His bad reputation of "man-eater" sticks to his skin. It is urgent, however, to change our perspective on this fragile animal that is essential to the balance of the oceans.
Storytelling (choose 1 of these 2 assignment: podcast OR storytelling) (option 3)
You will write your own story about your thesis or about a marine science topic which interests you. This story will be a minimum of 250 - 500 words or 1500 - 3000 characters.
This storytelling is about the natural and anthropogenic threats that sea turtles have to deal with nowadays since they hatch. The aim of its style is to catch the interest and transmit science to all the public, specially to the children. In my opinion, the youngest public has an important role on the conservation of marine ecosystems and even though science could be complex to understand, they should be aware about the current state with the new research outputs.
A fictional story of a true event: how a community of whale-sharks fishermen ended up by switching to Eco-tourism. Inspired on my personal experience.
In this short article I want to tell you the story of one of Germanys most remote islands that is a nature reserve in the Baltic Sea, a refuge for migrating birds crossing the sea and a site of special imortance for seabirds, waterbirds, seals and many more in a highly used and affected area.
International scientific collaboration – its importance and role in saving a species from the brink of extinction
Harbour porpoises are one of the many species listed under Annex II of the European Union Habitats Directive, requiring each member state to create Special Areas of Conservation (SAC) for them. Member states are also in charge of managing and monitoring these SACs and providing the EU with reports on their conservation status.
Harbour porpoises are well distributed in the northern hemisphere. There are a number of subspecies that have been identified and are divided into several populations. As a whole, the general population of harbour porpoises is thought to be in the hundreds of thousands. Unfortunately, like many other marine mammals harbour porpoises are an extremely mobile species and do not seem to stay in any given area for long. There are some areas that they are known to frequent, but these areas can often change due to various factors usually concerning their environment or their prey. Unfortunately, this makes their conservation a very difficult task.
Two sub-populations of harbour porpoise in the Baltic Sea have been recently discovered through nuclear and mitochondrial DNA analysis, skull morphometrics, and tracking via satellite and acoustic detections. These two populations have since then both been listed as vulnerable and critically endangered by the ICUN. The harbour porpoise is thought to be one of the only cetacean resident in the Baltic region, and their numbers have recently declined significantly due to several environmental and anthropogenic factors including severe ice conditions, environmental contaminants, and the introduction of new types of fishing gear which led to an increase in harbour porpoise bycatch.
Upon realising the danger that the populations were in, scientists from Sweden, Denmark, Germany, Finland, Poland, the United States and the United Kingdom came together to assist in the quest to find out more about these populations. A two-year acoustic monitoring project was launched to try and assess the movement patterns of each population, as well as attempts to identify which areas they frequented were of biological significance (i.e. mating grounds, feeding grounds).
The study was concluded in 2013, and the results were published earlier this year. The preliminary results were shared with governmental bodies and are now serving as a solid scientific foundation for taking decisive management actions for this critically endangered population. It is an excellent example of how nations need to come together for the conservation of transnationally migratory animals.
The story "lost bridge " contains my own experience on one of remarkable but hidden place in Sri Lanka. The place called Adam's bridge is ecologically significant as it contains numerous marine ecosystems and marine organisms. The higher security and the belief on this place is a reason for good protection of the place. Hope you enjoy the reading!
A short story about a disgusting but fascinating discovery we did when volunteering in the Caribbean.
- My apologies for the bad quality, I took a screenshot of the word document, since I could not upload word nor pdf.
Oh, oh, oh, I know that Christmas is coming, but if you prefer horror stories than fairytale stories, you should keep reading this dark letter. I advice the faint-hearted to continue their way.
