compared to these puppies. And here they swim to shore nine months out of the year (free from the sea) and to lobster aquaculture they are literally swimming gold. From this size small size a 'Tiger' lobster can, in less than 24 months, grow to over 1 kilo (1,000grams) and be worth over 2,800php per kilo (1,000gram) when sold to the lobster buyers.



Panulirus 'ornatus' (Tiger lobster) Pigment-puerulus early latent stage

This is the floating 'light' trap which I designed, and so far have built the bamboo frames for five units which will be deployed this Spring in the waters off Dinagat Island. I have chose a location within a short walking distance from the township of Cagdianao which is one of many collection hot-spots here in the Philippines. I intend to use various types, unit styles and methodologies when deployed. This is to help determine both effectiveness and optimum water depths to deploy these collectors and traps. If the deployment of these devices and methods prove successful, then it is my hope that this collaboration with the university and fishery departments will network allowing local small scale fishermen to use this knowledge to generate much needed revenue streams; while helping to also provide easier access and more abundance to healthy seedlings for their lobster grow-out operations.


The platform is constructed of bamboo and deployed generally in areas at a water depth of less than 9 meters. Nylon cord is tied to the bottom of the frame and suspend bundles of netting (1 meter apart) down to the seafloor. The platforms I built each suspend five lines of net bundles. These are deployed during the 'New Moon' cycles when the Pueruli are swimming to shore under the cover of darkness. You can see by the drawing that suspended in the center of the frame is a lamp.



This lamp can be fuel, battery or electric and is centered over the floating platform to help attract the incoming swimming Pueruli to the suspended bundle traps. Researchers have learned that the primary settlement of Pueruli are within 2 meters of the surface and 2 meters of the sea floor. The Pueruli are naturally drawn to the light source similar to that of a common moth. The light attracts the Pueruli directly under the platform where the suspended mesh bundles then entice them to settle within the bundled netting. These are harvested around midnight and at sunrise. The traps are deployed before dusk and collected after dawn when they are harvested. One advantage with these units is once they are deployed the fishermen can continue fishing and only has to attend to the unit to replenish fuel for the lamps or late-night harvesting.



The drawing of mine bellow shows the second prototype which I will be building over the next couple of months. These style of collector is known as a Vietnam style 'Coconut Log' Puerulus Trap. I will be building 5 of these units at first, I may have as many as 50 of these units in the water by the end of the year. My first 'coconut log' units will be deploying in the same general location were I will be using the floating 'light' traps. Over the next couple of years I will use five 'floating light traps' and the five 'coconut log traps' in the same general area in a cluster. Then as these units are built and added they will form another cluster in another location. By locating these clusters in many locations and maintaining records throughout the season, over several seasons, trends can be observed. These trends will help determine best locations and water depths in which to deploy them.



These units will be durable, inexpensive and easy to make and are permanently anchored to the sea floor during the whole of the collection season (9 months). These placed in locations with a minimum water depth of 2 meters, which means boat propellers have clearance and units can therefore remain stationary year around. These log traps are harvested each morning at daybreak during the collection season, this is because lobsters are nocturnal and will seek sheltering before sunlight. The floating 'light'' traps are more complex to deploy and use which restricts their usage for many poorer fishermen, but the 'coconut log traps are extremely low cost and being permanently located in the shallows allows poorer fishermen to build and maintain them. I have yet found any credible documentation showing the average yearly collection numbers capable of either trap type. What I have found says they were successful at collecting Pueruli, but not documented yearly results. My curiosity drives me to find out for myself, because if both types prove to be productive it could be a huge benefit to rural fishing communities.


This photo shows a Vietnam style 'Coconut Log' trap in usage, and actually shows several Puerulus who have settled in the shallow holes. You can see that they back into the hole and use their antenna to monitor the conditions outside of their newly settled habitats. If you look closely at the lower photo you can see their antenna protruding from the holes. Just those three Puerulus could easily net that fisherman 600php, and if he has 4 traps or more which each had 3 tenets to collect that fisherman would have collected a potential 2,400php that morning. One could then see the benefit such a simple device could have on a small-scale pueruli/juvenile fisherman and his family, but this would also benefit as it would allow commerce to small coastline communities. These Philippines has over 14,000 kilometers of coastlines with a huge number of small rural areas. I venture that most members of this forum have family members who are almost solely dependent on the sea, and such a simple venture would require very little venture capital for a start-up.


As my study expands over the next few years I will also start deploying several other Pueruli trap types and methods, but I feel these two mentioned above may be the most promising to start with. I am excited to start this little venture because perhaps it will allow me to gain answers to question that I have had for years. I promise that I will openly share any knowledge I gain with forum members, so you can share it with others.

[jamesmusslewhite]

Over the following weeks I will be adding quite a bit of new information to this thread, and there may be forum members who have a deep interest in lobster 'grow-out' aquaculture.

I fully understand just how difficult it is to find useful information on the subjects and topics involved in the industry. This is why I decided to make a 3-part Youtube video to hare what I have learned and I finished and uploaded the first video New Years eve. And I am working now the get the second video of this 3-part video series, and hope to have it ready sometime in March.

This Youtube series so far has taken three years organizing facts and information, writing and revising scripts, creating needed drawings and diagrams, seeking and collecting topic related photos, learning software and doing voiceovers; then 845 slides and an hour 27 minutes of my flapping lips into a cell phone. Here is the link to the first video of this 3-Part lobster tutorial for those interested. Subscribe, Like and Share with others. I doubt you will not find this much useful information on lobster aquaculture together anywhere on the net. Enjoy

[jamesmusslewhite]

There are certain advantages with Vietnam style 'coconut log' traps which I particularly like. They materials easily obtainable, unsophisticated and easily constructed, biodegradable and are excellent to place at a location with a minimum low-tide depth of 2 meters, This allows the bow of small boats and propellers to pass over the trap, even at low-tides, will little to no issue. Though they are more effective when nets are used with log traps, for the poorer fisherman they can be used without the additional expense of nets. They can be placed early Spring and remain the whole of the collection season with very little maintenance. And they are easily harvested each dawn throughout the collection season. And if 'Coconut Log' are deployed in conjunction and if used with other net collection methods and floating 'light' trap configurations pueruli and juvenile collection can be a very successful endeavor for coastal small scale fishermen.

[jamesmusslewhite]

The frame is constructed of a medium size lightweight bamboo lengths, which is lashed together with nylon monofilament 1.90mm line which is 150lbs.test rated, the local hardware stores simply referrer to it as #150 nylon. The can be as large or small as you like, but the preference for this project is a base measurement of (2 meter x 2 meter). This will allow the base to have a sufficient width to withstand wave action of the sea, while still being small enough to be easily deployed or removed from the water by a fisherman working solo using a small wooden boat. These floating platforms will most likely be deployed well within 200 yards of the shoreline in a water depth of less than 9 meters.



The base of the platform consist of three layers of bamboo . This allows the base of the framework to have the necessary tensile strength needed to withstand constant wave action, and the stresses imposed by the weight and constant tugging and pulling of the mooring lines and the five lines of mesh bundles which will be tied to the bottom of the frame. The bottom of the base frame will also be used to hash the flotation (plastic Jerry cans) in place once the frame is completed.