/!\ Projection of the results of my master thesis /!\
Better than watching television, having an aquarium can entertain you hours and hours. Being an aquarist is a passion necessitating patience, rigorousness and self-investment. So now imagine you, bringing a piece of the tropics into your house to shine the grey weather of Europe. What about corals? Keeping corals is not the most easy task and requires some experience. In fact, in order to survive, most of the corals require a very clean water (0 ppm of nitrate and phosphate), very stable water parameters, an efficient mixing current and a good light exposure. Keeping corals is therefore very rewarding. The more the coral will enjoy your tank, the more colorful it will be. But coral beauty has a price that was not taken into account during those marvelous underwater colonies' evolution: Humans love it! In fact, the fragile reefs are threatened by aquarist's coral collection but also by the climate change, the pollution, etc.
Even though it is not implemented/respected everywhere, coral collection has been limited and controlled, increasing its price for its exportation to Europe and the United States from countries such as Indonesia, Philippines, etc. Following this, it was then profitable to farm corals in Asia. While studying in Belgium, I worked in a shop that sells corals. Most of them came from Bali where they are aquacultured. As well as for (freshwater and saltwater) tropical fish importation, the only knowledge of where it comes from and how it has been collected/grown remain unclear as the supplying trade is only based on how the importer trusts the exporter. In fact, all the process before closing the animal's box for its exportation by plane is a black box. This poses ethical concern for the animal but even more for the Asian workers as we don't know how well they are treated. Even more, for a business of millions of dollars that should be transparent, only a few know exactly what is happening there, unfortunately.
Along with the development of the aquarium technology performance, culturing coral has become more profitable. In Europe and in the USA and Canada, for the past few years, start-ups have grown based on this serious idea and some coral production. Investors remain cautious though, as most of the start-up projects remain experimental. Nevertheless, as coral reefs habitat is collapsing, the coral individual itself is becoming more and more valuable. Rare specimens can be valued for more than 200$ for a piece of the size of a Brussels sprout!
As it is also possible to grow coral in a domestic aquarium, by taking a cutting from the colony, growing could also be profitable for aquarists... and their wallet. So, why don't you start?
How Much Do You Know About Hilsa? The National Fish of Bangladesh. I am here to help you to know about Hilsa, our national pride!
The Indian shad, Tenualosa ilisha (Hamilton), popularly known as Hilsa, GI (Geographical indicator) product of Bangladesh, belonging to the Family Clupeidae. Hilsa ilisha was renamed as Tenualosa ilisha by Fisher and Bianchi in 1984. However, the locally called ‘Hilsa or Ilish’ in use for more than over a century has stood the test of time. The Hilsa is considered as one of the most important commercial fishes dependent on the single species Tenualosa ilisha belonging to the habitats of Indo-Gangetic and Brahmaputra river basins. Though Hilsa is distributed wide geographical area but mostly abounded in Bangladesh, about 60-65 per cent of global Hilsa catch is reported from Bangladesh.
Hilsa shad (T. ilisha) is anadromous in nature, i.e., capable of withstanding a wide range of salinity and migrating long distance from marine habitat to up-stream freshwater. Hilsa lives in the sea for most of its life but migrates to inland freshwater. It starts spawning migration upstream during the southwest monsoon and consequent flooding of all rivers. The eggs are deposited in freshwater in river canal, creeks and hatching takes place within 23-26 hours at an average temperature of 23̊C. Hilsa is relatively fecund & Numbers of eggs are found to be 144 thousand in 28 cm long fish up to 2.3 million in 44.5 cm long fish reported from previous studies. The fecund Hilsa is known as Mother Hilsa, prohibited to catch or illegal fishing during September -October about 22 days for ensuring safe breeding of Mother Hilsa. The peak-breeding period of Hilsa is placed during the full moon in September- October. Larvae and juveniles make their way downstream to the sea during the period of 5-6 months.
Fig 1. Hilsa filsa (T ilisha), national fish of Bangladesh; the photo has taken on June 06, 2016, when I was based in WorldFish center.
In about 6-10 weeks, fry grows to about 10- 26 cm and the size range known as jatka, prohibited to catch by Bangladesh government all year round. At this stage, they start migration to the sea for further growth and maturity and a year in the sea, Hilsa become mature and their spawning migration towards inland rivers starts again thus continuing the cycle. Hilsa may reach up to 60 cm in total length, may attain first maturity at the end of the first year or at the beginning of the second year.
The average Hilsa production of Bangladesh is about 496,417 lakh metric tonne/year that contributes to 12 per cent of the total fish production of Bangladesh & it soared gross domestic product (GDP) at a rate of 1.5 per cent. About 0.46 million people are either directly or indirectly dependent on it, about 2 percent of the country’s total population (116 million) is involved in the Hilsa fishery either directly or indirectly for their subsistence. To increase natural production by ensuring safe breeding ground Bangladesh government declared 5 Hilsa sanctuary. All kind of illegal fish or jatka fishing, mother Hilsa fishing is completely banned and for the survival of the fishermen govt is providing 40 kg rice per family in each month during the ban period.
Hilsa, the king of all species has high demand due to its oily texture, mouth-watering flavor and unique taste, enriched with omega- 3 fatty acid which is good for controlling cholesterol and insulin level. The fats found are unsaturated in kind. This fish also contains proteins and other compounds, lipids and very low level of carbohydrates.
“IF YOU VISIT BANGLADESH DON’T FORGET TO TASTE OUR PRIDE THE NATIONAL FISH, HILSA “
Fig 2. Hilsa fishing by traditional fishing; Photo has taken Feb 26, 2016 during field visit when I was based in WorldFish center.
We must understand that everything is connected by the ecosystem chain. Animals and organisms are connected to contribute to the environment system in a perfect synchrony and mutualism. Now a days, the anthropogenic impact on the animals and in the environment is heavy, threatening since the small to the biggest organism on earth. Overfishing, bycatch and marine litter have an impact directly on marine birds, decreasing the population in the colonies drastically together with climate change. The Common and Roseate Tern colonies in Europe have projects of conservation continuously working since 1968 that is why they are considered Least concerned in the IUCN Red List. Only because of that effort, of many and many believing people and spending their time with a small bird that makes a huge difference in the environment. They are highly migratory birds which means that the migratory stations also must be preserved to complete the life cycle of this birds. They are a precious element for the biodiversity in the marine ecosystem and are considered sentinels when we have to analyze our waters. That is why we have to search partners to develop projects and understand more about the real situation affecting our colonies. As their diet are composed mainly of fish, they bioaccumulate xenobiotics and behave as host for many parasites, remembering that the fish they eat likely have commercial value. In Ireland, Colonies of Roseate Tern and Common Tern take their places in Rockbill Islands and Kilcoole. The previous studies show that the population is increasing but still there are many dead chicks found in the nests and in no other study they have reported any health assessment of this population. My study is aimed at accessing any possible information about the chick’s death among the colony identifying parasites, and organs alterations using histological tool analysis. The microscopic method will make me dive deep at the cell level, and the results will help me to come with a conclusion. The analysis of the body for me is something from another world, understand the organs alterations and outcome with possible death cause is priceless. The ante mortem and post mortem signs can be very subtle but the microscopic method many times certify the information in a cellular basis. I chose to dedicate my time with these birds because we can have big surprises inside of these organisms. The environment is changing giving more chances to infections and new diseases to show-up specially in a highly active animal. We already know that a long-term study is needed to keep up with the generations and record the annual trend, as the possible pathologies affecting the population. My study will be a support information to compare with other researches carried out by other institutions in other places that are migratory stations for these birds.
Phenomena give life, and inspire us in life, especially as aspiring scientists on Earth. To some, childbirth is a phenomenon that bring life on Earth, while to most, the Aurora is a rare beautiful phenomenon that can be witnessed more frequently in certain parts of the world; and to others, Paris Hilton is a walking phenomenon of timeless beauty.
And what kind of phenomena can bring awe in the eyes of marine scientists, that prompts us to redirect focus on self and towards our surroundings?