The roof of the platform is a pyramidal bamboo frame which is used to house a emitting light source and a foul weather shield. For my own purposes I will use a galvanized metal wash tub (inverted) with an additional sheet tin shroud added, with all the interior and exterior surfaces painted a reflective white using marine rated paint. For my light source I will use simple kerosene (hand-pump pressured) fuel lamps. These are extremely dependable and lightweight requiring only the occasional replacements of spent mantles. Kerosene pressure lamps can generate the bright light needed to attract swimming Pueruli towards the platform. The white painted inside of the metal frame helps to reflect the lamp light towards the water surface, but also serves two other functions. a) The (inverted) metal tub with the added metal shroud acts a a rain guard to prevent the rain from contacting the hot glass globe. b) Acts as a heat guard protecting the flammable bamboo framework as fuel lamps can get extremely hot during long usage. Most kerosene lamp have a minimum of 1 pint fuel reserve which is sufficient for 8-10 hours continuous operation. The illumination rate of an average single-wick lamp is approximately 784 lumens which is on par with a 60 Watt light bulb, and double-wick lamps can produce the light equivalent to that of a 100 Watt bulb. They also generate lots of heat, so properly venting that rising heat is important. Some may of course will want to use unleaded gasoline instead of kerosene, but there is an increased chance of a fireball if there is leaking of gasoline around seals especially during times of heavy waves action.

I could always use rechargeable LED lamps, fuel generators or use fuel lamps which are converted to use vegetable oils, but for the legitimacy of test I must use the simple materials and methods which will most likely be used by the average poorer small scale fishermen. They would not be able to purchase more expensive lighting systems. Simplicity is the methodology upon I will be establishing my primary baseline of the study, so I will be be employing the K.I.S.S. philosophy and good ole jungle-engineering during this project.



The framework has been fabricated in a miniature straw model which shows that is is durable enough to withstand the multiple directional stresses the framework will experience when deployed. So I am confident that the design is sound. My drawings which I have posted in this post only show the primary placement of the main bamboo used in the framework of the base. These drawings do not include the and do not show the braces do not show all the inner bracing and placement of cross-braces.



This shows the placement of the plastic 'Jerry' cans which will be used for buoyancy. These will be lashed to the bottom of the bamboo frame. There are some additional bracing which must be added first to the framework which are not shown in these drawings. These will be discussed later in this thread.



This shows a 2D view showing the light placement, bamboo frame and placement of the plastic 'Jerry' cans. These plastic cans are quite common here in the Philippines for shipping cooking oils, coconut wines, coconut vinegar an soy sauces. You can also easily find them being sold in local stores so they can be used to carry and store water and fuel.



they are perfect for lashing the plastic 'Jerry' cans onto the bamboo framework. Of course one can substitute these plastic cans for blocks of Styrofoam or other types of jugs, containers or small barrels. As long as it floats it will work, but always be mindful to keep the bottom of the frame as clutter-free as possible. This is so it will be easy to employ and harvest the 'net bundles' and to insure that as much light as possible can be delivered to the water surface below the platform.

This shows a 2D view showing the light placement, bamboo frame and placement of the plastic 'Jerry' cans. These plastic cans are quite common here in the Philippines for shipping cooking oils, coconut wines, coconut vinegar an soy sauces. You can also easily find them being sold in local stores so they can be used to carry and store water and fuel.



they are perfect for lashing the plastic 'Jerry' cans onto the bamboo framework. Of course one can substitute these plastic cans for blocks of Styrofoam or other types of jugs, containers or small barrels. As long as it floats it will work, but always be mindful to keep the bottom of the frame as clutter-free as possible. This is so it will be easy to employ and harvest the 'net bundles' and to insure that as much light as possible can be delivered to the water surface below the platform.

[jamesmusslewhite]

So you see my personal drawings above showing the types of traps I have already built or presently in the process of building, but do not understand what they are designed to catch. You may also not understand the terminologies I am using when describing the pueruli lobster fingerlings. This is primarily a different term used for each stage of development, and when talking about lobster fingerlings there are actually five distinct sizes (or stage of development) used within the industry.