The Barbie Lake
A metagenomic studies conducted by Australian Genome Research Facility (AGRF) Brisbane identified extremophiles specifically known as halophiles inhabiting the salty Lake Hillier which possess a pastel Barbie pink colour. AGRF found out that the creator behind this phenomenon is a bacterium species, Salinibacter ruber. During this research, scientists have stumbled upon an unexpected microbe, Dechloromonas aromatica,which can break down compounds used in chemical solvents. This may present evidence for a tanning station that once existed by the lake and used the lake for tanning purposes. The power of metagenomic analysis, don’t you think?
Optical illusion is often man-made, as we see in visual art museums. But could it be that these artists are also inspired by nature?
Here, an illusion of underwater waterfall in Mauritius is the result of seafloor spreading due to tectonic plate movement. Sand from the shore are pushed by the ocean currents and fall into the depth of the ocean trench, creating this illusion. No earthquakes, just the science behind this beautiful optical illusion, that leaves us in awe.
Famous among marine biologists, is the crop circle created by an alien that lives under the ocean. Do you recall about the conspiracy theory of aliens landing on Earth and creating patterns on the croplands in countries such as the USA? Well that is fake, and this perfectly symmetrical underwater crop circle is real! We have discovered a male alien species called the Japanese Pufferfish which created this crop circle to attract its potential mate. Very meticulous indeed, and I’m sure this pufferfish species must have picked up this cultural trait from its Japanese ancestors.
Friends or Foes?
Having being recently back from a whale watching trip in Tromso, nature has inspired me once again. Orcas and Humpbacks were feeding at the bay filled with Herrings. The tour guide observed a baby humpback swimming with some Orcas, which is an unusual sight considering the tension generally observed between the two Cetacean species. The Orcas would try to kill the Humpbacks, possibly due to the lack of food resource, or the interference in the Orca chase for its prey by the Humpback. On the other hand, with the Orcas ability to communicate over 100 miles, the Humpbacks pick up on the communication, relying on Orcas in the search for feeding grounds. With the effects of climate changes and fishing pressure, it looks like the political game between them will only get stronger
One of the biggest mysteries of cell biology is how mitochondria, an oval energy producing organ has its own DNA (MtDNA) and how they still kept this DNA considering the large size of DNA the cell itself has. Scientists think that mitochondria were once independent single-celled organisms until, more than a billion years ago, they were swallowed by larger cells. Instead of being digested, they settled down and developed a mutually beneficial relationship developed with their hosts that eventually enabled the rise of more complex life, like today’s plants and animals. The double membrane of mitochondria is a proof of this theory and it is also similar to how chloroplast in plant cells was also formed. The transfer of MtDNA is exclusively from mother to offspring (male & Female).
Over the years, the size of the mitochondria has reduced with the Nucleus containing a vast majority of genes of which some regulate the functions of the mitochondria itself. For example, there are 37 mitochondrial genes in humans against the over 20,000 genes in the nucleus. It is believed that over the years, genes have jumped from the mitochondria to the nucleus. That sounds interesting, but if that is true, why has the mitochondria still retained some genes up to now? Since their mutation can cause organelle related diseases and can subsequently lead to the dysfunction of brain, liver heart and other delicate organs?
Analyzing more than 2000 different mitochondrial genomes from animals, plants, fungi, and protists (like amoebas), scientists traced their evolutionary path, creating an algorithm that calculated the probabilities that different genes and combinations of genes would be lost at particular points in time. The study concluded that all the remaining mitochondria genes help in energy production and that a gene is more likely to stick around if it is very important to the energy production complex system.It is more likely that hydrophobic protein encoding genes are made in the mitochondria since they may get stuck in transit if they are made elsewhere other than the mitochondria and have to be transported to the mitochondria. The chemical make up of genes can also tell if they stick around or lost over time. The ability to withstand harsh environmental conditions in the mitochondria is one condition that determines the persistence of a gene
Keeping those genes locally in the mitochondria gives the cell a way to individually control mitochondria because pivotal proteins are created in the mitochondria themselves. That local control means the cell can more quickly and efficiently regulate energy production moment-to-moment in individual mitochondria, instead of having to make sweeping changes to the hundreds or thousands of mitochondria it contains.
In a nutshell, it is like grabbing a fire extinguisher to put out the flames when your car catches fire instead of picking up the phone to call the fire service. That is producing certain proteins in the mitochondria where they are mostly needed helps the cell to better regulate energy production
It is no news that we live in a society where flat-Earthers and those who genuinely believe dinosaurs did not exist still roam the Earth, despite all evidence from outer space pictures and fossil records. No wonder people are so suspicious about things they cannot see or experience within their lifetime. However, there is one process that even the most skeptical of the skeptics (e.g. Donald Trump) cannot ignore and that is Anthropogenic Climate Change.
The first climate change reports have drawn attention to how a continued rise in atmospheric CO2 will not only affect ecosystems but also hinder human welfare, for example, via extreme weather events. Perhaps, thanks to these short-lived bursts of tornadoes and heat-waves people have started to realize the importance of reducing our carbon footprint. On that note, one thing is certain: efforts to try to reduce CO2 emissions and increase the use of alternative energies are already on the rise. This led to an increase in support of research aimed at understanding mitigation in terms of its lasting effects and foreseeing the extent of human-induced disruption in natural cycles.
To try to understand how the Earth-System would respond to such changes, which are mainly caused by the steep increase of greenhouse gas emissions since the pre-industrial era, scientists are now concentrating their efforts on developing Earth-System models. These models simulate Earth as a whole and are composed of modules (Atmospheric, Land, Ocean Physics, Ocean Biogeochemistry, Seabed) which are interconnected and help make the future less opaque, showing how natural cycles would be affected by climate change.
|So how would the Oceans' carbon cycle respond to a scenario where humans actually start to reduce their CO2 footprint?
How long would it take until our oceans return to their pre-industrial state?
Is there even a turning back or have we already got past the tipping point?
These are some of the questions that will be addressed as part of a study conducted at the University of Bergen and NORCE, one of Norway's largest independent research institutes. Scientists will try to understand the lasting effects of human-induced climate change in the North Atlantic through a simulation experiment using one of the most advanced Earth-System Models to date. The experiment consists of increasing atmospheric CO2 emissions at a rate of 1% per year for 140 years from its pre-industrial level of ~290 ppm followed by a mitigation scenario, i.e. a decrease in atmospheric CO2 emissions at a rate of 1% per year for another 140 years and, finally, a post-mitigation phase lasting for another 200 years.
If we are to aim for a manageable future in the framework of a Blue Economy, assessing the effects of a CO2 ramp up/down on important elements of the Ocean's carbon cycle is fundamental. Changes in pH, particulate organic carbon export to the deep ocean and seabed dissolution could profoundly alter both marine life and ecosystem services, affecting for example ocean productivity and the capability of our oceans in being life-supporting systems.
Have you ever thought about how fish feel?
Personally, before being involved in a research project on the welfare of fish, I wasn’t really concerned about their emotions. But that changed, and I will tell you why.
Let me talk you through the procedure of how herring is fished and what a single fish endures during this process:
Imagine being a single herring, part of a huge school, thousands of fish are roaming through the ocean with you. Suddenly you hit a wall of netting, not passable for you or any fish part of your group. You turn together to find a way around it just to find out that you are surrounded by hundreds of meters of net. After a while you realize that the space in the net is becoming less. This continues until you’re crowded together with all the other fish. You get pushed into the net and lose scales and get scratches. You feel that the oxygen in the water around you is disappearing because of the little space and you start to swim faster, trying to escape that situation. This just leads to a higher need for oxygen and you realize that you quickly used all the oxygen available to you. Then you hear a loud noise and fish start disappearing in front of you. They are being sucked into a black tube. This is also your fate and you get lifted up outside the water. Inside the tube you’re getting shaken and pushed around. Your losing more scales and there is no water around you anymore to breathe. Then you finally end up in water again. But this water is freezing cold and quickly everything becomes dark around you and you stop feeling.
You are now inside a tank onboard of a fishing vessel. That does not sound like a nice experience, does it?