These little delectable sea-bugs are Pueruli (plural term) the singular term is a Puerulus. There are four developmental stages for Pueruli but the first occurs out on the edge of the Continental shelf, they Instar (moult) and transition to a clear little critter called a post-phyllosoma Panktonic-puerulus (stage 1). This stage will have developed to a (stage 2) Clear-puerulus by the she reaches the coastal coral/grass zones, and will be the smallest size Puerulus you will live-capture. Then over the next 4-5 weeks she will transition through the (stage 3) H-puerulus and the (stage 4) Pigment-puerulus. This is when for the first time they look like little facsimiles of their parents and is the first many of the 22 species of Panulirus lobsters can be properly identified, others will still need to transition to Algal-juveniles before reliable identification is possible due to lack of distinguishable markings.

Once (stage 4) Pigment-puerulus reaches their latent stage they face an Instar (moult) which naturally has a 40%-60% mortality. But those that survive this Instar (moult) will have transitioned to the Algal-juvenile developmental stage. Most of the seedstock sold to local lobster farmers for their 'grow-out nets are Pueruli because they see them as being cheaper to purchase. The price for a (stage 2) Clear-puerulus just three years ago was 90php but today ranges from 200php - 250php, and the price for a (stage 3) H-puerulus or (stage 4) Pigment-puerulus now sell for 250php - 350php each. And still 40%-60% of those will die, more if they are mishandled before being delivered to the lobster farmer. I have personally know buyers who lost more than 80% of their Pueruli within three weeks after they were delivered.

Once (stage4) Pigment-pueruli successfully moult to Algal-juveniles those prices double, because those within the industry know that more than 90% of Algal-juveniles will survive to reach the Sub-adult size (500+ gram) buyer's weight. Presently this Sub-adult size (500+ gram) weight buyer's price is 2,8000php (per kilogram), and at the right time of the season (around Chinese New Years) a (1,000+ gram) Adult size individual has a buyer's price of 3,is 4,000php (per kilogram).

If one specializes in the 'live-capture' of Pueruli and Algal-juveniles it can be quite profitable as a stand-alone venture. If in combination with the ability to also use 'grow-out' aquaculture to successfully raise the seedstock you caught to market weights you can generate exceptional profits. If you are in the right general locations.

[jamesmusslewhite]

[jamesmusslewhite]

I built one complete floating 'light' trap frame and but it through a lot of stress testing and I am quite pleased with the results..



I have three other frames constructed but have not lashed on the floats yet. This shows a top view as the units are lying on their side.

https://www.livingincebuforums.com/u...944b8e1f55.jpg

This shows bottom view of the three same units lying on their side.



and this photo shows the variety of dwarf bamboo used in the construction of these frames.

[jamesmusslewhite]

It took me a couple of months to find the species of bamboo I wanted to use to make the first four frames. This is a thick-walled dwarf bamboo species which will allow me to build a frame at a 3/4 scale.



This will show a step by step walk-through of the construction of the frame of a Floating 'Light' Trap to be used to 'live-capture' lobster Pueruli.



First cut the required bamboo lengths.



Lay out the the first four lengths to form a square and lash together the corners.



This photo shows the lashings.



Then the five remaining bamboo lengths which will form the frame base are then placed and lashed together.

[jamesmusslewhite]

Posted September 29, 2018

2060648852_018(Custom)(3).thumb.jpg.0766fac30422f0 cfd8e5526bc2104506.jpg

The frame base needs length sections which will allow the plastic 5gal.''Jerry' cans to be sufficiently lashed to be bottom of the framework.



This unit actually sits on 6 plastic cans (3 on the edge). Two shown in this photo are just being used while all the lashing are being completed.



Photo of the lashings used.







[jamesmusslewhite]

This photo shows the complete frame with all the bracing.


Moving the platform to the waters edge. As you can see the frame is light weight and very easy for two people to carry.



The unit was set in the water and it was sufficiently buoyant and stable.



We still need to fabricate lightweight holding racks in the topsides of the outriggers. There will be four floating traps (two on each side) and transported to and from the locations were they will be deployed.