Obviously, the fish are being caught for human consumption and worrying about their wellbeing might seem rather counterintuitive. The welfare of fish is only recently being considered an important factor of a sustainable fishery. Creating a more humane way of exploiting the worlds fish stocks is only one of the reasons. The main incentive is to save the fish that are actually not being caught. Some fish are released by opening the net after they endured all the stressors up until being landed using a fish pump. These stressors are usually severe enough to cause them to die, which goes unnoticed by the fishermen, which think they are releasing healthy fish. This way hundreds of tons of fish are being taken from the ecosystems without being used.
That is why, the fish’s welfare is important, and everyone should spare a thought about how fish actually feel. Fish wellbeing and how fish behaviour changes when exposed to stress is a relative novel field of research, trying to help create a more sustainable and humane fishery for future generations.
Sharks are nowadays trending topic, but why?
Here is the answer: they have been banished for long time, pop culture have seriously damaged their image as killer machines, with nothing else in their agenda but to kill people.
Wait, killer whales are also named killer because of one reason! Yes, yet movies and other media have made sure to picture them as gorgeous special animals we need to protect, and this is true. It is as crude true we need Willy and Flipper as we also need the astonishing paraphyletic group of elasmobranchs!
That is why I am so concern on giving them a high spot in protection, free-ranging in nature, many shark and ray species are social, but what that does mean? It means these animals with a similar proportion brain/body mass as mammals and birds are also highly intelligent and evolve in complex relation with others, difference is, they do not evolve from a close ancestor and yet main instincts, reflects and neuronal basics remain equally in bot mammals and sharks, they do have other developed tools among millennia which we didn’t know until recent times.
Electrical sensory system, olfactive, visual or pressure through the lateral line are more or less different than what we already know that, at first sight, evidence is ignore assuming they are not intelligent because they do not behave likelihood. However, I strongly stand there is much more behind the scene, and the first step is looking at their socialization, interaction patterns, repetitive responses or personality that they might have as it has been demonstrated yet poorly studied so there is room for discovering and improvement.
First step of activity budget, then philopatry, nursey areas, mating areas if so, interaction within and between groups, use of sensory systems to communicate and forage, use of habitat, memory, cognition and neural system are among my goals to achieve shorter or longer in time.
Oh, that is really cool, but why loosing effort in such? The answer is obvious, we don’t love what we don’t know, and we don’t protect what we don’t love. Eventually sharks and rays must move from Herring (my apologies for it, it is just getting a balance at the end of the day, we also want to survive) to cetacean. In other words, they must have a range of protection as high as cetaceans, considering that protection for cetaceans must also improve. The achievement is not just protecting sharks, it is a mean to protect the whole environment as if we protect the apex predator (case of wolf, bear or eagle, to noun some terrestrial better protected counter partners) we will protect species dependent of those populations an so on, resulting in protection for the small to the large live form.
Madeira archipelago is the place I will launch my ideas as it is a prodigious environment for migratory and resident populations, bearing a wide variety of elasmobranchs of the Atlantic as they can breed and feed on these rich volcanic isles and seamounts on the presence of upwelling. They are also very interesting in terms of protected areas as large part of Portuguese waters are protected here, with more pristine areas than others allowing to compare populations and presence the effect of human activities.
Last but not least, Universidade de Madeira together with CIIMAR and Museo de Madeira support this project via Teresa Margarida da Silva, who is really enthusiastic about those thoughts.
Sharks around the world are in grave danger; they are apex predators, controlling fish populations and maintaining healthy oceans. Ocean health, and therefore the health of the planet, are reliant on shark populations. The dangers that sharks face every single day have led to drastic decreases in their numbers. Sharks are generally large and long-lived, contributing to their evolutionary success, but they don’t produce many offspring which is now causing them problems when faced with human effects. This is why shark protection, and mitigation against human damage is so incredibly important.
A sometimes overlooked issue for sharks is bycatch, when non-target species are caught. Sharks can become tangled in gear, or are attracted to bait. Catching non-target species is disadvantageous for the fishermen, as well as for the sharks; it is a waste of time, money, and resources to catch a species that you are going to throw back into the sea, when you could be catching more economically viable species.
In the Gulf of California, Mexico is an important Pacific Sierra fishery. Pacific Sierra is used for the popular Mexican dish ceviche, raw fish, marinated in citrus juices for a tasty appetiser. This fish is caught with gill nets, large sheets of net that catch the fish’s gills as they attempt to swim through. However the Pacific Sierra fishermen of the Gulf of California have a huge Hammerhead shark bycatch problem. The famously shaped head easily becomes tangled in the net, catching the shark, and causing its death.
The Pacific Sierra fisheries are close to the coast, which also happens to be a busy Hammerhead nursery area. Hammerhead shark females come to birth their pups in the safe, shallow waters. However these waters are no longer as safe as they once were due to the fishing intensity, and the shark’s vulnerability to the gear. While the very young sharks may be safe due to their proximity to shore the problem arises when pregnant females or juveniles move into or out of the area. They effectively have to ‘swim the gauntlet’, avoiding fishing nets, to make it out to the open ocean.
The capture of juveniles and pregnant females is the worst scenario for shark bycatch. Sharks are being caught that are either too young to have reproduced yet, or haven’t even been born yet! Effectively wiping out an entire generation of Hammerhead sharks, causing serious consequences for the ocean. Sharks tend to eat large predatory fish, which in turn eat smaller predatory fish, like the Pacific Sierra. Therefore the consequences of Hammerhead bycatch loop back and impact the fishermen, as their catches of Pacific Sierra are depleted if their predators are no longer controlled by the sharks.
However the situation can still be changed, there is hope for Hammerhead sharks! If the nursery areas can be identified restricted areas can be created, where fishing cannot take place. With a large enough buffer zone around the nursery Hammerhead juveniles and females can go to and from the nursery areas safely, and the oceans can become healthy again!
Aguirre-Villaseñor H; Morales-Bojórquez E; Morán-Angulo RE; Madrid-Vera J; Valdez-Pineda MC. 2006. Biological indicators for the Pacific Sierra (Scomberomorus sierra) fishery in the southern Gulf of California, Mexico. Ciencias Marinas, 32(3):471-484
Coiraton C.; Amezcua F.; Salgado-Ugarte I.H. 2017. Estructura de longitudes de las capturas del tiburón martillo común (Sphyrna lewini) en el Pacífico mexicano. Ciencia Pesquera. 25(1): 253-259
Schindler D.E.; Essington T.E.; Kitchell J.F.; Boggs C.; Hilborn R. 2002. Sharks and tuna: Fisheries impacts on predators with contrasting life histories. Ecological Applications 12(3):735-748
Indonesia is always hit by deadly natural disasters every year. Earthquakes, volcano eruptions, forest fire, huge floods, tsunamis, as well as prolonged droughts in other regions are considered as the most frequent disasters occurred in this country. Let me take drought as an example. The National Disaster Mitigation Agency of Indonesia has released monthly data and reported that at least 78 cities and 19 million people were suffered from prolonged drought in July 2018. The prolonged drought caused a water shortage in those areas for months, leading a thousand hectares of fields into crop failures and threatening the country with the food crisis. One of the worst scenarios of this situation is the people in the affected area will suffer from starvation as the result of unsustainable food production. The government tried hard to overcome this condition by suggesting several solutions, which is in my opinion, aquaculture seems to be the most potential one.
The Ministry of Maritime Affairs and Fisheries of Indonesia has introduced catfish farming using biofloc system to the borderlands in 2017 and the outcome was quite successful. The reason behind its success is because biofloc system requires less water exchange, offers more advantages than the common aquaculture practice and can be integrated with polyculture so the farmers will not only cultivate fish but also vegetables. If this system is also introduced to the areas where prolonged droughts occur, it can be a potential solution to maintain food sustainability.
Biofloc system is an eco-friendly aquaculture which actually has been practiced in Indonesia years ago, for example in North Sumatera, the place where I lived. There, the farmers built their biofloc pools using plastic/canvas tanks and raised catfish as the dominant species. They chose catfish because of its popularity among consumers and also the good market price. Despite fewer articles reporting biofloc aquaculture practice in North Sumatera, this system is quite successful thus more people are interested to try it.
Bioflocs itself are the aggregates (flocs) of algae, bacteria, protozoans, and other kinds of particulate organic matter such as feces and uneaten feed. The basic principle of this system is the microbial conversion of nutrient waste in aquaculture (mainly ammonia) into microbial biomass. Using this technology, it is possible to minimize water exchange and water usage in aquaculture systems through maintaining adequate water quality within the culture unit, while producing low-cost bioflocs rich in protein, which in turn can serve as a feed for aquatic organisms.
Within 2 years after the introduction in the borderland, there are already several articles that reported the success of catfish farming using biofloc. In Manokwari (border of Indonesia-Papua New Guinea), the farmers were successfully cultivated 1.5 tons of catfish only from 6 biofloc pools with a selling price between 35.000-40.000 rupiah/kg. Other success stories came from Sanggau (border of Indonesia-Malaysia), where the farmers cultivated 3 tons of catfish from 10 pools with selling price 24.000 rupiah/kg. There are more success stories in other regions but unfortunately, they are not reported yet. I also witnessed local catfish farmers in North Sumatera who integrated their pools with polyculture system. The farmers utilized their biofloc waste to water the vegetable plants and some of them even made liquid organic fertilizer from the waste.
Despite the advantages of this promising system, convincing people to practice biofloc is still a big challenge, especially in the crisis areas where the condition is not conducive after the disaster. Firstly, water has become scarce and expensive to an extent of limiting aquaculture development. Secondly, the release of polluted effluents into the environment is prohibited in most countries. Thirdly, severe outbreaks of infectious diseases led to more stringent biosecurity measures, such as reducing water exchange rates. However, no need to worry if we are going to practice biofloc because this system does not require frequent water change and produces a small amount of waste that actually useful for plants. One of the challenges is that people tend to think that practicing a new thing will be difficult, expensive and only people with high education can do it—this is the common mindset of Indonesian that I often observe.
I am quite sure that if the government also introduce biofloc in the crisis area the way they introduced it in the borderlands, it will be successful as well. However, a good approach is needed in order to convince the people so they can be economically benefited by this practice. Providing them all the raw materials needed to set up the pools as well as high-quality fish seeds and competent instructors for free in the beginning to educate the new farmers are also a good choice so that they can run their own biofloc farming independently.
When fish farmers first decided to rear their fish in coastal waters, they didn't stop to think about where the fish waste and uneaten feeds would go. “After all,” they must’ve felt, “the ocean is huge, and already full of fish waste anyway!” Both assumptions are true, but don’t have much weight considering the magnitude of fish farming today. Every year, a single sea cage in Norway can grow ten times the entire biomass of the wild Norwegian salmon population. Multiply that amount to that which a whole farm can grow, times the number of farms along the coastline of the entire country, and you get an unimaginable amount of fish poop!
Scientists have only begun to unearth the horrors underneath the open sea cages. In many cases, the seafloor can look like a dead zone or a dirty rug composed of a single species of opportunistic polychaete, and this can extend to several meters beyond the jurisdiction of the farms. Even seabeds situated close to 100 m underneath an open cage can be compromised. This is especially true in the beautiful fjords of Norway, which sure can look pristine above water but can look like scenes straight out of a Lovecraft novel meters beneath the surface.
But there’s no need to fret and feel like salmon aquaculture is doomed to destroy the planet. Some of the biggest stockholder companies for salmon farming are beginning to test their prototypes of closed sea farms with mechanized water input and output valves. These farms can be equipped with sludge and waste collectors so that the extruded water is free of fish waste and uneaten feeds. And instead of dumping the collected waste into the ocean, it can be transported onto land and used to produce fertilizer. Indeed, that’s several steps towards keeping our oceans clean and keeping the economy green. Sensitive benthic species can rest assured that their genes will survive tomorrow!